Evaporative fuel vapor emission control systems

Abstract

To provide canister systems for suppressing evaporation of gasoline fuel from motor vehicle fuel systems.SOLUTION: The present disclosure describes an evaporative emission control canister system that includes one or more canisters comprising at least one vent-side particulate adsorbent volume comprising a particulate adsorbent having microscopic pores with a diameter of less than about 100 nm, macroscopic pores having a diameter of about 100 - 100,000 nm, and a ratio of a volume of the macroscopic pores to a volume of the microscopic pores that is greater than about 150%, and having a retentivity of about 1.0 g / dL or less. The system may further include a high butane working capacity adsorbent. The disclosure also describes a method for reducing emissions in an evaporative emission control system.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to U.S. Provisional Patent Application No. 62 / 521,912, filed June 19, 2017, and U.S. Provisional Patent Application No. 62 / 685,174, filed June 14, 2018, the contents of which are incorporated herein by reference in their entireties for all purposes.

[0002] 1.Technical Field FIELD OF THE DISCLOSURE The present disclosure relates generally to systems comprising particulate adsorbent materials and methods of using same. More specifically, the present disclosure relates to systems comprising low-retention-capacity particulate adsorbent materials and methods of using same in evaporative fuel vapor emission control systems. [Background technology]

[0003] 2. Background technology Evaporation of gasoline fuel from automotive fuel systems is a major source of hydrocarbon air pollution. Such emissions can be controlled by a canister system that uses activated carbon to adsorb fuel vapors generated by the fuel system. During certain engine operating modes, adsorbed fuel vapors are periodically removed from the activated carbon by purging the canister system with ambient air, causing the fuel vapors to desorb from the activated carbon. The regenerated carbon is then ready to adsorb additional fuel vapors.

[0004] Increasing environmental concerns have led to increasingly stringent regulations on hydrocarbon emissions from motor vehicles, even when the vehicle is not in operation. Vapor pressure within a vehicle's fuel tank increases as ambient temperatures rise while the vehicle is parked. Typically, to prevent fuel vapors from escaping the vehicle into the atmosphere, the fuel tank is vented through a conduit to a canister containing a suitable fuel adsorbent material capable of temporarily adsorbing fuel vapors. A mixture of fuel vapor and air from the fuel tank enters the canister through the canister's fuel vapor inlet, expands or diffuses into the adsorbent volume where the fuel vapor is adsorbed in a temporary storage area, and the purified air is released to the atmosphere through the canister's vent port. When the engine is running, ambient air is drawn into the canister system by a manifold vacuum through the canister's vent port. Purge air flows through the adsorbent volume within the canister, desorbing the adsorbed fuel vapors before entering the internal combustion engine through a fuel vapor purge conduit. The purge air does not desorb all of the fuel vapor adsorbed in the adsorbent volume, resulting in residual hydrocarbons (the "heel") that can be released to the atmosphere. Furthermore, the heel, in local equilibrium with the gas phase, also allows fuel vapors from the fuel tank to migrate through the canister system as emissions. Such emissions typically occur when a vehicle is parked and exposed to diurnal temperature fluctuations over a period of several days and are commonly referred to as "diurnal breathing losses."

[0005] In the United States, California's Low Emission Vehicle regulations require that diurnal breathing loss (DBL) emissions from canister systems be approximately 20 mg for many 2003 and later model-year vehicles ("PZEV") and less than approximately 50 mg for many 2004 and later model-year vehicles ("LEV-II"). Currently, California's Low Emission Vehicle regulations (LEV-III) and the EPA's Tier 3 Standard require that DBL emissions from canister systems be less than approximately 20 mg for many 2003 and later model-year vehicles ("LEV-II"). The March 22, 2012 California Evaporative Emissions Standards and Test Procedures for 2001 and Subsequent Model Motor Vehicles are also required. The EPA's Control of Air Pollution From Motor Vehicles: Tier 3 Motor Vehicle Emission and Fuel Standards; Final Rule, 40 CFR Parts 79, 80, 85, and others require that canister DBL emissions not exceed 20 mg per bleed emissions test procedure (BETP). In contrast, globally, evaporative emissions regulations have been less stringent than in the United States, but there is currently a trend toward stricter regulations along the path taken by the United States. There is growing recognition of the benefits of better vehicle fuel use and stricter controls for cleaner air, particularly in regions where light-duty vehicle use is rapidly increasing and air quality issues require urgent attention.

[0006] To meet evaporative fuel emission standards during the vehicle design phase, vehicle manufacturers typically provide potential suppliers with target specifications for the overall canister system performance in terms of functional content, appearance, physical properties, and durability, thus leaving the canister system manufacturer with suitable design flexibility to achieve these goals. For example, General Motors Corporation sets numerous design specifications for evaporative emission control canister systems (see GMW-16494). One notable specification is the total allowable pressure drop for carbon canister systems. In this example, the maximum flow limit for a canister system intended for on-board refueling vapor recovery (ORVR) is "0.90 ± 0.225 kPa at an air flow rate of 60 liters per minute (lpm), measured at the tank tube while air is flowing from the canister tank tube to the fresh air tube" (see section 3.2.1.3.2.2 of GMW-16494). This specification and others in GMW-16494 provide examples of the extent to which vehicle manufacturers are permitted to limit flow.

[0007] As a result of these specifications, canister system designers evaluate a wide range of adsorbent options, as requirements vary significantly for various vehicle platforms from various vehicle manufacturers according to engine type, engine operating design, space availability, purge availability, and canister system control strategy, in addition to various fuel emission regulations around the world. Indeed, "one size does not fit all" for canister system design and its adsorbent loading. Therefore, there is a strong need for new adsorbent options and methods to balance the tradeoffs in terms of cost, size, flow restriction, working capacity, diurnal breathing loss (DBL) performance, complexity, and deployment flexibility.

[0008] For example, several methods involving chamber design and adsorber properties have been reported to reduce DBL emissions, which is one aspect of the specifications that canister systems must meet.

[0009] One method for achieving low emissions is to significantly increase the purge gas volume to enhance desorption of the residual hydrocarbon heel from the adsorption volume. However, this method has the disadvantage of complicating fuel / air mixture management to the engine during the purge process, which tends to adversely affect tailpipe emissions. See U.S. Pat. No. 4,894,072. In certain high-performance, fuel-efficient engine designs, including turbocharged, gasoline direct injection, and hybrid electric vehicles, such high purges may not be available or may significantly affect engine performance.

[0010] Another approach is to design the canister so that the cross-sectional area on the vent side of the canister is relatively small, either by resizing the existing canister or by installing a suitably sized auxiliary vent-side canister chamber. See U.S. Pat. No. 5,957,114. ref. This method reduces the residual hydrocarbon heel by increasing the strength of the purge air. One drawback of such methods is that the relatively small cross-sectional area of ​​conventional particulate adsorbers, which are solid forms with diameters of 1-3 mm, imposes excessive flow restriction on the canister at all but the shortest bed lengths, compromising the effectiveness of this vent-side chamber for DBL emissions control at all but the shortest bed lengths. Thus, while potentially effective in reducing system bleed emissions, conventional particulate adsorbers cannot accommodate the excessive flow restriction.

[0011] Another method to increase purge efficiency is to heat the purge air, or a portion of the adsorbent volume that adsorbs the fuel vapor, or both. See U.S. Patent Nos. 6,098,601 and 6,279,548. However, this method increases the complexity of the control system management and raises several safety concerns.

[0012] Yet another approach is to select multiple adsorbents within the canister system chamber so that fuel vapor is routed through one or more fuel-side adsorbent volumes located proximate or near the fuel-side port of the canister system (i.e., upstream in the fluid or vapor path), and then to at least one vent-side or subsequent adsorbent volume located downstream (or distal) in the fluid or vapor path relative to the fuel-side adsorbent, before being vented to the atmosphere, with the initial adsorbent volume being selected to have a higher incremental adsorption capacity (greater slope of the butane adsorption isotherm from 5 to 50% concentration) than the subsequent adsorbent volumes. See U.S. Patent Nos. RE38,844 and 9,732,649, which are incorporated herein by reference in their entireties.

[0013] One effective type of trailing sorbent volume toward the vent side of a canister system is an elongated ceramic-bonded activated carbon honeycomb, such as Nuchar® HCA (Ingevity®, North Charleston, South Carolina, USA), typically available in diameters of 29, 35, and 41 mm and lengths ranging from 50 to 200 mm. While such sorbent structures offer desirable sorption characteristics with low flow restrictions, these designs are expensive to manufacture, require specialized skills and equipment, and canister system designers, who are their immediate first-line customers, are limited to only those honeycomb sizes typically available for system design, testing, and certification.

[0014] Another effective form of vent volume that allows flexibility in chamber design is in the form of 2-3 mm pellets, such as Nuchar® BAX LBE grade activated carbon (Ingevity®, North Charleston, South Carolina, USA) or 2GK-C7 grade activated carbon (Kuraray Chemical Co., Ltd., Bizen-shi, Japan). These pellets have useful adsorption properties for bleed emission control, and as particulate materials, they allow great flexibility in the dimensions of the adsorber chambers they are packed into. However, these pellets have higher flow restriction properties than carbon honeycombs, limiting potentially useful low-cross-sectional area geometries, as taught in U.S. Pat. No. 5,957,114.

[0015] The concept of a series of adsorbents, along with graduated adsorption volumes in adsorption working capacity, e.g., butane working capacity (BWC) and grams of total butane working capacity on the vent side of the system, is taught to be particularly useful for emission control canister systems when operated under low-volume purging, such as in "hybrid" vehicles where the internal combustion engine is shut off approximately half the time while the vehicle is in operation, resulting in much lower purging frequencies. See International Application Publication No. 2014 / 059190 (PCT / US2013 / 064407). Other engine designs that pose challenges for canister system purging include direct gasoline injection and turbocharged or turbo-assisted features. However, these methods typically utilize carbon honeycomb morphology. Limited.

[0016] The problem and desire described above, and others (see, e.g., U.S. Pat. Nos. 7,186,291 and 7,305,974), is to mitigate the detrimental effects of residual adsorbed vapors on the performance of evaporative emissions canister systems, particularly DBL emissions performance, which strongly demands a minimum amount of retained adsorbed vapors (minimum heel). Furthermore, the degradation (also known as "aging") of canister systems' DBL emissions and working capacity performance is also known to be due to the accumulation of less purgeable components in this adsorbed vapor heel (see, e.g., SAE Technical Paper Series 2000-01-895). Thus, the benefits of low post-purging hydrocarbon retention are two-fold: lower levels of DBL emissions in new vehicles, and the maintenance of working capacity and emissions performance over the life of the vehicle resulting from the low vapor retention capacity characteristics.

[0017] While highly desirable as a method, the combination of low cost, low production complexity, high material structural strength, low flow restriction, and minimal vapor retention capacity offered by particulate adsorbents for evaporative emission control is taught to present nearly insurmountable design challenges. For example, as taught in U.S. Pat. No. 9,174,195 (the "'195 patent"), the useful range of the ratio of macroscopic "M" pore volume to microscopic "m" pore volume is limited to 65% to 150% M / m due to reduced mechanical strength at higher ratios. Furthermore, within the claimed pore ratio range, vapor retention (retention capacity) asymptotically exceeds 1 g / dL, as measured by standard ASTM testing as butane residual, and (in addition to the reduced strength) exceeds the aforementioned 1.7 g / dL target when the pore ratio exceeds the claimed 150% limit. It is important to note that the '195 Patent teaches that typical 5 mm diameter pellets with M / m pore ratios greater than 150% are not robust enough for use (see Figure 6). The trade-off between pore ratio and pellet strength is highlighted by the 2GK-C7 pellet adsorbent material (Kuraray Chemical Co., Ltd., Bizen-shi, Japan). This material has an average diameter of 2.6 mm despite an M / m of approximately 170%, which improves its strength but has the undesirable effect of increasing flow restriction. In other words, despite its ability to control emissions, the '195 Patent teaches that the relatively high M / m ratio of 2GK-C7 reduces strength as it lowers flow restriction, making it unsuitable for larger diameter pellets with relatively higher retention capacity. Summary of the Invention [Problem to be solved by the invention]

[0018] Therefore, alternative adsorber options are needed for designers of evaporative emission control systems, particularly for vent-side adsorber volumes that are not only robust but also exhibit low vapor holding capacity and low flow restriction to help the system achieve high working capacity and low DBL emissions performance over the life of the vehicle. [Means for solving the problem]

[0019] Described herein are evaporative emission control canister systems having surprising and unexpected properties, including two-day diurnal breathing loss (DBL) emissions of less than about 50 mg or less than about 20 mg, with relatively low purge volumes (e.g., less than about 175 BV or less than 100 BV). Surprisingly and unexpectedly, it has been found that low purge and low DBL evaporative emission control canister systems are possible with the particulate adsorption volumes described herein, which are cost-effective to manufacture, have desirable retention capacities, high material structural strength, and low flow restrictions. For example, particulate adsorbent materials providing the low DBL canister systems described herein have macroporosity (M) and microporosity (m). (i.e., M / m) of greater than 150%, and a butane retention capacity of less than 1.0 g / dL, while also being large and robust enough to be utilized in systems without imposing undue flow restrictions.

[0020] Accordingly, in one aspect, the present disclosure provides an evaporative emission control canister system comprising one or more canisters having multiple chambers, each chamber defining a volume, the multiple chambers being in fluid communication to allow unidirectional flow of fluid (e.g., air, gas, or fuel vapor) from one chamber to the next, at least one chamber comprising at least one particulate sorbent volume comprising a particulate sorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, wherein the particulate sorbent volume has a flow restriction characteristic of less than 40 Pa / cm under conditions of an apparent linear air flow velocity of 46 cm / sec applied to a 43 mm diameter bed of particulate sorbent material, or a flow restriction of less than 0.3 kPa under an air flow rate of 40 lpm, or both. In certain embodiments, the particulate adsorbent volume has a length to diameter ratio of 2 or greater, a butane retention capacity of less than 1.0 g / dL, or a combination thereof. In certain embodiments, the butane retention capacity is less than 0.5 g / dL. In certain embodiments, the evaporative emission control canister system includes at least one fuel-side adsorbent volume, at least one vent-side subsequent adsorbent volume, or both. In certain embodiments, the adsorbent volumes are located within a single canister or within multiple canisters that are connected so as to be continuously accessible by fuel vapor. In certain embodiments, the at least one particulate adsorbent volume, the at least one fuel-side adsorbent volume, or both, have a nominal butane working capacity (BWC) of at least 8 g / dL (e.g., at least 10 g / L), a nominal incremental adsorption capacity (IAC) of at least 35 g / L at 25°C between 5 vol% and 50 vol% n-butane vapor concentrations, or both. In certain embodiments, at least one particulate adsorbent volume, at least one vent-side subsequent adsorbent volume, or both, has a nominal BWC of less than 8 g / dL, a nominal IAC of less than 35 g / L at 5 vol% to 50 vol% n-butane vapor concentrations at 25° C. In certain embodiments, the particulate volume has an M / m ratio of greater than about 200%.

[0021] In another aspect, the present description provides an evaporative emission control canister system comprising one or more canisters comprising at least one fuel-side sorbent volume (i.e., an sorbent volume at or near the fuel tank vapor inlet) and at least one vent-side particulate sorbent volume. In certain embodiments, at least one vent-side particulate sorbent volume is provided as an alternative to or in combination with one or more subsequent vent-side sorbent volumes. The at least one fuel-side sorbent volume, the at least one vent-side particulate sorbent volume, and / or the at least one subsequent vent-side sorbent volume can be contained either within a single canister or within separate canisters that are connected to allow continuous contact by fuel vapor (and conversely, purge air). In certain embodiments, the at least one subsequent vent-side sorbent volume comprises a non-particulate sorbent material, such as a foam, monolith, polymer or paper sheet, or honeycomb (e.g., activated carbon honeycomb), and the at least one subsequent vent-side sorbent volume provides low vapor or fluid flow restriction.

[0022] In certain embodiments, the evaporative emission control canister system comprises at least one vent-side subsequent adsorbent volume upstream of the at least one vent-side particulate adsorbent volume (i.e., located near the fuel-side adsorbent volume or the fuel vapor inlet in the flow path), at least one vent-side subsequent adsorbent volume downstream of the at least one vent-side particulate adsorbent volume (i.e., located near the vent port in the flow path), or a combination thereof.

[0023] In certain embodiments, the evaporative emission control canister system comprises at least one vent-side particulate adsorbent volume upstream of at least one vent-side subsequent adsorbent volume (i.e., located near a fuel-side adsorbent volume or a fuel vapor inlet in the flow path), at least one vent-side particulate adsorbent volume downstream of at least one vent-side subsequent adsorbent volume (i.e., located near a vent port in the flow path), or a combination thereof.

[0024] In any of the aspects or embodiments described herein, at least one vent-side subsequent sorbent volume comprises a non-particulate sorbent material, such as a foam, monolith, honeycomb, polymer, or paper sheet. In certain embodiments, the non-particulate sorbent material provides low vapor or fluid flow restriction. In certain embodiments, the non-particulate sorbent material is a honeycomb having a uniform cross-sectional area.

[0025] Adsorbents suitable for use as adsorbent volumes may be obtained from many different materials and in a variety of forms. They may be a single component or a mixture of various components. Additionally, adsorbents may include a volume diluent (either as a single component or a mixture of different components). Non-limiting examples of volume diluents may include, but are not limited to, spacers, inert gaps, foams, fibers, springs, or combinations thereof.

[0026] In any of the aspects or embodiments described herein, the fuel-side adsorbent volume, the vent-side particulate adsorbent volume, and the subsequent vent-side adsorbent volume may be made of known adsorbent materials, including, but not limited to, activated carbon, charcoal, zeolite, clay, porous polymer, porous alumina, porous silica, molecular sieve, kaolin, titania, ceria, or combinations thereof. Activated carbon can be derived from various carbon precursors. By way of non-limiting example, the carbon precursor can be wood, wood dust, wood flour, cotton linters, peat, coal, coconut, lignite, carbohydrates, petroleum pitch, petroleum coke, coal tar pitch, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables such as rice husks or straw, synthetic polymers, natural polymers, lignocellulosic materials, or combinations thereof. Furthermore, activated carbon can be manufactured using various processes, including, but not limited to, chemical activation, thermal activation, or combinations thereof.

[0027] In any of the aspects or embodiments described herein, any of a variety of adsorbent forms may be used for the fuel-side adsorbent volume, the vent-side particulate adsorbent volume, and the subsequent vent-side adsorbent volume. Non-limiting examples of adsorbent forms include granular, pelleted, spherical, honeycomb, monolithic, pellet-like cylinder, uniformly shaped particulate media, non-uniformly shaped particulate media, extruded structured media, wound structured media, folded structured media, pleated structured media, corrugated structured media, cast structured media, bonded structured media, nonwoven, woven, sheet, paper, foam, or combinations thereof. The adsorbent may also include a volumetric diluent (as a single component or a mixture of different components). Non-limiting examples of volumetric diluents include, but are not limited to, spacers, inert gaps, foams, fibers, springs, or combinations thereof. Additionally, the sorbent body may be extruded into particular thin-walled cross-sectional shapes, such as hollow cylinders, stars, twisted helices, asterisks, formed ribbons, or other shapes within the skill of the art. Inorganic and / or organic binders may be used in the shaping.

[0028] Honeycomb adsorbents may be of any geometric shape, including, but not limited to, circular, cylindrical, or square. Additionally, the cells of honeycomb adsorbents may be of any shape. Honeycombs of uniform cross-sectional area for flow-through passages, e.g., square honeycombs with square cross-sectional cells, or spirally wound corrugated honeycombs, are circular honeycombs with square cross-sectional cells in a right-angle matrix, with adjacent passages having varying cross-sectional areas. and therefore may perform better than a circular honeycomb with equivalently unpurged passages. Without being bound by any theory, it is believed that a more uniform cell cross-sectional area across the honeycomb face results in a more uniform flow distribution within the component during both adsorption and purge cycles, and therefore lower DBL emissions from the canister system.

[0029] In some embodiments, the evaporative emission control system can further include one or more heat input units for heating the one or more adsorbent volumes and / or one or more empty volumes. The heat input unit can include, but is not limited to, an internal resistive element, an external resistive element, or a heat input unit associated with the adsorbent. The heat input unit associated with the adsorbent can be an element separate from (i.e., not in contact with) the adsorbent. Alternatively, the heat input unit associated with the adsorbent can be a substrate or layer to which the adsorbent is attached, bonded, unbonded, or in physical contact. The heat input unit associated with the adsorbent can be an adsorbent that is electrically heated directly by having a suitable resistivity. The resistive properties of the adsorbent can be modified by adding conductive or resistive additives and binders during the initial preparation of the adsorbent and / or during the formation of the adsorbent into particulate or monolithic form. The conductive component can be a conductive adsorbent, a conductive substrate, a conductive additive, and / or a conductive binder. The conductive material can be added during the preparation of the adsorbent, during an intermediate forming process, and / or during the formation of the adsorbent into its final shape. Any type of heat input unit can be used. Non-limiting examples include heat transfer fluids, heat exchangers, thermally conductive elements, and positive temperature coefficient materials. The heat input unit may or may not be uniform along the length of the heated flowpath (i.e., it may or may not provide locally different intensities). Furthermore, the heat input unit may or may not be distributed to provide greater heating intensity and duration at various points along the length of the heated flowpath.

[0030] In certain embodiments, the vent-side subsequent adsorbent volume is an activated carbon monolith or an activated carbon honeycomb, and is located upstream in the fuel vapor path relative to the location of the vent-side particulate adsorbent volume, downstream in the fuel vapor path relative to the location of the vent-side particulate adsorbent volume, or a combination thereof.

[0031] In certain embodiments, at least one fuel-side adsorbent volume has at least one of a relatively high butane working capacity (BWC), an effective incremental adsorption capacity of n-butane of greater than about 35 grams per liter (g / L) at a vapor concentration of 5 vol% to 50 vol% n-butane, or both. For example, in certain embodiments, the system further comprises at least one additional high butane working capacity (BWC) adsorbent volume located upstream of or before the vent-side particulate adsorbent volume (i.e., the high butane working capacity adsorbent volume contacts fuel vapor before the vent-side particulate adsorbent volume while the vehicle is stationary). In certain embodiments, the fuel-side adsorbent volume has at least one or both of: i) a relatively high butane working capacity (BWC), for example, 8, 9, 10, 11, 12, 13, 14, 15, or more grams per deciliter (g / dL); ii) an incremental adsorption capacity for n-butane of 35, 40, 45, 50, 55, 60, 65, 70, 75, 80, 85, 90, or more grams per liter (g / L) at vapor concentrations of 5 vol% to 50 vol% n-butane.

[0032] In certain embodiments, the evaporative emission control canister system includes at least one vent-side particulate adsorber volume (i.e., downstream relative to at least one fuel-side adsorber volume in the vapor path from the fuel tank to the vent port). In certain embodiments, the at least one vent-side particulate adsorber volume has a low butane retention capacity, a relatively high ratio of macroscopic pore volume to microscopic pore volume (M / m), and relatively low flow restriction characteristics. In certain embodiments, a particulate adsorber having a low butane retention capacity and low flow restriction characteristics is , having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume (M / m) of about 150%, 160%, 170%, 180%, 190%, 200%, 210%, or 220% or greater, the particulate adsorbent material has a retention capacity of about 1.0 g / dL or less and a flow limit of less than 40 Pa / cm pressure drop under an apparent linear gas flow velocity of 46 cm / sec.

[0033] In any of the aspects or embodiments described herein, the vent-side particulate volume has a flow restriction of less than about 0.3 kPa under an airflow of 40 lpm.

[0034] In any of the aspects or embodiments described herein, at least one vent-side particulate adsorbent volume has a length to diameter ratio of about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5 or more. In certain embodiments, the vent-side particulate adsorbent volume has a length to diameter ratio, L / D, greater than about 2 and is elongated.

[0035] In certain embodiments, at least one vent-side particulate adsorption volume M / m is greater than 150% and has a flow restriction characteristic of less than 40 Pa / cm of pressure drop at an apparent linear air velocity of 46 cm / sec. In certain embodiments, the vent-side particulate adsorption volume M / m is greater than 200% and has a butane retention capacity of less than 1 g / dL. In certain embodiments, the vent-side particulate adsorption volume M / m is greater than 150% and has a butane retention capacity of less than 0.5 g / dL.

[0036] In certain embodiments, an evaporative emission control canister system includes at least one vent-side particulate adsorption volume as described herein, e.g., having a relatively low butane holding capacity and low flow restriction, wherein the canister system has two-day DBL emissions of about 50, 45, 40, 35, 30, 25, 20 mg or less at a bed volume purge of about 175, 150, 125, 120, 115, 110, 100 or less, or at a purge of 315, 300, 275, 250, 225, 200, 175, 150 liters or less, as measured by the California Bleed Emissions Test Procedure (BETP). In certain embodiments, the evaporative emission control canister system comprises at least one sorbent volume having a low butane holding capacity and a low flow restriction particulate sorbent, and has a bed volume of less than 100 in a BETP test, or day 2 DBL emissions of 50 mg or less, or 20 mg or less with a purge of less than 210 liters.

[0037] In some embodiments, the system comprises multiple vent-side particulate adsorbent volumes configured for serial contact by a fluid, e.g., fuel vapor, In certain embodiments, for example, the adsorbents are connected in series to define a fluid flow path therethrough.

[0038] In certain embodiments, the system includes multiple canisters connected together so that they are continuously accessible by a fluid, such as fuel vapor.

[0039] In another embodiment, the system further comprises a subsequent adsorbent volume downstream or subsequent to the vent-side particulate adsorbent volume described herein (i.e., the subsequent adsorbent volume contacts fuel vapor after the vent-side particulate adsorbent volume when the engine is off).

[0040] In certain embodiments, at least one subsequent adsorbent volume has at least one of: i) a BWC of less than about 8 g / dL, ii) an IAC of less than about 35 grams n-butane / L at a vapor concentration of 5 vol% to 50 vol% n-butane, or iii) a combination thereof. In certain embodiments, the subsequent adsorbent volume is an activated honeycomb.

[0041] In another aspect, the description provides an evaporative emission control canister system comprising: one or more canisters comprising: at least one fuel-side sorbent volume comprising a particulate adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, and a retention capacity less than about 1.0 g / dL; and at least one vent-side particulate adsorbent volume comprising a particulate adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, wherein the at least one vent-side particulate adsorbent volume has a butane retention capacity less than 1.0 g / dL. In certain embodiments, the vent-side particulate adsorber volume has a flow restriction characteristic of less than 40 Pa / cm when a nominal linear airflow velocity of 46 cm / sec is applied to a 43 mm diameter bed of the vent-side particulate adsorber volume. In further embodiments, at least one vent-side particulate adsorber volume has a flow restriction of less than about 0.3 kPa under an airflow of 40 lpm. In another embodiment, the vent-side particulate adsorber volume has a length to diameter ratio of 2 or greater. In further embodiments, at least one fuel-side adsorber volume has a nominal BWC greater than 8 g / dL, a nominal IAC greater than 35 g / L at 25°C between 5 vol% and 50 vol% n-butane vapor concentrations, or both. In certain embodiments, the evaporative emission control canister system further comprises at least one vent-side subsequent adsorber volume, wherein the at least one vent-side subsequent adsorber volume has a nominal BWC less than 8 g / dL, a nominal IAC less than 35 g / L at 25°C between 5 vol% and 50 vol% n-butane vapor concentrations, or both. In certain embodiments, at least one fuel-side sorbent volume, at least one vent-side particulate volume, or both, has a ratio of macropore volume to micropore volume greater than about 200%, and at least one vent-side particulate sorbent volume has a butane retention capacity of less than 1.0 g / dL.

[0042] In any of the aspects or embodiments described herein, the system further includes at least one of: a fuel vapor inlet conduit connecting the evaporative emission control canister system to a fuel tank; a fuel vapor purge conduit connecting the evaporative emission control canister system to an air induction system of the engine; a vent conduit for venting the evaporative emission control canister system and for admitting purge air to the evaporative emission control canister system; or a combination thereof.

[0043] In some embodiments, the system has at least one of a fuel vapor flow path from a fuel vapor inlet conduit through each of a plurality of adsorbent volumes (i.e., at least one fuel-side adsorbent volume upstream of at least one vent-side particulate adsorbent volume, and optionally at least one subsequent adsorbent volume) to a vent conduit, an air flow path from the vent conduit through each of a plurality of adsorbent volumes (i.e., at least one subsequent adsorbent volume, at least one vent-side specific adsorbent volume, and at least one fuel-side adsorbent volume, as required) to a fuel vapor purge outlet, or both.

[0044] In yet another embodiment, the packed bed of at least one vent-side particulate adsorbent volume has a pressure drop of 40 Pa / cm or less at a nominal linear air velocity of 46 cm / sec.

[0045] In another aspect, the disclosure provides an evaporative emission control canister system, comprising: a fuel tank for storing fuel; an engine configured to consume the fuel, the engine comprising an air induction system; an evaporative emission control canister system; a fuel vapor purge conduit connecting the evaporative emission control canister system to the air induction system of the engine; a vent conduit for venting the evaporative emission control canister system and drawing purge air into the evaporative emission control canister system; a fuel vapor inlet conduit connecting the evaporative emission control canister system to a fuel tank; a fuel vapor flow path from the fuel vapor inlet conduit through a plurality of adsorbent volumes to a vent conduit; and a fuel vapor flow path from the vent conduit to the plurality of adsorbent volumes and the fuel vapor purge conduit. an air flow path through the vapor purge outlet.

[0046] In certain embodiments, an evaporative emission control system includes one or more canisters with multiple sorbent volumes, including at least one vent-side particulate sorbent volume, the vent-side particulate sorbent volume comprising a low-capacity particulate sorbent having at least one of the following: (i) micropores less than about 100 nm in diameter, macropores between about 100 and 100,000 nm in diameter, a ratio of macropore volume to micropore volume (M / m) greater than about 150%, (ii) a retention capacity of less than about 1 to about 0.25 g / dL, (iii) a particle size of about 210 mm or greater, or (iv) a combination thereof. In certain embodiments, the particle size is 3-10 mm, about 3-9 mm, about 3-8 mm, about 3-7 mm, about 3-6 mm, about 3-5 mm, about 2-9 mm, about 2-8 mm, about 2-7 mm, or about 2-6 mm.

[0047] In certain embodiments, at least one vent-side particulate adsorption volume has a length / diameter (L / D) ratio of at least 0.5, 1, 1.5, 2, or more.

[0048] In another embodiment, the evaporative emission control system includes multiple canisters connected together for sequential access by fuel vapors.

[0049] In another aspect, the present disclosure provides a method of reducing fuel vapor emissions in an evaporative emission control system, the method comprising contacting fuel vapor with at least one vent-side particulate adsorber comprising at least one of: microscopic pores less than about 100 nm in diameter; macroscopic pores between about 100 and 100,000 nm in diameter; a ratio of macroscopic pore volume to microscopic pore volume (M / m) greater than about 150%; a retention capacity of about 1 to 0.25 g / dL or less; a particle size between 3 and 6 mm; or a combination thereof.

[0050] In some embodiments, the method further comprises contacting the fuel vapor with at least one fuel-side adsorbent volume described herein and then with at least one vent-side particulate adsorbent described herein.

[0051] In any of the aspects or embodiments described herein, the adsorbent is located within a single canister. In certain embodiments, the adsorbent is located within multiple canisters that are connected to allow serial access by the fuel vapor.

[0052] The foregoing general description of utility is presented for illustrative purposes only and is not intended to limit the scope of the present disclosure and the appended claims. Additional objects and advantages associated with the compositions, methods, and processes of the present disclosure will be apparent to those skilled in the art in view of the claims, detailed description, and examples. For example, the various aspects and embodiments of the present disclosure may be utilized in numerous combinations, all of which are expressly contemplated by this disclosure. These additional beneficial objects and embodiments are expressly included within the scope of the present disclosure. Publications and other materials used to describe the background of the invention and, in particular cases, to provide additional details regarding the implementation are incorporated by reference.

[0053] The accompanying drawings, which are incorporated in and form a part of this specification, illustrate several embodiments of the present invention and, together with the description, serve to explain the principles of the invention. The drawings are for the purpose of illustrating embodiments of the invention only and are not to be construed as limiting the invention. Further objects, features, and advantages of the present invention will become apparent from the following detailed description taken in conjunction with the accompanying drawings illustrating exemplary embodiments of the invention. become. [Brief explanation of the drawings]

[0054] [Figure 1] FIG. 1 is a cross-sectional view of an evaporative emission control canister system according to the present disclosure. [Figure 2]FIG. 2 is a cross-sectional view of an evaporative emission control canister system according to the present disclosure. [Figure 3A] FIG. 3A is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3B] FIG. 3B is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3C] FIG. 3C is an example of another adsorbent configuration for a low-loading volume particulate adsorbent. [Figure 3D] FIG. 3D is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3E] FIG. 3E is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3F] FIG. 3F is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3G] FIG. 3G is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3H1] FIG. 3H1 is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3H2] FIG. 3H2 is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 3I] FIG. 3I is an example of another adsorbent configuration for a low retention volume particulate adsorbent. [Figure 4] FIG. 4 is a cross-sectional view of an apparatus for measuring the pressure drop caused by a particulate adsorber. [Figure 5] Figure 5 helps explain how the nominal volume apparent density is calculated. [Figure 6] Figure 6 helps explain how the nominal volume apparent density is calculated. [Figure 7] Figure 7 helps explain how the nominal volume apparent density is calculated. [Figure 8] Figure 8 helps explain how the nominal volume apparent density is calculated. [Figure 9] Figure 9 helps explain how the nominal volume apparent density is calculated. [Figure 10]Figure 10 helps explain how the nominal volume apparent density is calculated. [Figure 11] Figure 11 helps explain how the nominal volume apparent density is calculated. [Figure 12] Figure 12 helps explain how the nominal volume apparent density is calculated. [Figure 13] FIG. 13 is a simplified schematic diagram of the apparatus used to measure butane adsorption capacity. [Figure 14] 14 is Table 1. In certain embodiments, the main canister configuration comprises a main canister comprising multiple chambers and / or multiple sorbent volumes. [Figure 15-1] Figure 15 is Table 2-A, Table 2-B, and Table 2-C. Auxiliary Canister Configurations. [Figure 15-2] Figure 15 is Table 2-A, Table 2-B, and Table 2-C. Auxiliary Canister Configurations. [Figure 15-3] Figure 15 is Table 2-A, Table 2-B, and Table 2-C. Auxiliary Canister Configurations. [Figure 15-4] Figure 15 is Table 2-A, Table 2-B, and Table 2-C. Auxiliary Canister Configurations. [Figure 15-5] Figure 15 is Table 2-A, Table 2-B, and Table 2-C. Auxiliary Canister Configurations. [Figure 15-6] Figure 15 is Table 2-A, Table 2-B, and Table 2-C. Auxiliary Canister Configurations. [Figure 15-7] Figure 15 is Table 2-A, Table 2-B, and Table 2-C. Auxiliary Canister Configurations. [Figure 16-1] FIG. 16, Tables 3-A, 3-B, and 3-C, provide information on the subsequent adsorption volume on the vent side of the auxiliary canisters for Examples 29-33, 73, 74, 94, 96, and 106-111. [Figure 16-2] FIG. 16, Tables 3-A, 3-B, and 3-C, provide information on the subsequent adsorption volume on the vent side of the auxiliary canisters for Examples 29-33, 73, 74, 94, 96, and 106-111. [Figure 16-3]FIG. 16, Tables 3-A, 3-B, and 3-C, provide information on the subsequent adsorption volume on the vent side of the auxiliary canisters for Examples 29-33, 73, 74, 94, 96, and 106-111. [Figure 17] FIG. 17 is a graph of emissions on day 2 for Examples 29-31 versus system purge BV. [Figure 18] FIG. 18 is a graph of incremental adsorption capacity versus vapor path length for the adsorber. [Figure 19] FIG. 19 is a graph of adsorber butane working capacity versus vapor path length. [Figure 20] FIG. 20 is a graph of adsorbent g-total butane working capacity versus vapor path length. [Figure 21] Figure 21 shows the well-known performance tradeoffs for conventional solid particulate adsorbents (cylindrical pellets) of 2-5 mm diameter in providing flexibility in reasonable flow restriction and DBL emissions performance targets. These examples are for a main canister with one or more vent-side adsorbent volumes filled with separate adsorbents, as described in Tables 2 and 3. [Figure 22] FIG. 22 shows the effect of length / diameter ratio on the 2-day DBL of an evaporative emission control system comprising a canister with one or more vent-side adsorbent volumes filled with separate adsorbents, as described in Tables 2 and 3. [Figure 23] Figure 23 is the effect of length / diameter ratio on pressure drop for an evaporative emission control system comprising a canister with one or more vent-side adsorbent volumes packed with another adsorbent, as described in Tables 2 and 3. Note that the particulate adsorbents described herein provide reduced bed pressure drop compared to currently available particulate adsorbents. [Figure 24] FIG. 24 shows the flow restriction of a conventional particulate adsorber and a carbon honeycomb for typical flow rates (slpm or lpm). [Figure 25] FIG. 25 shows typical flow rates for gas velocity in the vented volumes of FIGS. [Figure 26]FIG. 26 is an inventive example of a particulate adsorbent that can provide low DBL emissions and low flow restriction performance compared to the conventional material illustrated in FIG. [Figure 27] FIG. 27 shows the high performance exemplary or inventive vent side particulate adsorption capacity compared to carbon honeycomb with high chamber L / D greater than 2. [Figure 28] FIG. 28 shows the flow restriction of an exemplary or inventive particulate adsorber and carbon honeycomb versus typical flow rates (slpm). [Figure 29] FIG. 29 is the effect of length / diameter ratio on pressure drop of an evaporative emission control system having one or more exemplary or inventive vent-side particulate adsorption volumes compared to a carbon honeycomb. [Figure 30] FIG. 30 is the flow rate in relation to gas velocity for an exemplary or inventive vent-side particulate adsorber volume emission canister system compared to a carbon honeycomb. [Figure 31] FIG. 31 is an example of FIG. 26 where a purge of less than 100 BV and less than 210 liter level was applied after the 40 g / hr butane charge step. [Figure 32] FIG. 32 shows that when a second chamber containing an inventive embodiment of a bed ("Adsorbent 2") is added, the system exhibits low flow restriction and low emissions. [Figure 33] Figure 33 shows the DBL emissions over two days under low purge conditions (i.e., less than 100 BV) for the vent-side particulate adsorption volume described herein contained in the chamber of Adsorbent 2, which has an L / D ratio similar to that of the carbon honeycomb and shifts to lower L / D values. [Figure 34] FIG. 34 is the bed pressure drop for the exemplary or inventive vent-side particulate adsorbent volume of FIGS. 32 and 33 contained in a chamber of adsorbent 2 having an L / D ratio similar to that of a carbon honeycomb. [Figure 35]FIG. 35 shows the DBL emissions for two days under 315 L (139 BV) purge conditions for particulates of the present invention having an M / m ratio of 150% or greater. [Figure 36] FIG. 36 shows the DBL emissions over two days under 315 L (139 BV) purge conditions for particulates of the present invention having a retention volume of less than about 0.5 g / dL. [Figure 37] FIG. 37 shows the DBL emissions for two days under 315 L (137-147 BV) purge conditions for particulates of the present invention having an M / m ratio of 150% or greater. [Figure 38] FIG. 38 shows the DBL emissions over two days under 315 L (137-147 BV) purge conditions for particulates of the present invention having a retention volume of less than about 0.5 g / dL. [Figure 39] FIG. 39 is a low flow restriction characteristic of an exemplary vent-side low flow restriction particulate in an emissions canister system compared to carbon honeycomb and conventional particulate. [Figure 40] FIG. 40 is a low flow restriction characteristic of an exemplary vent-side low flow restriction particulate in an emissions canister system compared to carbon honeycomb and conventional particulate. [Figure 41] FIG. 41 is an exemplary vent-side particulate adsorption volume for high performance with a high chamber L / D of over 2 compared to carbon honeycomb and conventional particulates. [Figure 42] FIG. 42 shows pellet strength of the particulate adsorbent in the examples of FIGS. 26 and 27 as a function of M / m characteristics, where "LFR" is low flow restriction. [Figure 43] FIG. 43 is a low flow restriction particulate adsorbent example of FIGS. 26 and 27 that exhibits good pellet strength while having (or despite) high M / m characteristics and is capable of achieving excellent control of DBL emissions. [Figure 44] FIG. 44 is the pellet strength of an exemplary low flow restriction particulate adsorbent in the example of FIGS. DETAILED DESCRIPTION OF THE INVENTION

[0055] The present disclosure will now be described in more detail below, although not all embodiments of the present disclosure are shown. While the present disclosure has been described with reference to exemplary embodiments, those skilled in the art will recognize that various changes can be made and equivalents can be substituted for elements thereof without departing from the scope of the present disclosure. Furthermore, many modifications can be made to adapt a particular structure or material to the teachings of the present disclosure without departing from the essential scope of the present disclosure.

[0056] The drawings accompanying the application are for illustrative purposes only. They are not intended to limit the embodiments of the present disclosure. Also, the drawings are not to scale. Elements common between the figures may retain the same numerical designations.

[0057] When a range of values ​​is provided, it is understood that each value between the upper and lower limits of that range and any other stated range, as well as any value within that stated range, is included in the invention. The upper and lower limits of these smaller ranges may independently be included in the smaller ranges, and are also encompassed within the invention, as are any specifically excluded limits in the stated range. When the stated range includes one or both of the limits, ranges excluding either or both of those included limits are also included in the disclosure.

[0058] The following terms are used to describe the present invention: If a term is not specifically defined herein, the term is given its art-recognized meaning by those of ordinary skill in the art who apply the term in connection with its use in describing the present invention.

[0059] As used herein, unless the context clearly indicates otherwise, the articles "a" and "an" refer to one or to more than one (i.e., one or more than one) of the grammatical object of the article. As used herein, the term "an element" refers to one element or more than one element.

[0060] As used herein in the specification and claims, the term "and / or" should be understood to mean "either or both" of the elements so conjoined. That is, in some instances, the elements are present conjunctivly and in other instances, they are present disjointly. Multiple elements listed with "and / or" should be construed in the same manner, that is, "one or more" of the elements are so conjoined. Other elements other than the elements specifically identified by the "and / or" clause can optionally be present, whether related or not to those specifically identified elements. Thus, as a non-limiting example, when used in conjunction with open-ended language such as "comprising," a reference to "A and / or B" can, in one embodiment, refer only to A (optionally including elements other than B), in another embodiment to only B (optionally including elements other than A), and in yet another embodiment to both A and B (optionally including other elements).

[0061] As used herein in the specification and claims, "or" should be understood to have the same meaning as "and / or" as defined above. For example, when separating items in a list, "or" or "and / or" shall be interpreted as inclusive, i.e., including at least one, but also including more than one, of a number or list of elements, and optionally including additional unlisted items. Only terms clearly indicated to the contrary, such as "only one of," or "exactly one of," or, when used in the claims, "consisting of," will refer to the inclusion of exactly one element of a number or list of elements. Generally, as used herein, the term "or" should be interpreted to indicate exclusive alternatives (i.e., "one or the other, but not both") only when preceded by exclusive terms, such as "either," "one of," "only one of," or "exactly one of."

[0062] In the claims, as well as in the foregoing specification, all transitional phrases such as "comprising," "including," "carrying," "having," "containing," "involving," "holding," "composed of," and the like, are to be understood to be open-ended, i.e., to mean including but not limited to. The transitional phrases "consisting of" and "consisting essentially of," alone, shall be considered closed and semi-closed transitional phrases, respectively, as set forth in Section 2111.03 of the 10 United States Patent Office Manual of Patent Examining Procedures, 10th Edition.

[0063] As used herein, in the specification and claims, the phrase "at least one," in reference to a list of one or more elements, should be understood to mean at least one element selected from any one or more elements in the list of elements, but not necessarily including at least one of all elements specifically listed in the list of elements, and not excluding any combination of elements in the list of elements. Furthermore, this definition allows for the optional presence of elements other than those specifically identified in the list of elements to which the phrase "at least one" refers, whether related or not to those specifically identified elements. Thus, as a non-limiting example, "at least one of A and B" (or, equivalently, "at least one of A or B," or, equivalently, "at least one of A and / or B") can, in one embodiment, refer to any number of elements. In another embodiment, it refers to at least one A, optionally including multiple Bs, where no A is present (optionally including elements other than B). In yet another embodiment, it refers to at least one A, optionally including multiple As, and at least one B, optionally including multiple Bs (optionally including other elements). It should also be understood that, unless expressly stated otherwise, in any method claimed herein containing one or more steps or actions, the order of the method steps or actions is not necessarily limited to the order of the recited steps or actions of the method.

[0064] As used herein, the terms "gaseous" and "vaporous" are used in their general sense and are intended to be interchangeable unless the context clearly dictates otherwise.

[0065] As used herein, the term "adsorbent element" or "adsorbent volume" refers to the adsorbent or adsorbent-containing material along the vapor flow path, and can consist of a bed of particulate material, a monolith, a honeycomb, a sheet, or other material.

[0066] As used herein, the term "upstream" refers to a location / volume in a system that contacts a fluid, e.g., fuel vapor, before or prior to another location / volume in the system, i.e., the upstream location / volume is located toward the fuel vapor inlet relative to the location / volume.

[0067] As used herein, the term "downstream" refers to a location / volume in a system that contacts a fluid, e.g., fuel vapor, after or subsequent to another location / volume in the system, i.e., the downstream location / volume is located distal to the fuel vapor inlet relative to the location / volume.

[0068] The present specification provides an evaporative emission control canister system comprising one or more canisters comprising at least one particulate adsorber volume as described herein. The canister may further comprise another adsorbent volume as described herein, such as at least one fuel-side adsorbent volume and / or at least one subsequent vent-side adsorbent volume. In a preferred embodiment, the at least one particulate adsorber volume is located downstream in the fluid path from the fuel-side adsorbent volume (i.e., the vent-side particulate adsorber). In a further embodiment, the vent-side particulate adsorber is a low-retention-capacity vent-side particulate adsorber. As used herein, unless the context clearly indicates otherwise, "low retention capacity" or "low butane retention capacity" refers to a butane retention capacity of less than about 2 g / dL, preferably less than about 1 g / dL.

[0069] Evaporative Emission Canister System 1 illustrates a non-limiting example of some embodiments of the evaporative emission control canister system described herein, comprising a single canister having at least one adsorbent volume, e.g., a fuel-side adsorbent volume, and at least one vent-side adsorbent volume (i.e., downstream of the first adsorbent). Canister system 100 comprises support screen 102, bulkhead 103, fuel vapor inlet 104 from the fuel tank, vent port 105 to atmosphere, purge outlet 106 to the engine, fuel-side adsorbent volume 201, and at least one vent-side adsorbent volume 202, 203, 204. Note, however, that any particular adsorbent volume can comprise one or more of 201, 202, 203, 204. That is, the fuel-side adsorbent volume can comprise 201 and 202, and / or the vent-side adsorbent volume can comprise 203 and 204. The adsorbent volumes are coupled (in fluid communication) to allow directional, sequential contact with a fluid (e.g., air, gas, or fuel vapor).

[0070] When the engine is off, fuel vapor from the fuel tank enters canister system 100 through fuel vapor inlet 104. In this example, the fuel vapor diffuses first into fuel-side adsorbent volume 201, then into at least one vent-side (i.e., downstream) adsorbent volume before being released to the atmosphere through canister system vent port 105. When the engine is running, ambient air is drawn into canister system 100 through vent port 105. Purge air flows through at least one vent-side (i.e., downstream) adsorbent volume 204, 203, 202, and then through fuel-side adsorbent volume 201, desorbing fuel vapors adsorbed in adsorbent volumes 204, 203, 202, 201 and entering the internal combustion engine through purge outlet 106.

[0071] The evaporative emission control canister system may include an empty volume within the canister. As used herein, the term "empty volume" refers to a volume that does not contain any adsorbent. Such a volume may include any non-adsorbent, including, but not limited to, an air gap, a foam spacer, a screen, or a combination thereof. The empty volume may be located in any of the indicated volumes 201, 202, 203, and 204 shown in FIG. 1, or may be located between, before, or after any of the indicated volumes 201, 202, 203, and 204.

[0072] 2 shows a non-limiting example of a further embodiment of an evaporative emission control canister system comprising two or more canisters with multiple adsorbent volumes. For example, the fuel-side adsorbent volume and at least one vent-side adsorbent volume are located in separate canisters, and the adsorbent volumes are linked (in fluid communication) to allow directional, sequential contact of fuel vapors from one volume (and canister) to the next. 2, canister system 100 includes main canister 101, support screen 102, bulkhead 103, fuel vapor inlet 104 from the fuel tank, vent port 105 to atmosphere, purge outlet 106 to the engine, initial fuel-side adsorbent volume 201 within main canister 101, vent-side adsorbent volumes 202, 203, 204 downstream of initial fuel-side adsorbent volume 201 within main canister 101, auxiliary canister 300 including at least one additional vent-side adsorbent volume 301, 302, 303, 304, 305, and a conduit 107 connecting main canister 101 to auxiliary canister 300. Like that of the main canister, the additional vent-side adsorbent volume in the auxiliary canister may include a single adsorbent disposed in multiple of the indicated volumes 301, 302, 303, 304, 305.

[0073] Additionally, the auxiliary canister of the evaporative emission control canister system may include an empty volume, which may be located at any of the indicated volumes 301, 302, 303, 304, and 305 shown in FIG. 2 , or may be located between, before, or after any of the indicated volumes 301, 302, 303, 304, and 305. For example, at least one or both of 302 and 304 may be empty volumes. As previously mentioned, the term "empty volume" refers to a volume that does not contain any adsorbent. Such volumes may include any non-adsorbent material, including, but not limited to, an air gap, a foam spacer, a screen, a conduit, or a combination thereof.

[0074] When the engine is off, fuel vapor from the fuel tank enters the canister system 100 through the fuel vapor inlet 104 and into the main canister 101. The fuel vapor diffuses through first the fuel-side sorbent volume 201 in the main canister 101, then the vent-side sorbent volumes (202, 203, and 204), and then through conduit 107 into the auxiliary canister 300. The fuel vapor diffuses through the vent-side sorbent volumes or sorbent volumes 301, 302, 303, 304, and 305 inside the auxiliary canister 300, and is released to the atmosphere through the canister system vent port 105. When the engine is running, ambient air is drawn into the canister system 100 through the vent port 105. Purge air is used to purify the intake air. To desorb the fuel vapors adsorbed in the adsorption volumes (305, 304, 303, 302, 301, 204, 203, 202, 201), they flow through the vent-side adsorption volumes or volumes 305, 304, 303, 302, 301 in auxiliary canister 300, the vent-side adsorption volumes (204, 203, 202) in main canister 101, then the fuel-side adsorption volume 201 in main canister 101, and enter the internal combustion engine through purge outlet 106.

[0075] Additionally, the evaporative emission control canister system may include an empty volume between the main canister and the auxiliary canister.

[0076] If desired, the evaporative emission control canister system may include two or more auxiliary canisters as described herein. The evaporative emission control canister system may further include one or more empty volumes between the main canister and the first auxiliary canister, between the auxiliary canisters, and / or at the end of the last auxiliary canister. By way of non-limiting example, the evaporative emission control canister system may include a main canister, a first auxiliary canister, a second auxiliary canister, a third auxiliary canister, an empty volume between the main canister and the first auxiliary canister, an empty volume between the first auxiliary canister and the second auxiliary canister, and an empty volume at the end of the third auxiliary canister. Each of the auxiliary canisters may further include one or more additional adsorbent volumes.

[0077] If desired, the total adsorbent volume (i.e., the sum of the adsorbent volumes) may be the same as the volume of the evaporative emission control canister system, or the total adsorbent volume may be less than the volume of the evaporative emission control canister system.

[0078] Accordingly, in one aspect, the present disclosure provides an evaporative emission control canister system comprising one or more canisters having multiple chambers, each chamber defining a volume, the multiple chambers being connected or in fluid communication to allow unidirectional and continuous flow of fluid (e.g., air, gas, or fuel vapor) from one chamber to the next, at least one chamber containing microscopic pores having a diameter of less than about 100 nm, macroscopic pores having a diameter of about 100-100,000 nm, and a volume of the macroscopic pores greater than about 150% of the volume of the microscopic pores. The present invention provides an evaporative emission control canister system, comprising at least one particulate adsorbent volume comprising a particulate adsorbent having a pressure drop of less than 40 Pa / cm under conditions of an apparent linear airflow velocity of 46 cm / sec applied to a 43 mm diameter bed of particulate adsorbent material, the at least one particulate adsorbent volume having at least one of the following: (i) a flow restriction characteristic of less than 40 Pa / cm under conditions of an apparent linear airflow velocity of 46 cm / sec applied to a 43 mm diameter bed of particulate adsorbent material; (ii) a flow restriction of less than 0.3 kPa under an airflow of 40 lpm; (iii) a butane retention capacity of less than about 0.5 g / dL; (iv) a length to diameter (L / D) ratio of greater than about 2; or (v) a combination thereof.

[0079] In certain embodiments, the canister system includes at least one additional sorbent volume, in certain embodiments, the sorbent volumes are located within a single canister or within multiple canisters that are connected so as to be continuously accessible by the fuel vapor.

[0080] In certain embodiments, the canister system further includes at least one fuel-side sorbent volume, wherein the at least one fuel-side sorbent volume has a nominal BWC greater than 8 g / dL, a nominal IAC greater than 35 g / L at 25°C with a vapor concentration of 5 vol% to 50 vol% n-butane, or both.

[0081] In certain embodiments, the canister system further comprises at least one vent-side subsequent sorbent volume, wherein the at least one vent-side subsequent sorbent volume has a nominal B % n-butane vapor concentration at 25° C. has a BWC of less than 8 g / dL, a nominal IAC of less than 35 g / L at 5 vol% to 50 vol% n-butane vapor concentration at 25° C. In certain embodiments, at least one particulate adsorbent volume, at least one vent-side subsequent adsorbent volume, or both, has a BWC of less than 8 g / dL, an IAC of less than 35 g / L at 5 vol% to 50 vol% n-butane vapor concentration at 25° C.

[0082] In certain embodiments, the evaporative emission control canister system comprises at least one fuel-side adsorbent volume having a nominal butane working capacity (BWC) of at least 8 g / dL (e.g., at least 10 g / L), a nominal incremental adsorption capacity (IAC) of at least 35 g / L at 25°C with n-butane vapor concentrations between 5 vol% and 50 vol%, or both.

[0083] In certain embodiments, the sorbent volumes are located in a single canister or in multiple canisters that are connected so as to be continuously accessible by the fuel vapor.

[0084] In certain embodiments, the particulate adsorbent volume has an M / m ratio of greater than about 200%. In certain embodiments, the particulate adsorbent volume has a butane retention capacity of less than about 2.0 g / dL, or less than 1.0 g / dL, or less than 0.5 g / dL.

[0085] In certain embodiments, at least one particulate adsorber is located on the vent side of the canister system, the fuel side of the canister system, or both.

[0086] In certain embodiments, the evaporative emission control canister system includes at least one fuel-side adsorbent volume, at least one vent-side subsequent adsorbent volume, or both.

[0087] In certain embodiments, the adsorbent volumes are located in a single canister or in multiple canisters that are connected so as to be continuously accessible by fuel vapor. In certain embodiments, at least one particulate adsorbent volume, at least one vent-side adsorbent volume, or both, has a BWC of at least 8 g / dL (e.g., at least 10 g / L), an IAC of at least 35 g / L at 25°C between 5 vol% and 50 vol% n-butane vapor concentrations, or both. In certain embodiments, at least one particulate adsorbent volume, at least one subsequent vent-side adsorbent volume, or both, has a BWC of less than 8 g / dL, an IAC of less than 35 g / L at 25°C between 5 vol% and 50 vol% n-butane vapor concentrations, or both. In certain embodiments, the particulate volume has a ratio of macropore volume to micropore volume greater than about 200%.

[0088] In another aspect, the present description provides an evaporative emission control canister system comprising one or more canisters comprising at least one fuel-side adsorbent volume (i.e., an adsorbent volume at or near the fuel tank vapor inlet 104) and at least one vent-side particulate adsorbent volume, e.g., a vent-side low-retention-capacity particulate adsorbent volume. The term "vent-side" refers to a location downstream or closer to the vent port relative to the at least one fuel-side adsorbent volume. Thus, while the vehicle is stationary, the at least one fuel-side adsorbent volume contacts fuel vapor from the gas tank before any other adsorbent volumes located downstream of the fuel-side adsorbent volume in the flow path from the fuel tank to the vent port (i.e., downstream in the direction from 104 to 105).

[0089] In some embodiments, the system comprises a plurality of vent-side particulate volumes, e.g., vent-side low-retention-volume particulate adsorbent volumes, configured to allow sequential contact by a fluid, e.g., fuel vapor. In certain embodiments, for example, the adsorbents are connected in series to define a fluid flow path therethrough. In certain embodiments, the system comprises a plurality of vent-side particulate volumes, e.g., vent-side low-retention-volume particulate adsorbent volumes, configured to allow sequential contact by a fluid, e.g., fuel vapor. It has multiple canisters that are linked together to allow for more continuous contact.

[0090] 1 and 2, the sorbent can be located in a single canister or in multiple canisters (e.g., 2, 3, 4, 5, 6, 7, or 8 canisters) that are connected to allow continuous contact with a fluid, e.g., fuel vapor. In certain embodiments, the sorbent is located in multiple canisters that are connected to allow continuous contact with fuel vapor. For example, in certain embodiments, the vent-side particulate adsorbent volume, e.g., the vent-side low-retention-capacity particulate adsorbent volume, is located within at least one volume of the main canister, e.g., 202, 203, or 201, with reference to FIGS. 1 and 2, and / or at least one volume of the auxiliary canister, e.g., 301, 302, 303, 304, or 305. That is, in certain embodiments, the low retention volume particulate adsorbent can be present within the volume of at least one of the main canisters 201, 202, 203, and 204, within the volume of at least one of the auxiliary canisters 301, 302, 303, 304, 305, or a combination thereof.

[0091] The present disclosure also contemplates the inclusion of additional adsorbent volumes in any number of combinations that will be readily apparent from the present disclosure. For example, the additional vent-side or low-retention-capacity particulate adsorbents described herein can be present after or downstream of the vent-side subsequent adsorbent volumes. If an auxiliary canister is present, the auxiliary canister can include vent-side or low-retention-capacity adsorbent volumes on the vent port side (e.g., volume 305) and the main canister side (e.g., volume 301), with downstream vent-side subsequent adsorbent volumes (e.g., volumes 302, 303, 304) located therebetween. Similarly, vent-side or low-retention-capacity adsorbent volumes can be present on the main canister side of the auxiliary canister (e.g., volume 301) and the auxiliary canister side of the main canister (e.g., volume 204), with the canister system including a high butane working capacity adsorbent upstream of the vent-side or low-retention-capacity adsorbent. The system can also be configured to include a subsequent vent-side adsorbent volume (e.g., volume 304) downstream of the vent-side or low-holding capacity adsorbent volume (e.g., volume 301), and optionally include an even lower-holding capacity adsorbent volume after the subsequent adsorbent volume (e.g., volume 305).

[0092] In any of the aspects or embodiments described herein, the vent-side particulate adsorbent has microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume (M / m) greater than about 150%, 160%, 170%, 180%, 190%, 200%, 210%, 220%, 250%, 275%, 280%, or 300%. In certain embodiments, the vent-side particulate adsorbent has an M / m ratio between 150% and about 170%, between about 160% and about 180%, between about 170% and about 190%, between about 180% and about 200%, between 190% and about 210%, between 200% and about 220%, or greater than 220%. In another embodiment, the volume ratio is greater than 150% to about 1000%, greater than about 150% to about 800%, greater than about 150% to about 600%, greater than about 150% to about 500%, greater than about 150% to about 400%, greater than about 150% to about 300%, greater than about 150% to about 200%, about 175% to about 1000%, about 175% to about 800%, about 175% to about 600%, about 175% to about 500%, about 175% to about 400%, about 175% to about 300%, about 175% to about 200 %, about 200% to about 800%, about 200% to about 600%, about 200% to about 500%, about 200% to about 400%, about 200% to about 300%, about 300% to about 800%, about 300% to about 600%, about 300% to about 500%, about 300% to about 400%, about 400% to about 800%, about 400% to about 600%, about 400% to about 500%, about 500% to about 800%, about 500% to about 600%, or about 600% to about 800%.

[0093] In any of the aspects or embodiments described herein, the vent-side particulate adsorption capacity, e.g., the vent-side low retention capacity particulate adsorption capacity, is about 0.3 kPa under 40 lpm airflow. a flow restriction of less than 40 Pa / cm under an apparent linear air velocity of 46 cm / sec, or both.

[0094] In any of the aspects or embodiments described herein, the vent-side particulate adsorption volume, e.g., the vent-side low-retention-volume particulate adsorption volume, has a length to diameter (L / D) ratio of about 0.5, 1, 1.5, 2, 2.5, 3, 3.5, 4, 4.5, 5, 5.5, 6, 6.5, or greater, including all values ​​therebetween. In certain embodiments, the vent-side particulate adsorption volume is elongated, having an L / D ratio greater than about 2. In certain embodiments, the L / D ratio is about 1.0 to about 6.0, about 1.25 to about 5.75, about 1.5 to about 5.5, about 1.75 to about 5.0, or about 2 to about 4.75.

[0095] In any of the aspects or embodiments described herein, at least one vent-side particulate adsorption volume, e.g., a vent-side low retention volume particulate adsorption volume, has a butane retention capacity of about 2 g / dL or less, about 1.5 g / dL or less, about 1 g / dL or less, about 0.9 g / dL or less, about 0.8 g / dL or less, about 0.7 g / dL or less, about 0.6 g / dL or less, about 0.5 g / dL or less, about 0.4 g / dL or less, about 0.3 g / dL or less, about 0.2 g / dL, or about 0.1 g / dL or less. In certain embodiments, the particulate adsorption volume of at least one vent side, e.g., the particulate adsorption volume of the low vent side retention volume, is between about 0.01 g / dL and about 2.5 g / dL, between about 0.01 g / dL and about 2.0 g / dL, between about 0.01 g / dL and about 1.5 g / dL, between about 0.01 g / dL and about 1.0 g / dL, between about 0.01 g / dL and about 0.01 g / dL. The butane retention capacity is about 0.75 g / dL, about 0.25 g / dL to about 1.00 g / dL, about 0.25 g / dL to about 0.75 g / dL, about 0.25 g / dL to about 0.50 g / dL, about 0.50 g / dL to about 1.00 g / dL, about 0.50 g / dL to about 0.75 g / dL, or about 0.75 g / dL to about 1.00 g / dL.

[0096] An advantageous feature of the particulate adsorbents described herein, e.g., the low-retention-capacity adsorbents described herein, is that they have sufficiently low flow restriction characteristics that they can be used as replacements for, e.g., foam, polymer or paper sheets, or honeycomb monolith adsorbents. For example, Figure 21 shows how many times more flow-restrictive a prior art particulate adsorbent having a diameter of 2-3 mm is than a commercially available carbon honeycomb used on the vent side of a canister system as an emissions "scrubber." Thus, in any of the aspects or embodiments, the vent-side particulate adsorbent, e.g., the low-retention-capacity adsorbent on the vent side, has a particle size of about 3-10 mm, about 3-9 mm, about 3-8 mm, about 3-7 mm, about 3-6 mm, about 3-5 mm, or about 3-4 mm.

[0097] In certain embodiments, the main canister comprises a high butane working capacity adsorbent, the vent side of the main canister and / or the main canister side of the auxiliary canister comprises a low retention capacity particulate adsorbent as described herein, and the vent section of the auxiliary canister comprises a subsequent adsorbent volume on the vent side, which in certain embodiments is a material with low flow restriction, such as a foam, polymer or paper sheet, or a honeycomb, such as an activated carbon honeycomb.

[0098] In certain embodiments, at least one fuel-side adsorbent volume has at least one of a high butane working capacity (BWC) relative to the vent-side adsorbent volume, an effective incremental adsorption capacity of greater than about 35 grams per liter (g / L) of n-butane at vapor concentrations of 5 vol% to 50 vol% n-butane, or both.

[0099] In any of the aspects or embodiments described herein, the sorbent volume on the fuel side of the canister system is: i) 8, 9, 10, 11, 12, 13, 14, 15, 16, 17, 18, 19, 20, 21, 22, 23, 24, 25 g / dL or more grams per deciliter ( ii) a nominal butane working capacity (BWC) of 35, 36, 37, 38, 39, 40, 41, 42, 43, 44, 45, 46, 47, 48, 49, 50, 51, 52, 53, 54, 55, 60, 65, 70, 75, 80, 85, 90, or more grams of n-butane per liter (g / L) at vapor concentrations of 5 vol% to 50 vol% n-butane;

[0100] In certain embodiments, the high butane working capacity adsorbent comprises a high working capacity activated carbon, which is commercially available as NUCHAR® BAX 1100, NUCHAR® BAX 1100 LD, NUCHAR® BAX 1500, and NUCHAR® BAX 1700 (Ingevity®, North Charleston, South Carolina, USA). The high butane working capacity volume can comprise multiple volumes comprising high butane working capacity adsorbents. For example, a main canister can comprise two high butane working capacity volumes (e.g., a NUCHAR® BAX 1100 volume and a NUCHAR® BAX 1500 volume).

[0101] In any of the aspects or embodiments described herein, the evaporative emission control canister system further comprises at least one vent-side subsequent sorbent volume, wherein the at least one vent-side subsequent sorbent volume has a nominal BWC of less than 8, 7, 6, 5, 4, 3, 2, or 1 g / dL, a nominal IAC of less than 35, 34, 33, 32, 31, 30, 29, 28, 37, 36, 35, 34, 23, 22, 21, 20, 19, 18, 17, 16, 15, 14, 13, 12, 11, 10, 9, 8, 77, 6, 5, 4, 3, 2, or 1 g / L at 25°C with a vapor concentration of 5 vol% to 50 vol% n-butane, or both. In certain embodiments, the BWC of at least one vent-side subsequent adsorbent volume is from about 1 g / dL to about 8 g / dL, from about 1 g / dL to about 7 g / dL, from about 1 g / dL to about 6 g / dL, from about 1 to about 5 g / dL, from about 1 g / dL to about 4 g / dL, or from about 1 g / dL to about 3 g / dL. In certain embodiments, the IAC (grams n-butane / L) of from about 1 g / L to about 35 g / L, from about 2 g / L to about 30 g / L, from about 3 g / L to about 25 g / L, from about 3 g / L to about 20 g / L, from about 3 g / L to about 15 g / L, or from about 3 g / L to about 10 g / L at an n-butane vapor concentration of 5 vol% to 50 vol%.

[0102] In certain embodiments, at least one vent-side subsequent adsorbent volume has at least one of: i) a BWC of less than about 8, 7, 6, 5, 4, 3, 2, or 1 g / dL; ii) an IAC of less than about 35, 30, 25, 20, 15, 10, or 5 grams n-butane / L at a vapor concentration of 5 vol% to 50 vol% n-butane; or iii) a combination thereof. In certain embodiments, the subsequent adsorbent volume is an activated carbon honeycomb.

[0103] In certain embodiments, the subsequent adsorbent volume is upstream, downstream, or both in the vapor path from the vent-side particulate adsorbent volume described herein (ie, a vent-side subsequent adsorbent volume).

[0104] In any of the aspects or embodiments described herein, the subsequent / downstream adsorber / volume on the vent side is selected from the group consisting of a honeycomb adsorber (e.g., HCA, HCA-LBE, or Square HCA available from Ingevity®, North Charleston, South Carolina, USA), a monolith adsorber, or both.

[0105] The disclosed evaporative emission control systems provide low diurnal breathing loss (DBL) emissions even under low purge conditions. In certain embodiments, the disclosed evaporative emission control systems have an evaporative emissions performance of 50 mg or less, or less than 100 mg per gallon of fuel consumed by the California Bleed Emissions Test Procedure (BETP). In any aspect or embodiment described herein, the evaporative emissions canister system described herein may be within the regulatory limit of 20 as defined by the California Bleed Emissions Test Procedure. The 2-day DBL is about 5 to about 50 mg, about 6 to about 50 mg, about 7 to about 50 mg, about 8 to about 50 mg, about 9 to about 50 mg, about 10 to about 50 mg, about 5 to about 45 mg, about 5 to about 40 mg, about 5 to about 35 mg, about 5 to about 30 mg, about 5 to about 20 mg, about 5 to about 15 mg, or about 5 to about 10 mg, measured with a bed volume purge of about 175, 150, 125, 120, 115, 110, or 100 liters or less, or with a purge of 315, 300, 275, 250, 225, 200, 175, or 150 liters or less, as measured with a bed volume purge (BETP).

[0106] The evaporative emission control system can provide low diurnal breathing loss (DBL) emissions even when purged with 210 liters or less applied after a 40 g / hr butane fill step. In some embodiments, the evaporative emission control system may be purged with 157.5 liters or less applied after a 40 g / hr butane fill step.

[0107] The evaporative emission control system can provide low diurnal breathing loss (DBL) emissions even when purged at 150 BV or less applied after a 40 g / hr butane fill step. The evaporative emission control system can provide low diurnal breathing loss (DBL) emissions even when purged at 100 BV or less applied after a 40 g / hr butane fill step. In some embodiments, the evaporative emission control system can be purged at 75 BV or less applied after a 40 g / hr butane fill step.

[0108] In certain embodiments, the evaporative emission control canister system includes at least one vent-side particulate adsorber volume, e.g., a vent-side low-retention-capacity particulate adsorber volume, wherein the at least one vent-side particulate adsorber has an M / m ratio greater than 150% and at least one of a relatively low flow restriction characteristic and a butane retention capacity of less than 1.0 g / dL, or both. For example, in certain embodiments, the vent-side particulate adsorber has an M / m greater than 150% and at least one of a butane retention capacity of less than about 0.5 g / dL, a flow restriction of less than 40 Pa / cm pressure drop under a 46 cm / sec apparent linear gas velocity, a flow restriction of less than 0.3 kPa under a 40 lpm airflow, a length to diameter ratio (L / D) greater than 2, or a combination thereof. In another embodiment, the vent-side particulate adsorption capacity has at least one of: M / m greater than 200% and a butane retention capacity less than about 1 g / dL; a flow restriction of less than 40 Pa / cm pressure drop under an apparent linear gas flow velocity of 46 cm / sec; a flow restriction of less than 0.3 kPa under an airflow of 40 lpm; a length to diameter ratio (L / D) greater than 2; or a combination thereof.

[0109] In certain embodiments, the vent-side particulate adsorbents described herein, e.g., low vent-side load capacity particulate adsorbents, have a flow restriction characteristic of less than 40 Pa / cm pressure drop at 46 cm / sec apparent linear air velocity, M / m greater than 150%. In certain embodiments, the vent-side particulate adsorbents, e.g., low vent-side load capacity particulate adsorbents, have an M / m greater than 200% and a butane load capacity less than 1 g / dL. In certain embodiments, the vent-side particulate adsorbents have an M / m greater than 150% and a butane load capacity less than 0.5 g / dL.

[0110] In certain embodiments, an evaporative emission control system includes one or more canisters having a plurality of adsorbent volumes, including at least one vent-side particulate adsorbent volume, the vent-side particulate adsorbent volume comprising, for example, (i) microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of the volume of the macroscopic pores to the volume of the microscopic pores. The present invention provides a low-retention capacity particulate adsorbent having at least one of: (i) a ratio (M / m) of greater than about 150% of the butane retention capacity of about 1 g / dL to less than about 0.25 g / dL; (ii) a butane retention capacity of about 1 g / dL to less than about 0.25 g / dL; (iii) a particle size of about 210 mm or greater; or (iv) a combination thereof.

[0111] In any of the aspects or embodiments described herein, the evaporative emissions control canister system has 2-day DBL emissions of about 50, 45, 40, 35, 30, 25, 20 mg or less at a bed volume purge of about 175, 150, 125, 120, 115, 110, 100 or less, or at a purge of 315, 300, 275, 250, 225, 200, 175, 150 or less liters as measured by the California Bleed Emissions Test Procedure (BETP).

[0112] In certain embodiments, the evaporative emission control canister system includes at least one vent-side particulate adsorber having an M / m greater than 150%, and the vent-side particulate adsorber volume, e.g., a vent-side low retention capacity particulate volume, has at least one of a flow restriction of less than 40 Pa / cm pressure drop under a 46 cm / sec apparent linear gas flow velocity, or a flow restriction of less than 0.3 kPa under a 40 lpm air flow, and the canister system has day 2 DBL emissions of 50 mg or less, or 20 mg or less, under a bed volume of less than 100 or a purge of less than 210 liters in a BETP test.

[0113] In another aspect, the present disclosure provides an evaporative emission control canister system comprising at least one vent-side particulate adsorbent volume having a low retention capacity, and one or more canisters comprising the low retention capacity particulate adsorbent volume containing one or more low retention capacity particulate adsorbent materials. In certain embodiments, the low retention capacity particulate adsorbent material has microscopic pores less than about 100 nm in diameter and macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 200%, and the particulate adsorbent material has a retention capacity of about 1.0 g / dL or less.

[0114] For example, the system can include an upstream adsorbent volume comprising a high butane working capacity adsorbent located upstream of or before a low retention capacity adsorbent volume (i.e., the high butane working capacity adsorbent volume contacts the fluid, e.g., fuel vapor, before the low retention capacity adsorbent). The high butane working capacity adsorbent volume can have an adsorbent having at least one of a nominal butane working capacity of at least 8 g / dL (e.g., at least 10 g / dL), a nominal incremental adsorption capacity (IAC) of at least 35 g / L (e.g., at least 45 g / L), or a combination thereof.

[0115] The systems of the present disclosure may include an adsorbent volume located downstream of or after the low-retention-capacity adsorbent volume (i.e., the upstream adsorbent volume contacts the fuel vapor after the low-retention-capacity adsorbent volume). The downstream adsorbent volume may include an adsorbent body having microscopic pores less than about 100 nm in diameter and macroscopic pores between about 100 and 100,000 nm in diameter, with a ratio of macroscopic pore volume to microscopic pore volume of about 150% or less. For example, the downstream or subsequent adsorbent body may have a ratio of macroscopic pore volume to microscopic pore volume of about 150% or less, about 145% or less, about 140% or less, about 135% or less, or about 130% or less.

[0116] In certain embodiments, at least one vent-side particulate adsorbent volume, e.g., a vent-side low-retention-capacity particulate adsorbent volume, is provided as an alternative to or in combination with one or more subsequent vent-side adsorbent volumes. The at least one fuel-side adsorbent volume, the at least one vent-side particulate adsorbent volume, and / or the at least one subsequent vent-side adsorbent volume can be contained either in a single canister or in separate canisters that are connected to allow continuous contact by fuel vapor (and conversely, purge air). In certain embodiments, the at least one subsequent vent-side adsorbent volume is comprised of a non-particulate adsorbent material. For example, it comprises a foam, monolith, polymer or paper sheet, or honeycomb (eg, activated carbon honeycomb), with at least one vent-side subsequent adsorbent volume providing low vapor or fluid flow restriction.

[0117] In certain embodiments, the evaporative emission control canister system comprises at least one vent-side trailing adsorbent volume, such as a vent-side low-retention-capacity particulate adsorbent volume upstream of the at least one vent-side particulate adsorbent volume (i.e., located near the fuel-side adsorbent volume or fuel vapor inlet in the flow path), at least one vent-side trailing adsorbent volume downstream of the at least one vent-side particulate adsorbent volume (i.e., located near the vent port in the flow path), or a combination thereof.

[0118] In certain embodiments, the evaporative emission control canister system comprises at least one vent-side particulate adsorber volume, such as a vent-side low-retention-capacity particulate adsorber volume upstream of at least one subsequent vent-side adsorber volume (i.e., located near the fuel-side adsorber volume or fuel vapor inlet in the flow path), at least one vent-side particulate adsorber volume downstream of at least one subsequent vent-side adsorber volume (i.e., located near the vent port in the flow path), or a combination thereof.

[0119] In some embodiments, the evaporative emission control system can further include one or more heat input units for heating the one or more adsorbent volumes and / or one or more empty volumes. The heat input unit can include, but is not limited to, an internal resistive element, an external resistive element, or a heat input unit associated with the adsorbent. The heat input unit associated with the adsorbent can be an element separate from (i.e., not in contact with) the adsorbent. Alternatively, the heat input unit associated with the adsorbent can be a substrate or layer to which the adsorbent is attached, bonded, unbonded, or in physical contact. The heat input unit associated with the adsorbent can be an adsorbent that is electrically heated directly by having a suitable resistivity. The resistive properties of the adsorbent can be modified by adding conductive or resistive additives and binders during the initial preparation of the adsorbent and / or during the formation of the adsorbent into particulate or monolithic form. The conductive component can be a conductive adsorbent, a conductive substrate, a conductive additive, and / or a conductive binder. The conductive material can be added during the preparation of the adsorbent, during an intermediate forming process, and / or during the formation of the adsorbent into its final shape. Any type of heat input unit can be used. Non-limiting examples include heat transfer fluids, heat exchangers, thermally conductive elements, and positive temperature coefficient materials. The heat input unit may or may not be uniform along the length of the heated flowpath (i.e., it may or may not provide locally different intensities). Furthermore, the heat input unit may or may not be distributed to provide greater heating intensity and duration at various points along the length of the heated flowpath.

[0120] Generally, a low retention capacity particulate adsorbent comprises an adsorbent having microscopic pores less than about 100 nm in diameter and macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, wherein the particulate adsorbent material has a retention capacity of about 1.0 g / dL or less.

[0121] As described, any suitable adsorbent material used to prepare the adsorbent volume includes, but is not limited to, activated carbon, charcoal, zeolite, clay, porous polymer, porous alumina, porous silica, molecular sieve, kaolin, titania, ceria, or combinations thereof. Activated carbon can be derived from a variety of carbon precursors. Non-limiting examples of carbon precursors include wood, wood dust, wood flour, cotton linters, peat, coal, coconut, lignite, carbohydrates, petroleum pitch, petroleum coke, coal tar pitch, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables, such as rice husks or straw. The activated carbon may be a polymer, a synthetic polymer, a natural polymer, a lignocellulosic material, or a combination thereof. Additionally, activated carbon may be produced using a variety of processes, including, but not limited to, chemical activation, thermal activation, or a combination thereof.

[0122] The described low retention capacity particulate adsorbents may be at least one of activated carbon, charcoal, molecular sieves, porous polymers, porous alumina, clay, porous silica, kaolin, zeolites, metal organic frameworks, titania, ceria, or combinations thereof (which may be derived from at least one material selected from the group consisting of wood, wood dust, wood flour, cotton linters, peat, coal, coconut, lignite, carbohydrates, petroleum pitch, petroleum coke, coal tar pitch, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables, synthetic polymers, natural polymers, lignocellulosic materials, or combinations thereof).

[0123] Various adsorbent forms can be used. Non-limiting examples of adsorbent forms include granular, pelleted, spherical, honeycomb, monolithic, pellet-like cylinders, uniformly shaped particulate media, non-uniformly shaped particulate media, extruded structured media, wound structured media, folded structured media, pleated structured media, corrugated structured media, cast structured media, adhesive structured media, nonwovens, woven fabrics, sheets, paper, foams, or combinations thereof. The adsorbent may also include a volumetric diluent (as a single component or a mixture of different components). Non-limiting examples of volumetric diluents include, but are not limited to, spacers, inert gaps, foams, fibers, springs, or combinations thereof. Additionally, the adsorbent may be extruded into special thin-walled cross-sectional shapes, such as hollow cylinders, stars, twisted spirals, asterisks, formed ribbons, or other shapes within the skill of the art. Inorganic and / or organic binders may be used in the molding process.

[0124] Honeycomb adsorbents may be of any geometric shape, including, but not limited to, circular, cylindrical, or square. Furthermore, the cells of honeycomb adsorbents may be of any shape. Honeycombs with uniform cross-sectional areas for the flow-through passages, such as square honeycombs with square cross-sectional cells or spirally wound corrugated honeycombs, may perform better than circular honeycombs with square cross-sectional cells in a right-angle matrix, with adjacent passages having varying cross-sectional areas and therefore not being equally purged. Without being bound by any theory, it is believed that a more uniform cell cross-sectional area across the honeycomb face results in more uniform flow distribution within the part during both adsorption and purge cycles, and therefore lower DBL emissions from the canister system.

[0125] The disclosed system may include at least one of a fuel vapor inlet conduit connecting the evaporative emission control canister system to a fuel tank, a fuel vapor purge conduit connecting the evaporative emission control canister system to an air induction system of an engine, a vent conduit for venting the evaporative emission control canister system and for the intake of purge air into the evaporative emission control canister system, or a combination thereof. The system may have at least one of a fuel vapor flow path from the fuel vapor inlet conduit through each of a plurality of adsorbent volumes (i.e., a first adsorbent volume upstream of at least one subsequent adsorbent volume, at least one adsorbent volume comprising a low-loading capacity particulate adsorber) to a vent conduit, an air flow path from the vent conduit through each of a plurality of adsorbent volumes (i.e., a first adsorbent volume upstream of a subsequent adsorbent volume and the subsequent subsequent adsorbent volumes) to a fuel vapor purge outlet, or both.

[0126] In another aspect, the present disclosure provides a fuel tank for storing fuel and an air induction system. and an evaporative emission control system comprising: an engine configured to consume fuel; an evaporative emission control canister system; a fuel vapor purge conduit connecting the evaporative emission control canister system to an air induction system of the engine; and a vent conduit for venting the evaporative emission control canister system and for the induction of purge air into the evaporative emission control canister system, wherein the evaporative emission control canister system is defined by a fuel vapor inlet conduit connecting the evaporative emission control canister system to a fuel tank, a fuel vapor flow path from the fuel vapor inlet conduit through a plurality of adsorbent volumes to a vent conduit, and an air flow path from the vent conduit through the plurality of adsorbent volumes and the fuel vapor purge outlet. The evaporative emission control system includes one or more canisters having a plurality of adsorbent volumes, with at least one low-retention-capacity adsorbent volume comprising a low-retention-capacity particulate adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume (M / m) greater than about 150%, and a retention capacity of less than about 1.0 g / dL. The evaporative emission control system includes a plurality of canisters connected together so as to be continuously accessible by fuel vapor.

[0127] In some embodiments, the evaporative emission control system may include a heating unit to further enhance purging efficiency. By way of non-limiting example, the evaporative emission control system may include a heating unit to heat at least one or both of the purge air, the low-holding capacity adsorbent volume, and / or the subsequent adsorbent volume.

[0128] According to one aspect, the present disclosure provides a method for reducing fuel vapor emissions in an evaporative emission control canister system, the method including contacting fuel vapor with a particulate adsorbent volume, for example, a vent-side low retention capacity particulate adsorbent volume having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, and the particulate adsorbent material having a flow restriction characteristic of less than about 40 Pa / cm under conditions of an apparent linear air flow velocity of 46 cm / sec applied to a 43 mm diameter bed of particulate adsorbent material.

[0129] Fuel side and vent side In another embodiment, the description provides a method for producing a fuel-side particulate adsorbent having at least one fuel-side particulate adsorbent volume having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, and a retention capacity less than about 0.5 g / dL, or a ratio of macroscopic pore volume to microscopic pore volume greater than about 200%, and a retention capacity less than about 1 g / dL. and at least one vent-side particulate adsorbent volume comprising a particulate adsorbent having macroscopic pores and a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, wherein the at least one vent-side particulate adsorbent volume has a butane retention capacity of less than 0.5 g / dL, or a ratio of macroscopic pore volume to microscopic pore volume greater than about 200%, and a retention capacity of less than about 1 g / dL. In certain embodiments, the fuel-side particulate adsorbent volume, the vent-side particulate adsorbent volume, or both, have a flow restriction characteristic of less than 40 Pa / cm when a nominal linear airflow velocity of 46 cm / sec is applied to a 43 mm diameter bed of the vent-side particulate adsorbent volume. In further embodiments, the at least one fuel-side particulate adsorbent volume, the at least one vent-side particulate adsorbent volume, or both, have a flow restriction of less than 0.3 kPa under an airflow of 40 lpm. In another embodiment, the at least one vent-side particulate adsorbent volume has a length to diameter ratio of 2 or greater. In further embodiments, at least one fuel-side sorbent volume has a nominal BWC greater than 8 g / dL, a nominal IAC greater than 35 g / L at 25° C. with a vapor concentration of 5 vol% to 50 vol% n-butane, or both.

[0130] In certain embodiments, the low-holding-capacity particulate adsorbent has a pore volume of about 225 cc / L or less (about 0.5 cc / g or less). For example, the pore volume of the low-holding-capacity particulate adsorbent can be about 200 cc / L or less, about 175 cc / L or less, about 150 cc / L or less, about 125 cc / L or less, about 100 cc / L or less, about 75 cc / L or less, about 50 cc / L or less, or about 25 cc / L or less. As a further example, the pore volume of the low-holding-capacity particulate adsorbent can be from about 1.0 cc / L to about 225 cc / L, from about 1.0 cc / L to about 200 cc / L, from about 1.0 cc / L to about 175 cc / L, from about 1.0 cc / L to about 150 cc / L, from about 1.0 cc / L to about 125 cc / L, from about 1.0 cc / L to about 100 cc / L, from about 1.0 cc / L to about 75 cc / L, from about 1.0 cc / L to about 50 cc / L, from about 1.0 cc / L to about 25 cc / L, from about 25 cc / L to about 225 cc / L, from about 25 cc / L to about 200 cc / L, from about 25 cc / L to about 175 cc / L, from about 25 cc / L to about 150 cc / L, from about 25 cc / L to about 125 cc / L, from about 25 cc / L to about 100 cc / L, from about 25 cc / L to about 75 cc / L, from about 25 cc / L to about 50 cc / L, from about 50 cc / L to about 225 cc / L, from about 50 cc / L to about 200 cc / L, from about 50 cc / L to about 175 cc / L, from about 50 cc / L to about 150 cc / L, from about 50 cc / L to about 125 cc / L, from about 50 cc / L to about 100 cc / L, from about 50 cc / L to about 75 cc / L, from about 75 cc / L to about 225 cc / L, from about 75 cc / L to about 200 cc / L, from about 75 cc / L to about 175 cc / L, from about 75 cc / L to about 150 cc / L, from about 75 cc / L to about 125 cc / L, from about 75 cc / L to about 100 cc / L, from about 100 cc / L to about 225 cc / L, from about 100 cc / L to about 200 cc / L, from about 100 cc / L to about 175 cc / L, from about 100 cc / L to about 150 cc / L, from about 100 cc / L to about 125 cc / L, from about 125 cc / L to about 225 cc / L, from about 125 cc / L to about 200 cc / L, from about 125 cc / L to about 175 cc / L, from about 125 cc / L to about 150 cc / L, from about 150 cc / L to about 225 cc / L, from about 150 cc / L to about 200 cc / L, from about 150 cc / L to about 175 cc / L, from about 175 cc / L to about 225 cc / L, from about 175 cc / L to about 200 cc / L, or from about 200 cc / L to about 225 cc / L.

[0131] In some other embodiments, the low retention capacity particulate adsorbent comprises a body defining an outer surface and a three-dimensional low flow resistance shape or configuration. The three-dimensional low flow resistance shape or configuration can be any shape or configuration that one skilled in the art would understand to have low flow resistance. For example, the three-dimensional low flow resistance shape or configuration may be at least one of a substantially cylinder, a substantially elongated cylinder, a substantially sphere, a substantially cube, a substantially elliptical cylinder, a substantially rectangular cylinder, a lobed cylinder, a three-dimensional helix or spiral, or a combination thereof. Other useful examples of configurations include shapes of absorption column packing known to those skilled in the art, such as Rachig rings, cross-partition rings, Pall® rings, Intalox® saddles, Berl saddles, SuperIntalox® saddles, Conjugate rings, Cascade mini rings, and Lessing rings. Other useful examples of shapes include those known to those skilled in the art of pasta making, such as strips, springs, coils, corkscrews, shells, tubes, ribbon-like, solid, hollow, lobed, and lobed and hollow composite shapes, such as gemelli, fusilli, hollow fusilli, macaroni, rigatoni, celentani, farfalle, gormiti rigate, casarezzi, cavatelli, crestedigari, gigli, lumacconi, quadrefio, radiatori, lute, conchiglie, or combinations thereof.

[0132] As non-limiting examples, Figures 3A-3I show exemplary shape forms of the present disclosure, including a compound lobe shape (A), a square prism shape (B), a cylindrical shape (C), a shape with a star-shaped cross section (D), a cross section (E), a triangular prism with an inner wall that intersects the central axis (F), a triangular prism with an inner wall that does not intersect the central axis (G), a helical or twisted ribbon shape (H1 and standing view H2), and a hollow cylinder (I).

[0133] The low retention capacity particulate adsorbent material may have a cross-sectional width of about 1 mm to about 20 mm (e.g., about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm, or about 20 mm). In particulate embodiments, the cross-sectional width of the low retention capacity particulate adsorbent may be about 1 mm to about 18 mm, about 1 mm to about 16 mm, about 1 mm to about 14 mm, about 1 mm to about 12 mm, about 1 mm to about 10 mm, about 1 mm to about 8 mm, about 1 mm to about 6 mm, about 1 mm to about 4 mm, about 1 mm to about 3 mm, about 2 mm to about 20 mm, about 2 mm to about 18 mm, about 2 mm to about 16 mm, about 2mm to about 14mm, about 2mm to about 12mm, about 2mm to about 10mm, about 2mm to about 8mm, about 2mm to about 6mm, about 2mm to about 4mm, about 4mm to about 20mm, about 4mm to about 18mm, about 4mm to about 16mm, about 4mm to about 14mm, about 4mm to about 12mm, about 4mm to about 10mm, about 4mm to about 8mm, about 4mm to about 6mm, about 6mm to about 20mm , about 6mm to about 18mm, about 6mm to about 16mm, about 6mm to about 14mm, about 6mm to about 12mm, about 6mm to about 10mm, about 6mm to about 8mm, about 8mm to about 20mm, about 8mm to about 18mm, about 8mm to about 16mm, about 8mm to about 14mm, about 8mm to about 12mm, about 8mm to about 10mm, about 10mm to about 20mm, about 10mm to about 18mm, about 1 0 mm to about 16 mm, about 10 mm to about 14 mm, about 10 mm to about 12 mm, about 12 mm to about 20 mm, about 12 mm to about 18 mm, about 12 mm to about 16 mm, about 12 mm to about 14 mm, about 14 mm to about 20 mm, about 14 mm to about 18 mm, about 14 mm to about 16 mm, about 16 mm to about 20 mm, about 16 mm to about 18 mm, or about 18 mm to about 20 mm.

[0134] The low retention volume particulate adsorbent may comprise at least one cavity in fluid communication with the outer surface of the adsorbent.

[0135] The low retention capacity particulate adsorbent may have a hollow cross-section. The low retention volume particulate adsorbent can include at least one channel in fluid communication with at least one exterior surface.

[0136] In certain further embodiments, each portion of the low-loading capacity particulate adsorbent has a thickness of about 3.0 mm or less. For example, each portion of the low-loading capacity particulate adsorbent may have a thickness of 2.5 mm or less, 2.0 mm or less, 1.5 mm or less, 1.25 mm or less, 1.0 mm or less, 0.75 mm or less, 0.5 mm or less, or 0.25 mm or less. That is, each portion of the adsorbent is about 0.1 mm to about 3 mm, about 0.1 mm to about 2.5 mm, about 0.1 mm to about 2.0 mm, about 0.1 mm to about 1.5 mm, about 0.1 mm to about 1.0 mm, about 0.1 mm to about 0.5 mm, about 0.2 mm to about 3 mm, about 0.2 mm to about 2.5 mm, about 0.2 mm to about 2.0 mm, about 0.2 mm to about 1.5 mm, about 0.2 mm to about 1.0 mm, about 0.2 mm to about 0.5 mm, about 0.4 mm to about 3 mm, about 0.4 mm to about 2.5 mm, about 0.4 mm to about 2.0 mm, about 0.4 mm to about 1.5 mm, and about 0.4 mm to about 1.5 mm. The thickness may be about 0.0 mm, about 0.4 mm to about 3 mm, about 0.4 mm to about 2.5 mm, about 0.4 mm to about 2.0 mm, about 0.4 mm to about 1.5 mm, about 0.4 mm to about 1.0 mm, about 0.75 mm to about 3 mm, about 0.75 mm to about 2.5 mm, about 0.75 mm to about 2.0 mm, about 0.75 mm to about 1.5 mm, about 0.75 mm to about 1.0 mm, about 1.25 mm to about 3 mm, about 1.25 mm to about 2.5 mm, about 1.25 mm to about 2.0 mm, about 2.0 mm to about 3 mm, about 2.0 mm to about 2.5 mm, or about 2.5 mm to about 3.0 mm.

[0137] In one embodiment, at least one outer wall of the hollow shape of the low retention capacity particulate adsorbent has a thickness of about 1.0 mm or less (e.g., about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, or about 1.0 mm). For example, the outer wall of the hollow shape of the low retention capacity particulate adsorbent may have a thickness of about 0.1 mm to about 1.0 mm, about 0.1 mm to about 0.9 mm, about 0.1 mm to about 0.8 mm, about 0.1mm to approximately 0.7mm, approximately 0.1mm to approximately 0.6mm, approximately 0.1mm to approximately 0.5mm, approximately 0.1mm to approximately 0.4mm, approximately 0.1mm to approximately 0.3mm, approximately 0.1mm to approximately 0.2mm, approximately 0.2mm to approximately 1.0mm, approximately 0.2mm to approximately 0.9mm, approximately 0.2mm to approximately 0.8mm, approximately 0.2mm to approximately 0.7mm, approximately 0.2mm to approximately 0.6mm mm, about 0.2mm to about 0.5mm, about 0.2mm to about 0.4mm, about 0.2mm to about 0.3mm, about 0.3mm to about 1.0mm, about 0.3mm to about 0.9mm, about 0 .3mm~about 0.8mm, about 0.3mm~about 0.7mm, about 0.3mm~about 0.6mm, about 0.3mm~about 0.5mm, about 0.3mm~about 0.4mm, about 0.4mm~about 1.0mm, approximately 0.4mm to approximately 0.9mm, approximately 0.4mm to approximately 0.8mm, approximately 0.4mm to approximately 0.7mm, approximately 0.4mm to approximately 0.6mm, approximately 0.4mm to approximately 0.5mm, approximately 0.5mm to approximately 1.0mm, approximately 0.5mm to approximately 0.9mm, approximately 0.5mm to approximately 0.8mm, approximately 0.5mm to approximately 0.7mm, approximately 0.5mm to approximately 0.6mm, approximately 0.6mm The thickness may be in the range of about 0.6 mm to about 1.0 mm, about 0.6 mm to about 0.9 mm, about 0.6 mm to about 0.8 mm, about 0.6 mm to about 0.7 mm, about 0.7 mm to about 1.0 mm, about 0.7 mm to about 0.9 mm, about 0.7 mm to about 0.8 mm, about 0.8 mm to about 1.0 mm, about 0.8 mm to about 0.9 mm, or about 0.9 mm to about 1.0 mm.

[0138] In yet other embodiments, the hollow shape of the low retention capacity particulate adsorbent has at least one inner wall extending between outer walls and having a thickness of about 1.0 mm or less (e.g., about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, or about 1.0 mm). For example, the inner wall may have a thickness of about 0.1 mm to about 1.0 mm, about 0.1 mm to about 0.9 mm, about 0.1 mm to about 0.8 mm, about 0.1 mm to about 0.7 mm, about 0.1 mm to about 0.6 mm, about 0.1 mm to about 0.5 mm, about 0.1 mm to about 0.4 mm, about 0.1 mm to about 0.3 mm, about 0.1 mm to about 0.2 mm, about 0.2 mm to about 1.0 mm, about 0.2 mm to about 0.9 mm, or about 0.2mm to about 0.8mm, about 0.2mm to about 0.7mm, about 0.2mm to about 0.6mm, about 0.2mm to about 0.5mm, about 0.2mm to about 0.4mm, about 0.2mm to about 0.3mm , about 0.3mm to about 1.0mm, about 0.3mm to about 0.9mm, about 0.3mm to about 0.8mm, about 0.3mm to about 0.7mm, about 0.3mm to about 0.6mm, about 0.3mm to about 0.5 mm, about 0.3mm to about 0.4mm, about 0.4mm to about 1.0mm, about 0.4mm to about 0.9mm, about 0.4mm to about 0.8mm, about 0.4mm to about 0.7mm, about 0.4mm to about 0.6mm, about 0.4mm to about 0.5mm, about 0.5mm to about 1.0mm, about 0.5mm to about 0.9mm, about 0.5mm to about 0.8mm, about 0.5mm to about 0.7mm, about 0.5mm The thickness may be in the range of about 0.6 mm, about 0.6 mm to about 1.0 mm, about 0.6 mm to about 0.9 mm, about 0.6 mm to about 0.8 mm, about 0.6 mm to about 0.7 mm, about 0.7 mm to about 1.0 mm, about 0.7 mm to about 0.9 mm, about 0.7 mm to about 0.8 mm, about 0.8 mm to about 1.0 mm, about 0.8 mm to about 0.9 mm, or about 0.9 mm to about 1.0 mm.

[0139] In certain embodiments, the thickness of at least one of the inner wall, outer wall, or a combination thereof of the low-retention capacity particulate adsorbent is about 1.0 mm or less (e.g., about 0.1 mm, about 0.2 mm, about 0.3 mm, about 0.4 mm, about 0.5 mm, about 0.6 mm, about 0.7 mm, about 0.8 mm, about 0.9 mm, or about 1.0 mm). For example, the thickness of at least one of the inner wall, outer wall, or a combination thereof of the low-retention capacity particulate adsorbent is about 1.0 mm or less, about 0.6 mm or less, or about 0.4 mm or less. In certain embodiments, at least one of the inner wall, outer wall, or combinations thereof of the low retention volume particulate adsorbent has a thickness of about 0.1 mm to about 1.0 mm, about 0.1 mm to about 0.9 mm, about 0.1 mm to about 0.8 mm, about 0.1 mm to about 0.7 mm, about 0.1 mm to about 0.6 mm, about 0.1 mm to about 0.5 mm, about 0.1 mm to about 0.4 mm, about 0.1 mm to about 0.3 mm, about 0.1 mm to about 0.2 mm, about 0.2 mm to about 1.0 mm, about 0.2 mm to about 0.9 mm, about 0. 2mm~0.8mm, 0.2mm~0.7mm, 0.2mm~0.6mm, 0.2mm~0.5mm, 0.2mm~0.4mm, 0.2mm~0.3mm, 0.3mm~1.0mm, 0.3mm~0.9mm, 0.3mm~0.8m m, about 0.3mm to about 0.7mm, about 0.3mm to about 0.6mm, about 0.3mm to about 0.5mm, about 0.3mm to about 0.4mm, about 0.4mm to about 1.0mm, about 0.4mm to about 0.9mm, about 0.4mm to about 0.8mm, about 0.4mm to about 0.7mm, about 0.4mm to about The thickness ranges from 0.6 mm, about 0.4 mm to about 0.5 mm, about 0.5 mm to about 1.0 mm, about 0.5 mm to about 0.9 mm, about 0.5 mm to about 0.8 mm, about 0.5 mm to about 0.7 mm, about 0.5 mm to about 0.6 mm, about 0.6 mm to about 1.0 mm, about 0.6 mm to about 0.9 mm, about 0.6 mm to about 0.8 mm, about 0.6 mm to about 0.7 mm, about 0.7 mm to about 1.0 mm, about 0.7 mm to about 0.9 mm, about 0.7 mm to about 0.8 mm, about 0.8 mm to about 1.0 mm, about 0.8 mm to about 0.9 mm, or about 0.9 mm to about 1.0 mm.

[0140] In some embodiments, the interior wall of the low retention capacity particulate adsorbent extends bidirectionally from the hollow portion of the particulate adsorbent material (eg, from the center of the particulate adsorbent material) outward to the outer wall.

[0141] For example, the inner wall of the low retention capacity particulate adsorbent may extend outward from the hollow portion of the particulate adsorbent material (e.g., from the center of the particulate adsorbent material) in at least three directions, or from the hollow portion of the particulate adsorbent material (e.g., from the center of the particulate adsorbent material) in at least four directions toward the outer wall.

[0142] In certain embodiments, the low retention capacity particulate adsorbent material may have a length of about 1 mm to about 20 mm (e.g., about 1 mm, about 2 mm, about 3 mm, about 4 mm, about 5 mm, about 6 mm, about 7 mm, about 8 mm, about 9 mm, about 10 mm, about 11 mm, about 12 mm, about 13 mm, about 14 mm, about 15 mm, about 16 mm, about 17 mm, about 18 mm, about 19 mm, or about 20 mm). In certain embodiments, the length of the low retention capacity particulate adsorbent may be about 1 mm to about 18 mm, about 1 mm to about 16 mm, about 1 mm to about 14 mm, about 1 mm to about 12 mm, about 1 mm to about 10 mm, about 1 mm to about 8 mm, about 1 mm to about 6 mm, about 1 mm to about 4 mm, about 1 mm to about 3 mm, about 2 mm to about 20 mm, about 2 mm to about 18 mm, about 2 mm to about 16 mm, about 2 mm to about 20 ... or about 20 mm. m ~ about 14mm, about 2mm - about 12mm, about 2mm - about 10mm, about 2mm - about 8mm, about 2mm - about 6mm, about 2mm - about 4mm, about 4mm - about 20mm, about 4mm - about 1 8mm, about 4mm to about 16mm, about 4mm to about 14mm, about 4mm to about 12mm, about 4mm to about 10mm, about 4mm to about 8mm, about 4mm to about 6mm, about 6mm to about 20mm, Approximately 6mm to approximately 18mm, approximately 6mm to approximately 16mm, approximately 6mm to approximately 14mm, approximately 6mm to approximately 12mm, approximately 6mm to approximately 10mm, approximately 6mm to approximately 8mm, approximately 8mm to approximately 20mm, approximately 8mm to approximately 18mm, approximately 8mm to approximately 16mm, approximately 8mm to approximately 14mm, approximately 8mm to approximately 12mm, approximately 8mm to approximately 10mm, approximately 10mm to approximately 20mm, approximately 10mm to approximately 18mm, approximately 1 0 mm to about 16 mm, about 10 mm to about 14 mm, about 10 mm to about 12 mm, about 12 mm to about 20 mm, about 12 mm to about 18 mm, about 12 mm to about 16 mm, about 12 mm to about 14 mm, about 14 mm to about 20 mm, about 14 mm to about 18 mm, about 14 mm to about 16 mm, about 16 mm to about 20 mm, about 16 mm to about 18 mm, or about 18 mm to about 20 mm.

[0143] The low retention capacity particulate adsorbent may further comprise at least one of a pore-forming material, or processing aid, binder, filler, or combination thereof that sublimates, vaporizes, chemically decomposes, solubilizes, or melts when heated to a temperature of 100°C or greater.

[0144] In certain embodiments, the low retention capacity particulate adsorbent comprises from about 5% to about 60% adsorbent, up to about 60% filler, up to about 6% pore-forming material (or processing aid), up to about 10% silica The low retention capacity particulate adsorbent may comprise at least one of: salt, about 5% to about 70% clay, or a combination thereof. The low retention capacity particulate adsorbent may be present at about 5% to about 60%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 5% to about 20%, about 5% to about 10%, about 10% to about 60%, about 10% to about 50%, about 10% to about 40%, about 10% to about 30%, about 10% to about 20%, about 20% to about 60%, about 20% to about 50%, about 20% to about 40%, about 20% to about 30%, about 30% to about 60%, about 30% to about 50%, about 30% to about 40%, about 40% to about 60%, about 40% to about 50%, or about 50% to about 60% of the particulate adsorbent material.

[0145] The filler may comprise about 60% or less, about 50% or less, about 40% or less, about 30% or less, about 20% or less, about 10% or less, about 5% to about 60%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 5% to about 20%, about 5% to about 10%, about 10% to about 60%, about 10% to about 50%, about It can be present at 10% to about 40%, about 10% to about 30%, about 10% to about 20%, about 20% to about 60%, about 20% to about 50%, about 20% to about 40%, about 20% to about 30%, about 30% to about 60%, about 30% to about 50%, about 30% to about 40%, about 40% to about 60%, about 40% to about 50%, or about 50% to about 60%.

[0146] The pore-forming material of the low retention capacity particulate adsorbent can be present at ≦about 6%, ≦about 5%, ≦about 4%, ≦about 3%, ≦about 2%, or ≦about 1% of the particulate adsorbent material.

[0147] The silicate of the low retention capacity particulate adsorbent can be present at ≦about 10%, ≦about 9%, ≦about 8%, ≦about 7%, ≦about 6%, ≦about 5%, ≦about 4%, ≦about 3%, ≦about 2%, or ≦about 1% of the particulate adsorbent material.

[0148] The clay in the low retention capacity particulate adsorbent may comprise about 5% to about 70%, 5% to about 60%, about 5% to about 50%, about 5% to about 40%, about 5% to about 30%, about 5% to about 20%, about 5% to about 10%, about 10% to about 70%, about 10% to about 60%, about 10% to about 50%, about 10% to about 40%, about 10% to about 30%, about 10% to about 20%, about 20% to about 7% of the particulate adsorbent material. It may be present at 0%, about 20% to about 60%, about 20% to about 50%, about 20% to about 40%, about 20% to about 30%, about 30% to about 70%, about 30% to about 60%, about 30% to about 50%, about 30% to about 40%, about 40% to about 70%, about 40% to about 60%, about 40% to about 50%, about 50% to about 70%, about 50% to about 60%, or 60% to about 70%.

[0149] The pore-forming material (or processing aid) of the low-retention-capacity particulate adsorbent generates macroscopic pores when it sublimes, evaporates, chemically decomposes, solubilizes, or melts. This results in spatial dilution of the low-retention-capacity particulate adsorbent material. The pore-forming material may be a cellulose derivative, such as methyl cellulose, carboxymethyl cellulose, polyethylene glycol, phenol-formaldehyde resins (novolac, resole), polyethylene, or polyester resin. The cellulose derivative may include copolymers having methyl groups and / or partial substitution with hydroxypropyl and / or hydroxyethyl groups. The pore-forming material or processing aid may sublimate, evaporate, chemically decompose, solubilize, or melt when heated to temperatures ranging from about 125°C to about 640°C. For example, the processing aid for the low retention capacity particulate adsorbent may be heated to about 125°C to about 600°C, about 125°C to about 550°C, about 125°C to about 500°C, about 125°C to about 450°C, about 125°C to about 400°C, about 125°C to about 350°C, about 125°C to about 300°C, about 125°C to about 250°C, about 125°C to about 200°C, about 125°C to about 150°C, °C, about 150°C to about 640°C, 150°C to about 600°C, about 150°C to about 550°C, about 150°C to about 500°C, about 150°C to about 450°C, about 150°C to about 400°C, about 150°C to about 350°C, about 150°C to about 300°C, about 150°C to about 250°C, about 150°C to about 200°C, about 200°C to about 640°C, 200°C to about 60 0°C, about 200°C to about 550°C, about 200°C to about 500°C, about 200°C to about 450°C, about 200°C to about 400°C, about 200°C to about 350°C, about 200°C to about 300°C, about 200°C to about 250°C, about 250°C to about 640°C, 250°C to about 600°C, about 250°C to about 550°C, about 250°C to about 500°C, about 250°C to about 450°C, about 250°C to about 400°C, about 250°C to about 350°C, about 250°C to about 300°C, about 300°C to about 640°C, 300°C to about 600°C, about 300°C to about 550°C, about 300°C to about 500°C, about 300°C to about 450°C, about 300°C to about 400°C, about 300°C to about 350°C, about 350°C to about 640°C, 3 50°C to about 600°C, about 350°C to about 550°C, about 350°C to about 500°C, about 350°C to about 450°C, about 350°C to about 400°C, about 400°C to about 640°C, 400°C to about 600°C, about 400°C to about 550°C, about 400°C to about 500°C, about 400°C to about 450°C, about 450°C to about 640°C, 450°C to about 600°C When heated to a temperature in the range of about 450°C to about 550°C, about 450°C to about 500°C, about 500°C to about 640°C, 500°C to about 600°C, about 500°C to about 550°C, about 550°C to about 640°C, 550°C to about 600°C, or about 600°C to about 640°C, it may sublimate, evaporate, chemically decompose, solubilize, or melt.

[0150] The binder of the low retention capacity particulate adsorbent may be a clay or silicate material. For example, the binder of the low retention capacity particulate adsorbent may be at least one of zeolite clay, bentonite clay, montmorillonite clay, illite clay, French green clay, Pascalite clay, Redmond clay, Teramine clay, living clay, fuller's earth clay, omalite clay, vitalite clay, rectorite clay, cordierite, ball clay, kaolin, or a combination thereof.

[0151] The filler of the low-retention capacity particulate adsorbent can function in the particulate adsorbent structure to aid and preserve shape formation and mechanical integrity, and to enhance the amount of macropore volume in the final particulate product. In one embodiment, the filler of the low-retention capacity particulate adsorbent is a solid or hollow microsphere that may be micron-sized or larger. In another embodiment, the filler of the low-retention capacity particulate adsorbent is an inorganic filler, such as a glass material and / or a ceramic material. The filler of the low-retention capacity particulate adsorbent can be any suitable filler that provides the above-mentioned benefits, as understood by those skilled in the art.

[0152] Low retention capacity particulate adsorbent materials can be prepared by combining an adsorbent body having microscopic pores less than about 100 nm in diameter with a pore-forming material or processing aid that sublimes, evaporates, chemically decomposes, solubilizes, or melts when heated to a temperature of 100°C or greater, and heating the mixture to a temperature in the range of about 100°C to about 1200°C for about 0.25 hours to about 24 hours to form macroscopic pores about 100 to 100,000 nm in diameter when the core material sublimes, evaporates, chemically decomposes, solubilizes, or melts, wherein the ratio of macroscopic pore volume to microscopic pore volume in the adsorbent body is greater than 150%. The adsorbent body can have any of the characteristics of low retention capacity particulate adsorbent materials discussed throughout this disclosure.

[0153] The mixture may be heated at temperatures ranging from about 100°C to about 1200°C, from about 100°C to about 1000°C, from about 100°C to about 900°C, from about 100°C to about 800°C, from about 100°C to about 700°C, from about 100°C to about 600°C, from about 100°C to about 500°C, from about 100°C to about 400°C, from about 100°C to about 300°C, from about 100°C to about 200°C, from about 200°C to about 1200°C, from about 200°C to about 1100°C, from about 200°C to about 1000°C, from about 200°C to about 900°C, from about 200°C to about 800°C, from about 200°C to about 700°C, from about 200°C to about 600°C, or from about 200°C to about 1500°C. to about 500°C, about 200°C to about 400°C, about 200°C to about 300°C, about 300°C to about 1200°C, about 300°C to about 1100°C, about 300°C to about 1000°C, about 300°C to about 900°C, about 300°C to about 800°C, about 300°C to about 700°C, about 300°C to about 600°C, about 300°C to about 500°C, about 300°C to about 400°C, about 400°C to about 1200°C, about 400°C to about 1100°C, about 400°C to about 1000°C, about 400°C to about 900°C, about 400°C to about 800°C, about 400°C to about 700°C, about 40 0°C to about 600°C, about 400°C to about 500°C, about 500°C to about 1200°C, about 500°C to about 1100°C, about 500°C to about 1000°C, about 500°C to about 900°C, about 500°C to about 800°C, about 500°C to about 700°C, about 500°C to about 600°C, about 600°C to about 1200°C, about 600°C to about 1100°C, about 600°C to about 1000°C, about 600°C to about 900°C, about 600°C to about 800°C, about 600°C to about 700°C, about 700°C to about 1200°C , about 700°C to about 1100°C, about 700°C to about 1000°C, about 700°C to about 900°C, about 700°C to about 800°C, about 800°C to about 1200°C, about 800°C to about 1100°C, about 800°C to about 1000°C, about 800°C to about 900°C, about 900°C to about 1200°C, about 900°C to about 1100°C, about 900°C to about 1000°C, about 1000°C to about 1200°C, about 1000°C to about 1100°C, or about 1100°C to about 1200°C.

[0154] In some embodiments, heating the mixture comprises a ramp rate of about 2.5°C / min, about 1.0°C / min, about 1.25°C / min, about 1.5°C / min, about 1.75°C / min, about 2.0°C / min, about 2.25°C / min, about 2.75°C / min, about 3.0°C / min, about 3.25°C / min, about 3.5°C / min, about 3.75°C / min, about 4.0°C / min, or about 4.25°C / min. For example, the ramp rate may be from about 0.5°C / min to about 20°C / min, from about 0.5°C / min to about 15°C / min, from about 0.5°C / min to about 10°C / min, from about 0.5°C / min to about 5.0°C / min, from about 0.5°C / min to about 2.5°C / min, from about 1.0°C / min to about 20°C / min, from about 1.0°C / min to about 15°C / min, from about 1.0°C / min to about 10°C / min, from about 1.0°C / min to about 5.0°C / min, from about 1.0°C / min to about 2.5°C / min, or from about 2.0°C / min to about 3.0°C / min. °C / min to about 20°C / min, about 2.0°C / min to about 15°C / min, about 2.0°C / min to about 10°C / min, about 2.0°C / min to about 5.0°C / min, about 2.0°C / min to about 2.5°C / min, about 5.0°C / min to about 20°C / min, about 5.0°C / min to about 15°C / min, about 5.0°C / min to about 10°C / min, about 10°C / min to about 20°C / min, about 10°C / min to about 15°C / min, or about 15°C / min to about 20°C / min. In certain embodiments, the heat ramp rate is from about 20°C / min to about 100°C / min, 30°C / min to about 100°C / min, 40°C / min to about 100°C / min, 50°C / min to about 100°C / min, 60°C / min to about 100°C / min, 70°C / min to about 100°C / min, 80°C / min to about 100°C / min, or 90°C / min to about 100°C / min.

[0155] For example, the temperature ramp may be from about 5 minutes to about 2 hours, from about 5 minutes to about 1.75 hours, from about 5 minutes to about 1.5 hours, from about 5 minutes to about 1.25 hours, from about 5 minutes to about 1.0 hour, from about 5 minutes to about 45 minutes, from about 5 minutes to about 30 minutes, from about 5 minutes to about 15 minutes, from about 15 minutes to about 2 hours, from about 15 minutes to about 1.75 hours, from about 15 minutes to about 1.5 hours, from about 15 minutes to about 1.25 hours, from about 15 minutes to about 1.0 hour, from about 15 minutes to about 45 minutes, from about 15 minutes to about 30 minutes, from about 30 minutes to about 2 hours, from about 30 minutes to about 1.75 hours, from about 30 minutes to about 1.5 hours, from about 30 minutes to about 1.25 hours, It may take about 30 minutes to about 1.0 hour, about 30 minutes to about 45 minutes, about 45 minutes to about 2 hours, about 45 minutes to about 1.75 hours, about 45 minutes to about 1.5 hours, about 45 minutes to about 1.25 hours, about 45 minutes to about 1.0 hour, about 1.0 hour to about 2 hours, about 1.0 hour to about 1.75 hours, about 1.0 hour to about 1.5 hours, about 1.0 to about 1.25 hours, about 1.25 to about 2 hours, about 1.25 to about 1.75 hours, about 1.25 to about 1.5 hours, about 1.5 to about 2 hours, about 1.5 to about 1.75 hours, or about 1.75 hours to about 2.0 hours.

[0156] In another embodiment, the mixture is held at temperature (i.e., after ramping) for about 0.25 hours to about 24 hours. For example, the mixture may be held at temperature for about 0.25 hours to about 18 hours, about 0.25 hours to about 16 hours, about 0.25 hours to about 14 hours, about 0.25 hours to about 12 hours, about 0.25 hours to about 10 hours, about 0.25 hours to about 8 hours, about 0.25 hours to about 6 hours, about 0.25 hours to about 4 hours, about 0.25 hours to about 2 hours, about 1 hour to about 24 hours, or about 0.25 hours to about 18 hours. , about 1 hour to about 16 hours, about 1 hour to about 14 hours, about 1 hour to about 12 hours, about 1 hour to about 10 hours, about 1 hour to about 8 hours, about 1 hour to about 6 hours, about 1 hour to about 4 hours, about 1 hour to about 2 hours, about 2 hours to about 24 hours, about 2 hours to about 18 hours, about 2 hours to about 16 hours, about 2 hours to about 14 hours, about 2 hours to about 12 hours, about 2 hours to about 10 hours, about 2 hours 1 hour to about 8 hours, about 2 hours to about 6 hours, about 2 hours to about 3 hours, about 3 hours to about 24 hours, about 3 hours to about 18 hours, about 3 hours to about 16 hours, about 3 hours to about 14 hours, about 3 hours to about 12 hours, about 3 hours to about 10 hours, about 3 hours to about 8 hours, about 3 hours to about 6 hours, about 3 hours to about 4 hours, about 4 hours to about 24 hours, about 4 hours to about 18 hours, about 4 hours to about 16 hours, about 4 hours to about 14 hours, about 4 hours to about 12 hours, about 4 hours to about 10 hours, about 4 hours to about 8 hours, about 4 hours to about 6 hours, about 6 hours to about 24 hours, about 6 hours to about 18 hours, about 6 hours to about 16 hours, about 6 hours to about 14 hours, about 6 hours to about 12 hours, about 6 hours to about 10 hours, about 6 hours to about 8 hours, about 8 hours to about 24 hours, about 8 hours to about 1 8 hours, about 8 hours to about 16 hours, about 8 hours to about 14 hours, about 8 hours to about 12 hours, about 8 hours to about 10 hours, about 10 hours to about 24 hours, about 10 hours to about 18 hours, about 10 hours to about 16 hours, about 10 hours to about 14 hours, about 10 hours to about 12 hours, about 12 hours to about 24 hours, about 12 hours to about 18 hours, about 12 hours to about 16 hours, about 12 hours to about The temperature may be maintained for 14 hours, about 14 hours to about 24 hours, about 14 hours to about 18 hours, about 14 hours to about 16 hours, about 16 hours to about 24 hours, about 16 hours to about 18 hours, about 18 hours to about 24 hours, about 18 hours to about 22 hours, about 18 hours to about 20 hours, about 20 hours to about 24 hours, about 20 hours to about 22 hours, or about 22 hours to about 24 hours.

[0157] The method for making a low-retention-capacity particulate adsorbent can further include cooling the mixture (e.g., to about room temperature). In one embodiment, the mixture can be cooled for about 0.5 to about 10 hours. For example, the mixture may be cooled over a period of about 0.5 hours to about 9 hours, about 0.5 hours to about 8 hours, about 0.5 hours to about 7 hours, about 0.5 hours to about 6 hours, about 0.5 hours to about 5 hours, about 0.5 hours to about 4 hours, about 0.5 hours to about 3 hours, about 0.5 hours to about 2 hours, about 0.5 hours to about 1 hour, about 5 hours to about 10 hours, about 5 hours to about 9 hours, about 5 hours to about 8 hours, about 5 hours to about 7 hours, about 5 hours to about 6 hours, about 6 hours to about 10 hours, about 6 hours to about 9 hours, about 6 hours to about 8 hours, about 6 hours to about 7 hours, about 7 hours to about 10 hours, about 7 hours to about 9 hours, about 7 hours to about 8 hours, about 8 hours to about 10 hours, about 8 hours to about 9 hours, or about 9 hours to about 10 hours.

[0158] Heating of the mixture to produce the low retention capacity particulate adsorbent may be carried out in an inert atmosphere (e.g., nitrogen, argon, neon, krypton, xenon, radon, steam and oxygen content controlled flue gas, or combinations thereof).

[0159] The low retention capacity particulate adsorbent material can have a retention capacity of about 1.0 g / dL or less, about 0.75 g / dL or less, about 0.50 g / dL or less, or about 0.25 g / dL or less. For example, the low retention capacity adsorbent can have a retention capacity of about 0.25 g / dL to about 1.00 g / dL, about 0.25 g / dL to about 0.75 g / dL, about 0.25 g / dL to about 0.50 g / dL, about 0.50 g / dL to about 1.00 g / dL, about 0.50 g / dL to about 0.75 g / dL, or about 0.75 g / dL to about 1.00 g / dL.

[0160] In any aspect or embodiment described herein, at least one of the diameters of the microscopic pores of the low retention capacity adsorbent is less than about 100 nm, and the diameter of the macroscopic pores is greater than or equal to 100 nm and less than 100,000 nm, or a combination thereof.

[0161] The method of making the low retention capacity particulate adsorbent can further include extruding or compressing the mixture into a shaped structure. For example, the extruded or compressed low retention capacity particulate adsorbent material can comprise a body defining an outer surface and a three-dimensional low flow resistance shape or form. The low flow resistance shape or form of the low retention capacity particulate adsorbent can be, for example, any shape or form described herein for adsorbents. For example, the three-dimensional low flow resistance shape or form of the low retention capacity particulate adsorbent can be a substantially cylinder, a substantially elongated cylinder, a substantially sphere, a substantially cube, a substantially elliptical cylinder, a substantially rectangular cylinder, a lobed cylinder, or the like. , a three-dimensional spiral, the shapes or forms illustrated in Figures 3A-3I, or combinations thereof.

[0162] The adsorbent of the low retention volume particulate adsorbent may be at least one of activated carbon, molecular sieve, porous alumina, clay, porous silica, zeolite, metal organic framework, or combinations thereof.

[0163] The low retention capacity particulate adsorbent mixture may further include a binder (e.g., clay, silicate, or a combination thereof) and / or a filler. The filler may be any filler known or that becomes known in the relevant art.

[0164] The low retention capacity particulate adsorbent may have a cross-sectional width ranging from about 1 mm to about 20 mm. The low-retention-capacity particulate adsorbent material may have at least one cavity or channel in fluid communication with the outer surface of the adsorbent. The low-retention-capacity particulate adsorbent may have a hollow cross-section. Each portion of the low-retention-capacity particulate adsorbent may have a thickness of about 3.0 mm or less. The outer wall of the hollow shape may have a thickness of 3 mm or less (e.g., about 0.1 mm to about 1.0 mm). The hollow shape may have an inner wall extending between the outer walls, which may have a thickness of about 3.0 mm or less (e.g., about 0.1 mm to about 1.0 mm).

[0165] The inner wall may extend in at least two directions, at least three directions, or at least four directions from the interior volume (eg, from the hollow portion), eg, from the center, outward toward the outer wall.

[0166] In some embodiments, the low retention capacity particulate adsorbent has a length of from about 1 mm to about 20 mm (eg, from about 2 mm to about 7 mm).

[0167] method In another aspect, the present disclosure provides a method of reducing fuel vapor emissions in an evaporative emission control system, the method comprising contacting fuel vapor with at least one volume of a vent-side particulate adsorber comprising microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume (M / m) greater than about 150%, and at least one vent-side particulate adsorber volume comprising a butane retention capacity of about 1-0.25 g / dL or less, a particle size between 3 and 6 mm, or both.

[0168] In some embodiments, the method further includes contacting the fuel vapor with at least one fuel-side adsorbent volume described herein, e.g., a high BWC, high IAC adsorbent volume, and then contacting the fuel vapor with at least one vent-side particulate adsorbent described herein.

[0169] In any of the aspects or embodiments described herein, the adsorbent is located within a single canister. In certain embodiments, the adsorbent is located within multiple canisters that are connected to allow serial access by the fuel vapor.

[0170] In another embodiment, the method can include contacting the fuel vapor with a high butane working capacity adsorbent volume described herein and then with a vent-side low retention capacity particulate adsorbent volume. That is, the high butane working capacity adsorbent is located upstream in the fuel vapor flow path relative to the low retention capacity particulate adsorbent. For example, if the vent-side low retention capacity particulate adsorbent volume is located in volume 204 of the main canister, the high butane working capacity adsorbent is located in at least one of volumes 203, 202, 201, or a combination thereof of the main canister. Similarly, if an auxiliary canister includes a vent-side low retention capacity particulate adsorbent volume, the high butane working capacity adsorbent can be located in at least one of volumes 201-204 of the main canister. , and / or in at least one volume of the auxiliary canister before or upstream of the low-retention-capacity particulate adsorbent volume on the vent side of the auxiliary canister. For example, if the low-retention-capacity particulate adsorbent volume on the vent side is present in volume 304, the high butane working capacity adsorbent is present in at least one volume selected from volumes 201-204, 301-303, or a combination thereof. Those skilled in the art will appreciate that there are many other configurations that will satisfy this scheme. For example, in one embodiment, the main canister contains a high butane working capacity adsorbent (e.g., in at least one of volumes 201-204, or a combination thereof), while the auxiliary canister contains a high butane adsorbent (e.g., in volumes 301-305, or a combination thereof).

[0171] The method may further include contacting the fuel vapor with an additional vent-side particulate adsorbent volume, e.g., another downstream or subsequent vent-side low-retention-capacity particulate adsorbent volume in the fluid or vapor path, the subsequent vent-side adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume of about 150% or less. For example, if main canister volume 203 comprises a low-retention-capacity particulate adsorbent, the downstream vent-side subsequent adsorbent volume can be in main canister volume 204, at least one of auxiliary canisters 301-305, or a combination thereof. For example, in certain embodiments, the low-retention-capacity particulate adsorbent is present on the main canister side of the auxiliary canister (e.g., 301-303), and the downstream / subsequent adsorbent volume is present on the vent port side of the auxiliary canister (e.g., volumes 304 and 305).

[0172] That is, in certain embodiments, the method comprises contacting a high butane working capacity adsorbent / volume, a low retention capacity adsorbent / volume, and a subsequent adsorbent / volume, in that order, with fuel vapor through a fuel vapor inlet.

[0173] That is, in certain embodiments, the method comprises contacting a high butane working capacity adsorbent / volume, a low retention capacity adsorbent / volume, and a subsequent adsorbent / volume, in that order, with fuel vapor through a fuel vapor inlet.

[0174] Adsorbents suitable for use as adsorbent volumes may be obtained from many different materials and in a variety of forms. They may be a single component or a mixture of various components. Additionally, adsorbents may include a volume diluent (either as a single component or a mixture of different components). Non-limiting examples of volume diluents may include, but are not limited to, spacers, inert gaps, foams, fibers, springs, or combinations thereof. [Example]

[0175] Apparent density measurement Standard method ASTM D 2854-09(2014) (hereinafter "Standard Method") can be used to measure the apparent density of particulate adsorbents using the mean particle diameter measured according to a prescribed standard screening method, taking into account a prescribed minimum ratio of 10 of the measuring cylinder diameter to the mean particle diameter of the particulate material.

[0176] Measurement of macroscopic pore volume Macropore volume is measured by mercury intrusion porosimetry according to ISO 15901-1:2016. The equipment used in the examples was a Micromeritics Autopore V (Norcross, GA). The sample size used was approximately 0.4 g and was pretreated in an oven at 105°C for at least 1 hour. The surface tension and contact angle of mercury used in the Washburn equation were 485 dynes / cm and 130°, respectively. Macropores referred to herein are those having a diameter of approximately 100 nm to approximately 100,000 nm. be.

[0177] Measurement of micropore volume Micropore volume was measured by nitrogen adsorption porosimetry using a Micromeritics ASAP 2420 (Norcross, GA) according to nitrogen gas adsorption method ISO 15901-2:2006. Micropores, as referred to herein, are pores with diameters less than approximately 100 nm. The sample preparation procedure was degassing to a pressure less than 10 μm Hg. Measurements of pore volume for micropore sizes were taken from the desorption branch of the isotherm at 77 K for a 0.1 g sample. Nitrogen adsorption isotherm data was analyzed using the Kelvin and Halsey equation to determine the distribution of pore volume with pore sizes for cylindrical pores according to the Barrett, Joyner, and Halenda ("BJH") model. The nonideality factor was 0.0000620. The density conversion factor was 0.0015468. The diameter of the thermally evaporated hard sphere was 3.860 Å. The molecular cross-sectional area is 0.162 nm 2 The thickness of the condensed layer (Å) related to the pore diameter (D, Å) used in the calculation was 0.4977 [ln(D)] 2The target relative pressures for the isotherms were: -0.6981ln(D) + 2.5074. The target relative pressures for the isotherms were: 0.04, 0.05, 0.085, 0.125, 0.15, 0.18, 0.2, 0.355, 0.5, 0.63, 0.77, 0.9, 0.95, 0.995, 0.95, 0.9, 0.8, 0.7, 0.6, 0.5, 0.45, 0.4, 0.35, 0.3, 0.25, 0.2, 0.15, 0.12, 0.1, 0.07, 0.05, 0.03, and 0.01. Actual points were recorded within the absolute or relative pressure tolerance range of 5 mmHg or 5%, whichever was tighter. The time between successive pressure measurements during equilibration was 10 seconds.

[0178] Measurement of adsorption volume diameter The diameter D of the adsorption volume is the "circle equivalent diameter" and is derived from the volume V of the adsorption volume and the vapor path length L. The diameter D is (4V / πL) 1 / 2 For example, as a general example of calculation, the vapor path length for a 200cc adsorption volume is 10cm. The diameter is [(4x200) / (10π)] 1 / 2 = 5.0 cm. Therefore, L / D is 10 cm / 5 cm = 2.0.

[0179] Measuring flow limitation Flow restriction was measured as pressure drop (Pa / cm) for differently shaped adsorbent particles across a 30 mm long, densely packed bed at a given standard liters per minute (slpm) using the device shown in Figure 4. Specifically, pressure drop (Pa / cm) was measured at the center of a 43 mm diameter pellet bed over a 30 mm depth for an airflow range of 10 to 70 slpm (11.5 to 80.3 cm / s). The adsorbent was packed into a 43 mm inner diameter tube perforated with holes at + / - 15 mm, measured from the midpoint along the bed length, according to ASTM procedure D2854. Open-cell foam was used to contain the carbon bed. For pressure purging, compressed air was charged through port 1 to atmosphere at port 2. The pressure drop between port 3 and port 4 was measured. For vacuum purging, a vacuum was applied to port 1, and the pressure drop was measured between ports 3 and 4. The flow rate was adjusted from 10 to 70 SLPM (11.5 to 80.3 cm / s), and the pressure drop was measured at each adjustment. For the monoliths, the pressure drop (Pa / cm) was measured across the monolith from 10 to 70 SLPM. For the 35 mm diameter monolith, the pressure drop at 46 cm / s was approximated from measurements at a 30 lpm flow rate. For the 29 mm diameter monolith, the pressure drop at 46 cm / s was approximated from measurements at a 20 lpm flow rate.

[0180] The flow restriction of the component (e.g., between ports 1 and 2 in Figure 4) was measured as the pressure drop (kPa) of the component within the housing used in the canister test. The flow restriction of the component housing was also measured without the adsorbent. The flow rate was adjusted from 10 to 70 SLPM (11.5 to 80.3 cm / sec) and the pressure drop was measured at each adjustment. The pressure of the adsorbent bed or monolith component was The force drop kPa was recorded corrected for the pressure drop in the housing at the same flow rate.

[0181] For the adsorbent bed in a canister, as described above and illustrated in Figures 25 and 30, the pressure drop was calculated by first measuring the basic Pa / cm vs. cm / sec plot of a 43x110mm bed in a 43mm internal diameter (ID) auxiliary tube. The pressure drop at 40 LPM was then calculated using the average hydraulic diameter calculated above, and the Pa / cm of the adsorbent bed at a given cm / sec flow rate was measured and multiplied by the calculated bed length. The bed length was determined by dividing the volume by the average cross-sectional area of ​​the canister bed section.

[0182] As used herein, the term "total nominal volume" refers to the sum of the volumes of the adsorbent elements and does not include gaps, voids, ducts, conduits, tubes, plenum spaces, or other volumes along the length of the vapor flow path that are free of adsorbent material across a plane perpendicular to the vapor flow path. For example, in Figure 1, the total nominal volume of the canister system is the sum of the volumes of adsorbent volumes 201, 202, 203, and 204 minus any volumes that are empty volumes. In Figure 2, the total nominal volume of the canister system is the sum of the volumes of adsorbent volumes 201, 202, 203, 204, 301, 302, 303, 304, and 305 minus any volumes that are empty volumes.

[0183] Measurement of apparent density of nominal volume As used herein, the term "nominal volume apparent density" is the mass of a representative adsorbent in an adsorbent volume divided by the nominal volume of the adsorbent, where the length of the volume is defined as the in situ distance within the canister system between the vertical plane of the vapor flow path that first contacts the adsorbent element and the vertical plane of the vapor flow path that discharges the adsorbent element.

[0184] Non-limiting examples of methods for calculating the nominal volume apparent density of various forms of adsorbent bodies are provided herein. (A) Granular, pelleted, or spherical adsorbents with uniform adsorption capacity throughout the length of the adsorbent element flow path. Standard Method ASTM D 2854 (hereinafter "Standard Method") can be used to measure the apparent density of a nominal volume of particulate adsorbents, such as granular and pelleted adsorbents of sizes and shapes typically used for evaporative emission control in fuel systems. The apparent density of an adsorbent volume can be determined using the Standard Method if it gives the same apparent density value as the ratio of the mass of the adsorbent bed in a canister system to the nominal volume. The mass of the adsorbent according to the Standard Method is the mass of a representative adsorbent used in incremental adsorption analysis. That is, it includes or excludes the inert binders, fillers, and structural elements within the adsorbent volume, depending on which representative material is analyzed as the adsorbent sample.

[0185] Additionally, the apparent density of a nominal volume of an adsorbent volume may be determined using the Alternative Apparent Density Method, defined below. The Alternative Method may be applied to nominal adsorbent volumes having apparent densities that are not equivalent or suitable for measurement by the Standard Method. Furthermore, due to its general applicability, the Alternative Apparent Density Method may be applied to particulate adsorbents in place of the Standard Method. The Alternative Method may be applied to adsorbent volumes that may include particulate adsorbents, non-particulate adsorbents, and adsorbents of any form, augmented by spacers, voids, void additives within the volume or within successive similar adsorbent volumes for the effect of reducing the net incremental volume.

[0186] In another apparent density method, the apparent density of the adsorbent volume is obtained by dividing the mass of the adsorbent by the volume of the adsorbent.

[0187] (1) The dry mass basis of a representative adsorbent within the adsorption volume is measured. For example, the adsorption of a 0.200 g representative sample of 25.0 g total adsorbent mass within the adsorption volume by the McBain method. The capacity is measured. The McBain method gives the adsorption value of g-butane per g-adsorbent, but for the molecule of apparent density of adsorption volume, which can convert the McBain analysis value into the volumetric properties of adsorption volume, the applicable mass is 25.0 g.

[0188] (2) The volume of the adsorbent element in the denominator of the apparent density is defined as the in situ geometric volume within the canister system where the surface vapor flow path occurs. The length of the volume is bounded by a plane perpendicular to the superficial vapor inlet of the adsorbent volume in question (i.e., the point where the adsorbent is present on the vertical plane) and a plane perpendicular to the superficial flow at the vapor outlet of the adsorbent volume in question (i.e., the point where the adsorbent is absent across the plane perpendicular to the vapor flow). (B) Honeycomb adsorbent, monolith adsorbent, or foam adsorbent (1) Cylindrical honeycomb adsorbent The apparent density of a cylindrical honeycomb adsorbent is determined according to procedure SOP 500-115 of Purification Cellutions, LLC (Waynesboro, Ga.). The volume of the adsorbent is the product of the cross-sectional area (A) and length (h) of the adsorbent. The length (h) of the adsorbent is defined as the distance between the front of the adsorbent perpendicular to the vapor or gas flow entering the adsorbent and the back of the adsorbent where the vapor or gas exits the adsorbent. The volume measurement is a measure of the nominal volume and is also used to define the bed volume ratio for purging. For a cylindrical honeycomb adsorbent with a circular cross section, the cross-sectional area of ​​the adsorbent is πd 2 / 4, where d is the average diameter measured at four points on each edge of the honeycomb. The nominal adsorption volume and nominal volume apparent density are calculated as follows:

[0189] Nominal adsorption volume=h×A Nominal volume apparent density = part mass / (h × A), "Part weight" is the mass of adsorbent tested for adsorption properties of a representative adsorbent sample, including a representative proportion of inert or adsorbent binder and filler.

[0190] As a non-limiting example, Figure 5 shows a boundary definition of the nominal volume of a honeycomb adsorbent 109 having a cross-sectional area A. Vapors or gases flow through the honeycomb adsorbent 109 in a direction from D1 to D2. The vapors or gases enter the front (F) of the adsorbent 109, flow through the length (h) of the adsorbent 109, and exit the back (B) of the adsorbent 109. The nominal volume of the honeycomb adsorbent 109 is equal to the cross-sectional area A times the length h. Similarly, Figure 6 shows a boundary definition of the nominal volume of a foam adsorbent 110. (2) Pleated, corrugated, and sheet-shaped absorbents For pleated and corrugated adsorbents, the nominal adsorbent volume includes all voids caused by the pleats and corrugations. The volume measurement is a measure of the nominal volume and is also used to define the bed volume ratio for purging. The nominal volume and apparent density of the adsorbent are calculated as follows:

[0191] Nominal adsorption volume=h×A Nominal volume apparent density = part mass / (h × A), where: "Part weight" is the mass of adsorbent tested for adsorption properties of a representative adsorbent sample, including a representative proportion of inert or adsorbent binder and filler.

[0192] h is the length of the adsorber and is defined as the distance between the front face of the adsorber perpendicular to the vapor or gas flow entering the filter and the back face of the adsorber where the vapor or gas exits the filter.

[0193] A is the cross-sectional area of ​​the adsorbent. As a non-limiting example, Figure 7 shows the volumetric boundary definition of a stacked corrugated sheet adsorption monolith 111. It is also possible to form such a monolith as an extruded honeycomb. It is within the scope of the contractor.

[0194] For pleated adsorbents, the cross-sectional area of ​​the adsorbent is given by L x W, where L is the distance in the X direction from one end of the adsorbent to the opposite end of the adsorbent, and W is the distance in the Y direction from one end of the adsorbent to the opposite end of the adsorbent.

[0195] As non-limiting examples, Figure 8 shows the boundary definition of a volume of a single pleat or corrugation 112. Figure 9 shows the boundary definition of a volume of a pleated or corrugated sheet 113 with a vapor flow path through the sheet due to some permeability to gas flow. The plane of the sheet is perpendicular to the vapor flow. In contrast, Figure 10 shows the boundary definition of a volume of a pleated or corrugated sheet 114 with a surface inclined relative to the gas flow. Figure 11 shows the boundary definition of a volume of an adsorbent volume 115 of a parallel adsorbent sheet. Figure 12 shows the boundary definition of an adsorbent sleeve volume 116.

[0196] Incremental adsorption capacity measurement 13 shows a simplified schematic diagram of an apparatus used to measure butane adsorption capacity, known in the art as the McBain method. Apparatus 800 includes a sample pan 801 and spring 802 within a sample tube 803, a rough vacuum pump 804, a diffusion pump 805, a stopcock 806, metal / O-ring vacuum valves 807-809, a butane cylinder 810, a pressure reading unit 811, and at least one conduit 812 connecting the components of apparatus 800.

[0197] A representative adsorbent element sample ("adsorbent sample") was oven-dried at 110°C for at least three hours and then mounted on a sample pan 801 attached to a spring 802 in a sample tube 803. The sample tube 803 was then placed in the instrument 800. When the apparent density value is measured, the adsorbent sample includes a representative amount of inert binders, fillers, and structural components in the nominal volume of the adsorbent element if the mass of the inert binders, fillers, and structural components is equally included in the numerator. Conversely, when the apparent density value excludes the mass of inert binders, fillers, and structural components equally in the numerator, the adsorbent sample excludes these inert binders, fillers, and structural components. The general concept is to accurately define the adsorption characteristics for butane on a volumetric basis within the nominal volume.

[0198] A vacuum of less than 1 torr was applied to the sample tube, and the adsorbent sample was heated at 105°C for 1 hour. The mass of the adsorbent sample was then determined by the amount of spring extension using a cathetometer. The sample tube was then immersed in a water bath whose temperature was controlled at 25°C. When the pressure inside the sample tube reached 10 -4 Air was evacuated from the sample tube until the pressure reached 38 torr. n-Butane was introduced into the sample tube until equilibrium was reached at the selected pressure. Tests were conducted for two data sets of four selected equilibrium pressures, each acquired at approximately 38 torr and approximately 380 torr. The n-butane concentration was based on the equilibrium pressure in the sample tube. After each test at a selected equilibrium pressure, the mass of the adsorbent sample was measured based on the extension of a spring using a cathetometer. The increase in mass of the adsorbent sample was the amount of n-butane adsorbed by the adsorbent sample. For each test, the mass (grams) of n-butane adsorbed per mass (grams) of the adsorbent sample was determined at various n-butane equilibrium pressures and plotted as a function of the n-butane concentration (volume %). A 5 vol% n-butane concentration (volume concentration) at one atmosphere is given by an equilibrium pressure of 38 torr inside the sample tube. A 50 vol% n-butane concentration at one atmosphere is given by an equilibrium pressure of 380 torr inside the sample tube. Because exact equilibrium at 38 and 380 torr cannot be easily achieved, the mass of n-butane adsorbed per mass of adsorbent sample at 5 vol% and 50 vol% n-butane concentrations was interpolated graphically using data points collected near the target pressures of 38 and 380 torr.

[0199] Alternatively, instead of the McBain method, powder engineering (e.g., Powder Engineering ASAP 202 0) can be used to determine the incremental butane adsorption capacity.

[0200] Measurement of nominal incremental adsorption capacity As used herein, the term "nominal incremental adsorption capacity" is defined by the following formula: Nominal incremental adsorption capacity = [butane adsorbed at 50 vol% - butane adsorbed at 5 vol%] × apparent density of nominal volume × 1000, which refers to the adsorption capacity: where: "Butane adsorbed at 50 vol%" is the gram mass of n-butane adsorbed per gram mass of the adsorbent sample at a butane concentration of 50 vol%; "Butane adsorbed at 5 vol%" is the gram mass of n-butane adsorbed per gram mass of adsorbent sample at a butane concentration of 5 vol%; "Nominal volume apparent density" is as defined herein.

[0201] Butane working capacity measurement Standard method ASTM D5228-16 can be used to measure the butane working capacity (BWC) of an adsorption volume containing particulate granular and / or pelleted adsorbents. The retention capacity (g / dL) is calculated as the difference between the volumetric butane activity (g / dL) [i.e., the weight-based saturated butane activity (g / 100 g) multiplied by the apparent density (g / cc)] and the BWC (g / dL).

[0202] Measurement of Nominal Volumetric Butane Working Capacity (BWC) Standard method ASTM D5228 can be used to measure the nominal volumetric butane working capacity (BWC) of an adsorbent volume containing particulate granular and / or pelleted adsorbents.

[0203] A modified version of the ASTM D5228 method can be used to measure the nominal volumetric butane working capacity (BWC) of particulate, honeycomb, monolith, and / or sheet adsorbents. The modified version can also be used for particulate adsorbents, which include fillers, voids, structural elements, or additives. Additionally, the modified version of the ASTM D5228 method is used when the particulate adsorbent is not compatible with the standard method ASTM D5228, for example, when it is not easy to fill a 16.7 mL representative adsorbent sample into the test sample tube.

[0204] A modified version of the ASTM D5228 method is as follows: The adsorbent sample is oven-dried at 110±5°C for a minimum of 8 hours, then placed in an oven to cool. The dry mass of the adsorbent sample is recorded. The mass of the empty test assembly is measured, and the adsorbent sample is then assembled into the test assembly. The test assembly is then placed in a flow apparatus and charged with n-butane gas at 25°C and 1 atmosphere pressure at a butane flow rate of 500 ml / min for a minimum of 25 minutes (±0.2 minutes). The test assembly is then removed from the BWC test apparatus. The mass of the test assembly is measured and recorded to the nearest 0.001 gram. This n-butane charging process is repeated with 5-minute continuous flow periods until a constant mass is achieved. For example, the total butane charging time for a 35 mm diameter x 150 mm long honeycomb (auxiliary canister adsorbent of Example 27) was 66 minutes. The test assembly can be a container for a honeycomb or monolith part if the nominal volume can be removed and tested intact. Alternatively, the nominal volume may be part of a canister system or may need to be suitably reconfigured with the contents suitably oriented relative to the gas flow or as encountered within the canister system.

[0205] The test assembly is remounted in the test fixture and purged with 2.00 liters / minute of air at 25°C and 1 atmosphere pressure for a set of selected purge times (±0.2 minutes) according to the formula: Purge Time (minutes) = (719 x Nominal Volume (cc)) / (2000 (cc / min)).

[0206] The direction of the air purge flow in the BWC test is determined by the purge flow applied in the canister system. After the purging step, remove the test assembly from the BWC test apparatus. Measure the mass of the test assembly within 15 minutes of the end of the test and record it to the nearest 0.001 gram.

[0207] Calculate the butane working capacity (BWC) of the nominal volume of the adsorbent sample using the following formula: Nominal volume BWC (g / dL) = amount of butane purged (g) / nominal adsorption volume (dL), where: Amount of butane purged = mass of test assembly after filling - mass of test assembly after purging.

[0208] As used herein, the term "g-total BWC" refers to the g-amount of butane purged. As used herein, the term "approximate total vapor charge of the canister" refers to the total weight gain of the canister during the two-day diurnal test, which is equal to the charge on Day 1 (g) + the charge on Day 2 (g) - the backpurge (g).

[0209] As used herein, the term "backpurge" refers to the weight loss of the canister due to airflow caused by the vacuum in the fuel tank during cool down on day 1 of the diurnal test.

[0210] Measurement of diurnal breathing loss (DBL) emissions The evaporative emission control systems of Examples 1-118 are assembled with the amounts and types of adsorbents selected as shown in Tables 1-3 (see Figures 14-16).

[0211] Each example was uniformly preconditioned (aged) by repeated cycling of gasoline vapor adsorption using certified TF-1 fuel (9RVP, 10 vol% ethanol) or EPA-certified Tier-3 fuel (9RVP, 10 vol% ethanol) and a 300 nominal bed volume dry air purge (e.g., 630 liters for a 2.1 L main canister) at 22.7 lmp based on the main canister. The gasoline vapor charge rate was 40 g / h, the hydrocarbon composition was 50 vol%, and it was generated by heating 2 liters of gasoline to approximately 36°C and bubbling air through it at 200 mL / min. Two-liter aliquots of fuel were automatically replaced with fresh gasoline every two hours until a 5000 ppm breakthrough was detected by a flame ionization detector (FID). A minimum of 25 aging cycles was used for virgin canisters. The aging cycle was followed by a single butane adsorption / air purge step. In this process, butane was charged at 40 g / h at 50 vol% concentration in air at 1 atmosphere pressure until the breakthrough reached 5000 ppm, held for 1 hour, and then purged with dry air for 21 minutes. The total purged volume was achieved by selecting a constant air purge rate suitable for that period. During the previous butane charging and purging process, this was done in a chamber with an ambient temperature of approximately 20-25°C. The port was then sealed at 20°C for 24 hours to allow absorption into the canister.

[0212] DBL emissions were then generated by installing the example tank port in a fuel tank filled 40% by volume (based on the rated capacity of the fuel tank) with CARB LEV III fuel (7RVP, 10% ethanol by volume) or Phase II (7RVP, 0% ethanol by volume). Prior to installation, the filled fuel tank was stabilized at 18.3°C for 24 hours while vented. The tank and example were subjected to temperature cycling according to CARB's two-day temperature profile, with the temperature increasing from 18.3°C to 40.6°C over 11 hours each day, then returning to 18.3°C over 13 hours. During these two-day cycles for the 68 L tank and 2.1 L canister described in this invention, gasoline vapor production averaged about 34 g on day one, back-purge averaged about 8.2 g, and vapor production averaged about 34.3 g on day two for a net vapor load of about 61.7 g. In all cases, Vapor generation and backpurge were measured by example weight change of the canister during the first day of heating (Day 1 vapor generation), the first day of cooling (backpurge), and the second day of heating (Day 2 vapor generation). For fuel systems other than those described in this invention, vapor generation and backpurge are measured as described above using the fuel tank and canister of a specific or commercial vehicle system. Emission samples were collected into Kynar bags from the example vent at 6 and 12 hours during the heating phase. The Kynar bag was filled with nitrogen to a known total volume based on pressure and vented into an FID to determine hydrocarbon concentration. The FID was calibrated with a 5000 ppm butane standard. Emissions (as butane) were calculated based on the Kynar bag volume, emission concentration, and ideal gas assumptions. Six- and 12-hour emissions were added for each day. Per CARB protocol, the day with the highest total emissions was reported as the "2-day emissions." In all cases, the highest emissions were obtained on Day 2. This procedure is generally based on SAE Technical Paper 2001-01-0733, entitled "Impact and Control of Canister Bleed Emissions," by RS Williams and CR Clontz, as well as CARB's LEV III BETP procedure (California Evaporative Emissions Standards and Test Procedures for 2001). and Subsequent Model Motor Vehicles, Mar. 22, 2012, Section D.12).

[0213] Examples 1-16 used a 68-liter fuel tank and a 2.1-liter main canister (Tables 1 and 2, Main Canister Type #1), which was filled with 2.1 liters of commercially available activated carbon adsorbent pellets (NUCHAR® BAX 1500, manufactured by Ingevity, North Charleston, SC). The activated carbon adsorbent pellets in the main canister were typically about 2-2.8 mm in length and had a high BWC, low flow restriction, and low M / m compared to the vent-side particulate adsorbent materials described herein. The NUCHAR® BAX 1500 activated carbon adsorbent was present in two connected volumes: 1.4 liters and 0.7 liters. As shown in Table 1, Examples 17-25 and 99-100 used a 68-liter fuel tank and a 2.1-liter main canister (Tables 1 and 2, Main Canister Type #2), with two combined volumes of 1.4 and 0.4 liters filled with 1.8 liters of NUCHAR BAX® 1500 and 0.3 liters of another commercially available activated carbon sorbent pellet (NUCHAR® BAX LBE, manufactured by Ingevity, North Charleston, SC). Like NUCHAR® BAX 1500 and NUCHAR® BAX LBE, the activated carbon sorbent pellets are typically about 2-2.8 mm in length and have a high BWC, low flow restriction, and low M / m compared to the vent-side particulate sorbent materials described herein. As shown in Table 1, Examples 26 and 27 used a 68 liter fuel tank and a 2.1 liter main canister (Tables 1 and 2, Main Canister Type #3), with the main canister filled to two combined volumes of 1.4 and 0.4 liters with 1.8 liters of NUCHAR® BAX 1500 and 0.3 liters with commercially available activated carbon adsorbent pellets (MPAC I™ from Mahle Corporation) activated carbon adsorbent.Examples 29-62 and 101-111 used a 60 liter fuel tank and a 2.1 liter main canister (Tables 1 and 2, Main Canister Type #4), which had two combined volumes of 1.4 and 0.7 liters filled with 2.1 liters of commercially available activated carbon sorbent pellets (NUCHAR® BAX 1100, manufactured by Ingevity, North Charleston, SC). NUCHAR® BAX 1100 activated carbon sorbent pellets are typically about 2-2.8 mm in length and have a higher BWC, lower flow restriction, and lower M / m compared to the vent-side particulate sorbent materials described herein.

[0214] Examples 63-92 used a 60 liter fuel tank and a 2.1 liter main canister (Tables 1 and 2, Main Canister Type #5), and the main canister was filled with 2.1 liters of NUCHAR® BAX 1100 LD (low density) activated carbon sorbent to two combined volumes of 1.4 and 0.7 liters. Examples 93 and 94 used a 72.7 liter fuel tank and a 2.875 liter main canister (Tables 1 and 2, Main Canister Type #6), and the main canister was filled with NUCHAR® BAX 1100 LD (low density) activated carbon sorbent to two combined volumes of 2.7, 0.135, and 0.04 liters. Example 95, as shown in Table 1, used a 72 liter fuel tank and a 2.75 liter main canister (Tables 1 and 2, Main Canister Type #7). In Example 96, a 47-liter fuel tank and a 1.8-liter main canister (Tables 1 and 2, Main Canister Type #8) were used, and the main canister was filled with NUCHAR®BAX 1100 activated carbon adsorbent in combined volumes of 1.8 and 0.5 liters. The main canister was filled with NUCHAR®BAX 1100 activated carbon adsorbent in combined volumes of 1.4 and 0.4 liters. The main canister was filled with 1.8 liters of NUCHAR®BAX 1500 in combined volumes of 0.3 liters. In Examples 97-98, a 68-liter fuel tank and a 2.1-liter main canister (Tables 1 and 2, Main Canister Type #9) were used, and the main canister was filled with 1.8 liters of NUCHAR®BAX 1500 in combined volumes of 1.4 and 0.4 liters, and the 0.3 liter volume was filled with the low-retention-capacity particulate activated carbon adsorbent material described herein.

[0215] The properties of each adsorbent are listed in Tables 1-3 (see Figures 14-16). The adsorption capacity of the auxiliary canister, if present, is listed in Table 2. Additionally, Examples 29-33, 73, 74, 94, 96, and 106-111 comprise another adsorbent in an auxiliary canister downstream of the first adsorbent in the auxiliary canister listed in Table 1 (listed in Table 3, see Figure 15). The fill rates and dimensions of some of the adsorbent volumes of an exemplary main canister set forth in Table 1 are shown below. Adsorbent volumes 201, 202, 203, and 204 refer to the volumes shown in Figure 1. The designation "201+202" refers to a single adsorbent volume extending to the right side of the canister in the view of Figure 1. The designation "203+204" refers to a single adsorbent volume extending to the left side of the canister in the view of Figure 1.

[0216] About Canister Type #1 The 201+202 volume is 1400cc of NUCHAR® BAX 1500, and the length of the steam flow path for the 201+202 volume is 16.7cm. The average cross-sectional area is 84cm, the equivalent circle diameter is 10.3cm, and the L / D is 1.6.

[0217] The volume of 203+204 is 700cc of NUCHAR® BAX 1500, the length of the steam flow path of 203+204 is 16.6cm, the average cross-sectional area is 45cm2, the equivalent circle diameter is 7.6cm, and the L / D is 2.1.

[0218] About Canister Type #2 The 201+202 volume is 1400cc of NUCHAR® BAX 1500, and the length of the steam flow path for the 201+202 volume is 16.7cm. The average cross-sectional area is 84cm, the equivalent circle diameter is 10.3cm, and the L / D is 1.6.

[0219] The 203 volume is 400 cc of NUCHAR® BAX 1500, and the length of the 203 steam flow path is 7.8 cm. The average cross-sectional area is 51 cm, the equivalent circle diameter is 8.1 cm, and the L / D is 1.0.

[0220] The volume of the 204 NUCHAR® BAX LBE is 300 cc, the length of the steam flow path is 7.8 cm, the average cross-sectional area is 38 cm2, and the equivalent circle diameter is 7.0 cm. The L / D is 1.1.

[0221] About Canister Type #3 The 201+202 volume is 1400cc of NUCHAR® BAX 1500, and the length of the steam flow path for the 201+202 volume is 16.7cm. The average cross-sectional area is 84cm, the equivalent circle diameter is 10.3cm, and the L / D is 1.6.

[0222] The 203 volume is 400 cc of NUCHAR® BAX 1500, and the length of the 203 steam flow path is 7.8 cm. The average cross-sectional area is 51 cm, the equivalent circle diameter is 8.1 cm, and the L / D is 1.0.

[0223] The volume of 204 is 300 cc MPAC 1™, the length of the steam flow path is 7.8 cm, the average cross-sectional area is 38 cm2, the equivalent circle diameter is 7.0 cm, and the L / D is 1.1.

[0224] About Canister Type #4 The 201+202 volume is 1400cc of NUCHAR® BAX 1100, and the length of the steam flow path for the 201+202 volume is 16.7cm. The average cross-sectional area is 84cm, the equivalent circle diameter is 10.3cm, and the L / D is 1.6.

[0225] The volume of 203+204 is 700cc of NUCHAR® BAX 1100, the length of the steam flow path of 203+204 is 16.6cm, the average cross-sectional area is 45cm2, the equivalent circle diameter is 7.6cm, and the L / D is 2.1.

[0226] About Canister Type #5 The 201+202 volume is 1400cc NUCHAR® BAX 1100 LD, and the length of the steam flow path for the 201+202 volume is 16.7cm. The average cross-sectional area is 84cm, the equivalent circle diameter is 10.3cm, and the L / D is 1.6.

[0227] The volume of 203+204 is 700cc of NUCHAR® BAX 1100 LD, the length of the steam flow path of 203+204 is 16.6cm, the average cross-sectional area is 45cm2, the equivalent circle diameter is 7.6cm, and the L / D is 2.1.

[0228] About Canister Type #9 The 201+202 volume is 1400cc of NUCHAR® BAX 1500, and the length of the steam flow path for the 201+202 volume is 16.7cm. The average cross-sectional area is 84cm. 2 The equivalent circle diameter is 10.3 cm, and L / D is 1.6.

[0229] The 203 volume is 400 cc of NUCHAR® BAX 1500, and the length of the 203 steam flow path is 7.8 cm. The average cross-sectional area is 51 cm, the equivalent circle diameter is 8.1 cm, and the L / D is 1.0.

[0230] The volume of 204 is 300 cc of the low flow restriction pellet of the present invention, also found in Example 101, with a steam flow path length of 7.8 cm. The average cross-sectional area is 38 cm. 2 The equivalent circle diameter is 7.0 cm, and L / D is 1.1.

[0231] Tables 1-3 summarize the canister system conditions and measured 2-day DBL emissions for Examples 1-111. As noted above, the California Bleed Emissions Test Procedure (BETP) requires 2-day DBL emissions of less than 20 mg. As explained in the following section, 15 The requirement that BETP not exceed 20 mg under 0 BV or less purge was met by the evaporative emission control canister system of the present disclosure.

[0232] As can be seen from the data provided in Table 2 and as discussed below, the evaporative emission control canister systems of the present disclosure have low 2-day DBLs, e.g., less than about 50 mg or less than about 20 mg. The adsorbent volumes in the examples are described through the fuel vapor flow path, i.e., from the fuel vapor inlet to the vent port. The illustrations and descriptions of the adsorbent volumes as "fuel-side" and "vent-side" are provided for specific aspects and embodiments and, as will be understood by those skilled in the art, do not limit the scope of the present disclosure. It is expressly contemplated that the described low-retention-capacity particulate adsorbent volumes can be located at any number of locations within the flow path from the fuel inlet (104 in FIG. 2) to the vent port (105 in FIG. 2). Indeed, one or more of the described low-retention-capacity particulate adsorbent volumes can be located upstream and / or downstream of (i) one or more high-working-capacity adsorbent volumes, (ii) one or more other low-capacity adsorbent volumes, such as monoliths, honeycombs, polymers, or paper sheets, or (iii) any combination thereof.

[0233] For example, referring to FIG. 2 , in a particular example, fuel-side adsorbent volume 201 is the first adsorbent volume in the flow path from fuel vapor inlet 104 to vent port 105. In such a case, each additional adsorbent volume in the vapor flow path (i.e., 202, 203, 204, 301, 302, 303, 304, and 305) can be considered a vent-side adsorbent volume. In certain embodiments, the first adsorbent volume includes a high working capacity adsorbent material, e.g., particulates. However, the system is not so limited. For example, canister systems are contemplated in which the high working capacity adsorbent material is provided downstream of the first volume or in multiple adsorbent volumes along the flow path. In certain embodiments, the high working capacity adsorbent volume is upstream, downstream, or both of a low working capacity adsorbent volume, e.g., a particulate adsorbent volume as described herein, a monolith, a honeycomb, a polymer or paper sheet, or a combination thereof. Additionally, as will be appreciated by those skilled in the art, each of the adsorbent volumes described herein can be located within the same canister, separate canisters, or both, and the particular configuration of Figure 2 is not limited to the described canister system. Additionally, any number of adsorbent volumes can have voids between them.

[0234] Example Systems 32 and 33 utilize a main canister 4 equipped with NUCHAR® BAX 1100 LD on the fuel vapor side of the system. The auxiliary canister of Example 32 is equipped with MPAC I followed by 29x100 activated carbon honeycomb (HCA) (Ingevity®, Charleston, South Carolina, USA), and the auxiliary canister of Example 33 is equipped with a low retention capacity particulate adsorbent described herein followed by 29x100 HCA. As can be seen from Table 2, Example 33 has a substantially lower 2-day DBL (31.1 mg) compared to Comparative Example 32 (50.9 mg). Similarly, Example 31 (NUCHAR® BAX 1100, low retention capacity particulate adsorbent, 29x100 HCA) had a significant reduction (17.1 mg) compared to Example 29 (44.6 mg; NUCHAR® BAX 1100, 5 mm NUCHAR® BAX LBE, 29x100 HCA).

[0235] Additionally, the low-loading capacity particulate adsorbents, including Examples 43, 52, 53, 57, 58, 59, 60, and 62, also exhibited a 2-day DBL of less than 20 mg. As with Example 35, the NUCHAR® BAX 1100 was installed on the fuel vapor side of the main canister, with the low-loading capacity particulate adsorbent downstream (i.e., toward the vent port). Compared to comparative examples (e.g., Examples 64, 65, 66, 67, 89, 90, 91, and 68) that underwent similar purging (i.e., 150 purge BV and 315 L purge), these examples had substantially lower 2-day DBLs, meeting the 2-day DBL required by the California BETP. The concentration of NUCHAR® BAX 1100 in the main canister was less than 0 mg. Examples including a secondary canister with a LD fuel vapor side) and a low retention capacity particulate adsorbent (eg, Examples 80, 85, 79, 88, 86, 87) also had a 2-day DBL of less than 20 mg.

[0236] 17-20 show that the capacity versus path length function for the first adsorbent in the auxiliary canister of Example 31 (i.e., the low retention capacity adsorbent described herein) is non-monotonic, i.e., the unexpected increase in adsorbent capacity at certain path lengths was a surprising and unexpected observation.

[0237] Figure 21 shows examples of the well-known performance tradeoffs with conventional solid particulate adsorbents (cylindrical pellets, "packed diamonds") 2-5 mm in diameter when providing flexibility in targeting reasonable flow restriction and DBL emissions performance. These examples are for a main canister with one or more vent-side adsorbent volumes packed with another adsorbent, as described in Tables 2 and 3. When tested under the BETP protocol using a purge of less than 150 bed volumes (BV) based on the total nominal volume of adsorbent in the system applied after the 40 g / h butane charging step (see the conventional examples in Tables 1-3 for system description), only the carbon honeycomb example occupies a reasonable flow restriction of less than 0.3 kPa vent-side volume at 40 standard liters per minute (slpm) of chamber (i.e., the chamber including the adsorbent volume less the empty holder), resulting in BETP test results of less than 50 mg DBL emissions on day 2. In contrast, conventional pellets smaller than 3 mm, while offering a low-cost solution, present an unfortunate tradeoff between flow restriction and emissions performance. These pellets may match emissions performance, but require adsorbent bed geometric ratios (e.g., short bed length to diameter) that impose excessive flow restriction; more favorable bed ratios provide reasonable flow restriction but excessive DBL emissions. As noted above, following the teachings of U.S. Pat. No. 5,957,114, elongated chambers with length-to-diameter ratios L / D greater than 2 to accommodate small cross-sectional areas for adsorption volume or chamber dimensions favor the low DBL emissions response of conventional particulate adsorbents compared to similarly sized carbon honeycomb adsorbents ( FIG. 22 ), but these conventional adsorbents are excessively flow-restrictive ( FIG. 23 ). In particular, although large diameter solid pellets (Example 1) overcome the flow restriction barrier of the preferred chamber geometry with L / D greater than 2, the DBL emissions performance of the system is significantly impaired due to the poor purging capability of the large diameter solid pellets.

[0238] Figures 24 and 25 illustrate the flow limitations of conventional pellets and carbon honeycombs for flow rates often quoted in evaporative emission control canister systems. As noted above, canister system manufacturers first design an overall adsorption chamber strategy and then compare available products to balance factors such as cost, flow limitations, working capacity performance, and bleed control, among others. In comparing Figures 24 and 25, a 43 mm diameter x 150 mm long ("43x150") particulate adsorbent bed is representative of the volumetric filling of a chamber with a 35 mm diameter x 150 mm long carbon honeycomb ("35x150"), i.e., a 35 mm diameter carbon honeycomb and a 4 mm thick O-ring. The O-ring or other sealant material both holds the honeycomb in place and seals between the honeycomb outer skin and the chamber interior wall, preventing air and vapor flow through the honeycomb cells and bypassing the gaps around the monolith. Figure 24 highlights typical well-known flows applied in testing and qualification of canister systems. 15 slpm is the purge flow rate used in a 150BV DBL pretreatment for a 2.1 liter canister system. EPA GWC and GWC measurements typically use a purge rate of 22.7 slpm. The maximum fuel flow rate for an ORVR in the US is about 10 gallons per minute, which translates to about 40 slpm of exhaust air into the canister system. This refers to vapor flow. As cited in the Background section, the GM specification for canister systems for maximum flow restriction under ORVR is 60 slpm. Figure 25 shows these critical flows in terms of gas velocity for the vent-side volumes of Figures 21 through 23, not in terms of chamber restriction, but in terms of flow restriction per length of bed or portion of bed with a 43 mm diameter for the particulate example, as a means of comparing the flow restriction characteristics of materials. Clearly, conventional solid pellets, typically 2-2.8 mm in diameter, in the main canister chamber offer no advantage over carbon honeycomb, and their potential low-emission performance becomes impractical for chamber geometries requiring L / D ratios greater than 2.

[0239] To address the limitations presented by conventional pellet media for vent-side packing, the present description provides a particulate adsorbent in at least one volume within a canister system that: 1) employs a particulate shape of sufficiently large size, e.g., nominal diameter, to obtain low flow restriction characteristics (Pa / cm pressure drop), thereby advantageously mitigating flow restriction in elongated chambers, 2) avoids solid shapes, e.g., solid cylindrical shapes, to improve DBL emissions performance, and 3) uses an adsorbent material prepared with a suitable selection of fillers, binders, and extrusion aids to obtain an M / m ratio in the range of 150+% for low retention capacity, thereby, contrary to conventional wisdom, obtaining a low flow restriction vent-side particulate adsorbent. Thus, surprisingly and unexpectedly, the present description provides a canister system with a vent-side particulate adsorbent volume having flow restriction characteristics of 150+ M / m, with a pressure drop of less than 40 Pa / cm under an apparent linear airflow velocity of 46 cm / sec when measured as a 43 mm diameter bed.

[0240] For example, U.S. Patent No. 9,174,195 teaches away from producing low flow-limiting adsorbent particulate materials that provide excellent DBL emission control, good strength, and low retention capacity. Thus, the present discovery is surprising and unexpected. Furthermore, U.S. Patent Application Publication No. 2007 / 78056 A1 describes a conventional solid activated carbon pellet, 2GK-C7 (Kuraray Chemical Co., Ltd.), having a diameter of 2.6 mm (measured with a vernier caliper), also teaching that such performance cannot be achieved from larger pellets with limited flow-limiting properties.

[0241] The 2GK-C7 is a 2010 model year Mitsubishi Outlander™ "PZEV" and "federal" vehicle (i.e., EPA (Tier 2 certified, meeting the 500 mg / day, two-day full vehicle test requirement) and installed in a canister system installed on a 2010 model year Suzuki SX-4 vehicle. 2GK-C7 obtained from a canister system manufactured for such a vehicle in 2010 has a pellet diameter of approximately 2.7 mm and exhibits an M / m characteristic of 164% and a retention capacity of approximately 0.6 g / dL, as measured using the methods described herein. 2GK-C7 pellets have a strength of 99+ using the commercially accepted methods used herein. The '195 Patent teaches that when preparing larger diameter pellets with an increased M / m above 150%, the retention capacity asymptotically levels off to approximately 1 g / dL and the strength drops sharply (Figures 5 and 6 of the '195 Patent, respectively), thereby confining large diameter pellets with suitable strength and adsorption characteristics to the space defined by an M / m below 150%, preferably in the range of 65-150%.

[0242] In certain embodiments, the present description provides an evaporative emission canister system with at least one vent-side particulate sorbent volume, wherein the particulate sorbent material has a butane retention capacity of greater than 200% M / m and less than 1 g / dL. In another embodiment, the particulate sorbent material has a butane retention capacity of greater than 150% M / m and less than 0.5 g / dL. Examples of these embodiments of the invention are described herein.

[0243] For shapes other than easily determined diameters, such as circular-section cylinders, triangular solids, square solids, pentagonal solids, and hexagonal solids, the use of Pa / cm flow restriction as measured in the protocol defined herein is preferred over pellet diameter, since complex geometries can prevent accurate measurement of characteristic diameters. For purposes of the physical examples of the present invention, hollow, solid-walled cylinders are employed herein. Nevertheless, alternative shapes with low flow restriction that possess hollow characteristics (e.g., thin walls and low diffusion pathlength resistance between the bulk phase and the adsorbent interior) may also be utilized, including twisted ribbons, coil strands, saddles, or hollow shells. These shapes may also include striations, dimples, and perforations to impart better strength and adsorbate purgeability. Furthermore, these more complex shapes allow for smaller apparent geometric "diameters" that can accommodate lower flow restriction than simple cylinders, or otherwise geometric solids of similar diameter may accommodate, for example, open springs, twisted ribbons, or saddles compared to microparticles formed as solid-walled cylinders with axially parallel channels.

[0244] In contrast to the conventional particulate adsorber example of FIG. 21, FIG. 26 shows examples of particulate adsorber having the features described herein that can provide low DBL emissions and low flow restriction performance not possible with the conventional materials illustrated in FIG. 21. As with the materials described herein ("invention examples"), the specific configuration of carbon honeycomb does not tick the performance box. Numerous inventive examples tick the performance box with lower DBL emissions than exhibited by carbon honeycomb and chamber flow restrictions approaching that of carbon honeycomb. All of these high-performance examples are characterized by M / m properties greater than 150%, and many with M / m properties greater than 200%.

[0245] Figure 27 shows a high performance inventive embodiment with an advantageously high chamber L / D of greater than 2, which is believed to be a contributing factor to low DBL emissions. Figures 28, 29, and 30 illustrate how the low flow restriction characteristics of an inventive embodiment enable the feasibility of low flow restriction for an advantageously high L / D. At an apparent linear air velocity of 46 cm / sec, an inventive embodiment has a small fraction of the Pa / cm pressure drop flow restriction of a conventional 2-2.8 mm diameter solid conventional pellet when placed in a similar 43 mm diameter chamber.

[0246] A further surprising aspect of the present invention is the favorable strength characteristics of the samples of the present invention at M / m ratios of 150% or greater, despite the teachings of the prior art, particularly U.S. Pat. No. 9,174,195. FIG. 42 shows the pellet strength of the particulate adsorbent in the examples of FIGS. 26 and 27 as a function of M / m characteristics, where "LFR" indicates low flow restriction. For comparison, one metric of acceptable strength in this test is 35. The 35 strength is a characteristic measured on MPAC1 (Kuraray Chemical Co., Ltd., represented by a solid triangular symbol in FIG. 42) obtained from a canister system manufactured for vehicle evaporative emission control. MPAC1 is a hollow, cylindrical, low flow restriction pellet with a shape and characteristics that fall within the range taught by the pellets of U.S. Pat. No. 9,174,195, containing 66% M / m, and is an adsorbent packing in the vent-side volume of a commercially available canister system. For comparison purposes, a second industry-accepted metric is the minimum product strength specification of 40 required by some canister system manufacturers for high working capacity 2 mm Nuchar® BAX 1700 activated carbon pellets. As evident from FIG. 42, examples of the present invention have strengths well above the commercially typical value of 35 for low flow restriction pellets and well above the minimum specification of 40 for high working capacity pellets. As shown in FIG. 43 for the set of examples of the canister systems of the present invention in FIGS. 26 and 27, low flow restriction particulate adsorbers of the present invention have high M / m (or despite) exhibiting good pellet strength while still achieving excellent control of DBL emissions. Some low flow restriction particulate adsorbers of the present invention in examples of canister systems have comparative strengths of 35 and 40. Although the pellet strengths in the tensile strength metrics are at or just below the tensile strength of the samples, the strength of the samples can be further optimized, for example, by modifying the binder formulation according to the present disclosure while maintaining other desired properties.

[0247] The versatility of embodiments of the present invention is demonstrated by their performance under particularly challenging conditions of low purge. For example, U.S. Patent No. 9,732,649 teaches that it can be difficult to control DBL emissions to very low levels under low purge conditions of less than 100 BV or less than 210 liters of purge applied after a 40 g / hour butane charge, as tested under the BETP test protocol. Under these low purge loads, Figure 31 shows the example of Figure 26 filtered for an example where a purge level of less than 100 BV and less than 210 liters is applied after a 40 g / hour butane charge. All examples in Figures 26 and 31 had only one vent-side adsorbent volume external to the main canister. Figure 32 shows that low system emissions are observed at low flow restrictions when additional vent-side particulates are added to the bed ("Adsorbent 2"). As shown in Figures 33 and 34, the particulates of the present invention are contained as a bed in the Adsorbent 2 chamber with an L / D ratio similar to that of a carbon honeycomb. The shift to lower L / D values ​​reflects the absence of sealing and retaining O-rings or similar sealants that would otherwise consume space and limit cross-sectional area required for the carbon honeycomb. Importantly, the inventive particulate beds of Adsorbent 2 of Examples 107-110 that resulted in low emissions for these canister systems under low purge conditions had a pellet strength of 51 even at a high M / m ratio of 260%.

[0248] In this Type 4 main canister, the combination of the inventive pellet adsorbent along with a specific 35x100 carbon honeycomb in the subsequent adsorbent volume resulted in very low DBL emissions under low purge conditions. When the 35x100 carbon honeycomb was used as the final adsorbent volume toward the system vent (canister system of Example 106), the DBL emissions on day 2 were 15 mg. However, when the inventive pellets filled the final chamber containing the 43x100 adsorbent 2 (canister system of Example 107), the DBL emissions on day 2 were even lower, at 12 mg. This result is surprising, since industry wisdom suggests the advantage of a monotonically decreasing change in working volume toward the system atmosphere vent as being most beneficial for DBL emissions, especially to achieve less than 20 mg under low purge conditions. The present disclosure provides new options for vent-side particulate adsorbent packing to achieve this result, for example, with a single adsorbent volume in a canister system containing carbon honeycomb, rather than multiple volumes with flexibility in where the particulate volume may be placed. The porous properties of particulates, which have previously been taught to be disadvantageous, are shown to result in superior DBL emissions performance. The implications and opportunities for designing a canister system, for example, are to take advantage of existing canister systems, be designed with multiple in-line adsorbent volumes containing vent-side carbon honeycomb, and have the flexibility to select a vent-side particulate adsorbent solution in one or more of these volumes without redesigning or modifying the system, and still achieve the desired DBL emissions performance results within the overall system pressure drop constraints.

[0249] In a specific embodiment, the description provides an emissions control canister system with a vent-side particulate adsorbent having a butane retention capacity characteristic of less than 0.5 g / dL with M / m greater than 150% and moderate flow restriction of the vent-side adsorbent volume, resulting in low DBL emissions. For example, a Type 4 main canister (2.1 L carbon packing) is fitted on the vent side with a chamber containing a 43 mm diameter, 100 mm long adsorbent bed of low flow restriction hollow pellet particulates, and the system is cycled with a 315 L purge applied after a 40 g / hr butane loading step, or a 139 BV purge for its total adsorbent volume. The two-day DBL emissions for the base canister were 76 mg / L (see Examples 36-62). (For example, in Example 28, the main canister was tested without the 43x100 external vent chamber, and the 315 L purge was 150 BV for a total adsorbent bed of 2.1 L). The L / D ratio of the adsorbent volume in the auxiliary chamber installed on the vent side of the canister was 2.56. The flow restriction of the pellet bed in that chamber was 0.22 kPa (10.0 Pa / cm at an apparent linear air velocity of 46 cm / sec) at a 40 lpm flow rate, except for the higher 0.26 kPa (13.3 Pa / cm at an apparent linear air velocity of 46 cm / sec) for the prior art pellets, Kuraray MPAC1, in Example 47. As shown in Figures 35 and 36, this canister system has several inventive embodiments with 150+% M / m with emissions of less than 20 mg, and some embodiments with less than 10 mg when the butane retention capacity characteristics of the low flow restriction pellets were less than 0.5 g / dL. Figure 44 illustrates the pellet strength of the low flow restriction particulate sorbents of the present invention in the embodiments of Figures 35 and 36. The low flow restriction particulates of the present invention with 150+% M / m, including M / m characteristics well over 200+%, and butane retention capacity characteristics less than 0.5 g / dL, often have pellet strengths well above 35.

[0250] Another embodiment of a Type 5 main canister (2.1 L carbon-filled) with an adsorbent 1 auxiliary chamber attached to the vent side is shown. The base canister's two-day DBL emissions were 93 mg / L (e.g., Example 63, a main canister tested without an auxiliary adsorbent 1 chamber; a 315 L purge resulted in 150 BV of 2.1 L of total adsorbent bed). The auxiliary chamber consisted of various sizes of adsorbent 1 beds: conventional pellets, low-flow-restriction hollow pellet particulates, or carbon honeycomb. The canister system was cycled with a 315 L purge applied after a 40 g / h butane charge, or 137–147 BV of total nominal adsorbent volume. Although all examples were purged with the same 315 L, BV values ​​varied between examples depending on the size of the external vent-side chamber of the main canister (see Examples 64–69, 76, 79, and 88–92). Similar to the examples in Figures 35 and 36 of the tested adsorbents in both particulate and honeycomb forms, Figures 37 and 38 show that the lowest emissions were from a flow-limited particulate adsorbent with an M / m ratio of over 150% and a butane retention capacity of less than 0.5 g / dL. This material was repeatedly tested (Examples 86 and 87) due to its surprisingly low bleed emissions performance compared to the other tested particulates and honeycomb materials tested at the Adsorbent 1 volume. The low flow restriction characteristic of the low flow-restriction particulate (10 Pa / cm at 46 cm / sec apparent linear air velocity in Figure 39) allowed for a reasonably low flow restriction (0.72 kPa at 40 lpm in Figure 40) for an Adsorbent 1 bed with dimensions of 43 mm diameter and 132 mm length, thereby allowing for a good bed L / D of just over 3 (see Figure 41), contributing to improved bleed emissions control.

[0251] Illustrative Embodiments In one aspect, the disclosure provides an evaporative emission control canister system comprising one or more canisters having multiple chambers, each chamber defining a volume, the multiple chambers being in fluid communication to allow unidirectional flow of fluid or vapor from one chamber to the next, at least one chamber comprising at least one particulate adsorbent volume, the at least one particulate adsorbent volume comprising a particulate adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, the particulate adsorbent volume having a flow restriction characteristic of less than 40 Pa / cm under conditions of an apparent linear air flow velocity of 46 cm / sec applied to a 43 mm diameter bed of particulate adsorbent material.

[0252] In another aspect, the present disclosure provides a method for producing a sorbent comprising: at least one fuel-side sorbent volume; and a sorbent having a diameter of less than about 100 nm. and at least one vent-side particulate adsorbent volume comprising a particulate adsorbent having microscopic pores of less than 100 nm, macroscopic pores of about 100-100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume of greater than about 150%, wherein the vent-side adsorbent volume has a flow-limiting characteristic of a pressure drop of less than 40 Pa / cm when a nominal linear air flow velocity of 46 cm / sec is applied to a 43 mm diameter bed of the vent-side particulate adsorbent volume.

[0253] In another aspect, the present disclosure provides an evaporative emission control canister system comprising one or more canisters comprising at least one fuel-side sorbent volume and at least one vent-side low retention capacity particulate sorbent volume comprising a particulate sorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, wherein the at least one vent-side low retention capacity particulate sorbent volume has a butane retention capacity of less than 0.5 g / dL.

[0254] In another aspect, the present disclosure provides an evaporative emission control canister system comprising one or more canisters comprising at least one fuel-side sorbent volume and at least one vent-side low retention capacity particulate sorbent volume comprising a particulate sorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 200%, wherein the at least one vent-side particulate sorbent volume has a butane retention capacity of less than 1 g / dL.

[0255] In another aspect, the present disclosure provides an evaporative emission control canister system comprising: a fuel tank for storing fuel; an engine having an air induction system and configured to consume the fuel; one or more canisters having a plurality of sorbent volumes with at least one fuel-side sorbent volume; and at least one vent-side particulate sorbent volume comprising a particulate sorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, and a retention capacity of less than about 0.5 g / dL. an evaporative emission control canister system including a fuel vapor inlet conduit connecting the evaporative emission control canister system to a fuel tank; a fuel vapor purge conduit connecting the evaporative emission control canister system to an air induction system of the engine; and a vent port for venting the evaporative emission control canister system and for the induction of purge air into the evaporative emission control canister system, wherein the evaporative emission control canister system is defined by a fuel vapor flow path from the fuel vapor inlet conduit through a plurality of adsorbents to the vent port, and an air flow path from the vent port through the plurality of adsorbent volumes and the fuel vapor purge outlet.

[0256] In another aspect, the present disclosure provides a method for reducing fuel vapor emissions in an evaporative emission control system, the method comprising contacting fuel vapor with a plurality of adsorbents comprising at least one fuel-side adsorbent volume, the at least one vent-side particulate adsorbent volume comprising a particulate adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores greater than or equal to about 100 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, and a retention capacity less than about 1.0 g / dL.

[0257] In another embodiment, the present disclosure provides a method for producing a fuel-side particulate adsorbent comprising at least one fuel-side particulate adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%, and a retention capacity of less than about 1.0 g / dL; and at least one vent-side particulate adsorbent having microscopic pores less than about 100 nm in diameter, macroscopic pores between about 100 and 100,000 nm in diameter, and a ratio of macroscopic pore volume to microscopic pore volume greater than about 150%. and an evaporative emission control canister system including one or more canisters, wherein at least one vent-side particulate adsorption volume has a butane retention capacity of less than 1.0 g / dL.

[0258] In any of the aspects or embodiments described herein, at least one particulate adsorbent volume, at least one vent-side particulate adsorbent volume, or at least one vent-side low retention particulate volume has at least one of the following flow restriction characteristics: a flow restriction of less than 0.3 kPa under 40 lpm airflow, a pressure drop of less than 40 Pa / cm when a nominal linear air flow velocity of 46 cm / sec is applied to a 43 mm diameter bed, a length to diameter ratio of 2 or greater, or a combination thereof.

[0259] In any of the aspects or embodiments described herein, at least one particulate adsorption volume, at least one vent-side particulate adsorption volume, or at least one vent-side low retention capacity particulate volume has at least one of: (i) a retention capacity of less than 1.0 g / dL; (ii) a ratio of macroscopic pore volume to microscopic pore volume of greater than about 200%; (iii) a length to diameter ratio of 2 or greater; or (iv) a combination thereof.

[0260] In any of the aspects or embodiments described herein, the evaporative emission control canister system has a two-day diurnal breathing loss (DBL) of 50 mg or less with a purge of 315 liters or less applied after a 40 g / hr butane fill step, as measured by the 2012 California Bleed Emissions Test Procedure (BETP).

[0261] In any of the aspects or embodiments described herein, the evaporative emission control canister system has a two-day diurnal breathing loss (DBL) of 20 mg or less with a 210 liter purge or less applied after a 40 g / hr butane fill step, as measured by the 2012 California Bleed Emissions Test Procedure (BETP).

[0262] In any of the aspects or embodiments described herein, the evaporative emission control canister system has a two-day diurnal breathing loss (DBL) of 50 mg or less with a 150 or less bed volume purge applied after a 40 g / hr butane fill step, as measured by the 2012 California Bleed Emissions Test Procedure (BETP).

[0263] In any of the aspects or embodiments described herein, the evaporative emission control canister system has a two-day diurnal breathing loss (DBL) of 20 mg or less with a 100 or less bed volume purge applied after a 40 g / hr butane fill step, as measured by the 2012 California Bleed Emissions Test Procedure (BETP).

[0264] In any of the aspects or embodiments described herein, the evaporative emission control canister system comprises at least one fuel-side sorbent volume, at least one vent-side sorbent volume, or both.

[0265] In any of the aspects or embodiments described herein, the adsorbent volumes are located in a single canister or in multiple canisters that are connected so as to be continuously accessible by fuel vapor.

[0266] In any of the aspects or embodiments described herein, at least one particulate adsorbent At least one vent-side particulate adsorbent volume, or at least one vent-side low retention particulate volume, or at least one vent-side subsequent adsorbent volume, or a combination thereof, has a nominal BWC of less than 8 g / dL, a nominal IAC of less than 35 g / L at 25°C between 5 vol% and 50 vol% n-butane vapor concentrations, or both.

[0267] In any of the aspects or embodiments described herein, at least one vent-side subsequent adsorbent volume is an activated carbon honeycomb.

[0268] In any of the aspects or embodiments described herein, at least one particulate adsorption volume, at least one vent-side particulate adsorption volume, or at least one vent-side low retention capacity particulate volume has a retention capacity of less than 0.5 g / dL.

[0269] In any of the aspects or embodiments described herein, the fuel-side adsorbent volume has a nominal butane working capacity (BWC) of at least 8 g / dL (e.g., at least 10 g / L), a nominal incremental adsorption capacity (IAC) of at least 35 g / L at 25°C between 5 vol% and 50 vol% n-butane vapor concentrations, or both.

[0270] In any of the aspects or embodiments described herein, the at least one fuel-side adsorbent volume, the at least one particulate adsorbent volume, the at least one vent-side particulate adsorbent volume or the at least one vent-side low retention capacity particulate volume, the at least one vent-side subsequent adsorbent volume, or a combination thereof, comprises an adsorbent material selected from the group consisting of activated carbon, charcoal, zeolite, clay, porous polymer, porous alumina, porous silica, molecular sieve, ball clay, kaolin, titania, ceria, or a combination thereof.

[0271] In any of the aspects or embodiments described herein, at least one vent-side subsequent adsorbent volume is an activated carbon honeycomb.

[0272] In any of the aspects or embodiments described herein, the activated carbon is derived from a material comprising a member selected from the group consisting of wood, wood dust, wood flour, cotton linters, peat, coal, coconut, lignite, carbohydrates, petroleum pitch, petroleum coke, coal tar pitch, fruit pits, fruit stones, nut shells, nut pits, sawdust, palm, vegetables, synthetic polymers, natural polymers, lignocellulosic materials, or combinations thereof.

[0273] In any of the aspects or embodiments described herein, the sorbent form can comprise a member selected from the group consisting of granules, pellets, spheres, honeycombs, monoliths, pellet-like cylinders, uniformly shaped particulate media, non-uniformly shaped particulate media, extruded structured media, wound structured media, folded structured media, pleated structured media, corrugated structured media, cast structured media, bonded structured media, nonwovens, woven fabrics, sheets, paper, foams, hollow cylinders, stars, twisted spirals, asterisks, formed ribbons, or combinations thereof.

[0274] In any of the aspects or embodiments described herein, the adsorbent volume may comprise a volumetric diluent. In any of the aspects or embodiments described herein, the volumetric diluent comprises a member selected from the group consisting of inert spacer particles, trapped airspace, foam, fiber, screen, and combinations thereof.

[0275] In any of the aspects or embodiments described herein, the canister system may further comprise a heating unit.

[0276] Although several embodiments of the present invention have been shown and described herein, such embodiments It will be understood that the above descriptions are provided by way of example only. Numerous variations, changes, and substitutions will occur to those skilled in the art without departing from the spirit of the invention. Rather, this disclosure is intended to cover all modifications, equivalents, and alternatives falling within the scope of the present disclosure as defined by the appended claims and their legal equivalents. Accordingly, the description and appended claims are intended to cover all variations that fall within the spirit and scope of the invention.

[0277] The contents of all references, patents, pending patent applications and published patents cited throughout this application are hereby expressly incorporated by reference.

[0278] Those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims. It should be understood that the detailed examples and embodiments described herein are provided by way of example only for illustrative purposes and are not to be construed as limiting the invention in any way. Various modifications or variations therein will be suggested to those skilled in the art and are within the spirit and scope of this application and are contemplated within the scope of the appended claims. For example, the relative amounts of ingredients may be changed to optimize the desired effect, additional ingredients may be added, and / or similar ingredients may be substituted for one or more of the described ingredients. Further advantageous features and functionality associated with the systems, methods, and processes of the present invention will be apparent from the appended claims. Moreover, those skilled in the art will recognize or be able to ascertain using no more than routine experimentation, many equivalents to the specific embodiments of the invention described herein. Such equivalents are intended to be encompassed by the following claims.

Claims

1. Adsorbent material for controlling evaporation emissions, The material comprises a fine particle activated carbon material having microscopic pores with a diameter of less than approximately 100 nm and macroscopic pores with a diameter of approximately 100 to 100,000 nm, wherein the ratio of the volume of the macroscopic pores to the volume of the microscopic pores is greater than approximately 160%. The fine particle activated carbon material has a pressure drop of less than 40 Pa / cm when an apparent linear airflow velocity of 46 cm / sec is applied to a bed of the fine particle activated carbon material with a diameter of 43 mm, and is an adsorbent material having at least one of (i) a nominal butane working capacity (BWC) of less than 8 g / dL, (ii) a butane holding capacity of less than about 1 g / dL, or (iii) a combination of (i) and (iii).

2. The adsorbent material according to claim 1, wherein the adsorbent has a butane holding capacity of 1.0 g / dL or less.

3. The adsorbent material according to claim 1, wherein the adsorbent has a butane holding capacity of about 0.25 to 1.0 g / dL.

4. The adsorbent material according to claim 1, wherein the adsorbent further comprises at least one of a porous polymer, porous alumina, clay, porous silica, kaolin, zeolite, metal-organic structure, titania, ceria, or a combination thereof.

5. The adsorbent material according to claim 1, wherein the adsorbent has a pore volume of about 0.5 cc / g or less as measured by the BJH method.

6. The adsorbent material according to claim 1, wherein the adsorbent includes a body that defines the shape or form of the outer surface and the hollow.

7. The adsorption material according to claim 6, wherein the embodiment is at least one of substantially cylindrical, substantially oblong, substantially spherical, substantially cubic, substantially elliptical, substantially rectangular, trifoliate, three-dimensional spiral, or a combination thereof.

8. The adsorption material according to claim 1, wherein the fine particle activated carbon material has a cross-sectional width of about 1 mm to about 20 mm.

9. The adsorbent material according to claim 1, wherein the adsorbent has a hollow cross-section.

10. The adsorbent material according to claim 1, wherein the adsorbent includes at least one cavity that is in fluid communication with the outer surface of the adsorbent.

11. The adsorption material according to claim 10, wherein the outer surface of the adsorbent has a thickness of about 0.1 mm to about 3.0 mm.

12. At least one of the hollow outer walls has a thickness in the range of about 0.1 mm to about 1.0 mm, The hollow shape extends between the at least one outer wall and has at least one inner wall having a thickness in the range of about 0.1 mm to about 1.0 mm, or The adsorption material according to claim 9, which is at least one of those combinations.

13. The adsorption material according to claim 12, wherein the thickness of at least one of the inner wall, the at least one outer wall, or a combination thereof is about 0.3 mm to about 0.8 mm.

14. The adsorption material according to claim 13, wherein the thickness of at least one of the inner wall, the at least one outer wall, or a combination thereof is about 0.4 mm to about 0.7 mm.

15. The adsorption material according to claim 13, wherein the at least one inner wall extends outward from the hollow portion of the fine particle adsorption material toward the at least one outer wall in at least two directions.

16. The adsorption material according to claim 13, wherein the at least one inner wall extends outward from the hollow portion of the particulate material toward the at least one outer wall in at least three directions.

17. The adsorption material according to claim 13, wherein the at least one inner wall extends outward from the hollow portion of the particulate material toward the at least one outer wall in at least four directions.

18. The adsorbent material according to claim 1, wherein the adsorbent has a length of about 1 mm to about 20 mm.

19. The adsorbent material according to claim 1, wherein the activated carbon is derived from at least one material selected from the group consisting of wood, wood dust, wood powder, cotton linter, peat, coal, coconut, lignite, carbohydrates, petroleum pitch, petroleum coke, coal tar pitch, fruit pit, fruit stone, nut shell, nut pit, sawdust, palm, vegetables, synthetic polymers, natural polymers, lignocellulose materials, and combinations thereof.

20. The adsorbent material according to claim 4, wherein the clay is at least one of zeolite clay, bentonite clay, montmorillonite clay, illite clay, French green clay, Pascalite clay, Redmond clay, Teramine clay, Living clay, Fuller clay, Omalite clay, Vitalite clay, Rectolite clay, or a combination thereof.

21. A pore-forming material or processing aid that decomposes, solubilizes, sublimes, vaporizes, or melts when heated to a temperature of 100°C or higher. binder, Filler, or The adsorption material according to claim 1, further comprising at least one of these combinations.

22. The adsorption material according to claim 21, wherein the pore-forming material or processing aid is a cellulose derivative.

23. The adsorption material according to claim 21, wherein the pore-forming material or processing aid is methylcellulose.

24. The adsorbent material according to claim 21, wherein the pore-forming material or processing aid sublimes, vaporizes, chemically decomposes, solubilizes, or melts when heated to a temperature in the range of about 125°C to about 640°C.

25. The adsorbent material according to claim 21, wherein the binder is a clay or silicate material.

26. The adsorbent material according to claim 25, wherein the clay is at least one of zeolite clay, bentonite clay, montmorillonite clay, illite clay, French green clay, Pascalite clay, Redmond clay, Teramine clay, Living clay, Fuller clay, Omalite clay, Vitalite clay, Rectolite clay, or a combination thereof.

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