Entrained flow gasification process

Abstract

A method of generating syngas is provided. The method includes introducing a dry feedstock of solid biomass to a mill, the dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%. The method also includes milling the dry feedstock of solid biomass to form a milled output of solid particles, where at least 95% of the solid particles in the milled output have a size less than 2 mm. The method further includes gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

Description

ENTRAINED FLOW GASIFICATION PROCESSPRIORITY

[0001] This application claims priority to and the benefit of EP 23211316.7, filed November 21, 2023, the entire contents of which are incorporated by reference.FIELD

[0002] The present disclosure relates to the production of fuel sources, and more particularly, to the production of syngas from municipal solid waste.BACKGROUND

[0003] Crude oil and fossil based fuel sources, such as petroleum, are commonly used in a variety of applications. However, the use and exploration of alternative fuels, derived from sources other than crude oil, has been gaining in popularity. Alternative fuels may take many forms, such as a solid, a gas, and / or a liquid. For example, one source for alternative fuel being explored is synthesis gas (e.g., syngas). Syngas may include different ratios of a mixture of hydrogen and carbon monoxide that vary based on the manufacturing process and / or the raw materials used to derive the syngas. Fuels derived from syngas may provide a feasible alternative to some crude oil derived fuel sources, however, existing syngas production methods may limit the operational scalability and / or amount of syngas that may be extracted from a particular raw material.SUMMARY

[0004] In a first example embodiment, a method of generating syngas is provided. The method includes introducing a dry feedstock of solid biomass to a mill, the dry feedstock of solidbiomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%. The method also includes milling the dry feedstock of solid biomass to form a milled output of solid particles, where at least 95% of the solid particles in the milled output have a size less than 2 mm. The method further includes gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

[0005] In an embodiment, the method further includes pneumatically transferring the milled output of solid particles to the entrained flow gasifier for gasification.

[0006] In an embodiment, the dry feedstock of solid biomass has a moisture content of no more than 10%.

[0007] In an embodiment, the method further includes drying a wet feedstock in a dryer to form the dry feedstock.

[0008] In such an embodiment, drying the wet feedstock is carried out in a low temperature dryer operating in a range of 70-120 C°.

[0009] In an embodiment, at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

[0010] In an embodiment, the method further includes processing a source of biomass in an autoclave or pulper to form the wet feedstock.

[0011] In such an embodiment, the method further includes sifting the wet feedstock through a screen to remove contents above a predefined size.

[0012] In an embodiment, at least a portion of heat provided to the autoclave or pulper is generated from a Fischer-Tropsch process using the syngas.

[0013] In an embodiment, the source of biomass is municipal solid waste.

[0014] In an embodiment, the dry feedstock is formed of biomass pellets.

[0015] In a second example embodiment, a method of generating syngas is provided. The method includes preparing a dry feedstock of solid biomass in an upstream process excluding torrefaction, the dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%. The method also includes milling the dry feedstock of solid biomass in a mill to form a milled output of solid particles, where at least 95% of the solid particles in the milled output have a size less than 2 mm. The method further includes gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

[0016] In an embodiment, the dry feedstock of solid biomass has a moisture content of no more than 10%.

[0017] In an embodiment, the upstream process includes drying a wet feedstock in a dryer to form the dry feedstock.

[0018] In such an embodiment, drying the wet feedstock is carried out in a low temperature dryer operating in a range of 70-120 C°.

[0019] In an embodiment, at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

[0020] In an embodiment, the upstream process includes processing a source of biomass in an autoclave or a pulper to form the wet feedstock.

[0021] In an embodiment, the method further includes sifting the wet feedstock through a screen to remove contents above a predefined size.

[0022] In an embodiment, at least a portion of heat provided to the autoclave or the pulper is generated from a Fischer-Tropsch process using the syngas.

[0023] In an embodiment, the source of biomass is municipal solid waste.

[0024] In an embodiment, the dry feedstock is formed of biomass pellets.

[0025] In a third example embodiment, a system for generating syngas is provided. The system includes a dryer configured to receive a wet feedstock of solid biomass having a biogenic carbon content of at least 90% and dry the wet feedstock to produce a dry feedstock having a moisture content of at least 2%. The system also includes a mill configured to receive the dry feedstock and produce a milled output of solid particles, where at least 95% of the solid particles in the milled output have a size less than 2 mm. The system further includes an entrained flow gasifier configured to receive at least a portion of the milled output and form syngas.

[0026] In an embodiment, the dryer is a low temperature dryer configured to operate in a range of 70-120 C°

[0027] In an embodiment, the system further includes an autoclave configured to process a source of biomass to produce the wet feedstock.

[0028] In an embodiment, the system further includes a screen between the autoclave and the dryer for removing contents of the wet feedstock above a predefined size.

[0029] In an embodiment, the system further includes a pulper configured to process a source of biomass to produce the wet feedstock.

[0030] In an embodiment, the system further includes a screen between the pulper and the dryer for removing contents of the wet feedstock above a predefined size.

[0031] These as well as other aspects, advantages, and alternatives will become apparent to those of ordinary skill in the art by reading the following detailed description, with reference, when appropriate, to the accompanying drawings.BRIEF DESCRIPTION OF THE FIGURES

[0032] Figure 1 depicts a process flow for generating syngas, according to an example embodiment.

[0033] Figure 2 depicts a process flow for producing syngas, according to an example embodiment.

[0034] Figure 3 depicts an example process flow of the process flow shown in Figure 2, according to an example embodiment.

[0035] Figure 4 depicts another example process flow of the process flow shown in Figure 2, according to an example embodiment.

[0036] Figure 5 depicts another example process flow for generating syngas, according to an example embodiment.

[0037] Figure 6 depicts an example method for generating syngas, according to an example embodiment.

[0038] Figure 7 depicts another example method for generating syngas, according to an example method.DETAILED DESCRIPTION

[0039] Disclosed herein are example systems, methods, and devices for the generating syngas. The disclosed systems, methods, and devices may be utilized in any device or application where gasification to produce syngas and / or other gasses may occur. For example, entrained flow gasification may be used to produce syngas from municipal solid waste to ultimately provide a source of alternative fuel, such as in the form of hydrocarbons. The disclosed examples may be used to produce syngas from the municipal waste solids at a lower cost and higher biogenic fraction than other methods, which may increase productivity, scalability, and / or availability of syngas production and thereby provide a feasible alternative fuel source to fuel sources derived from fossil oil, crude oil, and / or mineral oils for example.

[0040] Figure 1 depicts a block diagram of a process flow 100 for generating syngas, according to an example embodiment. The process flow 100 includes a feedstock 110, a mill 112, a gasifier 114, and syngas 120. The feedstock 110 is input into the mill 112 for processing into an output which is then fed into the gasifier 114 which generates syngas 120 as an output. In some examples, the process flow 100 may be incorporated into a system for generating syngas.

[0041] The feedstock 110 may be a material input that is suitable for gasification in the production of syngas 120. For example, the feedstock 110 may be derived from biomass, such as waste biomass. The biomass may include organic matter from forestry products, agricultural products, and / or general household and industry waste. The feedstock 110 may be in pelletized or non-pelletized form. In some examples, the feedstock 110 may be a dry feedstock or a wet feedstock. For example, the feedstock 110 may be a dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%. However, in otherexamples the feedstock 110 may undergo further upstream processing prior to use in the process flow 100. For example, wet feedstock may be derived from waste biomass then further processed into dry feedstock for application as the feedstock 110. In some examples, the upstream processing of the feedstock 110 excludes torrefaction.

[0042] Peat, a fibrous material formed by decomposition of organic matter, is classified as a solid fuel and is therefore not a biomass. For purposes of this disclosure, the terms “biofuel,” “biogenic carbon,” and “biomass” do not include peat.

[0043] In some examples, pellet quality is in line with ISO 17225.

[0044] In some examples, the moisture content of the biomass and the biogenic carbon content of the biomass are each measured or determined in line with ISO standards. For example, the moisture content and the biogenic carbon content of the biomass are each measured or determined by the ISO standard for uncompressed fuels ISO 17827:2024 or the ISO standard for compressed fuels ISO 5370:2023. As another example, biomass moisture is measured or determined by ISO 18134, and biogenic carbon content is measured or determined by ASTM D6866 and ISO 21644.

[0045] The feedstock 110 may be input into the mill 112 for milling to reduce a particle size distribution and / or homogeneity of the feedstock 110. The mill 112 may be configured to receive the dry feedstock and produce a milled output of solid particles. For example, the dry feedstock of solid biomass may be input into the mill 112 which may break the solid biomass into a milled output of solid particles. In some examples, at least 95% of the solid particles in the milled output may have a size less than 2 mm. For example, at least 95% of the solid particles in the milled output may have a size less than 1.5 mm, a size less than 1 mm, a size lessthan 500 pm, a size less than 250 pm, and a size less than 100 pm. In some examples, increasing milling intensity may produce more solid particles in the milled output having a size less than 2 mm.

[0046] Milling the feedstock 110 may include grinding, cutting, chopping, and / or pulverizing, for example. Milling the feedstock 110 in the mill 112 to reduce the particle size distribution may allow for gasification of the solid particles to more efficiently occur by the gasifier 114. For example, decreasing the output size of the milled solid particles may allow for the milled solid particles to be pneumatically transferred into the gasifier. Further, in some examples decreasing the output size of the milled solid particles may allow for a uniform cloud distribution within the gasifier which may provide for uniform conversion of the milled solid particles into syngas 120 during gasification. Thus, in some examples the milled output of solid particles may be pneumatically transferred to the gasifier (e.g., an entrained flow gasifier) for gasification.

[0047] In some examples, the mill 112 may be a knife mill, a hammer mill, a tema mill, a ring roller mill, a centrifugal mill, and / or a vertical spindle mill. However, in other examples another type of mill may be used. The type of mill used may be based on the feedstock 110 chosen and / or the desired output particle size for gasification. In some examples, the mill 112 may aid in reducing moisture content of the feedstock 110. For example, the mill 112 may induce nonthermal drying of the feedstock 110 by forcing moisture from the feedstock during the milling process. In some examples, the mill 112 may include a classification system, which may recirculate and / or reject material that is above a threshold size. For example, the mill 112 may include a dynamic classifiers which may be configured to reject difficult-to-mill particles.

[0048] The milled output of solid particles may be input into the gasifier 114 for gasification.The gasifier may include a vessel (e.g., a pressure vessel) configured to receive the feedstock, aheating unit, and a controller for controlling gasification operations of the gasifier 114. For example, the controller may control processing time, temperature, pressure, and / or inputs into the gasifier 114 such as steam or oxygen. The gasifier 114 may further include a series of pipes connected to the vessel for transporting gasses produced by the gasified feedstock and / or for inputting steam and / or oxygen into the gasifier 114 during processing. The gasses produced by the gasified feedstock may be transported by the pipes to additional equipment, such as a vessel including at least one catalyst, for further processing and refining.

[0049] In some examples, the gasifier 114 may be an entrained flow gasifier. However, in other examples another gasifier may be used. The entrained flow gasifier may be configured to receive at least a portion of the milled output and form syngas. The entrained flow gasifier may allow for operation at a higher gasification temperature and / or pressure than other gasifiers and may further provide a turbulent environment. Gasification of the feedstock 110 at a higher temperature and / or pressure may increase efficiency and / or a production output of syngas though enhanced feed conversion rates and high throughput. In some examples, gasification of the feedstock 110 by the gasifier 114 may further be enhanced through upstream processing to reduce oxygen content, reduce particle size, and / or increase homogeneity of the feedstock 110.

[0050] Figure 2 depicts a process flow 200 for producing syngas 220, according to an example embodiment. In some examples, the process flow 200 may be included in a system for generating syngas. The process flow 200 for producing the syngas 220 includes municipal solid waste (MSW) 202, an autoclave 204, a sieve 206, a dryer 208, a mill 212, and a gasifier 214. The MSW 202 may be input into the autoclave 204 to break down a biogenic fraction of the MSW 202 into pieces for input into the sieve 206. The sieve 206 may separate the biogenic fraction of the MSW 202 for input into the dryer 208 for further processing into a feedstock. Forexample, the process flow 200 may be an upstream process for producing a dry feedstock of solid biomass 210. The dry feedstock of solid biomass 210 may serve as an input to the mill 212 for processing into a milled output of solid particles 213 that may undergo gasification by the gasifier 214 to extract the syngas 220. In some examples, the feedstock 110 (Figure 1) may include the dry feedstock of solid biomass 210. The dry feedstock of solid biomass 210 may have a moisture content of at least 2% and a biogenic carbon content of at least 90%. In some examples, the mill 212, the gasifier 214, and / or the syngas 220 may be the same as and / or similar to the mill 112, the gasifier 114, and / or the syngas 120 described in Figure 1.

[0051] In some examples, the moisture content and the biogenic carbon content of the MSW 202 are measured or determined in line with ISO standards. For example, the moisture content and the biogenic carbon content of the MSW 202 are each measured or determined by the ISO standard for solid recovered fuels ISO 21645, which references EN 15415. As another example, MSW moisture is measured or determined by ISO 21660-3 and biogenic carbon content is measured or determined by ASTM D6866 and ISO 21644.

[0052] The MSW 202 may include a variety of organic and inorganic matter. For example, the MSW 202 may include biomass and / or biogenic materials (e.g., paper products, animal products, forestry products, agricultural products, and / or yard waste), non-biomass materials (e.g., plastics and / or synthetic materials), and / or noncombustible materials (e.g., glass and / or metals). In some examples, the MSW 202 may include garbage or waste. One or more components that make up the MSW 202 may be desirable for the generation of syngas 220. For example, the biomass may be desirable as the feedstock for gasification to extract gasses, such as carbon monoxide (CO) and / or hydrogen (H2), that may ultimately be transformed into hydrocarbons. The MSW 202 may undergo further downstream processing to separate and refine the biomass for gasificationby the gasifier 214. While the MSW 202 is used to produce the syngas 220 in the example shown, in other examples another source that includes biomass may be used. Utilizing the MSW 202 as the feedstock for the production of syngas may provide an alternative fuel source to petroleum derived fuels while reducing an amount of garbage that is otherwise diverted to landfills.

[0053] In some embodiments, the MSW 202 is in a biogenic form. In other embodiments, the MSW 202 is in a non-biogenic form, which may include biomass and / or biogenic materials.

[0054] In the example shown, the MSW 202 may be fed into the autoclave 204 for further processing to break down the biomass fraction of the MSW 202 into smaller pieces for separation. The autoclave 204 may include a rotatable pressure vessel, a heating system, and a control system for controlling rotation, temperature, and / or pressure of the autoclave 204. For example, the pressure and / or the temperature of the autoclave 204 may be elevated above ambient levels for processing of the MSW 202. In some examples, steam may be injected into the autoclave 204 to assist in elevating the temperature and / or breaking down of the biomass.

[0055] In some examples, the autoclave 204 may process the MSW 202 at an elevated temperature and / or pressure, such as between 130-180 degrees Celsius and 3-8 bar gauge pressure. While exposed to elevated temperatures and / or pressure, the autoclave 204 may rotate about an axis. Rotation of the autoclave 204, combined with the elevated temperature and pressure, may cause the biomass / biogenic fraction of the MSW 202 to break down into smaller pieces while the fraction of the MSW 202 that is not biomass / biogenic (e.g., textiles, plastics, glass, and / or metals) remain whole. The biomass / biogenic fraction of the MSW 202 may then be separated from the non-biogenic portion of the MSW 202 for further preparation into thefeedstock. Thus, the autoclave 204 may allow for the biomass / biogenic fraction of the MSW202 to be homogenized and / or separated from the non-biogenic portion of the MSW 202.

[0056] In some examples, the autoclave 204 may be used to process a source of biomass to form a wet feedstock 205. However, in other examples a pulper may be used to process the source of biomass to form the wet feedstock 205. The wet feedstock 205 may be a feedstock having a moisture content that is less efficient for gasification than a dry feedstock, such as a moisture content greater than 10%. In some examples, the wet feedstock 205 may still include the non-biogenic portion of the MSW 202. Thus, it may be desirable to process the wet feedstock 205 to separate the biogenic portion from the non-biogenic portion of material.

[0057] For example, the wet feedstock 205 may be input into the sieve 206 for separation. The sieve 206 may include at least one screen having a predefined size to allow for separation of the biogenic fraction from the non-biogenic fraction of MSW 202. For example, the autoclave or pulper may reduce a portion of the biogenic fraction of the MSW 202 in the wet feedstock 205 to below the predefined size of the screen to allow the biogenic fraction in the wet feedstock 205 to be sifted from the non-biogenic portion. Thus, the wet feedstock 205 may be sifted through the screen to remove contents above a predefined size, such as non-biogenic material. In some examples, the portion of the wet feedstock 205 that passes through the at least one screen of the sieve 206 may form a screened wet feedstock 207. Using the autoclave 204 to reduce the particle size of the biomass / biogenic fraction of the MSW 202 then screening the output through the sieve 206 to separate non-biogenic matter from biogenic matter may increase the amount of biogenic carbon content within the screened wet feedstock 207.

[0058] After sifting the wet feedstock 205 in the sieve 206 to separate a portion of the biogenic fraction, forming the screened wet feedstock 207, it may be desirable to decrease the moisturecontent of the screened wet feedstock 207. For example, the screened wet feedstock 207 may be dried to produce a dry feedstock of solid biomass 210. Thus, processing of the screened wet feedstock 207 may include drying the screened wet feedstock 207 in the dryer 208 to form the dry feedstock of solid biomass 210. However, in other examples the wet feedstock 205 may be dried by the dryer 208 prior to screening by the sieve 406. The dryer 208 may include a vessel configured to receive and retain the screened wet feedstock 207 and at least one heating element that elevates the temperature of the screened wet feedstock 207 to reduce the moisture content. In some examples, the dryer 208 may further include an air circulator, such as a fan, to aid in removing moisture from the screened wet feedstock 207.

[0059] In some examples, drying of the screened wet feedstock 207 is carried out at a low temperature. For example, drying of the screened wet feedstock 207 may be carried out in a low temperature dryer operating in a range of 70-120 degrees Celsius. In some examples, the low temperature dryer may be a belt dryer. In some examples, the temperature at which the dryer 208 dries the screened wet feedstock 207 to form the dry feedstock of solid biomass 210 may not allow for torrefaction of the dry feedstock of solid biomass 210. The screened wet feedstock 207 may be dried by the dryer 208 until a desired moisture content in the dry feedstock of solid biomass 210 is reached. In some examples, the dry feedstock of solid biomass 210 may have a moisture content of at least 2%. However, in other examples the dry feedstock of solid biomass 210 may have a moisture content of no more than 10%. For example, dry feedstock of solid biomass 210 may have a moisture content of no more than between 8% to 10%, of no more than between 6% to 8%, of no more than between 4% to 6%, and of no more than between 2% to 4%. Decreasing the moisture content of the screened wet feedstock 207 to form the dry feedstock of solid biomass 210 may allow for more efficient conversion to gasses (e.g., hydrogen and / orcarbon monoxide) during the gasification process. The dry feedstock of solid biomass 210 may also provide better qualities for more uniform milling compared to the wet feedstock 205 and / or the screened wet feedstock 207. Further, decreasing the moisture content may allow for more effective pneumatic transferring of the feedstock, such as allowing for more effective pneumatic conveying of the feedstock into an entrained flow gasifier.

[0060] In some examples, the dry feedstock of solid biomass 210 may have a biogenic carbon content of at least 90%. For example, the dry feedstock of solid biomass 210 may have a biogenic carbon content of between at least 90% to 92%, of between at least 92% to 94%, of between at least 94% to 96%, of between at least 96% to 98%, and of between at least 98% to 99.9%. In some examples, the percentage of biogenic carbon content of the dry feedstock of solid biomass 210 may be determined according to ASTM D6866. Using a dry feedstock having the biogenic carbon content of at least 90% may allow for more syngas to be generated from a volume of feedstock during gasification which may increase efficiency of the gasification process.

[0061] Thus, in some examples of the process flow 200, the production of syngas 220 may include preparing the dry feedstock of solid biomass 210 in an upstream process (202-210) that excludes torrefaction.

[0062] Figure 3 depicts an example process flow 300 of the process flow 200 shown in Figure 2, according to an example embodiment. As shown, in the process flow 300, municipal solid waste (MSW) 302 is input into an autoclave 304 for processing into wet feedstock (WF) 305 which may then be screened by a sieve 306 to produce a screened wet feedstock (SWF) 307 as an output. The screened wet feedstock 307 may be dried by a dryer 308 to reduce moisture content within the screened wet feedstock 307 to produce a dry feedstock of solid biomass(DFSB) 310. The dry feedstock of solid biomass 310 may then be milled by a mill 312 to reduce the particle size to a desirable level for gasification. The solid particles (SP) 313 produced by milling of the dry feedstock of solid biomass 310 may then be input into a gasifier 314, such as an entrained flow gasifier, to undergo gasification. Gasification of the solid particles 313 by the gasifier 314 may produce syngas 320 which may be removed from the gasifier 314 and used as a base component in the generation of hydrocarbons. In some examples, the process flow from 302-310 may be an upstream process to produce the feedstock 110 that may be used as an input in the process flow 100.

[0063] Figure 4 depicts another example process flow 400 of the process flow 200 shown in Figure 2, according to an example embodiment. One or more of the blocks 402, and 405-420 may be the same as and / or similar to one or more of the blocks 302, and 305-320 shown as described in Figure 3. In some examples, the process flow 400 may differ from the process flow 300 through using a pulper 404 to process the MSW 402 into the wet feedstock 405. For example, the pulper 404 may aid in breaking down a size of the biomass / biogenic material in the MSW 402 to allow for screening by the sieve 406, such that a portion of biogenic material passes through a screen having a predefined size. In some examples, water may be added to the pulper 404 to aid in processing (e.g., crushing or pulping) the biomass. For example, heated water (e.g., greater than ambient temperature) and / or steam may be added to the pulper 404 which may increase a rate at which the biomass / biogenic material portion of the MSW 402 breaks down (e.g., reduces in size). In some examples, a portion of the biomass / biogenic material may reduce in size to form a slurry, while a portion of non-biogenic material might not substantially reduce in size.

[0064] Figure 5 depicts another example process flow 500 for generating syngas, according to an example embodiment. Similar reference numerals may correspond to similar components described in Figures 1 through 4, and thus may include similar features and / or functionality. Further, in some examples at least one aspect described in Figure 5 may be combinable with at least one aspect described in Figures 1 through 4. Thus, the process flows 100, 200, 300, and / or 400 may include at least one feature from the process flow 500.

[0065] As shown, municipal solid waste (MSW) 502 may be input into an autoclave 504 for processing (e.g., treatment under increased pressure and temperature) to break down the size of the biogenic fraction of the MSW 502 to allow for separation of a portion of the biogenic fraction from a non-biogenic portion of the MSW 502. The MSW 502 may serve as an input into the autoclave 504 which may process the MSW 502 into a wet feedstock as an output. The wet feedstock may include a portion of biogenic material having a reduced size compared to a portion of biogenic material in the MSW 502. While the autoclave 504 is shown in the example of Figure 5, in some examples a pulper may be used to generate the wet feedstock instead of an autoclave.

[0066] The wet feedstock may then pass through a screen 506, such as a screen having a predefined size, to separate materials above and below the predefined size. For example, the screen 506 may have a predefined size that allows a portion of the biogenic fraction to pass through while rejecting a portion of non-biogenic material. The process 500 downstream of the screen 506 is illustrated as overs 506A and unders 506B, with overs 506A representing material rejected by the screen 506 and unders 506B representing material admitted by the screen 506, such as screened wet feedstock. In some examples, the screened wet feedstock may include a portion of the biogenic fraction of the wet feedstock. The overs 506A may then be transferred toa picking station 540 that may separate a biogenic portion 542 of the overs 506A from a non- biogenic portion 544 of the overs 506A. In some examples, the biogenic portion 542 may be readmitted into the MSW 502 for reprocessing. The non-biogenic portion 544 may include recyclable (e.g., metals and / or plastics) and non-recyclable material. In some examples, non- recyclable material from the overs 506A may be burned by an incinerator to generate power. However, in other examples a portion of the non-recyclable, such as plastic material, may serve as an input into a pyrolysis reactor for use in generating liquid hydrocarbons that may be used in the production of a variety of products (e.g., alternative fuels).

[0067] The screened wet feedstock may be input into a dryer 508 to reduce the moisture content and produce a dry feedstock of solid biomass as an output. The dry feedstock of solid biomass may be input into a mill 512 for processing, such as to reduce a particle size of the dry feedstock of solid biomass. Decreasing the particle size and / or moisture content of the solid biomass may allow for the solid biomass to be more effectively transferred (e.g., pneumatically transferred) to a gasifier, such as an entrained flow gasifier. Further, decreasing the particle size and / or moisture content of the solid biomass may allow for more efficient pneumatic conveyance through the entrained flow gasifier, which may enable more gasification of the solid biomass to syngas during processing within the gasifier. For example, decreasing the size and / or moisture content of the solid particles may increase a suspension time of the solid particles within the gasifier, as heavier particles (e.g., being larger and / or having more moisture content) may fall faster than smaller particles, which may allow for more gasification to occur. Thus, the mill 512 may process the dry feedstock of solid biomass into a milled output of solid particles. In some examples, upon exiting the mill 512 at least 95% of the solid particles in the milled output may have a size less than 2 mm.

[0068] The milled output of solid particles may be input into the gasifier 514. During processing by the gasifier 514, the milled output of solid particles may under gasification to form syngas. For example, while in the gasifier 514 the milled output of solid particles may be subjected to above atmospheric temperature and / or pressure to induce a chemical reaction that outputs the syngas. Oxygen and / or steam may further be injected and regulated in the gasifier to increase a rate of gasification. In some examples, such as in an entrained flow gasifier, turbulent flow may aid in the gasification process to further increase the rate at which the chemical reaction occurs. The syngas that is output during the gasification process by the gasifier 514 may be collected by a pipe and transported for further downstream processing.

[0069] For example, the syngas may be subjected to acid gas removal 522. The acid gas removal 522 may involve subjecting the syngas to a first catalyst that reacts with the syngas to remove acidic gases, such as removing hydrogen sulfide from the syngas. In some examples, the hydrogen sulfide removed by the first catalyst may be further refined into sulfuric acid which may be used in various industry settings. During reaction with the first catalyst in the acid gas removal 522, biogenic carbon dioxide 524 may further be removed from the syngas.

[0070] After removal of the acidic gasses, the refined syngas may undergo a Fischer-Tropsch process 526. The Fischer-Tropsch process 526 may include at least one catalyst, such as a metal catalysts, that further refines the syngas into hydrocarbons 528 (e.g., liquid hydrocarbons). In some examples, the Fischer-Tropsch process 526 may occur at an above atmospheric pressure (e.g., greater than one atmospheric pressure) and / or temperature (e.g., between 150-300 degrees Celsius). The Fischer-Tropsch process 526 may allow the syngas to be transformed into the hydrocarbons 528 which may then be further used as an alternative fuel (e.g., naphtha, diesel, and / or aviation fuel) and / or in the production of materials, such as plastics. In some examples, aportion of the hydrocarbons 528 generated by subjecting the syngas to the Fischer-Tropsch process 526 may be used to provide inputs to the process flow 500. For example, syngas produced by the process flow 500 may be transformed by the Fischer-Tropsch process 526 to produce hydrocarbons 528. Because the Fischer-Tropsch process 526 involves an exothermic reaction, a portion of heat generated by the exothermic reaction of the Fischer-Tropsch process 526 may be used to provide heat and / or generate steam 530 as an input back into the process flow 500. Thus, in some examples, at least a portion of heat provided as an input back into the process flow 500 may be generated from the Fischer-Tropsch process 526 using the syngas, where the heat is from the exothermic reaction of the Fischer-Tropsch process 526.

[0071] In some examples, at least a portion of heat provided to the dryer 508 is generated from the Fischer-Tropsch process 526 using the syngas. In further examples, at least a portion of heat provided to the autoclave 504 or pulper is generated from the Fischer-Tropsch process 526 using the syngas. For example, the portion of heat provided to the dryer 508, the autoclave 504, and / or the pulper may be heat generated by the exothermic reaction of the Fischer-Tropsch process 526 in processing the syngas. By utilizing a portion of heat generated from the Fischer-Tropsch process using the syngas, processing of the municipal solid waste into feedstock may rely on less outside energy sources which may help to decrease operating expenses and / or reliance on petroleum based fuels as a heat source. However, in other examples at least a portion of the heat provided to the autoclave 504, the pulper, and / or the dryer 508 may be provided by heat generated through an exothermic gasification reaction in the gasifier 514. In such examples, the heat provided by the exothermic gasification reaction in the gasifier 514 may be separate from, and / or in addition to, the portion of heat supplied from the Fischer-Tropsch process 526.

[0072] In some examples, the biogenic carbon dioxide 524 removed from the syngas may undergo a reverse water gas shift reaction (RWGS). In such examples, the biogenic carbon dioxide 524 may be reacted with hydrogen (H2) to produce water (H2O)and carbon monoxide (CO). The carbon monoxide may be combined with the extracted syngas and undergo the Fischer-Tropsch process 526 to produce hydrocarbons.

[0073] Figure 6 depicts a flowchart of a method 600 for generating syngas, according to an example embodiment. The method 600 may include one or more operations, or actions as illustrated by one or more blocks 602-606. Although the blocks are illustrated in a sequential order, these blocks may in some instances be performed in parallel, and / or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and / or removed based upon the desired implementation. One or more examples of the method 600 may be performed by the system shown in any of Figures 1 through 5.

[0074] As illustrated, at block 602, the method 600 may include introducing a dry feedstock of solid biomass to a mill. In some examples, the dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%.

[0075] At block 604, the method 600 may also include milling the dry feedstock of solid biomass to form a milled output of solid particles. In some examples, at least 95% of the solid particles in the milled output have a size less than 2 mm.

[0076] At block 606, the method 600 may further include gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

[0077] In some examples, the method 600 further includes pneumatically transferring the milled output of solid particles to the entrained flow gasifier for gasification.

[0078] In some examples of the method 600, the dry feedstock of solid biomass has a moisture content of no more than 10%.

[0079] In some examples, the method 600 further includes drying a wet feedstock in a dryer to form the dry feedstock.

[0080] In such examples of the method 600, drying the wet feedstock is carried out in a low temperature dryer operating in a range of 70-120 C°.

[0081] In such examples of the method 600, at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

[0082] In some examples, the method 600 further includes processing a source of biomass in an autoclave or pulper to form the wet feedstock.

[0083] In such examples, the method 600 further includes sifting the wet feedstock through a screen to remove contents above a predefined size.

[0084] In some examples of the method 600, at least a portion of heat provided to the autoclave or pulper is generated from a Fischer-Tropsch process using the syngas.

[0085] In some examples of the method 600, the source of biomass is municipal solid waste.

[0086] In some examples of the method 600, the dry feedstock is formed of biomass pellets.

[0087] Figure 7 depicts a flowchart of another method 700 for generating syngas, according to an example embodiment. The method 700 may include one or more operations, or actions as illustrated by one or more blocks 702-706. Although the blocks are illustrated in a sequentialorder, these blocks may in some instances be performed in parallel, and / or in a different order than those described herein. Also, the various blocks may be combined into fewer blocks, divided into additional blocks, and / or removed based upon the desired implementation. One or more examples of the method 700 may be performed in a similar manner to the examples described in Figure 6.

[0088] As illustrated, at block 702, the method 700 may include preparing a dry feedstock of solid biomass in an upstream process excluding torrefaction. In some examples, the dry feedstock of solid biomass may have a moisture content of at least 2% and a biogenic carbon content of at least 90%.

[0089] At block 704, the method 700 may also include milling the dry feedstock of solid biomass in a mill to form a milled output of solid particles. In some examples, at least 95% of the solid particles in the milled output have a size less than 2 mm.

[0090] At block 706, the method 700 may further include gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

[0091] In some examples, the method 700 further includes pneumatically transferring the milled output of solid particles to the entrained flow gasifier for gasification.

[0092] In some examples of the method 700, the dry feedstock of solid biomass has a moisture content of no more than 10%.

[0093] In some examples of the method 700, the upstream process includes drying a wet feedstock in a dryer to form the dry feedstock.

[0094] In such examples of the method 700, drying the wet feedstock is carried out in a low temperature dryer operating in a range of 70-120 C°.

[0095] In such examples of the method 700, at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

[0096] In some examples of the method 700, the upstream process includes processing a source of biomass in an autoclave or pulper to form the wet feedstock.

[0097] In such examples, the method 700 further includes sifting the wet feedstock through a screen to remove contents above a predefined size.

[0098] In some examples of the method 700, at least a portion of heat provided to the autoclave or pulper is generated from a Fischer-Tropsch process using the syngas.

[0099] In some examples of the method 700, the source of biomass is municipal solid waste.

[0100] In some examples of the method 700, the dry feedstock is formed of biomass pellets.

[0101] Additional aspects of the disclosure are provided by the following enumerated embodiments, which may be combined in any number and in any combination that is not logically or technically inconsistent.

[0102] Enumerated Embodiments:

[0103] Embodiment 1 is a method of generating syngas, the method comprising: introducing a dry feedstock of solid biomass to a mill, the dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%; milling the dry feedstock of solid biomass to form a milled output of solid particles, wherein at least 95% of the solidparticles in the milled output have a size less than 2 mm; and gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

[0104] Embodiment 2 is the method according to embodiment 1, the method further comprises pneumatically transferring the milled output of solid particles to the entrained flow gasifier for gasification.

[0105] Embodiment 3 is the method according to embodiment 1 or embodiment 2, wherein the dry feedstock of solid biomass has a moisture content of no more than 10%.

[0106] Embodiment 4 is the method according to any of embodiments 1 to 3, further comprising drying a wet feedstock in a dryer to form the dry feedstock.

[0107] Embodiment 5 is the method according to embodiment 4, wherein drying the wet feedstock is carried out in a low temperature dryer operating in a range of 70-120 C°.

[0108] Embodiment 6 is the method according to embodiment 4 or embodiment 5, wherein at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

[0109] Embodiment 7 is the method according to any of embodiments 4 to 6, further comprising processing a source of biomass in an autoclave or a pulper to form the wet feedstock.

[0110] Embodiment 8 is the method according to embodiment 7, further comprising sifting the wet feedstock through a screen to remove contents above a predefined size.

[0111] Embodiment 9 is the method according to embodiment 7 or embodiment 8, wherein at least a portion of heat provided to the autoclave or the pulper is generated from a Fischer-Tropsch process using the syngas.

[0112] Embodiment 10 is the method according to any of embodiments 6 to 9, wherein the source of biomass is municipal solid waste.

[0113] Embodiment 11 is the method according to any of embodiments 1 to 3, wherein the dry feedstock is formed of biomass pellets.

[0114] Embodiment 12 is a method of generating syngas, the method comprising: preparing a dry feedstock of solid biomass in an upstream process excluding torrefaction, the dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%; milling the dry feedstock of solid biomass in a mill to form a milled output of solid particles, wherein at least 95% of the solid particles in the milled output have a size less than 2 mm; and gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

[0115] Embodiment 13 is the method according to embodiment 12, wherein the dry feedstock of solid biomass has a moisture content of no more than 10%.

[0116] Embodiment 14 is the method according to embodiment 12 or embodiment 13, wherein the upstream process includes drying a wet feedstock in a dryer to form the dry feedstock.

[0117] Embodiment 15 is the method according to embodiment 14, wherein drying the wet feedstock is carried out in a low temperature dryer operating in a range of 70-120 C°.

[0118] Embodiment 16 is the method according to embodiment 14 or embodiment 15, wherein at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

[0119] Embodiment 17 is the method according to any of embodiments 14 to 16, wherein the upstream process includes processing a source of biomass in an autoclave or a pulper to form the wet feedstock.

[0120] Embodiment 18 is the method according to embodiment 17, further comprising sifting the wet feedstock through a screen to remove contents above a predefined size.

[0121] Embodiment 19 is the method according to embodiment 17 or embodiment 18, wherein at least a portion of heat provided to the autoclave or the pulper is generated from a Fischer- Tropsch process using the syngas.

[0122] Embodiment 20 is the method according to any of embodiments 16 to 19, wherein the source of biomass is municipal solid waste.

[0123] Embodiment 21 is the method according to embodiment 12 or embodiment 13, wherein the dry feedstock is formed of biomass pellets.

[0124] Embodiment 22 is a system for generating syngas, the system comprising: a dryer configured to receive a wet feedstock of solid biomass having a biogenic carbon content of at least 90% and dry the wet feedstock to produce a dry feedstock having a moisture content of at least 2%; a mill configured to receive the dry feedstock and produce a milled output of solid particles, wherein at least 95% of the solid particles in the milled output have a size less than 2 mm; and an entrained flow gasifier configured to receive at least a portion of the milled output and form syngas.

[0125] Embodiment 23 is the system according to embodiment 22, wherein the dryer is a low temperature dryer configured to operate in a range of 70-120 C°.

[0126] Embodiment 24 is the system according to embodiment 22 or embodiment 23, further comprising an autoclave configured to process a source of biomass to produce the wet feedstock.

[0127] Embodiment 25 is the system according to embodiment 24, further comprising a screen between the autoclave and the dryer for removing contents of the wet feedstock above a predefined size.

[0128] Embodiment 26 is the system according to embodiment 22 or embodiment 23, further comprising a pulper configured to process a source of biomass to produce the wet feedstock.

[0129] Embodiment 27 is the system according to embodiment 26, further comprising a screen between the pulper and the dryer for removing contents of the wet feedstock above a predefined size.

[0130] The above detailed description describes various features and functions of the disclosed systems, devices, and methods with reference to the accompanying Figures. In the Figures, similar symbols typically identify similar components, unless context dictates otherwise. The illustrative embodiments described in the detailed description, Figures, and claims are not meant to be limiting. Other embodiments can be utilized, and other changes can be made, without departing from the scope of the subject matter presented herein. It will be readily understood that the aspects of the present disclosure, as generally described herein, and illustrated in the Figures, can be arranged, substituted, combined, separated, and designed in a wide variety of different configurations, all of which are explicitly contemplated herein.

[0131] While various aspects and embodiments have been disclosed herein, other aspects and embodiments will be apparent to those skilled in the art. The various aspects and embodimentsdisclosed herein are for purposes of illustration and are not intended to be limiting, with the true scope being indicated by the following claims.

Claims

CLAIMSWhat is claimed is:

1. A method of generating syngas, the method comprising: processing a source of biomass in an autoclave or a pulper to form a wet feedstock; drying the wet feedstock in a dryer to form a dry feedstock of solid biomass, the dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%; introducing the dry feedstock of solid biomass to a mill; milling the dry feedstock of solid biomass to form a milled output of solid particles, wherein at least 95% of the solid particles in the milled output have a size less than 2 mm; and gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

2. The method according to claim 1, wherein the dryer is a low temperature dryer operating in a range of 70-120 C°.

3. The method according to claim 1, wherein the autoclave forms the wet feedstock at a 3-8 bar gauge pressure.

4. The method according to claim 1, further comprising pneumatically transferring the milled output of solid particles to the entrained flow gasifier for gasification.

5. The method according to claim 1, wherein the dry feedstock of solid biomass has a moisture content of no more than 10%.

6. The method according to claim 2, wherein at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

7. The method according to claim 6, further comprising sifting the wet feedstock through a screen to remove contents above a predefined size, or wherein at least a portion of heat provided to the autoclave or the pulper is generated from a Fischer-Tropsch process using the syngas.

8. The method according to claim 1, wherein the source of biomass is municipal solid waste.

9. The method according to claim 1, wherein the dry feedstock is formed of biomass pellets.

10. A method of generating syngas, the method comprising: processing a source of biomass in an autoclave or a pulper to form a wet feedstock; drying the wet feedstock in a dryer to form a dry feedstock of solid biomass, the dry feedstock of solid biomass having a moisture content of at least 2% and a biogenic carbon content of at least 90%;preparing the dry feedstock of solid biomass in an upstream process excluding torrefaction; milling the dry feedstock of solid biomass in a mill to form a milled output of solid particles, wherein at least 95% of the solid particles in the milled output have a size less than 2 mm; and gasifying at least a portion of the milled output in an entrained flow gasifier to form syngas.

11. The method according to claim 10, wherein the dry feedstock of solid biomass has a moisture content of no more than 10%.

12. The method according to claim 10, wherein at least a portion of heat provided to the dryer is generated from a Fischer-Tropsch process using the syngas.

13. The method according to claim 10, wherein the dryer is a low temperature dryer operating in a range of 70-120 C°.

14. The method according to claim 10, wherein the autoclave forms the wet feedstock at a 3-8 bar gauge pressure.

15. The method according to claim 14, further comprising sifting the wet feedstock through a screen to remove contents above a predefined size, orwherein at least a portion of heat provided to the autoclave or the pulper is generated from a Fischer-Tropsch process using the syngas.

16. The method according to claim 10, wherein the source of biomass is municipal solid waste.

17. The method according to claim 10, wherein the dry feedstock is formed of biomass pellets.

18. A system for generating syngas, the system comprising: an autoclave or a pulper configured to form a wet feedstock from a source of biomass; a dryer configured to receive the wet feedstock of solid biomass having a biogenic carbon content of at least 90% and dry the wet feedstock to produce a dry feedstock having a moisture content of at least 2%; a mill configured to receive the dry feedstock and produce a milled output of solid particles, wherein at least 95% of the solid particles in the milled output have a size less than 2 mm; and an entrained flow gasifier configured to receive at least a portion of the milled output and form syngas.

19. The system according to claim 18, wherein the dryer is a low temperature dryer configured to operate in a range of 70-120 C°.

20. The system according to claim 18, wherein the autoclave forms the wet feedstock at a 3-8 bar gauge pressure.

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