Method and system for producing synthesis gas

Abstract

The present invention provides a method for producing syngas, the method comprising: heating a cellulosic material in a vessel comprising a pathway and a heat generator in thermal communication with the pathway, thermally degrading the cellulosic material by pyrolysis wherein the cellulosic material upon pyrolysis forms a biochar releasing syngas; displacing the produced syngas along the pathway whereby the syngas is filtered by at least one of the pyrolyzed cellulosic material and the biochar; reacting at least a portion of the produced syngas with a catalytic material provided along the pathway to reform the at least a portion of the produced syngas displaced along the pathway; and discharging the filtered synthesis gas from the vessel; the cellulosic material comprises at least one of wood chips, wood balls, biomass and biological waste.

Description

Technical Field

[0001] The present invention generally relates to a method and system for generating syngas. Background Art

[0002] Low-density agricultural biomass, such as bark and sawdust, is often widely dispersed in a specific geographic area, difficult to collect and economically expensive to transport. In the process of rapid pyrolysis of low-density agricultural biomass, a common problem that makes the process uneconomical is the high cost of transporting these loose materials to a central processing site. Therefore, it is necessary to significantly reduce or eliminate the transportation costs of these materials. It is therefore desirable to provide a compact, mobile, stand-alone rapid pyrolysis processing device that can be set up and operated close to the source location of the raw materials. In order to make it easier for farmers and workers, especially in the developing world, to use the device, it is also desirable that the device be easy to operate and flexible in the choice of fuel sources. The process used when using the device is loose in terms of particle size and biomass moisture content. In addition, the process also utilizes rapid heat transfer and a short solid residence time to reduce container size and increase throughput.

[0003] To date, conventional fast pyrolysis processes have utilized multiple vessels, are complex to operate, inflexible, and / or not suitable for mobile operation. Compact systems that combine a combustion chamber and a pyrolysis reactor within a single vessel typically involve mixing of fluids and / or solids between the two portions of the vessel; thereby resulting in contamination and / or destruction of the most valuable condensable liquid products in the product gas. Therefore, there is a need for an improved apparatus for pyrolysis of low-density agricultural biomass and a process for its use.

[0004] Combustible gas can be produced by thermochemical conversion of biomass. Biomass can be any suitable carbonaceous fuel. Non-limiting examples of biomass include wood in any suitable form such as sawdust, shavings, pellets and cellulose materials, and other wood residues, municipal waste, sewage, coal, asphalt, fossil fuels, food waste and vegetable matter. In an oxygen-reduced environment, biomass is heated to release combustible gas from biomass. Heating can be performed by partial oxidation of biomass or by a separate heat source. Biomass is caused to release combustible gas by heating, and these gases are also referred to as "synthesis gas", "synthetic gas", "production gas" and "product gas".

[0005] The synthesis gas produced by biomass can be used in various applications. For example, these gases can be burned to generate heat, these gases can be processed to produce synthetic fuels (synthetic fuels can include gaseous, liquid or solid fuels), these gases can be used to run engines, these gases can be used as fuel for fuel cells or these gases can be used as fuel for running turbines. The synthesis gas released from biomass can include fractions such as tar and heavier hydrocarbons, which can be condensed in pipelines and other equipment. This can cause major operation and maintenance problems. Similarly, the increase in the production of useful components of synthesis gas such as hydrogen can also be hindered. A practical, energy-saving method and device for producing clean synthesis gas from biomass, particularly from cellulosic materials, is needed. Summary of the invention

[0006] According to a first aspect of the present invention, a method for generating synthesis gas is provided, which comprises: heating a cellulosic material in a container comprising a passage and a heat generator thermally connected to the passage, degrading the cellulosic material in a thermal manner by pyrolysis, wherein the cellulosic material forms biochar upon pyrolysis to release synthesis gas; displacing the generated synthesis gas along the passage thereby filtering the synthesis gas through at least one of the pyrolyzed cellulosic material and the biochar; reacting at least a portion of the generated synthesis gas with a catalytic material provided along the passage to reform the at least a portion of the generated synthesis gas displaced along the passage; and discharging the filtered synthesis gas from the container; the cellulosic material comprises at least one of wood chips, wood pellets, biomass and biological waste.

[0007] According to a second aspect of the present invention, there is provided a system for producing syngas, the system comprising: a container containing a passage for heating a cellulosic material and a heat generator in thermal communication with the passage, so as to thermally degrade the cellulosic material by pyrolysis, wherein the cellulosic material forms biochar upon pyrolysis to release syngas. The passage is shaped and adapted for displacing the produced syngas along the passage thereby filtering the syngas through at least one of the cellulosic material that has been pyrolyzed and the biochar, the passage having a catalytic material provided along it for reacting with at least part of the produced syngas to reform at least part of the produced syngas circulating along the passage. The filtered syngas may be discharged from the container, and the cellulosic material comprises at least one of wood chips, wood pellets, biomass and biowaste. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1 An exemplary process flow diagram of a method for generating syngas according to one aspect of the present invention is shown.

[0009] Figure 2 Shown for Figure 1An exemplary system schematic diagram of a system for generating syngas is shown, wherein the system includes a vessel and a passageway wherein syngas is displaced in a direction generally opposite to the direction of flow of cellulosic material along the passageway made of catalytic material.

[0010] Figure 3 Shows Figure 2 An exemplary system schematic diagram of a system for generating syngas for further processing syngas discharged from a vessel is shown.

[0011] Figure 4 Shows Figure 1 An exemplary system schematic diagram of a system for generating syngas is shown, wherein the pathway is formed by a closed loop circuit.

[0012] Figure 5 Shows Figure 1 An exemplary system schematic diagram of a system for generating syngas is shown, wherein an auger forms a conveying system. DETAILED DESCRIPTION

[0013] According to an exemplary embodiment of the present invention, a method 100 for generating synthesis gas ("synthesis gas method 100") is provided, which is implemented using a system 20 for generating synthesis gas ("synthesis gas system 20"), hereinafter referred to as Figures 1 to 5 The method is described. The syngas method 100 includes: step 110, heating a cellulosic material 22 in a container 24 including a passage 26 and a heat generator 28 in thermal communication with the passage 26 to thermally degrade the cellulosic material 22 by pyrolysis. The cellulosic material 22 is used to release syngas 32 by forming biochar 30 when pyrolyzed. The syngas method 100 also includes: step 112, displacing the generated syngas 32 along the passage 26 thereby filtering the syngas 32 through at least one of the pyrolyzed cellulosic material 22 and the biochar 30, and step 114, reacting at least a portion of the generated syngas 32 with a catalytic material 33 provided along the passage 26 to reform at least a portion of the generated syngas displaced along the passage 26. The syngas method 100 also includes: step 116, discharging the filtered syngas 32 from the container 24. Since the syngas 32 is produced together with tar, soot and similar impurities, the cellulosic material 22 at any stage of pyrolysis will perform the role of a filter medium to remove, capture or wash the impurities in the syngas 32 to clean the syngas 32. The container 24 and the catalytic material 33 are components of the syngas system 20. Preferably, the cellulosic material 22 includes at least one of wood chips, wood pellets, biomass and biowaste. An example of at least one of wood chips and wood pellets is wood biomass. Examples of biowaste include food waste, plant fibers, agricultural biomass and similar cellulose and hemicellulose containing materials and items.

[0014] Preferably, when in use, the passage 26 is used to shift the cellulosic material 22 through the heat generator 28 at different stages of carbonization, and to shift the generated syngas 32 through the pyrolyzed cellulosic material 22 and at least one of the biochar 30. Preferably, the container 24 is a pressure vessel made of a heat-resistant, high-strength material such as steel. In addition, the heat generator 28 is capable of generating heat in excess of 400 degrees Celsius. In addition, preferably, the heat generator 28 is capable of generating heat in excess of 900 degrees Celsius to achieve flash pyrolysis of the cellulosic material 22, such as vacuum flash pyrolysis. The passage 26 includes a closed loop circuit for recirculating the syngas for filtration through at least one of the cellulosic material 22 and the biochar, such as Figure 4 Passageway 26 may be formed from one or more channels (not shown).

[0015] In one implementation of the synthesis gas method 100, the container 24 includes at least one pipe 35 for forming the passage 26. The at least one pipe 35 can be a pipe having a generally cylindrical structure, the interior space of which forms the passage 26 in this case. In this implementation, the at least one pipe 35 is coated with a catalytic material 33 for exposing the generated synthesis gas 32 when the synthesis gas passes through the passage 26.

[0016] In another implementation, the container 24 also includes at least one conduit 35 for forming the passage 26. In this implementation, the at least one conduit is substantially entirely made of the catalytic material 33 for exposing the generated syngas 32 as the syngas passes through the passage 26. Since the at least one conduit 25 is made of the catalytic material 33, the interior surface of the conduit 35 will naturally provide the catalytic material 33 to the generated syngas.

[0017] The catalytic material 33 is preferably made of at least one of the following catalysts: nickel (Ni), molybdenum (Mo), platinum (Pt), ruthenium (Ru), cobalt / molybdenum (CoMo), nickel / molybdenum (NiMo), nickel oxide (NiO) catalyst. In various implementations, it is preferred that the catalytic material 33 has a high Ni content.

[0018] Preferably, the step 112 of displacing the generated syngas 32 along the path 26 includes: step 120, displacing the cellulosic material 22 along the path 26 by a conveying system 34, such as an auger conveying system, for heating by the heat generator 28 to form the biochar 30. Preferably, at least a portion or substantially all of the surface of the conveying system 34 that contacts the syngas 32 is formed with a catalytic material 33, including coating. Optionally, the conveying system 34 may partially or entirely rely on gravity feeding of the cellulosic material 22 along the path 26 for pyrolysis or flash pyrolysis thereof. However, preferably, the conveying system 34 is an auger having the catalytic material 33 coated thereon. The step 112 of displacing the generated syngas 32 along the path 26 may also include: step 122, displacing the generated syngas 32 along the path 26 using the displacement system 36 and generally passing through the pyrolyzed cellulosic material 22. The cellulosic material 22 is preferably preheated before introduction into the container 24. The displacement system 36 may, for example, be a blower or by utilizing a Coanda effect / flow pattern. In one implementation, the displacement system 36 may be integrally formed with the heat generator 28 .

[0019] In one embodiment where the delivery system 34 is an auger, the vessel 24 generally functions as an auger-type pyrolyzer, wherein the heat generator 28 is disposed on the outer surface of at least one conduit 35, such as Figure 5 As shown. By forming or coating the inner surface of the container 24, specifically the passage 26 of the container and the conveying system 34, such as the above-mentioned auger, or at least a portion thereof, with a catalytic material, the generated synthesis gas 32 can react with the catalytic material as a catalyst and reform, thereby, for example, when the synthesis gas 32 is filtered through at least one of the cellulosic material 22 and the biochar 30, the hydrogen content and / or the amount of methane are increased substantially simultaneously or sequentially. This not only improves the cleanliness of the synthesis gas 32 passing through, but also improves its fuel gas quality. Optionally, the auger can be substantially or entirely formed of a catalytic material.

[0020] The heat generator 28 is one of an electric heater and a heat exchanger, and the released or generated synthesis gas 32 is at least one of hydrogen, methane, carbon monoxide and carbon dioxide. The heat exchanger used is an ablation heat exchanger fueled by, for example, flue gas.

[0021] The syngas method 100 further includes: step 130, before performing the step 110 of heating the cellulosic material 22 in the container 24, injecting the cellulosic material 22 into the passage 26 of the container 24 through the displacement screw conveyor 38 or a similar displacement system. The syngas method 100 further includes: step 132, in response to the syngas 32 being discharged from the container in large quantities, discharging the biochar 30 from the container 24.

[0022] Step 116 of discharging the filtered syngas 32 from the container 24 includes: step 140, discharging the filtered syngas 32 to one of a downstream process 40 and a storage system 42, and step 142, using a gas engine as part of the downstream process 40 to generate at least one of thermal energy and mechanical energy from the filtered syngas 32.

[0023] The syngas system 20 includes a vessel 24 including and defining a passage 26 and a heat generator 28 in thermal communication with the passage 26. Preferably, the syngas system 20 further includes a conveying system 34, a displacement system 36, and a displacement screw conveyor 38. The syngas system 20 further includes at least one of an apparatus or system for performing a downstream process 40 and a storage system 42.

[0024] Preferably, the container 24 also includes: a first opening 50 for receiving the cellulosic material 22 into the container 24 for heating and pyrolysis, and a second opening 52 for removing or discharging the biochar 30 from the container 24. Preferably, each of the first opening 50 and the second opening 52 has a door, cover, gate or access control system that is operable and adapted to effectively prevent fluids such as syngas 32 from escaping from the container 24 when pressurized and partially define the passage 26. The discharge or discharge of the biochar 30 can be one or both of gravity-assisted and mechanical using a displacement system similar to the displacement screw conveyor 38. In some embodiments, the container 24 includes only one opening, which performs both the functions of the first opening 50 and the second opening 52 for introducing the cellulosic material 22 and discharging or removing the biochar 30 from the container 24. In this embodiment, the same displacement screw conveyor system 38 or a similar displacement system can be used to displace the cellulosic material into the container through the opening and remove the biochar 30 from the container 24.

[0025] When pressure builds up in the vessel 24 due to the generated syngas 32, the pressure in the vessel can be utilized and filtered syngas 32 can be discharged from the vessel 24 with or without the presence or use of a displacement system. The syngas 32 is preferably displaced in the pyrolysis or flash pyrolysis generally in the direction opposite to the direction in which the flow of the cellulosic material 22 travels in the passage 28 to enhance its filtration. Although this is preferred, the syngas 32 can additionally or alternatively be displaced generally in the direction in which the flow of the cellulosic material 22 travels in the passage 28 or perpendicular thereto.

[0026] The discharge of the filtered syngas 32 may be performed at one or both of the first opening 50 and the second opening 52. Additionally or alternatively, the filtered syngas 32 may be discharged through a port 53 defined by or formed with the container 24. The container 24 may further include a discharge valve 54, which is automatically operated by pressure reduction or time delay or remotely operated by wireless or wired control or manually operated to control or measure the filtered syngas 32 discharged from the container 24. When implemented, the discharge valve 54 is configured and disposed at one of the port 53, the first opening 50, and the second opening 52. The port 53 may be defined adjacent to one of the first opening 50 and the second opening 52.

[0027] Various aspects of specific embodiments of the present invention address at least one aspect, problem, limitation and / or weakness associated with existing synthesis gas production methods. Although features, aspects and / or advantages associated with certain embodiments have been described in the present invention, other embodiments may also display such features, methods and / or advantages, and not all embodiments need to display such features, methods and / or advantages to fall within the scope of the present invention. Those of ordinary skill in the art understand that a plurality of the structures, components or their substitutes disclosed above may be expected to be incorporated into alternative structures, components and / or applications. In addition, those of ordinary skill in the art may make various changes, modifications and / or improvements to the various embodiments disclosed within the scope of the present invention. The scope of protection of the present invention is limited only by the attached claims.

Claims

1. A method for producing synthesis gas, characterized in that include: heating a cellulosic material in a vessel including a passageway and a heat generator in thermal communication with the passageway to thermally degrade the cellulosic material by pyrolysis, wherein the cellulosic material forms biochar and releases syngas when pyrolyzed; displacing the generated syngas along the pathway thereby filtering the syngas through at least one of the pyrolyzed cellulosic material and the biochar; reacting at least a portion of the produced syngas with a catalytic material provided along the pathway to reform the at least a portion of the produced syngas displaced along the pathway; as well as discharging the filtered synthesis gas from the container, The cellulosic material comprises at least one of wood chips, wood pellets, biomass and biowaste.

2. The method according to claim 1, characterized in that: The container includes at least one conduit for forming the passageway, and the at least one conduit is substantially and entirely formed of the catalytic material for exposing the generated syngas as the syngas passes through the passageway.

3. The method according to claim 1, characterized in that The container includes at least one pipe for forming the passage, and the at least one pipe is internally coated with the catalytic material for exposing the generated syngas when the syngas passes through the passage.

4. The method according to claim 1, characterized in that The catalytic material is made of at least one of the following catalysts: nickel (Ni), molybdenum (Mo), platinum (Pt), ruthenium (Ru), cobalt / molybdenum (CoMo), nickel / molybdenum (NiMo), nickel oxide (NiO) catalyst.

5. The method according to claim 1, characterized in that The pathway includes a closed loop for recirculating the syngas for filtration through at least one of a cellulosic material and a biochar.

6. The method according to claim 1, characterized in that Displacing the generated syngas along the pathway includes: The cellulosic material is displaced along the pathway by a conveying system to be heated by the heat generator to form the biochar, wherein the conveying system is one of a displacement screw conveyor and a gravity feed system.

7. The method according to claim 6, characterized in that The conveying system is a spiral auger made of the catalytic material and coated with the catalytic material.

8. The method according to claim 1, characterized in that: Displacing the generated syngas along the pathway includes: displacing the generated syngas along the pathway using a displacing system and generally through the pyrolyzed cellulosic material, The heat generator is one of an electric heater, a heat exchanger and an ablative heat exchanger.

9. The method according to claim 1, characterized in that: Further including: injecting the cellulosic material into the passageway of the container via a displacement screw conveyor; as well as In response to the syngas being discharged in a substantial amount from the vessel, the biochar is discharged from the vessel.

10. The method according to claim 1, characterized in that Discharging the filtered syngas from the container comprises: discharging the filtered syngas through a port to one of a downstream process and a storage system, wherein the port is defined by the container and is configured to facilitate flow of the filtered syngas in a direction generally opposite to the direction of flow of the cellulosic material along the passageway, and The synthesis gas is at least one of hydrogen, methane, carbon monoxide and carbon dioxide.

11. A system for generating synthesis gas, characterized in that: include: A container comprising: A passage for heating the cellulosic material therein; as well as, a heat generator in thermal communication with the passageway for thermally degrading the cellulosic material by pyrolysis, wherein the cellulosic material forms biochar upon pyrolysis to release syngas, wherein the pathway is shaped and adapted for displacing the produced syngas along the pathway thereby filtering the syngas through at least one of the pyrolyzed cellulosic material and the biochar, the pathway having catalytic material provided along the pathway for reacting with at least a portion of the produced syngas to reform at least a portion of the produced syngas circulating along the pathway, wherein the filtered syngas is discharged from the container, and, The cellulosic material comprises at least one of wood chips, wood pellets, biomass and biowaste.

12. The system according to claim 11, characterized in that The container includes at least one conduit for forming the passageway, and the at least one conduit is substantially and entirely formed of the catalytic material for exposing the generated syngas as the syngas passes through the passageway.

13. The system according to claim 11, characterized in that The container includes at least one pipe for forming the passage, and the at least one pipe is coated with the catalytic material inside for exposing the generated synthesis gas when the synthesis gas passes through the circulation passage.

14. The system according to claim 11, characterized in that The catalytic material is made of at least one of the following catalysts: nickel (Ni), molybdenum (Mo), platinum (Pt), ruthenium (Ru), cobalt / molybdenum (CoMo), nickel / molybdenum (NiMo), nickel oxide (NiO) catalyst.

15. The system according to claim 11, characterized in that The pathway includes a closed loop for recirculating the syngas for filtration through at least one of a cellulosic material and a biochar.

16. The system according to claim 11, characterized in that Further including: A conveying system for displacing the cellulosic material along the pathway for heating by the heat generator to form the biochar, wherein the conveying system is one of a displacement screw conveyor and a gravity feed system.

17. The system according to claim 16, characterized in that The conveying system is a spiral auger made of the catalytic material and coated with the catalytic material.

18. The system according to claim 11, characterized in that Further including: a displacement system for displacing the generated syngas along the pathway and generally through the pyrolyzed cellulosic material, The heat generator is one of an electric heater, a heat exchanger and an ablative heat exchanger.

19. The system according to claim 11, characterized in that Further including: a displacement screw conveyor for injecting the cellulosic material into the passageway of the container, wherein the biochar is discharged from the container in response to a substantial discharge of syngas from the container.

20. The system according to claim 11, characterized in that the filtered syngas is discharged from a port to one of a downstream process and a storage system, the port being defined by the vessel and configured to facilitate flow of the filtered syngas in a direction generally opposite to the direction of flow of the cellulosic material along the passageway, The synthesis gas is at least one of hydrogen, methane, carbon monoxide and carbon dioxide.

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