Continuous and scalable processing of rapidly pyrolytic oils to obtain heavy aromatic fractions.

Abstract

Producing a heavy aromatic fraction from a rapidly pyrolysis oil includes the steps of: mixing the rapidly pyrolysis oil with a first solvent to obtain an emulsion; heating the emulsion to obtain an organic phase and an aqueous phase; vapor stripping the organic phase with a second solvent to obtain the heavy aromatic fraction and a condensate containing the first solvent, the second solvent, and water; concentrating the aqueous phase to obtain a water-soluble organic fraction, water, and a light component containing an organic compound having 1 to 6 carbon atoms; mixing the condensate with the light component to obtain a mixture; distilling the mixture to obtain a first stream containing the first solvent and water, and a second stream containing the second solvent; mixing the first stream with the rapidly pyrolysis oil to obtain an emulsion; and mixing the second stream with the organic phase to obtain the heavy aromatic fraction and the condensate. TIFF2026521720000003.tif118166

Description

Technical Field

[0001] Cross - reference to Related Applications This application claims the benefit of U.S. Patent Application No. 63 / 521,060, filed on June 14, 2023, which is hereby incorporated by reference in its entirety.

[0002] Technical Field The present invention relates to quantitatively fractionating fast pyrolysis oil (FPO) from lignocellulosic biomass into high - energy - density streams (e.g., heavy aromatic fraction and water - soluble organic fraction), and to a comprehensive upgrading method for recovering high - value - added products (e.g., precursors of fuel - range hydrocarbons, fuel oils, fuel additives, and fuel blends; concentrated fermentable sugars; industrial solvents, and chemicals).

Background Art

[0003] Background Fast pyrolysis oil (FPO) is a liquid product generated from the fast pyrolysis of biomass. In the fast pyrolysis process, biomass is rapidly heated to 450 - 550 °C in the absence of oxygen and with a short residence time, and then rapidly cooled to produce FPO in the form of a condensate. Depending on the process conditions and the condensation train, FPO can be either a single - phase mixture or a two - phase mixture containing a heavy aromatic fraction (HAF) and a water - soluble organic fraction (WSOF).

Summary of the Invention

[0004] Summary In the first general phase, a system for separating heavy aromatic fractions from rapidly pyrolytic oil includes a mixing system having a raw material intake and configured to receive recycled downstream water and solvent. A separator is connected to the mixing system. A liquid-liquid extractor is connected to the separator. A collector vessel is connected to the separator and configured to receive the input flow from the liquid-liquid extractor. A solvent stripping column is connected to the collector vessel. A distillation column is connected to the solvent stripping column. An evaporator is configured to receive the aqueous extract residue from the liquid-liquid extractor. The distillation column is configured to receive overhead from the solvent stripping column and the evaporator. In some cases, the separator is configured to provide heavy aromatic fractions and water-soluble organic fractions by solvent-assisted emulsion inversion. In specific cases, a collector is configured to receive the aqueous extract residue from the liquid-liquid extractor.

[0005] In the second general aspect, the production of a heavy aromatic fraction from a rapidly pyrolytic oil includes the steps of: mixing the rapidly pyrolytic oil with a first solvent to obtain an emulsion; heating the emulsion to obtain an organic phase and an aqueous phase; vapor stripping the organic phase with a second solvent to obtain a condensate containing a heavy aromatic fraction and the first solvent, the second solvent, and water; concentrating the aqueous phase to obtain a light end containing a water-soluble organic fraction, water, and an organic compound having 1 to 6 carbon atoms; mixing the condensate with the light end to obtain a mixture; distilling the mixture to obtain a first stream containing the first solvent and water and a second stream containing the second solvent; mixing the first stream with the rapidly pyrolytic oil to obtain an emulsion; and mixing the second stream with the organic phase to obtain a heavy aromatic fraction and a condensate.

[0006] Details of one or more aspects of the subject matter of this disclosure are described in the accompanying drawings and specification. Other features, aspects, and advantages of the subject matter will become apparent from the specification, drawings, and claims. [Brief explanation of the drawing]

[0007] [Figure 1] This is a block flowchart of a system and process for preparing heavy aromatic fractions (HAF) and water-soluble organic fractions (WSOF) from rapidly pyrolytic oil (FPO). [Modes for carrying out the invention]

[0008] Detailed explanation Rapid pyrolysis oil (FPO) as a fuel offers many environmental advantages compared to fossil fuels. For example, the combustion of FPO produces negligibly small amounts of SOx and half the amount of NOx as the combustion of fossil fuels, and is CO2 neutral. However, the large-scale use of FPO as a liquid fuel may be limited due to its high acidity and thermal instability. Furthermore, FPO has a high water content (e.g., 25-30%), a high oxygen content (e.g., 40-50%), is immiscible with fossil fuels, and undergoes phase separation and viscosity increase during long-term storage (aging).

[0009] FPO is a complex mixture containing various types of oxygen-containing organic compounds (e.g., acids, aldehydes, alcohols, phenols, phenolic lignin derivatives, anhydrous sugars, and other substances with multiple functional groups). These oxygen-containing organic compounds can destabilize FPO, make it corrosive, make it incompatible with conventional fuels, and directly impact its commercial applications. Therefore, FPO is typically upgraded before it can be used in current infrastructure as a viable renewable fuel to replace or blend with petroleum sources.

[0010] Before FPO can be used as a substitute for fossil fuels or for any other purpose, upgrades to FPO are initiated. Several FPO upgrade technologies have been proposed to improve the properties of the product and expand the range of possible applications. The main upgrade technologies include hydrodesoxidation (HDO) and hydrocracking. Both of these technologies consume a lot of hydrogen, which in turn affects process scale-up and economics. It has become customary to hydroprocess FPO using a two-stage approach, with the first stage involving a hydrotreating stage carried out at a moderate temperature (below 300°C) for the reaction. This first stage reduces the polymerization of FPO that occurs when crude FPO is subjected to temperatures above 100°C. Then, hydrocracking of the lightly hydrotreated product is achieved in the second stage reaction at a higher temperature (above 350°C). The second stage of the hydrotreatment method usually requires two reactors, thereby increasing the equipment costs of the hydrotreatment technology. It may also require longer reaction times, which increases variable costs. Even without considering the high hydrogen consumption, these technologies face challenges in terms of corrosion, catalyst fouling, catalyst stability, catalyst lifespan, and product selectivity.

[0011] In some cases, the chemical upgrade of FPO has been achieved by esterification with alcohols (e.g., ethanol and butanol) under mild conditions using inorganic acid catalysts (e.g., sulfuric acid and / or various heterogeneous catalysts including resin acid catalysts). Organic acids and aldehydes can be converted to esters and acetals, respectively, by reaction with alcohols. Products from the above processes using different catalysts contain large amounts of water and alcohol and generate little heat. Undesirable properties of FPO can be related to certain types of compounds. For example, acids contribute to the corrosiveness of FPO, and the instability of FPO is typically caused by aldehydes, ketones, and phenols. Therefore, it is advantageous to suppress acids, aldehydes, ketones, and phenols in the final product.

[0012] Oxygen-containing compounds with furan rings readily form aldehydes and coke due to their thermal instability. These precursors can react on the catalyst surface, clogging pores and contributing to catalyst deactivation during FPO upgrades and hydrodeoxygenation treatments. Small aldehyde molecules can condense with aromatic substances to form polymers. While coking on the catalyst surface can be suppressed by increasing hydrogen pressure and reaction temperature while reducing catalyst acidity, minimizing hydrogen consumption and coking under mild conditions can be challenging.

[0013] The efficient separation of pyrolytic sugars and phenol oligomers offers numerous industrial opportunities and improves the quality of FPO for further processing. Pyrolytic sugars can be useful for direct upgrades to liquid transport fuels and / or fermentation to corresponding alcohols. Phenol oligomers have potential applications in a wide range of uses, including the manufacture of resins, binders, asphalts, coatings, adhesives, aromatic chemicals, proprietary polymers, and fuels and preservatives.

[0014] The process described herein is designed to separate highly reactive components in FPO, which could clog the hydrogenation apparatus, into the aqueous phase, and to convert the remaining organic components into hydrocarbons. The fractional distillation of FPO described herein removes water and reduces the concentrations of aldehydes, sugars, acids, and metals in the organic phase, which is referred to herein as the heavy aromatic fraction (HAF). Table 1 lists the properties of this HAF compared to commercially available wood-derived FPO. The resulting HAF enables the hydrogenation of downstream distillates with a high carbon yield from biomass to biofuels using commercially available base metal sulfide catalysts.

[0015] (Table 1) Improved properties of the rapid pyrolysis oil heavy aromatic fraction described herein compared to commercially available rapid pyrolysis oil (FPO). TIFF2026521720000002.tif48128

[0016] FPO is an oil-in-water microemulsion in which pyrolysis lignin fragments, collectively referred to herein as “heavy aromatic fractions” (HAF), are held by small polar molecules in the presence of water and pyrolysis cellulose / hemicellulose fragments. The process described herein utilizes the emulsion behavior of FPO by using a hydrophobic organic solvent and water in a solvent / antisolvent process. As water and hydrophobic organic solvents are added sequentially, the solvent displaces water and small oxygen compounds from the HAF, producing solvated pyrolysis lignin with a lower density than the aqueous phase containing water, pyrolysis sugars, and small oxygen compounds. Furthermore, unlike conventional solvent extraction processes that depend on the solubility of lignin in the solvent, the amount of solvent required by this emulsion destabilization process is typically much smaller.

[0017] As defined in ASTM D7544-23 Standard Specification for Pyrolysis Liquid Biofuel, FPO is a single-phase substance. This single-phase substance contains water at a mass fraction of approximately 25% within what is recognized as an emulsion. The remainder of the substance consists of water-soluble small molecules such as acetic acid, acetol, glycolaldehyde, anhydrous sugars, anhydrous sugar polymers derived from cellulose, and hydrophobic aromatic fractions (HAF) derived from lignin and cellulose decomposition. HAF is often described as "pyrolysis lignin," which is typically understood to describe the precipitates that form when FPO is mixed with cold water.

[0018] The amount of pyrolysis lignin can be assessed by mixing FPO with an equal mass of water to obtain a crude precipitate. This precipitate typically contains about 50% of the initial mass of FPO. However, precipitates that typically contain other substances from FPO can be redissolved in methanol (e.g., an equal mass of methanol) to obtain a mixture. Water (e.g., another equal mass) can be mixed with this mixture to precipitate the purified pyrolysis lignin, from which the methanol can be evaporated.

[0019] The main phase of an FPO emulsion is thought to contain aggregates of lignin-derived molecules, while the dispersed phase contains water and water-soluble molecules. The aggregates tend to grow with aging, typically reaching the same volume as four coniferyl alcohol C-9 lignin units (typically called G-lignin based on the guaiacyl OH and methoxy substituents in the ring). The molecular weight of 4G-lignin (tetrameric lignin) is approximately 700-750 g / mol.

[0020] As FPO ages, chemical reactions occur that lead to the formation of water, crosslinking of some small molecules, and aggregation of tetrameric units into larger units (e.g., based on electrostatic interactions), with these aggregates leaving the solution and resulting in phase separation. The pyrolytic lignin is thought to be held in place by cosolvent molecules within a loose network that solubilizes water and water-soluble organic matter. Cosolvent molecules are typically small organic molecules (C1-C6) with polar groups (e.g., -OH, >C=O, -COOH) and nonpolar hydrocarbons or aromatic "forms". The water-soluble phase holds most of the water and highly polar organic molecules (e.g., sugars including anhydrous sugars such as levoglucosan, and polyols or sugar oligomers). This emulsion can be destabilized by increasing the ratio of water to water-soluble organic matter so that the water-insoluble tetrameric lignin separates, and then by adding the cosolvent again to the newly phase-separated material so that a single homogeneous phase is formed.

[0021] Single-phase FPO exists as a type IV Windsor emulsion. In this case, HAF (pyrolytic lignin) behaves as a surfactant and as an oil that is usually immiscible with water, while polar organic substances exist in an aqueous solution referred to herein as the water-soluble organic fraction (WSOF). As the water concentration increases, the HAF forms a lower phase due to its density, and the WSOF forms an upper phase consisting mainly of water and water-soluble polar substances. That is, a Windsor type II emulsion is produced.

[0022] Type I Winsor emulsions, which can be prepared by adding a lipophilic polar solvent, have Hansen solubility parameters in the range of (dispersion 8 - 10 MPa 0.5 , polarity 2 - 3 MPa 0.5 , and hydrogen bonding 2 - 4.5 MPa 0.5 ). When the critical point where the Winsor IV emulsion converts to the Winsor I emulsion is approached, the amount of lipophilic polar solvent required is only slight. Thus, the addition of only a small amount of additional water as an anti-solvent will cause the formation of a Type I emulsion in which most of the sugar and WSOF are contained in the aqueous phase and HAF is contained in the solvent phase.

[0023] For the recovery of HAF, a very concentrated solution in a lipophilic polar solvent can be extracted from a small amount of distilled water. After drying the solvent phase, the residual heavy oil can be recovered by evaporation of the solvent. The combined aqueous phase can be extracted with an organic solvent and then distilled to produce a pure fraction of pyrolysis sugar and phenolic monomers. Furthermore, these phenolic monomers can be added back to the HAF fraction for future upgrading purposes.

[0024] The behavior of the Windsor emulsion minimizes the amount of additional solvent and water required. The process flowchart is shown in Figure 1. First, an organic solvent is added to the FPO and vigorously mixed in a batch, semi-continuous, or continuous process using an overhead or static mixing unit 100 (e.g., for about 1 to 30 minutes at ambient temperature ~60°C). Water is added to this mixture and vigorously mixed in a batch, semi-continuous, or continuous process using an overhead or static mixing unit (e.g., for about 1 to 30 minutes at ambient temperature ~60°C). After the mixture is allowed to stand in a separator 200 (e.g., for about 1 to 90 minutes), clear and distinct phase separation is achieved between the upper organic phase and the lower aqueous phase. The organic phase is sent to a mixer unit 400, and the aqueous phase is sent to an optional liquid-liquid extraction (LLE) unit 300. In the LLE unit, a solvent (new, recycled, or both) is used to extract residual HAF organic matter from the aqueous phase. When LLE is used, the extracted organic matter is sent to a mixer unit 400, and the resulting residue is sent to a concentration unit 500. In the concentration unit 500, excess water and volatile organic compounds are removed from the aqueous mixture by heat with or without vacuum, or by membrane treatment, producing WSOF with a water mass fraction of approximately 20-30%. Furthermore, the organic matter stream collected from the mixer unit is sent to a solvent stripping unit 700, where it is mixed with ethanol (e.g., 1-25% by mass fraction). Vacuum and heat are applied to remove the solvent, water, and ethanol, and HAF is obtained. The mixture of ethanol, water, and solvent is sent to an alcohol stream stripping unit, where water, solvent, and ethanol are recovered and recycled.

[0025] A system for separating HAF from FPO includes a raw material inlet and a mixing system configured to receive recycled downstream water and solvent. A separator is connected to the mixing system. A liquid-liquid extractor is connected to the separator. A collector vessel is connected to the separator and is configured to receive an input stream from the liquid-liquid extractor. A solvent stripping column is connected to the collector vessel. A distillation column is connected to the solvent stripping column. An evaporator is configured to receive an aqueous raffinate from the liquid-liquid extractor. The distillation column is configured to receive overheads from the solvent stripping column and from the evaporator. In some cases, the separator is configured to provide HAF and WSOF by solvent-assisted emulsion inversion. In certain cases, the collector is configured to receive an aqueous raffinate from the liquid-liquid extractor.

[0026] Generating HAF from FPO includes a step of mixing FPO with a first solvent, wherein an emulsion is obtained. The first solvent is an organic solvent. The step of mixing FPO with the first solvent is performed before mixing FPO with water or an aqueous composition. The emulsion is heated to obtain an organic phase and an aqueous phase. The organic phase is steam stripped with a second solvent to obtain a condensate containing HAF, the first solvent, the second solvent, and water. The aqueous phase is concentrated to obtain WSOF and a light component containing water and an organic compound having 1 to 6 carbon atoms. The condensate is mixed with the light component to obtain a mixture. The mixture is distilled to obtain a first stream containing the first solvent and water and a second stream containing the second solvent. The first stream is mixed with FPO to obtain an emulsion. The second stream is mixed with the organic phase to obtain HAF and the condensate.

[0027] FPO is typically derived from lignocellulosic biomass such as wood, straw, grass, or any combination thereof. The first solvent includes C4-C8 alcohols, methyl or ethyl esters derived from C4-C8 alcohols, water-insoluble ketones, or combinations thereof. In one example, the water-insoluble ketone is methyl ethyl ketone, methyl isobutyl ketone, or a combination thereof. The second solvent is typically a C1-C4 alcohol such as methanol, ethanol, n-propanol, isopropanol, or butanol, or a combination thereof. HAF includes polymers, oligomers, and monomeric aromatic derivatives of lignin. The aqueous phase includes water-soluble organic and water-soluble inorganic compounds from rapidly pyrolytic oils.

[0028] Water typically constitutes 15–30% by mass fraction of FPO. The first solvent typically constitutes 1–25% by mass fraction of the emulsion. The second organic phase typically contains phenolic compounds and neutral compounds.

[0029] Combining FPO with a first solvent before combining FPO with water or an aqueous composition reduces or eliminates HAF precipitation. The step of combining FPO with the first solvent can be achieved by processes such as stirring or static in-line mixing. The combination of FPO with the first solvent is carried out at a pressure ranging from atmospheric pressure to approximately 100 psig. The step of heating the emulsion is carried out at a temperature range of 15°C to 65°C. In one example, the combining step is carried out at a temperature of approximately 40°C. The liquid flow mode of the emulsion provides a Reynolds number of 5 to 1,000,000, with a preferred minimum value greater than 200. The temperature, pressure, and flow conditions for the combining and heating steps are selected so that the total amount of aromatic compounds in the organic phase is at least 80% by mass fraction of the total amount of aromatic compounds in FPO. In another example, the temperature, pressure, and flow conditions for the steps of combining FPO with the first solvent and heating the emulsion are selected such that the total amount of aromatic compounds in the organic phase is at least 85% by mass fraction of the total amount of aromatic compounds in FPO, or at least 90% by mass fraction of the total amount of aromatic compounds in FPO.

[0030] In some embodiments, after combining FPO with a first solvent, water or an aqueous composition (e.g., an aqueous solution) is combined with FPO (e.g., water or an aqueous composition is combined with an emulsion). In one example, the aqueous composition is recovered from the aqueous phase by distillation and combined with FPO and the first solvent in a recycling loop (see, for example, “Recycled Water” in Figure 1). In this example, the aqueous composition includes acetic acid (e.g., about 2 wt% to about 7 wt%), acetol (e.g., about 1 wt% to about 3 wt%), glycoaldehyde (e.g., about 0.1 wt% to about 1 wt%), or any combination thereof, and may include other low-boiling point water-soluble organic substances derived from the FPO raw materials.

[0031] The step of combining water or an aqueous composition with FPO and a first solvent (e.g., an emulsion) may include stirring or static in-line mixing after adding water or the aqueous composition to obtain a second emulsion, and before allowing the HAF to settle. Heating of the second emulsion is carried out at a temperature in the range of 15°C to 65°C. In one example, the combination of water or an aqueous composition with FPO and the first solvent (e.g., an emulsion) is carried out at a temperature of about 40°C. The liquid flow mode of the mixture of FPO, the first solvent and water or aqueous composition (e.g., the second emulsion) provides a Reynolds number of 5 to 1,000,000, with a preferred minimum value greater than 200.

[0032] In the vapor stripping process, the mass fraction of the second solvent relative to the total amount of the heavy aromatic fraction and the first solvent is in the range of 5% to 20%. Distillation is typically carried out at atmospheric pressure, and concentration is typically carried out below atmospheric pressure.

[0033] The total amount of carbon in the heavy aromatic fraction and the water-soluble organic fraction is typically at least 90% or at least 95% of the total amount of carbon in FPO. The total amount of aromatic compounds in HAF is typically at least 95% of the aromatic content of FPO by mass fraction. At least 95% of the pyrolysis sugars in FPO by mass fraction typically migrate to WSOF. At least 80% of the inorganic compounds in FPO by mass fraction migrate to WSOF. In one example, at least 90% of the inorganic compounds in FPO by mass fraction migrate to WSOF.

[0034] Certain embodiments include steps of extracting the aqueous phase with an additional amount of a first solvent to obtain an additional organic phase and an aqueous residue, and combining the additional organic phase with the organic phase and then vapor stripping the organic phase. Certain embodiments also include steps of removing water from the aqueous residue to obtain a first stream containing residual pyrolysis oil and a second stream containing water. In some cases, the second stream is a stream of pure water. The step of removing water from the aqueous residue may include using a multiple-effect evaporator or a membrane filtration unit.

[0035] The concept of the disclosed invention includes those defined in the attached claims, but it should be understood that the concept of the invention may also be defined in the following aspects.

[0036] In addition to the embodiments of the attached claims and the embodiments described above, the following numbered embodiments are also innovative.

[0037] Embodiment 1 is as follows: A process for producing heavy aromatic fractions from rapidly pyrolytic oil, including the following steps: A step of mixing a rapidly pyrolysis oil with a first solvent to obtain an emulsion; A step of heating the emulsion to obtain an organic phase and an aqueous phase; A step of vapor stripping the organic phase with a second solvent, wherein the heavy aromatic fraction and a condensate containing the first solvent, the second solvent, and water are obtained; A step of concentrating the aqueous phase, wherein a water-soluble organic fraction, water, and a light end containing an organic compound having 1 to 6 carbon atoms are obtained; A step of mixing the condensate with the light component to obtain a mixture; A step of distilling the mixture, wherein a first stream containing the first solvent and water, and a second stream containing the second solvent are obtained; A step of mixing the first stream with the rapidly pyrolysis oil to obtain the emulsion; and A step of mixing the second stream with the organic phase to obtain the heavy aromatic fraction and the condensate.

[0038] Embodiment 2 is as follows: The process according to embodiment 1, wherein the rapidly pyrolytic oil is derived from lignocellulosic biomass including wood, straw, grass, or any combination thereof.

[0039] Embodiment 3 is as follows: The process according to embodiment 1 or 2, wherein the first solvent comprises a C4-C8 alcohol, a methyl or ethyl ester derived from a C4-C8 alcohol, a water-insoluble ketone, or a combination thereof.

[0040] Appearance 4 is as follows: The process according to embodiment 3, wherein the water-insoluble ketone includes methyl ethyl ketone, methyl isobutyl ketone, or a combination thereof.

[0041] Embodiment 5 is as follows: The process according to any one of embodiments 1 to 4, wherein the second solvent contains C1 to C4 alcohols.

[0042] Embodiment 6 is as follows: The process according to embodiment 5, wherein the second solvent comprises methanol, ethanol, n-propanol, isopropanol, butanol, or a combination thereof.

[0043] Appearance 7 is as follows: The process according to any one of embodiments 1 to 6, wherein the heavy aromatic fraction comprises lignin polymers, oligomers, and monomeric aromatic derivatives.

[0044] Embodiment 8 is as follows: A process according to any one of embodiments 1 to 7, wherein the aqueous phase comprises water-soluble organic compounds and water-soluble inorganic compounds from the rapidly pyrolysis oil.

[0045] Appearance 9 is as follows: The process according to any one of embodiments 1 to 8, wherein the step of mixing the rapidly pyrolysis oil and the first solvent is performed before the step of mixing water or an aqueous composition with the rapidly pyrolysis oil.

[0046] Embodiment 10 is as follows: A process according to any of embodiments 1 to 9, wherein the step of mixing the rapidly pyrolytic oil and the first solvent includes stirring or static in-line mixing.

[0047] Embodiment 11 is as follows: A process according to any of embodiments 1 to 10, wherein the step of mixing the rapidly pyrolysis oil and the first solvent is performed at a pressure in the range of atmospheric pressure to about 100 psig.

[0048] Embodiment 12 is as follows: The process according to any of embodiments 1 to 11, wherein the step of heating the emulsion is performed at a temperature in the range of 15°C to 65°C.

[0049] Embodiment 13 is as follows: The process according to embodiment 12, wherein the step of heating the emulsion is performed at a temperature of approximately 40°C.

[0050] Embodiment 14 is as follows: A process according to any of embodiments 1 to 13, wherein the liquid flow mode of the emulsion provides a Reynolds number of 5 to 1,000,000.

[0051] Embodiment 15 is as follows: A process according to any one of embodiments 1 to 14, wherein the temperature, pressure, and flow conditions are selected for the steps of mixing the rapidly pyrolysis oil and the first solvent such that the total amount of aromatic compounds in the organic phase is at least 80% by mass fraction of the total amount of aromatic compounds in the rapidly pyrolysis oil, and heating the emulsion.

[0052] Embodiment 16 is as follows: A process according to any of embodiments 1 to 15, wherein the water constitutes 15% to 35% of the emulsion by mass fraction.

[0053] Embodiment 17 is as follows: A process according to any of embodiments 1 to 16, wherein the first solvent constitutes 1% to 25% of the emulsion by mass fraction.

[0054] Embodiment 18 is as follows: A process according to any of embodiments 1 to 17, wherein the second organic phase comprises a phenolic compound and a neutral compound.

[0055] Appearance 19 is as follows: A process according to any of embodiments 1 to 18, wherein in the vapor stripping step, the mass fraction of the second solvent relative to the total amount of the heavy aromatic fraction and the first solvent is in the range of 5% to 20%.

[0056] Embodiment 20 is as follows: The process according to any of embodiments 1 to 19, wherein the distillation step is performed at atmospheric pressure.

[0057] Embodiment 21 is as follows: A process according to any of embodiments 1 to 20, wherein the concentration step is performed at a pressure below atmospheric pressure.

[0058] Embodiment 22 is as follows: A process according to any of embodiments 1 to 21, wherein the total amount of carbon in the heavy aromatic fraction and the water-soluble organic fraction constitutes at least 90% or at least 95% of the total amount of carbon in the rapidly pyrolysis oil.

[0059] Embodiment 23 is as follows: A process according to any one of embodiments 1 to 22, wherein the total amount of aromatic compounds in the heavy aromatic fraction is at least 95% by mass fraction of the aromatic content of the rapidly pyrolysis oil.

[0060] Embodiment 24 is as follows: A process according to any of embodiments 1 to 23, wherein at least 95% by mass fraction of the pyrolysis sugars in the rapidly pyrolysis oil is transferred to the water-soluble organic fraction.

[0061] Embodiment 25 is as follows: A process according to any one of embodiments 1 to 24, wherein at least 80% by mass fraction of the inorganic compounds in the rapidly pyrolysis oil are transferred to the water-soluble organic fraction.

[0062] Embodiment 26 is as follows: A step of mixing water or an aqueous composition with the emulsion, wherein a second emulsion is obtained. A process in any of embodiments 1 to 25, further including the above.

[0063] Embodiment 27 is as follows: A process according to any of embodiments 1 to 26, wherein the step of mixing the water or aqueous composition with the emulsion includes stirring or static in-line mixing.

[0064] Embodiment 28 is as follows: The process according to embodiment 26 or 27, wherein the step of mixing the water or aqueous composition with the emulsion is performed at a pressure in the range of atmospheric pressure to about 100 psig.

[0065] Appearance 29 is as follows: A process according to any of embodiments 26 to 28, wherein the liquid flow mode of the second emulsion provides a Reynolds number of 5 to 1,000,000.

[0066] Embodiment 30 is as follows: The process according to any one of embodiments 26 to 29, wherein the step of heating the emulsion includes the step of heating the second emulsion, and the step of heating the second emulsion is performed at a temperature in the range of 15°C to 65°C.

[0067] Embodiment 31 is as follows: The process according to embodiment 30, wherein the step of heating the second emulsion is performed at a temperature of approximately 40°C.

[0068] Embodiment 32 is as follows: A process according to any one of embodiments 26 to 31, wherein the temperature, pressure, and flow conditions are selected for the steps of mixing the emulsion with water or an aqueous composition such that the total amount of aromatic compounds in the organic phase is at least 80% by mass fraction of the total amount of aromatic compounds in the rapidly pyrolysis oil, and heating the second emulsion.

[0069] Embodiment 33 is as follows: A step of extracting the aqueous phase with an additional amount of the first solvent, thereby obtaining an additional organic phase and an aqueous extract; and The process involves mixing the additional organic phase with the organic phase, and then steam stripping the organic phase. A process in any of embodiments 1 to 32, further including the above.

[0070] Embodiment 34 is as follows: A step of removing water from the aqueous extraction residue, wherein a first stream containing residual pyrolysis oil and a second stream containing water are obtained. A process according to embodiment 33, further including the process according to embodiment 33.

[0071] Embodiment 35 is as follows: The process of embodiment 34, wherein the second stream is a stream of pure water.

[0072] Embodiment 36 is as follows: The process according to embodiment 34, wherein the second stream contains a water-soluble organic compound.

[0073] Embodiment 37 is as follows: The process according to embodiment 36, wherein the water-soluble organic compound comprises acetic acid, acetol, glycoaldehyde, or any combination thereof.

[0074] Embodiment 38 is as follows: The process of embodiment 37, wherein the second stream contains approximately 2 wt% to approximately 7 wt% acetic acid.

[0075] Embodiment 39 is as follows: The process according to embodiment 37 or 38, wherein the second stream contains approximately 1 wt% to approximately 3 wt% of acetol.

[0076] Embodiment 40 is as follows: A process according to any of embodiments 37 to 39, wherein the second stream contains approximately 0.1 wt% to approximately 1 wt% glycolaldehyde.

[0077] Embodiment 41 is as follows: A process according to any one of embodiments 34 to 40, further comprising the step of mixing the second stream with the emulsion in a recycling loop.

[0078] Embodiment 42 is as follows: The process according to embodiment 41, wherein the step of mixing the second stream with the emulsion is performed before the step of heating the emulsion.

[0079] Embodiment 43 is as follows: A process in any of embodiments 34 to 42, wherein the step of removing water from the aqueous extract residue includes using a multi-effect evaporator or a membrane filtration unit.

[0080] Appearance 44 is as follows: A system for separating heavy aromatic fractions from rapidly pyrolytic oil, the following: A mixing system that includes a raw material intake and is configured to receive recycled downstream water and solvents; A separator connected to the mixing system; A liquid-liquid extractor connected to the separator; A collection container connected to the separator and configured to receive the input stream from the liquid-liquid extractor; A solvent stripping tower connected to the collection container; A distillation column connected to the solvent stripping column; and Evaporator configured to receive aqueous residue from the liquid-liquid extractor The distillation column includes, and the distillation column is configured to receive overhead from the solvent stripping column and the evaporator. system.

[0081] Embodiment 45 is as follows: The system according to embodiment 44, wherein the separator is configured to provide a heavy aromatic fraction and a water-soluble organic fraction by solvent-assisted emulsion inversion.

[0082] Embodiment 46 is as follows: A system according to embodiment 44 or 45, wherein the collector is configured to receive aqueous residue from the liquid-liquid extractor.

[0083] While this disclosure includes many specific details of embodiments, these should not be interpreted as limitations on the scope of the subject matter or the scope of what is claimed, but rather as descriptions of features that may be specific to particular embodiments. Certain features described in this disclosure in the context of separate embodiments may also be implemented in combination in a single embodiment. Conversely, various features described in the context of a single embodiment may also be implemented in multiple embodiments, separately, or in any preferred partial combination. Furthermore, even if the aforementioned features are described as acting in a particular combination and were initially claimed as such, one or more features from the claimed combination may be removed from the combination, and the claimed combination may be directed towards a partial scope or a variation of a partial scope.

[0084] Specific aspects of the subject matter have been described. Other aspects, modifications, and variations of the described aspects are included in the appended claims, as will be obvious to those skilled in the art. Although operations are shown in a specific order in the drawings or claims, this should not be understood as meaning that such operations must be performed in a specific order or sequence, or that all illustrated operations must be performed, in order to achieve the desired result (some operations may be considered optional).

[0085] Therefore, the exemplary embodiments described above do not define or limit this disclosure. Other modifications, substitutions, and alterations are possible without departing from the spirit and scope of this disclosure.

Claims

1. A process for producing heavy aromatic fractions from rapidly pyrolytic oil, including the following steps: A step of mixing a rapidly pyrolysis oil with a first solvent to obtain an emulsion; A step of heating the emulsion to obtain an organic phase and an aqueous phase; A step of vapor stripping the organic phase with a second solvent, wherein the heavy aromatic fraction and a condensate containing the first solvent, the second solvent, and water are obtained; A step of concentrating the aqueous phase, wherein a water-soluble organic fraction, water, and a light end containing an organic compound having 1 to 6 carbon atoms are obtained; A step of mixing the condensate with the light component to obtain a mixture; A step of distilling the mixture, wherein a first stream containing the first solvent and water, and a second stream containing the second solvent are obtained; A step of mixing the first stream with the rapidly pyrolysis oil to obtain the emulsion; and A step of mixing the second stream with the organic phase to obtain the heavy aromatic fraction and the condensate.

2. The process according to claim 1, wherein the rapidly pyrolytic oil is derived from lignocellulosic biomass including wood, straw, grass, or any combination thereof.

3. The process according to claim 1, wherein the first solvent comprises a C4-C8 alcohol, a methyl or ethyl ester derived from a C4-C8 alcohol, a water-insoluble ketone, or a combination thereof.

4. The process according to claim 3, wherein the water-insoluble ketone includes methyl ethyl ketone, methyl isobutyl ketone, or a combination thereof.

5. The process according to claim 1, wherein the second solvent comprises C1-C4 alcohols.

6. The process according to claim 5, wherein the second solvent comprises methanol, ethanol, n-propanol, isopropanol, butanol, or a combination thereof.

7. The process according to claim 1, wherein the heavy aromatic fraction comprises lignin polymers, oligomers, and monomeric aromatic derivatives.

8. The process according to claim 1, wherein the aqueous phase comprises a water-soluble organic compound and a water-soluble inorganic compound from the rapidly pyrolysis oil.

9. The process according to claim 1, wherein the step of mixing the rapidly pyrolysis oil and the first solvent is performed before the step of mixing water or an aqueous composition with the rapidly pyrolysis oil.

10. The process according to claim 1, wherein the step of mixing the rapidly pyrolytic oil and the first solvent includes stirring or static in-line mixing.

11. The process according to claim 1, wherein the step of mixing the rapidly pyrolytic oil and the first solvent is performed at a pressure in the range of atmospheric pressure to about 100 psig.

12. The process according to claim 1, wherein the step of heating the emulsion is performed at a temperature in the range of 15°C to 65°C.

13. The process according to claim 11, wherein the step of heating the emulsion is performed at a temperature of about 40°C.

14. The process according to claim 1, wherein the liquid flow mode of the emulsion provides a Reynolds number of 5 to 1,000,000.

15. The process according to claim 1, wherein the temperature, pressure, and flow conditions are selected for the steps of mixing the rapid pyrolysis oil and the first solvent, and heating the emulsion, such that the total amount of aromatic compounds in the organic phase is at least 80% by mass fraction of the total amount of aromatic compounds in the rapid pyrolysis oil.

16. The process according to claim 1, wherein the water constitutes 15% to 35% of the emulsion by mass fraction.

17. The process according to claim 1, wherein the first solvent constitutes 1% to 25% of the emulsion by mass fraction.

18. The process according to claim 1, wherein the second organic phase comprises a phenol compound and a neutral compound.

19. The process according to claim 1, wherein in the vapor stripping step, the mass fraction of the second solvent relative to the total amount of the heavy aromatic fraction and the first solvent is in the range of 5% to 20%.

20. The process according to claim 1, wherein the distillation step is performed at atmospheric pressure.

21. The process according to claim 1, wherein the concentration step is performed at a pressure below atmospheric pressure.

22. The process according to claim 1, wherein the total amount of carbon in the heavy aromatic fraction and the water-soluble organic fraction constitutes at least 90% or at least 95% of the total amount of carbon in the rapidly pyrolysis oil.

23. The process according to claim 1, wherein the total amount of aromatic compounds in the heavy aromatic fraction is at least 95% by mass fraction of the aromatic content of the rapidly pyrolysis oil.

24. The process according to claim 1, wherein at least 95% by mass fraction of the pyrolysis sugars in the rapidly pyrolysis oil is transferred to the water-soluble organic fraction.

25. The process according to claim 1, wherein at least 80% by mass fraction of the inorganic compounds in the rapidly pyrolysis oil are transferred to the water-soluble organic fraction.

26. A step of mixing water or an aqueous composition with the emulsion, wherein a second emulsion is obtained. The process according to claim 1, further comprising:

27. The process according to claim 26, wherein the step of mixing the water or aqueous composition with the emulsion includes stirring or static in-line mixing.

28. The process according to claim 26, wherein the step of mixing the water or aqueous composition with the emulsion is performed at a pressure in the range of atmospheric pressure to about 100 psig.

29. The process according to claim 26, wherein the liquid flow mode of the second emulsion provides a Reynolds number of 5 to 1,000,000.

30. The process according to claim 26, wherein the step of heating the emulsion includes the step of heating the second emulsion, and the step of heating the second emulsion is performed at a temperature in the range of 15°C to 65°C.

31. The process according to claim 30, wherein the step of heating the second emulsion is performed at a temperature of about 40°C.

32. The process according to claim 30, wherein the temperature, pressure, and flow conditions are selected for the steps of mixing the emulsion with water or an aqueous composition and heating the second emulsion, such that the total amount of aromatic compounds in the organic phase is at least 80% by mass fraction of the total amount of aromatic compounds in the rapidly pyrolysis oil.

33. A step of extracting the aqueous phase with an additional amount of the first solvent, thereby obtaining an additional organic phase and an aqueous extractant; and The process involves mixing the additional organic phase with the organic phase, and then steam stripping the organic phase. The process according to claim 1, further comprising:

34. A step of removing water from the aqueous extraction residue, wherein a first stream containing residual pyrolysis oil and a second stream containing water are obtained. The process according to claim 33, further comprising:

35. The process according to claim 34, wherein the second stream is a stream of pure water.

36. The process according to claim 34, wherein the second stream comprises a water-soluble organic compound.

37. The process according to claim 36, wherein the water-soluble organic compound comprises acetic acid, acetol, glycoaldehyde, or any combination thereof.

38. The process according to claim 37, wherein the second stream contains about 2 wt% to about 7 wt% acetic acid.

39. The process according to claim 37, wherein the second stream contains about 1 wt% to about 3 wt% acetol.

40. The process according to claim 37, wherein the second stream contains approximately 0.1 wt% to approximately 1 wt% glycolaldehyde.

41. The process according to claim 34, further comprising the step of mixing the second stream with the emulsion in a recycling loop.

42. The process according to claim 41, wherein the step of mixing the second stream with the emulsion is performed before the step of heating the emulsion.

43. The process according to claim 34, wherein the step of removing water from the aqueous extract residue includes using a multi-effect evaporator or a membrane filtration unit.

44. A system for separating heavy aromatic fractions from rapidly pyrolytic oil, the following: A mixing system that includes a raw material intake and is configured to receive recycled downstream water and solvents; A separator connected to the mixing system; Liquid-liquid extractors connected to the separator; A collection container connected to the separator and configured to receive the input stream from the liquid-liquid extractor; A solvent stripping tower connected to the collection container; A distillation column connected to the solvent stripping column; and Evaporator configured to receive aqueous residue from the liquid-liquid extractor The distillation column includes, and the distillation column is configured to receive overhead from the solvent stripping column and the evaporator. system.

45. The system according to claim 44, wherein the separator is configured to provide a heavy aromatic fraction and a water-soluble organic fraction by solvent-assisted emulsion inversion.

46. The system according to claim 44, wherein the collector is configured to receive aqueous residue from the liquid-liquid extractor.

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