Systems and methods for the thermochemical production and purification of hydrocarbon compounds

Abstract

To provide pyrolysis, roasting, and / or gasification systems and methods. [Solution] A system is provided that enables a continuous process involving the introduction of particles into a reactor drum having a low-oxygen environment. Heavy hydrocarbons are boiled off from the particles during heating of the particles. The boiled-off heavy hydrocarbons are mixed with a heated gas stream that heats the particles in the reactor drum. The heated gas stream (with the boiled-off heavy hydrocarbons) is recirculated back to the heat source to reheat the gas stream before leaving the drum and re-entering the reactor drum. Repeated exposure to high temperatures in the reactor drum decomposes the heavy hydrocarbons into lighter hydrocarbons. The lighter hydrocarbons are then separated out of the heated gas stream and can be collected for sale or use.

Description

Technical Field

[0001] (Cross - reference to Related Applications) This patent application claims the priority of U.S. Patent Application No. 63 / 311,220, filed on February 17, 2022, the entire disclosure of which is incorporated herein by reference for all purposes.

[0002] (Technical Field) The present disclosure generally relates to pyrolysis, roasting, and / or gasification systems and methods, and more specifically, to the production of gas and liquid hydrocarbon products via biomass pyrolysis, roasting, and gasification systems and methods.

Background Art

[0003] The roasting / pyrolysis / gasification of biomass particles is well - known and is a process in which biomass and / or other organic particles are heated in a low - oxygen environment. This causes volatile compounds within the particles to be boiled off and the cellular structure of the particles to be decomposed, resulting in a partial loss of mass and an increase in friability. Roasting / pyrolysis / gasification causes reactions within the remaining cellular structure, and these reactions improve the moisture resistance of the resulting products. The particles remaining after undergoing the roasting / pyrolysis / gasification process have an improved energy value when measured in terms of thermal energy per unit weight. The degree of roasting / pyrolysis / gasification of biomass and / or other organic particles depends on several factors, including composition, the level of heat applied, the length of time the heat is applied, and ambient gas conditions (particularly with respect to oxygen level).

[0004] Electrocautery / pyrolysis / gasification systems, as part of the process for producing roasted particles, remove / release volatile substances (sometimes referred to as tar) in the gas phase from the raw material particles introduced into the system. These volatile substances are typically treated as waste / by-products that need to be disposed of as part of the roasting / pyrolysis / gasification process. The production, capture, and disposal of these tars reduce the efficiency of the roasting / pyrolysis / gasification system. [Overview of the project] [Means for solving the problem]

[0005] The embodiments described herein provide systems and methods that are well-suited, in particular, to roast organic particles of various sizes (including cellulosic biomass particles) in an efficient and consistent manner, while simultaneously purifying the removed volatiles into by-products, which may be collected in place of or in addition to the roasted organic particles. The systems and methods are readily scalable to meet the needs of a wide variety of industries and provide improved process control for monitoring and adjusting operating parameters, thereby optimizing or regulating the properties of the resulting roasted / pyrolytic / gasified biomass particles, purified volatiles, or both.

[0006] Roasting, gasification, and pyrolysis (TGP) reactions are similar in nature and are distinguished primarily by the temperature range in which the reaction takes place. For the purposes of this disclosure, TGP reactions broadly include the thermochemical decomposition of organic compounds in a manner in which the oxidizing agent is controlled or completely eliminated. For the purposes of this disclosure, the use of the terms “roasting,” “pyrolysis,” and “gasification” is understood to be interchangeable unless otherwise specified.

[0007] Thermochemical bio-oils include a range of hydrocarbon products produced from the thermochemical treatment of biologically generated organic materials. Thermochemical treatment typically produces hydrocarbon compounds derived from fossil fuels. Examples include crude oil, jet fuel, gasoline, alcohol, diesel, solvents, polymers, alkanes, alkenes, alkadienes, aromatics, carboxylic acids, and many other organic compounds.

[0008] Pyrolysis is a process that uses heat and / or pressure to break down larger, heavier hydrocarbon molecules into smaller, lighter molecules. Pyrolysis, as used herein, refers to the decomposition of hydrocarbon compounds. Pyrolysis can result from TGP reactions (e.g., in the systems disclosed herein). Catalytic decomposition is another process for purifying hydrocarbon molecules. Catalytic decomposition uses a catalyst to facilitate the breakdown of larger, heavier hydrocarbon molecules into smaller, lighter molecules. Catalysts can allow for modifications of the reaction temperature, pressure, the ratio and type of compounds produced, or any combination thereof.

[0009] According to one embodiment, the TGP system can be summarized as comprising an inlet for receiving particles (e.g., biomass particles), a reactor drum rotatable about its longitudinal axis, a heat source located upstream of the reactor drum and heating the gas contained in the system to a temperature sufficient to start and sustain the TGP reaction of the particles in the reactor drum during the operation of the system, a fan device that, as the reactor drum rotates when the system is in operation, generates a flow of heated gas through the reactor drum that is sufficient to sustain the TGP reaction of the particles in the reactor drum along the length of the reactor drum so that the particles interact with the heated gas flow, and a gas duct coupled to at least the reactor drum, the heat source, and the fan device, which recirculates the gas or a portion of the gases leaving the reactor drum back to the heat source and reheats the gas for reintroduction into the reactor drum.

[0010] The heated gas flow directly heats the particles as the gas flow circulates through the reactor drum. As the particles are heated, the compounds within them can be thermochemically decomposed via the TGP reaction within the reactor (for example, into compounds containing elements, organic, hydrocarbon compounds / mixtures, or any combination thereof, which can be in the form of one or more of the following: gas, steam, and aerosol). These gas mixtures are commonly referred to as synthesis gas or syngas. Heating the particles may produce an amount of syngas exceeding what is needed to maintain the TGP reaction in the reactor drum as it circulates through the system.

[0011] The reactor drum may be configured to regulate the movement of particles through the reactor drum, thereby influencing the residence time of particles within the reactor drum. The reactor drum may interact with the heated syngas flow and include features that classify particles according to particle density, particle size, or both (for example, by moving more relatively dense particles through the reactor drum more slowly than particles of similar size, or by moving more relatively large particles through the reactor drum more slowly than particles of similar density, etc.).

[0012] The TGP system may further include a hopper located downstream of the reactor drum, which collects solid particles exiting the reactor drum and discharges the solid particles from the system. The system may further include ducts at various locations to remove gases from the system and / or introduce gases into it. The ducts may include control valves and dampers positioned to regulate the pressure level within the system and prevent oxygen intrusion, while allowing gaseous phase elements and / or compounds to enter and / or exit the system.

[0013] Ducts may deliver gas from the system to remote devices or a group of devices for use in auxiliary or complementary processes. Remote devices or a group of devices may include, for example, systems and methods for isolating, separating, collecting, or any combination thereof, components from the delivered gas. Examples of remote devices may include condensers, separators, quenchers, purifiers, compressors, expanders, or any combination thereof. Remote devices may include heat sources, such as combustion systems that generate heat, which can then be used to supply the gas flow (e.g., via heat exchangers) to the reactor drum, utilizing a portion (as all or any of the selected components) of the delivered gas.

[0014] The system may further include at least one airlock located between the inlet and the reactor drum, which limits the amount of oxygen entering the system when receiving particles. The system may further include at least one sealing mechanism between the reactor drum and an adjacent structure. The sealing mechanism may maintain the separation of the contents of the reactor drum from the ambient atmosphere. The TGP system may include a mechanism coupled to an inert or semi-inert gas or vapor source for selective purging of the reactor drum (e.g., during startup or shutdown operations) to maintain an oxygen-free environment within the reactor drum.

[0015] According to one embodiment, the system can be calibrated so that the gas, water vapor, and / or compounds (e.g., hydrocarbons) generated from the TGP reaction are contained within the system at a high temperature (e.g., about 220°F to about 1,250°F) for a period exceeding that of solid particles, for example, about 110% to about 1,000% of the time it takes for solid particles to transition through the length of the reactor drum.

[0016] The system can be assembled so that a circulating gas mixture passes through a gas circulation loop multiple times. The loop may include a high-temperature area within the system. The high-temperature area may include a reactor drum, an area containing or adjacent to a heating element, an area containing or adjacent to a combustion element, an area containing or adjacent to a heated bed material, an area containing or adjacent to a heat exchanger, or any combination thereof, and may facilitate the purification of the gas mixture (e.g., pyrolysis of heavy hydrocarbons). The high-temperature area may serve as a primary method for increasing the temperature of the gas in the loop. The system may include, for example, an electric heater, heated bed material, a heat exchanger, direct combustion of the material in the loop, or any combination thereof. The system can also be assembled so that the high-temperature zone is separated / independent from the heating of particles in the reactor drum. For example, the system may include a flash / reflux drum, a high-temperature pyrolysis unit, a packed column, or any combination thereof.

[0017] According to one embodiment, the system may include a temperature difference along a loop that separates specific components (e.g., hydrocarbon compounds) from the rest of the circulating gas mixture. Separation may occur via phase change behavior (e.g., distillation and condensation of individual hydrocarbon compounds). Localized separation of hydrocarbon compounds allows for the selective removal of these compounds from the system. The system may include components that permanently remove compounds from the loop and guide the compounds for further processing or use in other processes of the system. The system may also include components that reintroduce compounds into the loop after further processing or at a different location within the system.

[0018] According to one embodiment, the flow of a particular hydrocarbon compound, isomer, element, mixture, or any combination thereof can be selectively removed from the circulating loop (for example, for the purpose of generating a chemical equilibrium imbalance within the process). The chemical equilibrium imbalance may be designed to increase the production of a particular hydrocarbon compound, isomer, element, mixture, or any combination thereof by the system. According to one embodiment, the system may include components that influence the TGP reaction and thereby favor the production of a particular element, hydrocarbon compound, isomer, and / or precursor compound / radical to restore equilibrium.

[0019] According to one embodiment, the system may include components and systems that carry out the thermal decomposition or decomposition of heavier hydrocarbons within the system (e.g., outside the reactor drum), which facilitates the production of specific hydrocarbon compounds, elements, and / or precursor compounds / radicals to restore equilibrium. The system thermally decomposes the gases within the system into compounds and elements to restore equilibrium (e.g., directly or through side reactions).

[0020] The system may be assembled to carry out repeated decomposition, isomerization, reformation, or any combination thereof of compounds, mixtures, molecules, or any combination thereof contained within the loop. The system may, during operation, preserve isomers, molecules, compounds, or any combination thereof that are thermally stable under the conditions contained within the system. Preservation of thermally stable molecules may allow for the targeting of unstable / less stable molecules, isomers, compounds, or any combination thereof for destruction within the system. The system may include components that maintain conditions that are favorable for the production of target isomers, molecules, compounds, substances, or any combination thereof within the system.

[0021] According to one embodiment, the roasting, gasification, and / or pyrolysis system includes a reactor drum, a heat source for heating a gas contained within the system to a temperature sufficient to roast particles in the reactor drum, a device for moving the heated gas and thereby forming a heated gas stream that passes through the reactor drum, a duct system configurably connected to the heat source and the reactor drum and thereby forming a recirculation loop that allows the heated gas to pass through the reactor drum multiple times, and a region for separating a first hydrocarbon compound contained within the heated gas stream from the remainder of the heated gas stream, the remainder of the heated gas stream containing a second hydrocarbon compound heavier than the first hydrocarbon compound.

[0022] According to one embodiment, a method for roasting particles includes producing a heated gas stream, moving the particles into the internal space of a reactor drum, guiding the heated gas stream to pass through a first end of the reactor drum and enter the internal space of the reactor drum, heating the particles in the internal space of the reactor drum to release hydrocarbon compounds from the particles in the gas phase and mixing the released hydrocarbon compounds with the heated gas stream, and guiding the released hydrocarbon compounds through the heated gas stream to pass through a second end of the reactor drum and thereby exit the internal space of the reactor drum.

[0023] The method further includes guiding the released hydrocarbon compound, after it has left the internal space, along a route to a first end of the reactor drum; guiding the released hydrocarbon compound through the first end of the reactor drum and through the internal space of the reactor drum; decomposing the released hydrocarbon compound while it is in the internal space, thereby forming at least one lighter hydrocarbon compound; and separating at least one lighter hydrocarbon compound from the rest of the heated gas stream. The present invention provides, for example, the following items: (Item 1) A system, wherein the system is Reactor drum and A heat source for heating the gas contained within the system to a temperature sufficient to roast the particles within the reactor drum, A device for moving the heated gas, thereby forming a heated gas stream that passes through the reactor drum, A duct system communicatively coupled to the heat source and the reactor drum, thereby forming a recirculation loop that allows the heated gas to pass through the reactor drum multiple times, A region that facilitates the separation of a first hydrocarbon compound contained within the heated gas stream from the remainder of the heated gas stream and comprising, where the remainder of the heated gas stream comprises a second hydrocarbon compound heavier than the first hydrocarbon compound, A system. (Item 2) The system according to item 1, further comprising an inlet communicatively coupled to the reactor drum, whereby the particles received by the inlet subsequently enter the reactor drum. (Item 3) The system according to item 2, wherein the heat source heats the gas contained within the system to a temperature sufficient to liberate the second hydrocarbon compound from the particles in the gas phase. (Item 4) The system according to item 3, wherein the heat source heats the gas to a temperature of about 220°F to about 1,250°F when measured while the heated gas stream is within the reactor drum. (Item 5) The system according to item 3, wherein the liberated second hydrocarbon compound travels along the recirculation loop and passes through the reactor drum multiple times. (Item 6) The system according to item 1, further comprising at least one component that facilitates the separation of the first hydrocarbon from the remainder of the heated gas stream. (Item 7) The system according to item 6, wherein at least one component changes the temperature, pressure, or both of the heated gas flow as the heated gas flow passes through the region. (Item 8) The system according to item 7, wherein the component lowers the temperature of the heated gas flow below the dew point of the first hydrocarbon, thereby causing the first hydrocarbon to transition from the gas phase to the liquid phase. (Item 9) The system according to item 8, further comprising an outlet for removing the first hydrocarbon in the liquid phase from the recirculation loop. (Item 10) The system according to item 9, wherein the outlet includes an airlock, the airlock restricting at least oxygen to entering the recirculation loop while the first hydrocarbon is being removed from the recirculation loop. (Item 11) A method for producing hydrocarbons, wherein the method is To produce a heated gas stream, Moving particles into the internal space of the reactor drum, To guide the heated gas flow through the first end of the reactor drum and into the internal space of the reactor drum, The particles in the internal space of the reactor drum are heated, thereby releasing the hydrocarbon compound from the particles in the gas phase, and the released hydrocarbon compound is mixed with the heated gas flow. The heated gas flow guides the released hydrocarbon compound through the second end of the reactor drum, thereby exiting the internal space of the reactor drum. After leaving the internal space, the released hydrocarbon compound is guided along the route to the first end of the reactor drum, To guide the open hydrocarbon compound through the first end of the reactor drum and through the internal space of the reactor drum, While the released hydrocarbon compound is present in the internal space, the released hydrocarbon Decompose the compound, thereby forming at least one lighter hydrocarbon compound, To separate the at least one lighter hydrocarbon compound from the rest of the heated gas stream and Methods that include... (Item 12) The method according to item 11, wherein heating the particles includes heating the particles to about 220°F to about 1,250°F. (Item 13) The method according to item 11, wherein the route is formed by ducts connecting the second end of the reactor drum to the first end of the reactor drum without passing through the internal space of the reactor drum. (Item 14) The method according to item 11, wherein the decomposition of the released hydrocarbon comprises passing the released hydrocarbon through the reactor drum multiple times. (Item 15) The method according to item 11, wherein the decomposition of the released hydrocarbons includes exposing the released hydrocarbons to the internal space of the reactor drum for a certain residence time. (Item 16) The residence time is determined by the method of item 15, wherein the residence time occurs over multiple passes through the internal space of the reactor drum. (Item 17) The method according to item 11, which involves moving the particles through the entire length of the internal space of the reactor drum, including a particle residence time. (Item 18) The method according to item 16, wherein the decomposition of the released hydrocarbons comprises exposing the released hydrocarbons to the internal space of the reactor drum for a total residence time, the total residence time being 100% to 1,000% of the particle residence time. (Item 19) The method according to item 11, wherein the decomposition of the released hydrocarbon comprises passing the released hydrocarbon through a catalyst. (Item 20) The method according to item 11, wherein separating the at least one lighter hydrocarbon compound from the remainder of the heated gas stream comprises changing the temperature, pressure, or both of the heated gas stream. (Item 21) The method according to item 11, wherein separating the at least one lighter hydrocarbon compound from the remainder of the heated gas stream includes transitioning the at least one lighter hydrocarbon compound from the gas phase to the liquid phase. [Brief explanation of the drawing]

[0024] [Figure 1] Figure 1 is a schematic diagram of a system according to one embodiment.

[0025] [Figure 2] Figure 2 is a schematic diagram of an integrated processing system according to one embodiment.

[0026] [Figure 3] Figure 3 is an isometric view of the system according to another embodiment.

[0027] [Figure 4] Figure 4 is a rear isometric view of the system shown in Figure 3.

[0028] [Figure 5] Figure 5 is a side elevation view of the system shown in Figure 3.

[0029] [Figure 6] Figure 6 is a top plan view of the system shown in Figure 3.

[0030] [Figure 7] Figure 7 is a side elevation view of the reactor drum and adjacent components of the system shown in Figure 3.

[0031] [Figure 8]Figure 8 is a cross-sectional view of the reactor drum of Figure 7 obtained along line 6-6. [Modes for carrying out the invention]

[0032] In the following description, certain specific details are included to provide a complete understanding of the various disclosed embodiments. However, those skilled in the art will recognize that embodiments can be practiced without one or more of these specific details. In other instances, well-known structures or steps associated with industrial process equipment and industrial processes are not shown or described in detail to avoid unnecessarily obscuring the description of the embodiments.

[0033] For example, those skilled in the art will understand that various sensors (e.g., temperature sensors, oxygen sensors, etc.), control devices, and other industrial process controls can be provided and managed via a programmable logic controller (PLC) or other suitable control system for monitoring the system described herein, controlling the operating parameters of the process, and optimizing or adjusting the characteristics of the resulting roasted particles.

[0034] Unless the context requires otherwise, throughout the specification and the claims thereafter, variations of the words “comprise,” “comprises,” and “comprising,” etc., should be interpreted in a non-restrictive, inclusive sense, that is, “including, but not limited to.”

[0035] Throughout this specification, the terms "one embodiment" or "an The reference to “in one embodiment” means that a particular feature, structure, or characteristic described in relation to an embodiment is included in at least one embodiment. Therefore, the expressions “in one embodiment” or “in an embodiment” in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, the particular features, structures, or characteristics described herein may be combined in one or more embodiments in any suitable manner.

[0036] As used herein and in the appended claims, the singular forms “a,” “an,” and “the” include plural references unless otherwise clearly determined by the context. Furthermore, the term “or” is generally adopted in its meaning including “and / or,” unless otherwise clearly determined by the context.

[0037] The enumeration of value ranges in this specification is merely intended to serve as a simple means of individually referring to each distinct value that falls within the range including the stated endpoint of the range, unless otherwise indicated herein, and each distinct value is incorporated into the specification as if it were individually enumerated herein.

[0038] The headings and summaries provided herein are for convenience only and do not constitute any interpretation of the scope or meaning of the embodiments.

[0039] Figure 1 shows a schematic diagram of a system 10 (e.g., a roasting, gasification, and / or pyrolysis system) according to an exemplary embodiment. The system 10 includes a reaction chamber or vessel (referred to herein as a reactor drum 12) which is supported to rotate around a longitudinal axis 16 of the reactor drum 12. The reactor drum 12 includes an internal volume which may be cylindrical as shown, or another tubular shape (e.g., rectangular, square, irregular, etc.) corresponding to the shape of the outer wall of the reactor drum 12. The shape of the internal volume may be constant along part or all of the length of the reactor drum 12, or the shape may vary along the length of the reactor drum 12 (e.g., tapered). The system 10 may further include an inlet 22 for receiving particles to be processed (e.g., biomass particles), as indicated by an arrow labeled 24. An airlock or double airlock 26 with an optional inert or semi-inert gas purge 27 or similar device may be coupled to the inlet 22 to substantially prevent oxygen from entering the system 10 as particles are fed into the system 10. Particles may be fed to the inlet 22 via a conveyor or other conventional material transport mechanism. In one embodiment, a plug-feed screw conveyor may be used instead of an airlock to generate a plug of material, which may function as a seal as particles pass through the inlet 22.

[0040] System 10 may further include a heat source 30 located upstream of the reactor drum 12. The heat source may supply heat to the gas flow 34 generated within System 10 (e.g., by a fan device 32). According to one embodiment, the fan device 32 may be, for example, a ventilating fan device or a forced-ventilating fan device. The fan device 32 may be operable to draw or push the gas through the reactor drum 12 in a recirculation manner and circulate the gas (or substantial portion of the gas) back to the heat source 30 so that it is reheated and supplied to the reactor drum 12. In some embodiments, 80 percent or more of the gas by volume leaving the reactor drum 12 may be recirculated to the inlet of the reactor drum 12. In some embodiments, 90 percent or more of the gas by volume leaving the reactor drum 12 may be recirculated to the inlet of the reactor drum 12. In some embodiments, 95 percent or more of the gas by volume leaving the reactor drum 12 may be recirculated to the inlet of the reactor drum 12.

[0041] During operation, the gas flow 34 functions as a thermal fluid, capable of transferring thermal energy to particles within the reactor drum 12. According to one embodiment, the gas flow 34 may also provide a propulsive force for particle transport. The gas flow 34 may also heat the internal structure of the reactor drum 12 (e.g., several lifting flights 170, or other structures within the reactor drum 12 that are in direct contact with the particles), and the internal structure, in turn, may heat the particles. Two of the several lifting flights 170 are visible through a cutout 17 provided within the illustration of the reactor drum 12, providing visibility of a portion of the internal structure of the reactor drum 12, including the lifting flights 170.

[0042] The system 10 may include a appropriately sized gas duct 36, which is coupled to at least the reactor drum 12, the heat source 30, and the fan device 32 to recirculate the gas flow 34 within the system 10. According to one embodiment, a portion, or up to all, of the gas entering the reactor drum 12 is recirculated in a continuous manner to return to the inlet of the reactor drum 12. In some embodiments, new gas (other than unintended leakage) is not supplied to the recirculating gas flow 34 during operation.

[0043] According to one embodiment, system 10 may include multiple stages with different temperatures, residence times, chemical properties, and / or operating conditions. The stages may be mechanically separated from each other. System 10 may include, for example, multiple drums with airlocks and hoppers. System 10 may also include drums that provide separation between sections using solids (e.g., progressive screw features, conical geometry, circulating / fluidized solid traps, and / or porting). System 10 may use solids involved in the TGP process or solids independent of the TGP process (e.g., ceramic media and / or sand). System 10 may include features, cavities, ducts, and / or other components that add and / or remove elements and / or compounds from the gas flow 34 between mechanically separated sections.

[0044] Roasting, gasification, and / or thermal decomposition of particles in the reactor drum 12 may release compounds (e.g., hydrocarbons in the gas phase) that enter the gas stream 34 and mix with it. System 10 may include components that release or exhaust a certain amount of gas from the gas stream 34 to maintain a relatively stable pressure within System 10. According to one embodiment, System 10 may include components 15 that enable the extraction of specific (e.g., targeted) compounds from the gas stream 34. Component 15 may include a heater, a cooler, a pressurizer, a separator, or any combination thereof. Component 15 may be applied to the entire gas stream 34 or any proportion of the gas stream 34.

[0045] Region 18 may include a medium and / or a medium system that can complement the separation of compounds from the gas stream 34. System 10 may include the medium in a separate container (e.g., a structured medium column). The structured medium column may operate in a dry state and provide a large surface area for condensation and / or evaporation. The column may operate with a fluid or a fluidized solid, for example, and may utilize the adsorption / desorption of elements and compounds in the gas stream 34. System 10 may also include the medium directly within the system (e.g., a ceramic medium bed introduced with the material at the inlet). The system may also include a medium that is regenerative via another process and operates in batch mode. System 10 may also include a medium that is continuously regenerated or consumed as part of a cycle and / or another process, for example. System 10 may also include a medium that operates via an established method, such as an electrostatic precipitator.

[0046] System 10 may include a region 18 from which components enabling the extraction of a specific compound are removed from the gas stream 34. According to one embodiment, region 18 may include both a temperature range and a pressure range that facilitates the liquid dropout of the target compound. The target compound may include a category of specific compounds (e.g., alkanes, alkenes, etc.) or the target compound may include a specific compound (e.g., methane, butane, etc.). For example, the gas stream 34 may include both light hydrocarbons and heavy hydrocarbons. As used herein, “light hydrocarbons” refers to hydrocarbons with a lower molecular weight (e.g., hydrocarbons containing 1 to 11 carbon atoms), examples of which include octane, propane, propanol, cyclohexane, and pentane. As used herein, “heavy hydrocarbons” refers to hydrocarbon compounds with a higher molecular weight (e.g., hydrocarbons containing 12 or more carbon atoms), examples of which include dodecane, pentadecane, eicosane, and polymerized light hydrocarbon molecules / chains.

[0047] Region 18 may include temperatures and pressures below the dew point of the target compound (e.g., heavy hydrocarbons) so that as heavy hydrocarbons pass through region 18, they transition from their current gaseous phase to the liquid phase, while light hydrocarbons remain in the gaseous phase. The liquid form of the heavy hydrocarbons can then be extracted from system 10, as indicated by arrow 21, while the light hydrocarbons pass through region 18 and remain in the circulation loop.

[0048] Region 18 may include features that allow for the removal of gaseous light hydrocarbons from system 10 (for example, once heavy hydrocarbons have been removed, as described above). Region 18 may also include features that allow condensed heavy hydrocarbons removed from gaseous flow 34 to be returned to a gaseous state and then reintroduced into the gaseous flow from which light hydrocarbons have been removed, as described above.

[0049] According to one embodiment, the temperature of region 18 can be about 0°F to about 1,200°F, and the pressure can be about 0.01 psia and about 2,500 psia. As the gas flow 34 passes through region 18, heavier hydrocarbons (e.g., dodecane) may transition from the gas phase to the liquid phase and drop out of the gas flow 34. The liquid can then be removed from system 10 and collected, or returned to a gaseous state and reintroduced into system 10.

[0050] System 10 can be calibrated to increase the production of the target compound. According to one embodiment, roasting, gasification, and / or pyrolysis of particles (e.g., biomass particles) in the reactor drum 12 releases hydrocarbons from the particles. These hydrocarbons can be “boiled off” from the particles so that they are released in the gas phase. Upon release from the particles, the released hydrocarbons are typically of a heavier type. Gaseous byproducts boiled off from particles in previous roasting systems / processes are typically treated as waste or excess material to be discarded. In some cases, the gaseous byproducts can be sent to a burner to heat System 10 and extract any benefit as low-quality fuel to help minimize losses.

[0051] However, according to one embodiment, the gaseous byproduct may be purified within the system 10 into a more valuable compound (e.g., a “lighter” hydrocarbon), which can then be extracted for use or sale. The system 10 may circulate the gas stream 34 so that the gas stream 34 is exposed to a target temperature range over a target time interval, the specific target range and interval being selected based on the time and temperature required to thermally decompose the heavier hydrocarbon compound into a lighter hydrocarbon compound. According to one embodiment, the products of the system 10 may include roasted material, biochar, activated carbon precursor, liquid bio-oil, and gas.

[0052] System 10 can also be used to treat, reduce, and incinerate waste such as that generated in other industries (e.g., public solid waste, abandoned materials, plastics, and agricultural by-products). These waste materials may first undergo at least one TGP reaction that liquefies the material. Devolatilization allows for the treatment of potentially undesirable compounds prior to thermal decomposition within System 10 and combustion of the remaining solid (e.g., dechlorination of polyvinyl chloride-contaminated construction / demolition waste, which, if burned or treated in a conventional TGP system / method without treatment thereby, may result in the production of toxic compounds such as dioxins).

[0053] The time required for the decomposition of heavy hydrocarbons into lighter hydrocarbons may be longer than the amount of time it takes for the gas stream 34 to pass through the length of the reactor drum 12. Therefore, the system 10 can be calibrated so that the gas stream 34 (containing gases, water vapor, and / or compounds generated from the TGP reaction) is circulated multiple times through the reactor drum 12. This may result in certain portions of the gas stream 34 (e.g., heavy hydrocarbons) being exposed to high temperatures (e.g., about 400°F to about 1,600°F) for a period exceeding the amount of time the particles are exposed to high temperatures within the reactor drum 12.

[0054] The temperature used to decompose heavy hydrocarbons into lighter hydrocarbons and / or for the thermal decomposition of compounds may be higher than the temperature used for roasting particles. Therefore, system 10 may be calibrated so that the gas stream 34 (containing gases, steam, and / or compounds generated from the TGP reaction) is circulated through the heat exchanger 60 and its temperature rises above that used in drum 12 (e.g., above about 400°F to about 2,400°F).

[0055] According to one embodiment, a specific portion of the gas flow 34 may be exposed to high temperatures for about 100% to about 1,000% of the time it takes for solid particles to pass through the length of the reactor drum. For example, a specific portion of the gas flow 34 may be circulated through the reactor drum 12 at least 2 to 100 times.

[0056] System 10 may include components that enable catalytic decomposition of heavy hydrocarbons in a gaseous flow 34 into lighter hydrocarbons. According to one embodiment, System 10 may include a catalyst (e.g., a fluidization of material or a low-density bed) through which the gaseous flow 34 passes to facilitate the decomposition of heavy hydrocarbons in the gaseous flow 34 into lighter hydrocarbons.

[0057] System 10 may include solid-phase catalysts and / or catalytic elements to facilitate the adsorption, decomposition, reformation, and / or separation of elements and / or compounds from the gas flow 34. System 10 may also include catalysts and / or catalytic elements to modify the characteristics of the TGP reaction and / or modify the products / results generated during the TGP reaction / system operation. System 10 may include catalysts and / or catalytic elements that are regenerated or consumed during operation. System 10 may include catalysts and / or catalytic elements that are entrained in the gas flow 34 and can be circulated by the fan device 32. System 10 may include catalysts and / or catalytic elements that are regenerated or consumed during operation. System 10 may include catalysts and / or catalytic elements that form a floor within the drum and absorb, for example, chlorine and / or sulfur compounds.

[0058] System 10 may include a fluidized bed within the reactor drum 12, or a fluidized bed as an external component. System 10 may include features for passing a circulating gas flow 34 through the fluidized bed, independently or by utilizing a gas loop as the primary means of fluidization. System 10 may include a catalyst and / or catalytic element within the fluidized bed and / or bed material. System 10 may include features for mechanically fluidizing the bed (e.g., holes, screens, and / or flights incorporated within the reactor drum 12). System 10 may also include additional elements and / or compounds in the fluidized bed to facilitate / cause additional reactions. System 10 may include features, systems, and / or mechanisms for introducing an oxidizer containing about 1% to about 100% oxygen for the purpose of combustion and / or oxidation reactions within the bed.

[0059] As shown in the illustrated embodiments, the heat source 30 may be in the form of a gas / gas heat exchanger 60. A high-temperature gas flow 35 (e.g., in the range of about 800°F to about 2,400°F) may be supplied to the heat exchanger 60 via an inlet conduit 62. The high-temperature gas flow 35 may interact with the recirculating gas flow 34 of the system 10, as shown, and transfer heat to the gas flow 34. In some embodiments, the heat exchanger 60 may raise the inlet temperature of all or part of the recirculating gas flow 34 into the heat exchanger 60 (e.g., from about 500°F ± 100°F to an outlet temperature of about 1,600°F ± 150°F).

[0060] By doing so, the temperature of the high-temperature gas flow 35 in the heat exchanger 60 is inevitably lowered before it exits the heat exchanger 60 via the outlet conduit 66. However, the temperature of the high-temperature gas flow 35 can still be high enough to be useful in other processes, such as drying particles, prior to entering the system 10. Therefore, in some embodiments, the high-temperature gas flow 35 discharged from the heat exchanger 60 via the outlet conduit 66 may be sent to a drying system 70 (as shown in Figure 2) or other device. In some embodiments, the discharged high-temperature gas flow 35 may be sent back to the inlet of the heat exchanger 60 to adjust the inlet temperature of the high-temperature gas flow 35 to a desired level (or to be within a desired temperature range) when it enters the heat exchanger 60, and may be mixed with other heated gases having a higher temperature (e.g., other heated gases sent from the burner 76).

[0061] While the illustrated embodiment of the heat source 30 in Figure 1 is shown as a gas / gas heat exchanger 60, it should be understood that various other heat sources 30 may be provided. For example, in some embodiments, an electro-immersion heat source may be provided within the path of the gas flow 34 in the system 10. In other embodiments, a low-oxygen burner may be introduced directly into the system 10 to heat the gas flow 34 without significantly increasing the oxygen level in the system 10. However, regardless of the heat source 30, it may be beneficial to separate the gas flow 34 in a recirculation manner to facilitate the maintenance of a low-oxygen environment within the reactor drum 12, which would lead to the roasting of particles.

[0062] System 10 may include a separator hopper 38 (for example, at the downstream end of the reactor drum 12) for collecting roasted particles (e.g., roasted wood chips, roasted giant cane chips, other roasted cellulosic biomass) as the particles exit the reactor drum 12. These particles can then be fed mechanically and / or by gravity toward the outlet 40 for collection. One or more airlock devices 42 may be coupled to the outlet 40 to substantially prevent oxygen from entering System 10 as the roasted particles are withdrawn from System 10.

[0063] Smaller particles that can pass through the separator hopper 38 (e.g., roasted wood particles, roasted giant cane particles, other roasted cellulosic biomass) can be filtered and removed from the gas stream 34 by a filtration device 44 (e.g., a cyclone-type filtration device). One or more additional airlock devices 46 may be coupled to a secondary outlet 48 to remove filtered material from the system 10 without introducing a significant amount of oxygen into the system 10. As shown, smaller particles exiting the separator hopper 38 via one or more airlock devices 46 may be guided to be mixed / combined with the roasted particles exiting the separator hopper 38.

[0064] In some embodiments, the chamber or space between a pair of consecutively aligned airlocks 42, 46 may be coupled to a steam source, inert or semi-inert gas source to selectively purge the chamber or space, as indicated by arrows labeled 43 and 47. In some embodiments, the system 10 may include a cyclone-type filtration device instead of a hopper 38 to separate and / or filter roasted particles from the gas flow 34. In some embodiments, the system 10 may include one or more pneumatic discharge devices (not shown) for discharging roasted particles from the system 10.

[0065] As already described, the gas flow 34 can be drawn in or pushed through the reactor drum 12 under the influence of the fan device 32 and returned to the heat source 30 (e.g., after separating roasted particles, chips, particulate matter, dust, and / or any debris). Substantial majority of the gas is recirculated, but some gas can be redirected to the exhaust ducts 50. The gas exhausted through the exhaust ducts 50 can be used either in the process or another process, as indicated by the arrow labeled 52. For example, the exhaust gas can be used as fuel to generate heat, which helps the heat source 30 increase the temperature of the gas flow 34 (e.g., via the fuel inlet 23 of the burner 76). The burner 76 can operate on a “complementary fuel” source (e.g., fuel added to system 10 rather than produced by system 10) via the fuel inlet 23 and the oxygen inlet 25. The gas duct 36 (e.g., exhaust ducts 50) may include a variable position damper 54, which can be used to balance the pressure inside the reactor drum 12 from slightly negative to slightly positive. Depending on the setting, this can be used to prevent oxygen from entering the system 10.

[0066] Referring to Figure 2, an embodiment of the integrated processing system 11 (e.g., a roasting, gasification, and / or pyrolysis system) is shown in schematic form. System 11 may include, among other things, the system 10 described above and a drying system 70 for drying the particles prior to their introduction into system 10. In some embodiments, system 10 may receive particles having a moisture content reduced by the drying system 70 to less than 20 percent on a wet weight basis. In some embodiments, the biomass particles may be wood chips having an average particle size of about 1 / 16 cubic inch to about 1 cubic inch and an initial moisture content of more than 40 percent on a wet weight basis. In some embodiments, the particles may have a substantially consistent size (with a difference of less than 10 percent), and in other embodiments, the particle size may vary by up to 10 percent, up to 20 percent, up to 30 percent, or more.

[0067] As shown, the drying system 70 may include a rotary drum 71 supported to rotate around a longitudinal axis 72 of the rotary drum 71. The drying system 70 may further include an inlet 74 to receive particles to be processed, as indicated by the arrow labeled 75. The particles may be fed into the inlet 74 via a conveyor or other conventional material transport mechanism.

[0068] The drying system 70 may be coupled to a burner (e.g., burner 76) which feeds a heated gas stream through a rotating drum 71 for heating and drying, as indicated by arrow 84, and the drying system 70 may also transport particles through the drum 71 as it rotates (e.g., intermittently). According to one embodiment, the heated gas stream 84 may simultaneously dry the particles as the heated gas stream propels them through the rotating drum 71. The burner 76 may be configured to burn bark, crushed fuel, or other fuel (e.g., waste wood) to heat the heated gas stream 84 fed into the drying system 70. The heated gas stream 84 entering the drying system 70 may be complemented by or mixed with other gas streams of an integrated processing system 11, as described in further detail elsewhere herein.

[0069] At the downstream end of the rotary drum 71, the integrated processing system 11 may include a separator hopper 78 for collecting dried particles (e.g., dried wood chips, dried giant cane chips, other dried cellulosic biomass) as the particles exit the rotary drum 71. These particles can then be fed mechanically and / or by gravity toward an outlet 79 for collection for future use or packaging. Smaller particles and dust (e.g., dried wood particulates, dried giant cane particulates, other dried cellulosic biomass) that can pass through the separator hopper 78 can be filtered and removed from the heated gas stream 84 by a filtration device 80, such as a cyclone-type filtration device. These particles can then be fed toward a secondary outlet 81 for future use or packaging. In some embodiments, the drying system 70 may include a cyclone-type filtration device instead of a hopper 78 to separate and / or filter the dried particles from the heated gas stream. In some embodiments, the drying system 70 includes one or more pneumatic discharge devices (not shown) that can discharge the dried particles from the drying system 70.

[0070] A fan device 92 may be provided to draw or push the heated gas flow through the rotating drum 71, as indicated by the arrow labeled 83, and to direct the exhaust gas from the rotating drum 71 toward an environmental release control device 82 to treat the exhaust of the dryer system 70 before releasing it into the environment or other systems. For example, the release control device 82 may include a wet electrostatic precipitator (WESP) to facilitate the removal of submicron-sized solid particles and liquid droplets from the exhaust gas flow. The release control device 82 may further include a regenerative thermal oxidizer (RTO) to break down air toxins and volatile organic compounds (VOCs) that may be present in the exhaust gas. In some embodiments, an RTO may be provided that uses natural gas to heat the exhaust gas to about 1,500°F, and the VOCs are oxidized. In other embodiments, roasted off-gas may be used for heating the RTO, which can significantly reduce the operating cost of the RTO (since natural gas is otherwise a major cost in operating such equipment).

[0071] At least a portion of the exhaust from the dryer system 70 may be sent back toward the inlet 74 of the rotary drum 71 or recirculated (e.g., via ducts) and combined with heated gas from the burner 76 to dry particles continuously fed into the rotary drum 71. Additional gas from the outlet of the heat exchanger 60 of system 10 may also be combined with the exhaust gas from the dryer system 70 to clean it before discharge into the environment and / or to introduce it back into the dryer system 70, as indicated by the arrow labeled 85.

[0072] According to the embodiment illustrated in Figure 2, the dried particles (e.g., dried wood chips and fine particles) may be sent to another location for further processing, storage, or packaging as standalone products, as indicated by the arrow labeled 86. Some or all of the supply of dried particles may be sent to system 10 for further processing, as indicated by the arrow labeled 87.

[0073] As shown in Figure 2, the dried particles generated via the drying system 70 can serve as input material for system 10. In some embodiments, the dried particles may have an average moisture content of less than 20 percent on a wet weight basis when they enter system 10. In other embodiments, the average moisture content of the dried particles may be about 5 percent to about 15 percent on a wet weight basis. In yet another embodiment, the average moisture content of the dried particles may exceed 20 percent on a wet weight basis.

[0074] The drying system 70 is illustrated as a rotary drum type drying system, such as one designed and commercialized by TealSalesin Corporation, the assignee of this application. However, it should be understood that other drying systems may be used in connection with embodiments of the present invention, for example, those including ovens having rotary screws and conveyor bed type transport mechanisms. Therefore, embodiments of particle processing systems described herein are not limited to the specific drying systems illustrated, but may incorporate a wide range of conventional drying systems.

[0075] As shown, system 11 may include a heat source 30 (e.g., a gas / gas heat exchanger 60) that receives a heated gas flow (e.g., a heated gas flow 35 from a burner 76), as indicated by the arrow labeled 88. The heated gas flow entering the heat exchanger 60 is mixed with gas from the output of the heat exchanger 60 (e.g., via the burner 76) to adjust the input temperature of the heated gas flow entering the heat exchanger 60. In some embodiments, the inlet temperature of the gas flow entering the heat exchanger 60 may be about 600°F to about 1,400°F, and in some embodiments, the inlet temperature of the gas flow entering the heat exchanger 60 may be about 800°F to about 1,000°F.

[0076] The recirculating gas flow 34 of the system 10 passing through the heat exchanger 60 can be heated to a reactor drum inlet temperature of at least 500°F according to some embodiments. After passing through the reactor drum 12, the heated gas flow may have a reactor drum outlet temperature of at least 400°F. As a result, during operation, particles passing through the reactor drum 12 may be directly exposed to a heated gas flow having a temperature of at least 400°F throughout the entire length of the reactor drum 12. In some embodiments (for example, when processing cellulosic biomass), the reactor drum inlet temperature is about 700°F ± 150°F and the reactor drum outlet temperature is about 500°F ± 100°F. The reactor drum inlet and outlet temperatures may vary to correspond to the processing temperature for other particles (e.g., including plastics). The temperatures at the reactor drum inlet and outlet of the heated gas flow are monitored using appropriate temperature sensors and controlled via a general-purpose or cascaded control loop, allowing the temperature gradient through the reactor drum to be maintained at a desired level during operation.

[0077] The exhaust gas from the roasting, gasification, and / or pyrolysis process may, according to some embodiments, be sent to a burner 76 for combustion, as indicated by the arrow labeled 91. The exhaust gas from the roasting, gasification, and / or pyrolysis process may contain hydrocarbon compounds that are “boiled off” (i.e., generated during its roasting) from the particles, in addition to other components such as water vapor and any ambient air that leak into the system. System 11 may include a separator 13, which separates all or part of the hydrocarbon compounds from the rest of the exhaust gas. System 11 may thus guide the hydrocarbon compounds back toward the reactor drum 12, thereby increasing their exposure time to retain the hydrocarbon compounds and allow for the thermal / catalytic decomposition of the hydrocarbon compounds into lighter hydrocarbon compounds. The separator 13 may guide at least part of the rest of the exhaust gas (e.g., tar or other residual hydrocarbons) toward the burner 76 for combustion.

[0078] Thus, the energy contained in the exhaust gas can be used to heat the heat transfer medium for use in the heat exchanger 60 and to maintain the heated gas flow 34 flowing through the reactor drum 12 at a desired elevated inlet temperature. The reactor drum temperature gradient can be controlled through a cascaded control loop, which sets the reactor drum inlet temperature. The reactor drum inlet temperature can be controlled, for example, by varying the amount of heated gas supplied from the burner 76 to the heat exchanger 60.

[0079] According to one embodiment, the burner 76 may operate primarily on roasted particles exiting the reactor drum 12 as the primary fuel source (supplemented during starting / stopping and other unstable conditions). In some embodiments, the burner 76 may receive supplemental fuel, as indicated by arrow 77. The burner 76 may include an air intake, indicated by arrow 89, to assist the combustion process. According to one embodiment, the burner 76 may burn bark, crushed fuel, or other fuel to heat a gas stream 35 fed through the heat exchanger 60. This heating of the gas stream 35 may be supplemented by the combustion of exhaust gases from the system 10, as indicated by the arrow labeled 91.

[0080] In some embodiments, steam from a separate boiler of a steam plant 93, which can be ignited by the exhaust gas from the reactor drum 12 (as indicated by the arrow labeled 94) or by another fuel or heat source, may be injected into the system 10 (as indicated by the arrow labeled 95) to further control oxygen in the process, or as a safety suppression and cooling flow, and the steam may also be used as an inert or semi-inert purge gas in the process. In addition, using steam passing through the reactor drum 12 as part of the process gas may also improve heat transfer to the particles. In some embodiments, the boiler may be heated by off-gas supplied to the boiler by ducts 96 coupled to the reactor drum 12. In other embodiments, the steam plant 93 may be heated by a burner 76 or another heat source. In some embodiments, depending on the failure conditions, steam may be introduced into the reactor drum 12 in an amount sufficient to suppress and / or cool the particles. Thus, the operational safety of the system 10 may be improved.

[0081] As shown, system 11 (e.g., system 10) may include one or more of the regions 18. One or more regions may include a first region 18a and a second region 18b, as shown. Each of the one or more regions 18 may be calibrated to allow extraction of a particular compound from the gas stream 34. According to one embodiment, the first region 18a may include at least one first component 15a, and the second region 18b may include at least one second component 15b.

[0082] According to one embodiment, the first region 18a may include both a first temperature range and a first pressure range that result in a first liquid dropout from the gas flow 34. The second region 18b may include both a second temperature range and a second pressure range that result in a second liquid dropout from the gas flow 34. According to one embodiment, the first temperature may differ from the second temperature, and the first and second temperatures may differ from the exhaust gas temperature when leaving the reactor drum 12. According to one embodiment, the first pressure may differ from the second pressure, and the first temperature and second pressure may differ from the exhaust gas pressure when leaving the reactor drum 12. According to one embodiment, the pressure of the gas flow 34 remains substantially constant, while one or more regions 18 alter the temperature of the gas flow 34.

[0083] According to one embodiment, the first region 18a separates the first target compound from the remainder of the gas stream 34 without causing the first target compound to transition from the gas phase to the liquid phase. According to one embodiment, the second region 18b separates the second target compound from the remainder of the gas stream 34 without causing the second target compound to transition from the gas phase to the liquid phase. The first target compound can be removed from the system 11 via the first outlet 21a, whether in the liquid phase, gas phase, solid phase, or a combination thereof. The second target compound can be removed from the system 11 via the second outlet 21b, whether in the liquid phase, gas phase, solid phase, or a combination thereof.

[0084] Referring to Figure 3-8, a roasting, gasification, and / or pyrolysis system 110 according to one embodiment may be similar to the previously described system 10, thereby the present disclosure relating to system 10 is also applicable to system 110, with the differences described below. According to one embodiment, system 110 may include additional structural components, different heat sources 130, or both. System 110 may include a reactor drum 112 (e.g., reactor drum 12) supported on a structural frame 114 and rotating around a longitudinal axis 116. The reactor drum 112 may be driven by a drive motor 118, which may be electrically coupled to a control system, which selectively controls the rotation of the reactor drum 112 and adjusts its speed as needed. The control system may include a control panel 120 with appropriate controls (switches, dials, gauges, touch screens, etc.) for selectively controlling and monitoring system 110. Other gauges and controls (e.g., sensors, valves, etc.) may also be located remotely and coupled to specific components of system 110 for monitoring and control purposes.

[0085] System 110 may further include an inlet 122 (e.g., inlet 22) in the form of a chute receiving particles to be processed (e.g., biomass particles), as indicated by an arrow labeled 124. An airlock or double airlock 126 (e.g., airlock 26) with optional steam, inert, or semi-inert gas purging or similar device may be coupled to the inlet 122 to substantially prevent oxygen from entering System 110 when particles are introduced. Particles may be fed to the inlet 122 via a conveyor or other conventional material transport mechanism. The particle introduction rate may be monitored and controlled to optimize or adjust the properties of the resulting roasted particles. Stairs 128 or other access devices may be provided to allow a user access to the inlet 122 and other components of System 110 for monitoring, maintenance, and other purposes.

[0086] System 110 may also include a heat source 130 (for example, located upstream of the reactor drum 112, as shown) that supplies heat generated within System 110 (which may be a ventilating fan device or a forced-ventilating fan device) to the gas flow (for example, by a fan device 132 such as fan device 32). In a recirculation manner, the fan device 132 may be driven by a drive motor 134 and circulate the gas so that it is drawn or pushed through the reactor drum 112, reheated, and returned to the heat source 130 for supply to the reactor drum 112. For this purpose, System 110 may include a gas duct 136 that is appropriately sized and coupled to at least the reactor drum 112, the heat source 130, and the fan device 132.

[0087] At the downstream end of the reactor drum 112, a separator hopper 138 (e.g., separator hopper 38) may be provided to separate the roasted particles from the gas flow as the particles exit the reactor drum 112. These particles may then be fed mechanically and / or under gravity toward the outlet 140 for collection for future use or packaging. An airlock device 142 (e.g., airlock device 42) may be coupled to the outlet 140 to substantially prevent oxygen from entering the system 110 as the roasted particles are withdrawn.

[0088] Smaller particles and dust that can pass through the separator hopper 138 can be filtered and removed from the gas flow by a filtration device 144 (e.g., filtration device 44), such as a cyclone-type filtration device. Another airlock device 146 (e.g., airlock device 46) can be coupled to the secondary outlet 148 to remove the filtered material from the system 110 without introducing a significant amount of oxygen into the system 110. In some embodiments, the system 110 may include a cyclone-type filtration device instead of the hopper 138 for separating and / or filtering roasted particles from the gas flow passing through the reactor drum 112. In some embodiments, the system 110 may include one or more pneumatic discharge devices (not shown) for discharging roasted particles from the system 110.

[0089] As already described, the gas flow, under the influence of the fan device 132, can be drawn in or pushed through the reactor drum 112 and returned to the heat source 130 (e.g., after separating roasted particles, dust, and any debris). While substantially the majority of the gas can be recirculated to the reactor drum 112, some gas can be redirected to the exhaust stack 150. The gas exhausted through the stack 150 can be recaptured for use in either the process or another process, for example, as fuel to generate heat. The stack 150 may include a variable-position damper 152, which can be used to balance the pressure inside the reactor drum 112 from slightly negative to slightly positive. Depending on the configuration, it can be used to prevent oxygen from entering the system 110.

[0090] Further details of the reactor drum 112 will be described here with reference to Figures 7 and 8. As shown in the illustrated embodiment, the reactor drum 112 may be supported horizontally on several rollers 160. The rollers 160 may contact the drum 112 along bearing tracks 162 fixed around the circumference of the drum 112. The diameter of the drum 112 may be 3 feet, 4 feet, 5 feet, or greater (e.g., up to 20 feet or greater), and may be configured to receive and process more than 50 tons of roasted biomass particles per hour.

[0091] A drive motor 118 is coupled to a drive belt or chain 164 and controlled via a control system to selectively rotate the drum 112 at various speeds, for example, above or below approximately 3 rpm. A high-precision seal 166 is positioned between the rotating drum 112 and the static components to prevent oxygen from entering the system. Thus, the seal 166 and other features of the system make it possible to maintain the gas flow at a consistently low level of oxygen by creating a substantially sealed container.

[0092] Within the reactor drum 112, there may be several lifting flights 170 spaced circumferentially at each of several locations along its longitudinal length. The density of the lifting flights 170 may be designed to suit the various needs of the system 110 and may depend on several interrelated factors, such as the rotation speed of the reactor drum 112, the rate at which material is fed into the system 110, and the speed of the fan device 132 or the intensity of the heated gas flow passing through the reactor drum 112.

[0093] Flights 170 may be configured to lift particles (represented by circles labeled as 177) as the reactor drum 112 rotates in the direction indicated by arrow 172, and then guide and bathe the particles 177 in the gas flow so that they are intermittently carried along the length of the reactor drum 112, primarily by the kinetic energy of the gas flow, and simultaneously roasted. As shown, flights 170 may be fixed to the reactor drum 112 so that they rotate with the reactor drum 112 around the longitudinal axis 116. Flights 170 include a shovel-like shape to scoop up and levitate particles (for example, thereby spacing the particles away from the periphery of the reactor drum 112 for at least part of the rotation). For illustrative purposes, five “particles” 177 are shown being carried by each flight 170. When a flight 170 rotates with the particles in contact with the flight, the movement of the particles is minimal (or zero). When the flight reaches a certain point in its individual rotation (for example, about 3 o'clock as shown in Figure 8), the particle is "drenched" in a heated gas flowing through the reactor drum 112 as it falls out of flight 170. As it falls, the heated gas flow carries the particle along a portion of the length of the reactor drum 112.

[0094] This is advantageous in that the transport mechanism for particles provides a highly efficient medium for directly transferring heat to the particles. Therefore, large quantities of particles can be processed by the system with reduced energy demand. In addition, the throughput or rate (tons / hour) of roasted biomass particles can generally be relatively high compared to conventional roasting systems of comparable size.

[0095] The system 110 (e.g., flight 170 of the reactor drum 112) can generally be calibrated so that the reactor drum 112 provides sufficient forward movement of particles (via repeated drops into a heated gas stream) and requires several turns to pass through the length of the reactor drum 112. The soaking and transporting process within the drum 112 can classify the particles. Lighter and smaller particles can pass through the drum 112 faster than heavier and larger particles because larger and heavier particles, compared to smaller and lighter particles, can fall more quickly and / or travel a shorter distance along the length of the reactor drum 112 with each successive "soaking". This allows larger particles to remain in the drum 112 for a relatively longer residence time, producing a more uniform final product (i.e., large and small particles can be processed together to have similar final properties despite differences in mass and volume).

[0096] For example, in some embodiments, particle size may vary within a particular step of the roasted particles, ranging from 10 percent to 20 percent, 10 percent to 30 percent, or above 30 percent (e.g., up to 100 percent or more), but the energy density and moisture properties of the particles are maintained relatively consistently regardless of particle size. In some embodiments, the flights 170 may vary with respect to location and / or flight density in different embodiments, and may be designed to affect the residence time of the particles in the reactor drum 112.

[0097] Particles residing in drum 112 for a period of time are then discharged into separator hopper 138 or other separation device for further handling, and sent in the direction indicated by the arrow labeled 174. The main or substantial portion of the gas stream may be sent in the direction indicated by the arrow labeled 176, recirculated, heated, and reintroduced into reactor drum 112, as indicated by the arrow labeled 178. Recirculation and reheating may be calibrated to facilitate the decomposition of larger hydrocarbons that are boiled off from the particles by roasting, gasification, and / or pyrolysis processes into smaller / lighter hydrocarbons, as described in detail above.

[0098] System 110 can therefore enable a continuous roasting, gasification, and / or pyrolysis process, which involves introducing particles into a rotating reactor drum 112 via an airlock or airlock 126 to maintain a low oxygen level inside System 110, which leads to the roasting of particles. The particles can be transported through the reactor drum 112 by the kinetic energy of a heated gas flow generated by creating airflow or forced airflow via a fan device 132 connected to the outlet of the drum 112 by a duct 136, or alternatively, by conventional means of transport (e.g., a mechanical screw).

[0099] System 110 may include a heat source 130 upstream of the reactor drum 112, such as an electric immersion duct heater (as shown in Figure 3) or a gas / gas heat exchanger (as shown in Figure 1). A fan device 132 may draw or push gas through the reactor drum 112 across or through the heat source 130. Recirculation of gas leaving the drum 112 and returning to the heat source 130 for reheating is beneficial for process feasibility. The ability of a heated gas flow to directly heat particles in a low-oxygen environment is also beneficial for process feasibility, as the gas flow intermittently and simultaneously transports particles through the reactor drum 112, as will be discussed in more detail elsewhere.

[0100] System 110 may include components that remove / discharge a certain amount of gas (for example, an amount substantially equal to the sum of the gas displaced from the particles due to heating and any leakage that may enter System 110). As shown in Figure 5, the components that remove / discharge a certain amount of gas may include region 18, component 15, and outlet 21, as described above. The components that remove / discharge a certain amount of gas may further include an outlet to the external environment or another related or unrelated process component.

[0101] When using system 110 to roast biomass particles, the heat source 130 may provide additional heat to recirculate the gas within system 110. The heated gas flow recirculating within system 110 can then heat the particles as they are transported through system 110. Thus, the heated gas flow directly heats the particles and simultaneously transports them. This is advantageous in that the transport mechanism for the particles provides a highly efficient medium for directly transferring heat to the particles. Therefore, large quantities of biomass particles can be processed by the system with reduced energy demand. In addition, the throughput or rate (tons / hour) of roasted biomass particles can be relatively high compared to conventional roasting systems of comparable size. This is advantageous in that it allows the system described herein to be implemented, in particular, in a commercially viable form.

[0102] The elements of the heat source 130 can provide heat by any readily available energy source. In some embodiments, for example, direct heat can be added to the gas flow by an electrical element (e.g., an electric immersion duct heater 130). In other embodiments, heat can be supplied to the gas flow through a gas / gas heat exchanger 60 coupled to a combustion and / or waste heat system (e.g., burner 76 in Figures 1 and 2) (as shown in Figures 1 and 2). In another embodiment, a low-oxygen burner can be directly introduced into the system 110 to heat the gas flow without significantly increasing the oxygen level in the system 110. According to one embodiment, heat can be supplied to the gas flow by the localized introduction of an oxidizer containing about 1% to about 100% oxygen.

[0103] In some embodiments, the exhaust gas discharged from the stack 150 may be used as part of the process to heat the fuel. According to one embodiment, the roasted particles exiting the reactor drum 112 may be directed to be consumed as fuel for a heat source 130. Regardless of the heat source 130, a very small amount of additional oxygen may be added to the system 110 throughout the heating portion of the process.

[0104] Roasting, gasification, and / or pyrolysis systems and processes can be obtained based on a heat-energy balance that balances the required energy with the process rate, heat source, and required residence time. Embodiments of roasting, gasification, and / or pyrolysis systems and methods described herein are particularly well suited to providing systems and methods that manipulate and control these factors and can be easily scaled up or down to meet various industrial needs.

[0105] For example, the residence time of particles in the reactor drum 112, the gas flow (e.g., hydrocarbons removed by boiling from the particles in the reactor drum 112), or both, can be controlled by various design and process factors. For instance, the speed and size of the fan device 132 may be selected to regulate the rate of the circulating heated gas in the drum 112. In addition, the speed and volume of the heated gas flow can also be regulated by the fan inlet damper of the fan device 132. As another example, the rotation speed of the drum 112 can be set higher or lower to regulate the rate of lifting and splashing effects in the drum 112, and thus produce more or less time for the particles to be suspended.

[0106] Furthermore, since the flights 170 can be designed to operate over a wide range of rotational speeds, the rotational speed of the drum 112 can be selectively adjusted by appropriate control (e.g., a variable-speed drive motor) to adjust the residence time. The density of the flights 170 within the reactor drum 112 can also be used to change the flow conditions inside the reactor drum 112, giving shorter or longer residence times specific to individual designs. Moreover, the size and shape of the flights 170 can be modified to meet the needs of the material being processed, producing more or less noticeable splashing effects, thereby influencing the residence time within the drum 112.

[0107] In some embodiments, the flights 170 are fixed to the drum 112 at specific densities and arrangements, which can optimize or adjust the characteristics of the resulting roasted particles, circulating gas flow, or both. The length of the reactor drum 112 can also be varied in the initial design to produce more or less residence time for the particles, circulating gas flow, or both. In addition, the particle loading conditions can be varied to produce more or less resistance to the gas flow within the reactor drum 112, and thus affect the residence time.

[0108] For example, in some embodiments, a relatively larger volumetric flow rate of particles may be set to slow down the movement of particles through the reactor drum 112, causing them to cluster inside the drum 112. Conversely, a relatively smaller volumetric flow rate of biomass particles may be set to reduce clustering inside the reactor drum 112 and accelerate the movement of biomass particles through the reactor drum 112.

[0109] The oxygen level inside the drum 112 can also be controlled by various design and process factors. For example, the mechanical design of the particle inlet can be selected to include, for example, an airlock, a gas-purging double airlock, a screw mechanism, etc., each mechanism having a different level of capability to prevent oxygen intrusion. Preferably, the amount of oxygen entering the system 110 with the particles is minimized, but is likely to vary with the design according to the particle size of the biomass being processed and / or the desired production rate. In addition, the water content of the particles can be varied to control the oxygen level.

[0110] During processing, the resulting evaporated moisture partially replaces the oxygen in the system 110, and thus the moisture level can be varied to suit production requirements (for example, less initial moisture means less energy is required to roast the particles, and more initial moisture brings less oxygen into the system). Furthermore, it should be recognized that as volatiles and moisture are evaporated from the particles, there is a net addition of gas to the system. As already described, this excess gas can be exhausted from the system 110 via the stack 150 and, according to some embodiments, can be recaptured for use in either the process or another process, for example, as fuel to generate heat. The stack 150 may include a variable-position damper 152, which can be used to balance the pressure inside the reactor drum 112 from slightly negative to slightly positive. Depending on the setting of the damper 152, it can be used to prevent oxygen from entering the system 110.

[0111] In some embodiments, the humidity level can be precisely controlled within system 110 to modify compounds contained in the gas stream via established principles of water-gas shift / reverse water-gas shift reactions (e.g., water combines with carbon monoxide to produce hydrogen and carbon dioxide).

[0112] In some embodiments, many of the various operating parameters discussed above and other operating parameters can be adjusted (manually or automatically) during operation. In other embodiments, the operating parameters can be established prior to operation. Regardless of the specific control scheme, the ability to independently control the various operating parameters of the systems described herein provides versatile systems and methods that can be adapted to changing conditions such as, for example, the water content of the particles selected to be processed and the desired energy density (which may vary) of the resulting roasted particles.

[0113] System 110 is supplied with precision seals 166 at the connections between rotating and stationary parts, and at other low-leakage connections and components, in particular providing a well-sealed container and enabling the maintenance of consistently low levels of oxygen within System 110.

[0114] Various safety devices can also be incorporated into roasting, gasification, and / or pyrolysis systems to improve operational safety. For example, the system may be equipped with vents that will rupture or open in the event of a small explosion or deflagration large enough to potentially cause equipment damage. As another example, spark detection and extinguishing systems, such as the spark detection and extinguishing systems and components commercially available from GreCoN, Inc., based in Tigard, Oregon, can also be integrated into roasting, gasification, and / or pyrolysis systems. In addition, system operating characteristics can be monitored by various sensors (e.g., temperature, pressure, oxygen, etc.), and the acquired operating data can be used, as necessary, to adjust and control the system to improve safety or optimize the roasting, gasification, and / or pyrolysis process. In some embodiments, real-time mass spectrometry can also be used to identify compounds in the gas stream and, as necessary, to adjust or control the system to improve safety or optimize the roasting, gasification, and / or pyrolysis process.

[0115] Overall, by understanding the controlled process and having flexibility through the initial design and numerous process variables described herein, embodiments of the system and method can be configured to accommodate various raw materials under various local conditions and to provide the flexibility and control required to achieve consistent roasting, gasification, and / or pyrolysis results. In some embodiments, for example, the system and method may be configured to roast biomass particles in the form of wood chips at a minimum rate of 1 ton of roasted biomass particles / hour, so that the resulting roasted biomass particles have an energy density of at least 20 GJ / ton. In some embodiments, the system and method may also purify heavy hydrocarbons while roasting, gasifying, and / or pyrolysis the particles, the heavy hydrocarbons being boiled off from the particles to light hydrocarbons, which are then extractable from the system.

[0116] The systems and methods described herein are particularly well suited to providing continuous processes that offer many advantages over conventional systems, especially batch systems and methods that require batch processing of biomass particles in blast furnaces, kilns, or other similar devices. The continuous nature of the systems and methods described herein, among other things, enables relatively higher production rates. In addition, the efficiency with which biomass particles can be processed using the systems and methods enables high material throughput with relatively lower energy demands.

[0117] Embodiments of the systems and methods described herein are illustrated in the figures to include a reactor drum rotating around a horizontally aligned axis of rotation, but it should be understood that in some embodiments the axis of rotation may be tilted. In such embodiments gravity may play a significant role in transporting biomass particles through the reactor drum. In addition, embodiments of the systems and methods are described herein to involve a heated gas flow passing through the reactor drum to transport (or transport) the biomass particles while simultaneously transferring heat to the biomass particles and roasting them, but it should be understood that in some embodiments the biomass particles may be transported by an alternative mechanism (e.g., gravity, screw device, conveyor device, etc.) and roasted by being exposed to a backflowing heated gas flow within the reactor drum.

[0118] Furthermore, the various embodiments described above can be combined to provide further embodiments. These and other modifications can be made to the embodiments in light of the detailed description above. In general, the terms used in the following claims should not be construed to limit the claims to the specification and specific embodiments disclosed herein, but rather to include all possible embodiments, along with the full scope of equivalents to which such claims are entitled.

Claims

[Claim 1] The invention described herein.

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