A device and method for producing hydrogen by biomass gasification

Abstract

A device and method for producing hydrogen by biomass gasification, relating to the technical field of producing hydrogen by biomass gasification, comprises a gasifier, a primary cyclone separator, a cracking furnace, a heat recovery device, a secondary cyclone separator, a filter, a water washing unit, a desulfurization unit, a conversion unit, a pressure swing adsorption unit, a return device, a steam drum, an ash hopper I and a fly ash cooler; a distribution plate is arranged in the gasifier, and a biomass feed port is arranged above the distribution plate; a slag discharge ring pipe is connected at the central notch of the cone bottom of the distribution plate of the gasifier, and a gasifying agent nozzle is arranged in the slag discharge ring pipe; a gasifying agent inlet is arranged in the gas chamber area of ​​the gasifier; a dense phase section and a dilute phase section are arranged from bottom to top above the distribution plate of the gasifier; the top outlet of the gasifier is connected with the inlet of the primary cyclone separator, and the scheme greatly increases the primary conversion efficiency of the fly ash, and correspondingly reduces the invalid fly ash circulation amount between the gasifier and the primary cyclone separator.

Description

Technical field:

[0002] The present invention relates to the technical field of biomass gasification hydrogen production, and in particular to a device and method for biomass gasification hydrogen production. Background technology:

[0004] Since my country's energy structure is mainly based on fossil energy such as coal and oil, and the reserves of fossil fuels (coal, oil, natural gas) are limited, and the environmental problems caused by their use are becoming increasingly serious, the development and utilization of new energy has received widespread attention.

[0005] Renewable energy, including solar energy, wind energy, biomass energy, hydropower, geothermal energy, and ocean energy, is a primary energy source that is widely available, inexhaustible, freely available, and ultimately reliable. Until the large-scale development and use of fossil energy in the past two or three hundred years, it has always been the main source of energy for human survival and development.

[0006] Considering the characteristics of my country's biomass resources, such as a wide variety, large total amount and various forms of existence (such as trees and plants, straw crops, animal feces, domestic waste, etc.), and the characteristics of hydrogen energy such as high calorific value, easy utilization and environmental protection, research on biomass hydrogen production technology can not only promote the development and utilization of hydrogen energy, but also provide important guarantees for the sustainable development of my country's energy structure adjustment and industrialization process.

[0007] A patent application with application number 201710646153.7 and publication number CN107601427A involves a biomass gasification hydrogen production device. The gasifier in the device adopts a two-stage fluidized bed type, the lower part is a fast pyrolysis section, and the upper part is a catalytic cracking section. The catalytic reaction between the material rising from the fast pyrolysis section and the added water vapor is carried out in the upper catalytic cracking section, the purpose of which is to increase the hydrogen yield. In fact, if the gasifier is used in the operation of a large-scale industrial device, the temperature of the upper catalytic cracking section must be lower than that of the lower fast pyrolysis section, that is, the catalytic cracking section is difficult to reach the temperature range required for efficient cracking of tar, and the gas-solid phase at the top outlet of the gasifier will still contain a large amount of tar and other hydrocarbons that have not been cracked; at the same time, there is no high-temperature zone and fly ash recycling system in the gasifier, and there will be problems of low carbon conversion rate and fly ash discharge. Summary of the invention:

[0009] In order to solve the above technical problems, the present invention provides a device and method for producing hydrogen by biomass gasification.

[0010] The present invention is achieved through the following technical solutions:

[0011] A biomass gasification hydrogen production device, characterized in that it includes a gasifier, a primary cyclone separator, a cracking furnace, a heat recovery device, a secondary cyclone separator, a filter, a water washing unit, a desulfurization unit, a conversion unit, a pressure swing adsorption unit, a material return device, a steam drum, an ash hopper I and fly ash cooler; a distribution plate is provided in the gasifier, and a biomass feed port is provided above the distribution plate; a slag discharge ring pipe is connected to the central notch at the cone bottom of the distribution plate of the gasifier, and a gasifying agent nozzle is provided in the slag discharge ring pipe; a gasifying agent inlet is provided in the gas chamber area of ​​the gasifier; a dense phase section and a dilute phase section are respectively provided above the distribution plate of the gasifier from bottom to top; the top outlet of the gasifier is connected to the inlet of the first-stage cyclone separator; the cone bottom of the first-stage cyclone separator is connected to the distribution plate of the gasifier through a return device, and the top outlet of the first-stage cyclone separator is connected to the crude synthesis gas inlet of the cracking furnace; the high-temperature hydrogen-containing crude synthesis gas outlet of the cracking furnace is connected to the top hot side inlet of the heat recovery device; the hydrogen-containing crude synthesis gas outlet after cooling of the heat recovery device is connected to the hydrogen-containing crude synthesis gas inlet of the secondary cyclone separator; the top outlet of the secondary cyclone separator is connected to the hydrogen-containing crude synthesis gas inlet of the filter, and the bottom outlet of the secondary cyclone separator is connected to the ash hopper I ; The bottom of the filter cone section is connected to the distribution plate of the gasifier, and the hydrogen-containing synthesis gas after filtering by the filter is connected to the hydrogen-containing synthesis gas inlet of the water washing unit; the hydrogen-containing synthesis gas outlet of the water washing unit is connected to the hydrogen-containing synthesis gas inlet of the desulfurization unit; the hydrogen-containing synthesis gas outlet of the desulfurization unit after desulfurization is connected to the hydrogen-containing synthesis gas inlet of the conversion unit; the hydrogen-containing gas after conversion of the conversion unit is connected to the hydrogen-containing gas inlet of the pressure swing adsorption unit; the water / steam side of the heat recovery device is connected to the steam drum, the saturated water outlet at the bottom of the steam drum is connected to the saturated water inlet of the heat recovery device, the saturated water / steam outlet at the top of the water / steam side of the heat recovery device is connected to the saturated water / steam inlet at the bottom of the steam drum, the saturated steam outlet at the top of the steam drum is connected to the saturated steam inlet of the heat recovery device, the superheated steam outlet of the heat recovery device is respectively connected to the gasifier inlet of the cracking furnace and the gasifier inlet of the gas chamber area of ​​the gasifier, and the bottom of the ash hopper I cone section is connected to the gasifier nozzle position on the distribution plate of the gasifier.

[0012] In another aspect of the present invention, the material return device includes a material sealing valve and a material return ejector, the cone bottom of the first-stage cyclone separator is connected to the material sealing valve, the material sealing valve is connected to the material return ejector, and the material return ejector is connected to the distribution plate of the gasifier.

[0013] In another aspect of the present invention, part of the by-product carbon dioxide of the pressure swing adsorption unit is used as the ejector gas of the return material ejector, and also as the conveying gas for pneumatic conveying of fly ash between the ash hopper I and the bottom of the filter.

[0014] In another aspect of the present invention, the material return device includes an ash hopper II, the cone bottom of the primary cyclone separator is connected to the ash hopper II, and the bottom of the cone section of the ash hopper II is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier.

[0015] In another aspect of the present invention, a fly ash cooler is provided on the fly ash inlet pipeline of the ash hopper II.

[0016] In another aspect of the present invention, the bottom of the cone section of the ash hopper I is combined with the bottom of the cone section of the filter and connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier.

[0017] A method for producing hydrogen by biomass gasification, characterized in that:

[0018] The raw biomass is fed into the gasifier, and undergoes a gasification reaction with gasifying agents such as oxygen / oxygen-enriched air / water vapor in the gasifier to generate biomass ash and dusty hydrogen-containing crude synthesis gas;

[0019] The biomass ash is discharged from the bottom of the gasifier; the dusty hydrogen-containing raw synthesis gas enters the primary cyclone separator from the top of the gasifier;

[0020] The solid fly ash separated by the primary cyclone separator falls from the cone bottom of the primary cyclone separator to the return device, and enters the local high-temperature area in the dense phase section of the gasifier through the return device;

[0021] The hydrogen-containing raw synthesis gas after rough dust removal by the primary cyclone separator enters the cracking furnace from the top of the primary cyclone separator, and undergoes cracking reaction of hydrocarbon components such as tar and methane with gasifying agents such as oxygen / enriched oxygen / air / water vapor in the cracking furnace, thereby cracking the hydrocarbon components such as tar and methane into hydrogen, carbon dioxide and carbon monoxide;

[0022] The outlet gas after being fully cracked by the cracking furnace enters the heat recovery device to recover the sensible heat of the high-temperature hydrogen-containing synthesis gas and produce superheated steam as a by-product;

[0023] The water / steam side of the heat recovery equipment forms a heat recovery system with natural water / steam circulation with the steam drum. The liquid level of the steam drum is maintained at a reasonable level by adding fresh boiler feed water.

[0024] The superheated steam produced as a byproduct of the heat recovery equipment can be used as a gasifying agent to supply the superheated steam required by the gas chamber of the cracking furnace, the gasifying furnace, and the gasifying agent nozzle of the gasifying furnace;

[0025] The hydrogen-containing crude synthesis gas cooled by the heat recovery device enters the secondary cyclone separator, and fly ash particles in the hydrogen-containing crude synthesis gas are further separated in the secondary cyclone separator. The separated fly ash particles fall and are collected in the ash hopper I. The hydrogen-containing crude synthesis gas after dust removal by the secondary cyclone separator is sent to the filter for further dust removal;

[0026] After further dust removal by the filter, the fly ash concentration in the hydrogen-containing raw synthesis gas is reduced to 5~20mg / Nm 3 , sent to the downstream water washing unit;

[0027] The hydrogen-containing synthesis gas after further dust removal and purification in the water washing unit is sent to the desulfurization unit, and the hydrogen-containing net synthesis gas after desulfurization treatment at the outlet of the desulfurization unit is sent to the conversion unit;

[0028] The hydrogen-containing synthesis gas after the conversion and hydrogen extraction by the conversion unit is sent to the pressure swing adsorption unit. The hydrogen outlet of the pressure swing adsorption unit is the hydrogen product, and the other gas outlet is the by-product carbon dioxide;

[0029] In another aspect of the present invention, the return material device includes a material sealing valve and a return material ejector. The solid fly ash separated by the primary cyclone separator falls from the cone bottom of the primary cyclone separator to the material sealing valve, and then passes through the return material ejector, using carbon dioxide as the ejector gas, and is ejected into the local high-temperature zone in the dense phase section of the gasifier.

[0030] In another aspect of the present invention, the fly ash collected in the ash hopper 1 and the cone section below the filter is combined and transported to the local high temperature area in the dense phase section of the gasifier.

[0031] In another aspect of the present invention, the material return device includes an ash hopper II, a fly ash cooler is arranged on the inlet pipeline of the ash hopper II, the cone bottom of the primary cyclone separator is connected to the ash hopper II, and the bottom of the cone section of the ash hopper II is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier; the fly ash collected by the ash hopper II, the ash hopper I and the cone section below the filter are combined and transported to the local high temperature area in the dense phase section of the gasifier.

[0032] The beneficial effects of the present invention are:

[0033] (1) The present invention directly circulates the high-temperature fly ash captured by the primary cyclone separator connected to the top outlet of the fluidized bed gasifier to the high-temperature zone in the center of the dense phase section of the gasifier, thereby greatly increasing the primary conversion efficiency of the fly ash and correspondingly reducing the amount of ineffective fly ash circulation between the gasifier and the primary cyclone separator.

[0034] (2) The present invention adopts heat recovery equipment to produce water vapor as a by-product, which greatly reduces the water vapor consumption in the fresh gasification agent required for unit hydrogen production, thereby effectively improving the thermal efficiency of the gasification system;

[0035] (3) The present invention recycles the fly ash collected by the secondary cyclone separator and the filter back to the high-temperature area in the center of the dense phase section of the fluidized bed gasifier, greatly improving the carbon conversion rate of the gasification system and effectively solving the problem of exhausting and treating the escaped fly ash in the fluidized bed gasification system;

[0036] (4) The present invention can effectively convert tar and other hydrogen-containing elements produced during the biomass gasification process into hydrogen products, thereby effectively increasing the hydrogen production per unit biomass consumption. Description of the drawings:

[0038] Figure 1 This is a schematic diagram of the device structure of Example 1 of the present invention.

[0039] Figure 2 This is a schematic diagram of the device structure of Example 2 of the present invention.

[0040] Figure 3 This is a schematic diagram of the device structure of Example 3 of the present invention.

[0041] Figure 4 This is a schematic diagram of the device structure of Example 4 of the present invention.

[0042] Figure 5 This is a schematic diagram of the gasifier furnace body structure and the division of various areas in the gasifier furnace used in the present invention.

[0043] Among them: 1. gasifier, 2. primary cyclone separator, 3. cracking furnace, 4. heat recovery equipment, 5. secondary cyclone separator, 6. filter, 7. water washing unit, 8. desulfurization unit, 9. conversion unit, 10. pressure swing adsorption unit, 11. material sealing valve, 12. reflux ejector, 13. steam drum, 14. ash hopper I, 15. ash hopper II, 16. fly ash cooler, 17. oxygen / oxygen-enriched air / air / water vapor, 18. boiler feed water, 19. raw biomass, 20. slag discharge, 21. carbon dioxide, 22. hydrogen, 23. gasifier dilute phase section, 24. gasifier dense phase section, 25. distribution plate, 26. gasifier gas chamber, 27. gasifying agent nozzle, 28. slag discharge ring pipe. Specific implementation method:

[0045] The following is a further description of the embodiments of the present invention in conjunction with the accompanying drawings and embodiments:

[0046] In the description of the present invention, it is necessary to understand that the description indicating the orientation or positional relationship is based on the orientation or positional relationship shown in the accompanying drawings, and is only for the convenience of describing the present invention and simplifying the description, rather than indicating or implying that the device or element referred to must have a specific orientation, be constructed and operated in a specific orientation, and therefore cannot be understood as limiting the scope of protection of the present invention.

[0047] In the description of the present invention, it should be noted that, unless otherwise clearly specified and limited, the terms "disposed", "connected", and "connected" should be understood in a broad sense, for example, it can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection, or it can be indirectly connected through an intermediate medium, or it can be the internal communication of two elements. For ordinary technicians in this field, the specific meanings of the above terms in the present invention can be understood according to specific circumstances.

[0048] Example 1

[0049] A biomass gasification hydrogen production device, comprising a gasifier 1, a primary cyclone separator 2, a cracking furnace 3, a heat recovery device 4, a secondary cyclone separator 5, a filter 6, a water washing unit 7, a desulfurization unit 8, a conversion unit 9, a pressure swing adsorption unit 10, a material return device, a steam drum 13, an ash hopper 1 14 and fly ash cooler 16; a distribution plate is provided in the gasifier 1, and a biomass feed port is provided above the distribution plate; a slag discharge ring pipe is connected to the center notch of the cone bottom of the distribution plate of the gasifier 1, and a gasifying agent nozzle is provided in the slag discharge ring pipe; a gasifying agent inlet is provided in the gas chamber area of ​​the gasifier 1; a dense phase section and a dilute phase section are respectively provided above the distribution plate of the gasifier 1 from bottom to top; the top outlet of the gasifier 1 is connected to the inlet of the first-stage cyclone separator 2; the cone bottom of the first-stage cyclone separator 2 is connected to the distribution plate of the gasifier 1 through a return device, and the top outlet of the first-stage cyclone separator 2 is connected to the crude synthesis gas inlet of the cracking furnace 3; the high-temperature hydrogen-containing crude synthesis gas outlet of the cracking furnace 3 is connected to the top hot side inlet of the heat recovery device 4; the hydrogen-containing crude synthesis gas outlet after cooling of the heat recovery device 4 is connected to the hydrogen-containing crude synthesis gas inlet of the second-stage cyclone separator 5; the top outlet of the second-stage cyclone separator 5 is connected to the hydrogen-containing crude synthesis gas inlet of the filter 6, and the bottom outlet of the second-stage cyclone separator 5 is connected to the ash hopper I 14; the bottom of the conical section of the filter 6 is connected to the distribution plate of the gasifier 1, and the hydrogen-containing synthesis gas after filtering by the filter 6 is connected to the hydrogen-containing synthesis gas inlet of the water washing unit 7; the hydrogen-containing synthesis gas outlet of the water washing unit 7 is connected to the hydrogen-containing synthesis gas inlet of the desulfurization unit 8; the hydrogen-containing synthesis gas outlet of the desulfurization unit 8 after desulfurization is connected to the hydrogen-containing synthesis gas inlet of the conversion unit 9; the hydrogen-containing gas after conversion of the conversion unit 9 is connected to the hydrogen-containing gas inlet of the pressure swing adsorption unit 10; the water / steam side of the heat recovery device 4 is connected to the drum 13, the saturated water outlet at the bottom of the drum 13 is connected to the saturated water inlet of the heat recovery device 4, the saturated water / steam outlet at the top of the water / steam side of the heat recovery device 4 is connected to the saturated water / steam inlet at the bottom of the drum 13, the saturated steam outlet at the top of the drum 13 is connected to the saturated steam inlet of the heat recovery device 4, the superheated steam outlet of the heat recovery device 4 is connected to the gasifying agent inlet of the cracking furnace 3 and the gasifying agent inlet of the gas chamber area of ​​the gasifier 1, respectively, the ash hopper I The bottom of the cone section 14 is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier 1. The return material device includes a material sealing valve 11 and a return material ejector 12. The cone bottom of the primary cyclone separator 2 is connected to the material sealing valve 11. The material sealing valve 11 is connected to the return material ejector 12. The return material ejector 12 is connected to the distribution plate of the gasifier 1. Part of the by-product carbon dioxide of the pressure swing adsorption unit 10 is used as the ejection gas of the return material ejector 12, and also as the conveying gas for the pneumatic conveying of the fly ash under the ash hopper 114 and the filter 6. The bottom of the cone section of the ash hopper 114 and the bottom of the cone section of the filter 6 are combined and connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier 1.

[0050] The device for producing hydrogen by biomass gasification includes a gasifier 1, a primary cyclone separator 2, a cracking furnace 3, a heat recovery device 4, a secondary cyclone separator 5, a filter 6, a water washing unit 7, a desulfurization unit 8, a conversion unit 9, a pressure swing adsorption unit 10, a material sealing valve 11, a reflux ejector 12, a steam drum 13 and an ash hopper 1 14. The biomass feed port above the gasifier 1 distribution plate is connected to the raw biomass; the central notch at the cone bottom of the gasifier 1 distribution plate is connected to the slag discharge ring pipe, and the gasified bottom slag is discharged from the slag discharge ring pipe; a gasifying agent nozzle is provided in the slag discharge ring pipe, which is connected to a part of the raw material oxygen / oxygen-enriched / air / water vapor and other gasifying agents; a gasifying agent inlet is provided in the gas chamber area of ​​the gasifier 1, which is connected to another part of the raw material oxygen / oxygen-enriched / air / water vapor and other gasifying agents; the top of the gasifier 1 distribution plate is respectively a dense phase section and a dilute phase section from bottom to top; the top outlet of the gasifier 1 is connected to the inlet of the primary cyclone separator 2; the primary cyclone The cone bottom of the air separator 2 is connected to the material sealing valve 11, and the top outlet of the first-stage cyclone separator 2 is connected to the crude synthesis gas inlet of the cracking furnace 3; the gasifying agent inlet of the cracking furnace 3 is connected to the gasifying agent such as oxygen / oxygen-enriched air / water vapor, and the high-temperature hydrogen-containing crude synthesis gas outlet of the cracking furnace 3 is connected to the top hot side inlet of the heat recovery device 4; the hydrogen-containing crude synthesis gas outlet after cooling of the heat recovery device 4 is connected to the hydrogen-containing crude synthesis gas inlet of the second-stage cyclone separator 5; the top outlet of the second-stage cyclone separator 5 is connected to the hydrogen-containing crude synthesis gas inlet of the filter 6, and the bottom outlet of the second-stage cyclone separator 5 is connected to the ash hopper I 14; the bottom of the cone section of the filter 6 is connected to the position of the gasifier nozzle near the distribution plate of the gasifier 1, and the hydrogen-containing synthesis gas after filtering by the filter 6 is connected to the hydrogen-containing synthesis gas inlet of the water washing unit 7; the hydrogen-containing synthesis gas outlet of the water washing unit 7 is connected to the hydrogen-containing synthesis gas inlet of the desulfurization unit 8; the hydrogen-containing synthesis gas outlet of the desulfurization unit 8 after desulfurization is connected to the hydrogen-containing synthesis gas inlet of the conversion unit 9; the hydrogen-containing gas after conversion by the conversion unit 9 is connected to the hydrogen-containing gas inlet of the pressure swing adsorption unit 10;

[0051] The material sealing valve 11 is connected to a return material ejector 12, and the return material ejector 12 is connected to a position on the distribution plate of the gasifier 1 close to the gasifying agent nozzle;

[0052] The water / steam side of the heat recovery device 4 is connected to the drum 13. The drum 13 maintains its liquid level by supplementing boiler feed water, the saturated water outlet at the bottom of the drum 13 is connected to the saturated water inlet of the heat recovery device 4, the saturated water / steam outlet at the top of the water / steam side of the heat recovery device 4 is connected to the saturated water / steam inlet at the bottom of the drum 13, the saturated steam outlet at the top of the drum 13 is connected to the saturated steam inlet of the heat recovery device 4, and the superheated steam outlet of the heat recovery device 4 is respectively connected to the gasification agent inlet of the cracking furnace 3 and the gasification agent inlet of the gas chamber area of ​​the gasifier 1;

[0053] The filter 6 can be made of metal filter element or ceramic filter element;

[0054] The bottom of the cone section of the ash hopper 1 14 is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier 1;

[0055] The hydrogen outlet of the pressure swing adsorption unit 10 is the final hydrogen product, and the other gas outlet is the by-product carbon dioxide gas;

[0056] The bottom of the cone section of the ash hopper 1 14 is combined with the bottom of the cone section of the filter 6 and connected to the distribution plate of the gasifier 1 near the gasification agent nozzle;

[0057] Part of the by-product carbon dioxide of the pressure swing adsorption unit 10 can be used as the ejection gas of the return material ejector 12, and can also be used as the conveying gas for the pneumatic conveying of the fly ash under the ash hopper I 14 and the filter 6;

[0058] The biomass gasification hydrogen production device comprises the following steps when used:

[0059] (1) The raw biomass is fed into the gasifier 1 and undergoes a gasification reaction with a gasifying agent such as oxygen / oxygen-enriched air / water vapor in the gasifier 1 to generate biomass ash and dusty hydrogen-containing raw synthesis gas;

[0060] (2) Biomass ash is discharged from the bottom of the gasifier 1; the dusty hydrogen-containing raw synthesis gas enters the primary cyclone separator 2 from the top of the gasifier 1;

[0061] (3) The solid fly ash separated by the primary cyclone separator 2 falls from the cone bottom of the primary cyclone separator 2 to the material sealing valve 11, and then passes through the return material ejector 12, using carbon dioxide as ejector gas, and is ejected to the local high-temperature area in the dense phase section of the gasifier;

[0062] (4) The hydrogen-containing raw synthesis gas after rough dust removal by the primary cyclone separator 2 enters the cracking furnace 3 from the top of the primary cyclone separator 2, and undergoes cracking reaction of hydrocarbon components such as tar and methane with gasifying agents such as oxygen / enriched oxygen / air / water vapor in the cracking furnace 3, thereby cracking the hydrocarbon components such as tar and methane into hydrogen, carbon dioxide and carbon monoxide;

[0063] (5) The outlet gas after being fully cracked by the cracking furnace 3 enters the heat recovery device 4 to recover the sensible heat of the high-temperature hydrogen-containing synthesis gas and produce superheated steam as a by-product;

[0064] (6) The water / steam side of the heat recovery device 4 forms a heat recovery system with natural water / steam circulation with the steam drum 13. The liquid level of the steam drum 13 is maintained at a reasonable level by adding fresh boiler feed water;

[0065] (7) The superheated steam produced as a byproduct of the heat recovery device 4 can be used as a gasifying agent to supply the superheated steam required by the cracking furnace 3, the gas chamber of the gasifier 1, and the gasifying agent nozzle of the gasifier 1;

[0066] (8) The hydrogen-containing crude synthesis gas cooled by the heat recovery device 4 enters the secondary cyclone separator 5, and fly ash particles in the hydrogen-containing crude synthesis gas are further separated in the secondary cyclone separator 5. The separated fly ash particles fall and are collected in the ash hopper I 14. The hydrogen-containing crude synthesis gas after dust removal by the secondary cyclone separator 5 is sent to the filter 6 for further dust removal;

[0067] (9) After further dust removal by filter 6, the fly ash concentration in the hydrogen-containing raw synthesis gas is reduced to 5~20 mg / Nm 3 , sent to the downstream water washing unit 7;

[0068] (10) The hydrogen-containing synthesis gas after further dust removal and purification in the water washing unit 7 is sent to the desulfurization unit 8, and the hydrogen-containing clean synthesis gas after desulfurization treatment at the outlet of the desulfurization unit 8 is sent to the conversion unit 9;

[0069] (11) The hydrogen-containing synthesis gas after the conversion and hydrogen extraction by the conversion unit 9 is sent to the pressure swing adsorption unit 10. The hydrogen outlet of the pressure swing adsorption unit 10 is a qualified hydrogen product, and the other gas outlet is a by-product carbon dioxide;

[0070] (12) The fly ash collected by the ash hopper I 14 and the cone section below the filter 6 in step (8) and step (9) is combined and transported to the local high temperature area in the dense phase section of the gasifier;

[0071] The positive effects of this program are:

[0072] (1) This scheme directly circulates the high-temperature fly ash captured by the first-stage cyclone separator connected to the top outlet of the fluidized bed gasifier to the high-temperature zone in the center of the dense phase section of the gasifier, greatly increasing the primary conversion efficiency of the fly ash and correspondingly reducing the amount of ineffective fly ash circulation between the gasifier and the first-stage cyclone separator.

[0073] (2) This scheme uses heat recovery equipment to produce by-product water vapor, which greatly reduces the water vapor consumption in the fresh gasification agent required for unit hydrogen production, effectively improving the thermal efficiency of the gasification system;

[0074] (3) This scheme recycles the fly ash collected by the secondary cyclone separator and filter back to the high-temperature area in the center of the dense phase section of the fluidized bed gasifier, greatly improving the carbon conversion rate of the gasification system and effectively solving the problem of exhausting and treating the escaped fly ash in the fluidized bed gasification system;

[0075] (4) This scheme can effectively convert the tar and other hydrogen-containing elements produced during the biomass gasification process into hydrogen products, thereby effectively increasing the hydrogen production per unit biomass consumption.

[0076] Example 2

[0077] In this embodiment, the material sealing valve 11 and the return material ejector 12 in the embodiment 1 are replaced by an ash hopper II 15.

[0078] Example 3

[0079] In this embodiment, a fly ash cooler 16 is added between the primary cyclone separator 2 and the ash hopper II 15 in the second embodiment.

[0080] Example 4

[0081] In this embodiment, based on the embodiment 3, the fly ash collected from the ash hopper II 15, the ash hopper I 14 and the cone section below the filter 6 are combined into one place through a pneumatic conveying pipeline and transported to a local high temperature area in the dense phase section of the gasifier.

[0082] Example 5

[0083] A method for producing hydrogen by biomass gasification, specifically comprising:

[0084] The raw biomass is fed into the gasifier 1 and reacts with a gasifying agent such as oxygen / oxygen-enriched air / water vapor in the gasifier 1 to generate biomass ash and dusty hydrogen-containing raw synthesis gas;

[0085] The biomass ash is discharged from the bottom of the gasifier 1; the dusty hydrogen-containing raw synthesis gas enters the primary cyclone separator 2 from the top of the gasifier 1;

[0086] The solid fly ash separated by the primary cyclone separator 2 falls from the cone bottom of the primary cyclone separator 2 to the return device, and enters the local high-temperature area in the dense phase section of the gasifier through the return device;

[0087] The hydrogen-containing raw synthesis gas after rough dust removal by the primary cyclone separator 2 enters the cracking furnace 3 from the top of the primary cyclone separator 2, and undergoes cracking reaction of hydrocarbon components such as tar and methane with gasifying agents such as oxygen / enriched oxygen / air / water vapor in the cracking furnace 3, thereby cracking the hydrocarbon components such as tar and methane into hydrogen, carbon dioxide and carbon monoxide;

[0088] The outlet gas after being fully cracked by the cracking furnace 3 enters the heat recovery device 4 to recover the sensible heat of the high-temperature hydrogen-containing synthesis gas and produce superheated steam as a by-product;

[0089] The water / steam side of the heat recovery device 4 forms a heat recovery system with natural water / steam circulation with the drum 13. The liquid level of the drum 13 is maintained at a reasonable position by adding fresh boiler feed water.

[0090] The superheated steam produced as a byproduct of the heat recovery device 4 can be used as a gasifying agent to supply the superheated steam required by the cracking furnace 3, the gas chamber of the gasifying furnace 1, and the gasifying agent nozzle of the gasifying furnace 1;

[0091] The hydrogen-containing crude synthesis gas cooled by the heat recovery device 4 enters the secondary cyclone separator 5, and fly ash particles in the hydrogen-containing crude synthesis gas are further separated in the secondary cyclone separator 5. The separated fly ash particles fall and are collected in the ash hopper I 14. The hydrogen-containing crude synthesis gas after dust removal by the secondary cyclone separator 5 is sent to the filter 6 for further dust removal.

[0092] After further dust removal by filter 6, the fly ash concentration in the hydrogen-containing raw synthesis gas is reduced to 5~20mg / Nm 3 , sent to the downstream water washing unit 7;

[0093] The hydrogen-containing synthesis gas after further dust removal and purification in the water washing unit 7 is sent to the desulfurization unit 8, and the hydrogen-containing clean synthesis gas after desulfurization treatment at the outlet of the desulfurization unit 8 is sent to the conversion unit 9;

[0094] The hydrogen-containing synthesis gas after the conversion and hydrogen extraction by the conversion unit 9 is sent to the pressure swing adsorption unit 10. The hydrogen outlet of the pressure swing adsorption unit 10 is the hydrogen product, and the other gas outlet is the by-product carbon dioxide;

[0095] The return material device includes a material sealing valve 11 and a return material ejector 12. The solid fly ash separated by the primary cyclone separator 2 falls from the cone bottom of the primary cyclone separator 2 to the material sealing valve 11, and then passes through the return material ejector 12, using carbon dioxide as an ejector gas, and is ejected to the local high-temperature area in the dense phase section of the gasifier.

[0096] The fly ash collected in the ash hopper 114 and the cone section below the filter 6 is combined and transported to the local high temperature area in the dense phase section of the gasifier.

[0097] The positive and progressive effects of the present invention are:

[0098] (1) This scheme directly circulates the high-temperature fly ash captured by the first-stage cyclone separator connected to the top outlet of the fluidized bed gasifier to the high-temperature zone in the center of the dense phase section of the gasifier, greatly increasing the primary conversion efficiency of the fly ash and correspondingly reducing the amount of ineffective fly ash circulation between the gasifier and the first-stage cyclone separator.

[0099] (2) This scheme uses heat recovery equipment to produce by-product water vapor, which greatly reduces the water vapor consumption in the fresh gasification agent required for unit hydrogen production, effectively improving the thermal efficiency of the gasification system;

[0100] (3) This scheme recycles the fly ash collected by the secondary cyclone separator and filter back to the high-temperature area in the center of the dense phase section of the fluidized bed gasifier, greatly improving the carbon conversion rate of the gasification system and effectively solving the problem of exhausting and treating the escaped fly ash in the fluidized bed gasification system;

[0101] (4) This scheme can effectively convert the tar and other hydrogen-containing elements produced during the biomass gasification process into hydrogen products, thereby effectively increasing the hydrogen production per unit biomass consumption.

[0102] Example 6

[0103] A method for producing hydrogen by gasifying biomass,

[0104] The raw biomass is fed into the gasifier 1 and reacts with a gasifying agent such as oxygen / oxygen-enriched air / water vapor in the gasifier 1 to generate biomass ash and dusty hydrogen-containing raw synthesis gas;

[0105] The biomass ash is discharged from the bottom of the gasifier 1; the dusty hydrogen-containing raw synthesis gas enters the primary cyclone separator 2 from the top of the gasifier 1;

[0106] The solid fly ash separated by the primary cyclone separator 2 falls from the cone bottom of the primary cyclone separator 2 to the return device, and enters the local high-temperature area in the dense phase section of the gasifier through the return device;

[0107] The hydrogen-containing raw synthesis gas after rough dust removal by the primary cyclone separator 2 enters the cracking furnace 3 from the top of the primary cyclone separator 2, and undergoes cracking reaction of hydrocarbon components such as tar and methane with gasifying agents such as oxygen / enriched oxygen / air / water vapor in the cracking furnace 3, thereby cracking the hydrocarbon components such as tar and methane into hydrogen, carbon dioxide and carbon monoxide;

[0108] The outlet gas after being fully cracked by the cracking furnace 3 enters the heat recovery device 4 to recover the sensible heat of the high-temperature hydrogen-containing synthesis gas and produce superheated steam as a by-product;

[0109] The water / steam side of the heat recovery device 4 forms a heat recovery system with natural water / steam circulation with the drum 13. The liquid level of the drum 13 is maintained at a reasonable position by adding fresh boiler feed water.

[0110] The superheated steam produced as a byproduct of the heat recovery device 4 can be used as a gasifying agent to supply the superheated steam required by the cracking furnace 3, the gas chamber of the gasifying furnace 1, and the gasifying agent nozzle of the gasifying furnace 1;

[0111] The hydrogen-containing crude synthesis gas cooled by the heat recovery device 4 enters the secondary cyclone separator 5, and fly ash particles in the hydrogen-containing crude synthesis gas are further separated in the secondary cyclone separator 5. The separated fly ash particles fall and are collected in the ash hopper I 14. The hydrogen-containing crude synthesis gas after dust removal by the secondary cyclone separator 5 is sent to the filter 6 for further dust removal.

[0112] After further dust removal by filter 6, the fly ash concentration in the hydrogen-containing raw synthesis gas is reduced to 5~20mg / Nm 3 , sent to the downstream water washing unit 7;

[0113] The hydrogen-containing synthesis gas after further dust removal and purification in the water washing unit 7 is sent to the desulfurization unit 8, and the hydrogen-containing clean synthesis gas after desulfurization treatment at the outlet of the desulfurization unit 8 is sent to the conversion unit 9;

[0114] The hydrogen-containing synthesis gas after the conversion and hydrogen extraction by the conversion unit 9 is sent to the pressure swing adsorption unit 10. The hydrogen outlet of the pressure swing adsorption unit 10 is the hydrogen product, and the other gas outlet is the by-product carbon dioxide;

[0115] The material return device includes an ash hopper II 15, a fly ash cooler 16 is arranged on the inlet pipeline of the ash hopper II 15, the cone bottom of the primary cyclone separator 2 is connected to the ash hopper II 15, and the bottom of the cone section of the ash hopper II 15 is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier 1; the fly ash collected by the ash hopper II 15, the ash hopper I 14 and the cone section below the filter 6 are combined and transported to the local high temperature area in the dense phase section of the gasifier.

[0116] The positive effects of this program are:

[0117] (1) This scheme directly circulates the high-temperature fly ash captured by the first-stage cyclone separator connected to the top outlet of the fluidized bed gasifier to the high-temperature zone in the center of the dense phase section of the gasifier, greatly increasing the primary conversion efficiency of the fly ash and correspondingly reducing the amount of ineffective fly ash circulation between the gasifier and the first-stage cyclone separator.

[0118] (2) This scheme uses heat recovery equipment to produce by-product water vapor, which greatly reduces the water vapor consumption in the fresh gasification agent required for unit hydrogen production, effectively improving the thermal efficiency of the gasification system;

[0119] (3) This scheme recycles the fly ash collected by the secondary cyclone separator and filter back to the high-temperature area in the center of the dense phase section of the fluidized bed gasifier, greatly improving the carbon conversion rate of the gasification system and effectively solving the problem of exhausting and treating the escaped fly ash in the fluidized bed gasification system;

[0120] (4) This scheme can effectively convert the tar and other hydrogen-containing elements produced during the biomass gasification process into hydrogen products, thereby effectively increasing the hydrogen production per unit biomass consumption.

[0121] In conclusion, the above is only a preferred embodiment of the present invention, and all equivalent changes and modifications made according to the scope of the patent application of the present invention should fall within the scope of the patent of the present invention.

Claims

1. A biomass gasification hydrogen production device, characterized in that: The invention comprises a gasifier (1), a primary cyclone separator (2), a cracking furnace (3), a heat recovery device (4), a secondary cyclone separator (5), a filter (6), a water washing unit (7), a desulfurization unit (8), a conversion unit (9), a pressure swing adsorption unit (10), a return device, a steam drum (13), an ash hopper I (14) and a fly ash cooler (16); a distribution plate is arranged in the gasifier (1), and a biomass feed port is arranged above the distribution plate; a slag discharge ring pipe is connected to the central notch at the cone bottom of the distribution plate of the gasifier (1), and a gasifying agent nozzle is arranged in the slag discharge ring pipe; a gasifying agent inlet is arranged in the gas chamber area of ​​the gasifier (1); a dense phase section and a dilute phase section are arranged above the distribution plate of the gasifier (1) from bottom to top; the top outlet of the gasifier (1) is connected to the inlet of the primary cyclone separator (2); the cone bottom of the primary cyclone separator (2) is connected to the separator of the gasifier (1) through the return device. The top outlet of the primary cyclone separator (2) is connected to the crude synthesis gas inlet of the cracking furnace (3); the high-temperature hydrogen-containing crude synthesis gas outlet of the cracking furnace (3) is connected to the top hot side inlet of the heat recovery device (4); the cooled hydrogen-containing crude synthesis gas outlet of the heat recovery device (4) is connected to the hydrogen-containing crude synthesis gas inlet of the secondary cyclone separator (5); the top outlet of the secondary cyclone separator (5) is connected to the hydrogen-containing crude synthesis gas inlet of the filter (6), and the bottom outlet of the secondary cyclone separator (5) is connected to the ash hopper I (14); the filter The bottom of the cone section (6) is connected to the distribution plate of the gasifier (1); the hydrogen-containing synthesis gas after filtering by the filter (6) is connected to the hydrogen-containing synthesis gas inlet of the water washing unit (7); the hydrogen-containing synthesis gas outlet of the water washing unit (7) is connected to the hydrogen-containing synthesis gas inlet of the desulfurization unit (8); the hydrogen-containing synthesis gas outlet of the desulfurization unit (8) after desulfurization is connected to the hydrogen-containing synthesis gas inlet of the conversion unit (9); the hydrogen-containing gas after conversion by the conversion unit (9) is connected to the hydrogen-containing gas inlet of the pressure swing adsorption unit (10); the water of the heat recovery device (4) The steam / steam side is connected to the drum (13), the saturated water outlet at the bottom of the drum (13) is connected to the saturated water inlet of the heat recovery device (4), the saturated water / steam outlet at the top of the water / steam side of the heat recovery device (4) is connected to the saturated water / steam inlet at the bottom of the drum (13), the saturated steam outlet at the top of the drum (13) is connected to the saturated steam inlet of the heat recovery device (4), the superheated steam outlet of the heat recovery device (4) is connected to the gasifying agent inlet of the cracking furnace (3) and the gasifying agent inlet of the gas chamber area of ​​the gasifier (1), respectively, and the bottom of the cone section of the ash hopper I (14) is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier (1); The material return device comprises a material sealing valve (11) and a material return ejector (12); the cone bottom of the primary cyclone separator (2) is connected to the material sealing valve (11); the material sealing valve (11) is connected to the material return ejector (12); and the material return ejector (12) is connected to the distribution plate of the gasifier (1); The bottom of the cone section of the ash hopper I (14) and the bottom of the cone section of the filter (6) are combined and connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier (1).

2. The device for producing hydrogen by biomass gasification according to claim 1, characterized in that: Part of the by-product carbon dioxide of the pressure swing adsorption unit (10) is used as the ejection gas of the return material ejector (12), and also as the conveying gas for pneumatic conveying of fly ash between the ash hopper I (14) and below the filter (6).

3. The device for producing hydrogen by biomass gasification according to claim 1, characterized in that: The material return device comprises an ash hopper II (15), the cone bottom of the primary cyclone separator (2) is connected to the ash hopper II (15), and the cone bottom of the ash hopper II (15) is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier (1).

4. The device for producing hydrogen by biomass gasification according to claim 3, characterized in that: A fly ash cooler (16) is provided on the fly ash inlet pipeline of the ash hopper II (15).

5. A method for producing hydrogen by biomass gasification, characterized in that: The raw biomass is fed into a gasifier (1) and reacts with a gasifying agent in the gasifier (1) to generate biomass ash and dusty hydrogen-containing raw synthesis gas; The biomass ash is discharged from the bottom of the gasifier (1); the dusty hydrogen-containing raw synthesis gas enters the primary cyclone separator (2) from the top of the gasifier (1); The solid fly ash separated by the primary cyclone separator (2) falls from the cone bottom of the primary cyclone separator (2) to the material return device, and enters the local high-temperature zone in the dense phase section of the gasifier through the material return device; The hydrogen-containing raw synthesis gas, which has been roughly dust-removed by the primary cyclone separator (2), enters the cracking furnace (3) from the top of the primary cyclone separator (2), and undergoes a cracking reaction of hydrocarbon components with a gasifying agent in the cracking furnace (3), thereby cracking the hydrocarbon components into hydrogen, carbon dioxide and carbon monoxide; The outlet gas after being fully cracked by the cracking furnace (3) enters the heat recovery device (4) to recover the sensible heat of the high-temperature hydrogen-containing synthesis gas and produce superheated steam as a by-product; The water / steam side of the heat recovery device (4) and the steam drum (13) form a heat recovery system with natural water / steam circulation. The liquid level of the steam drum (13) is maintained at a reasonable level by adding fresh boiler feed water. The superheated steam produced as a byproduct of the heat recovery device (4) can be used as a gasifying agent to supply the superheated steam required by the cracking furnace (3), the gas chamber of the gasifying furnace (1), and the gasifying agent nozzle of the gasifying furnace (1); The hydrogen-containing crude synthesis gas cooled by the heat recovery device (4) enters the secondary cyclone separator (5), and fly ash particles in the hydrogen-containing crude synthesis gas are further separated in the secondary cyclone separator (5). The separated fly ash particles fall and are collected in the ash hopper I (14). The hydrogen-containing crude synthesis gas after dust removal by the secondary cyclone separator (5) is sent to the filter (6) for further dust removal; After further dust removal by the filter (6), the fly ash concentration in the hydrogen-containing raw synthesis gas is reduced to 5-20 mg / Nm3 and sent to the downstream water washing unit (7); The hydrogen-containing synthesis gas after further dust removal and purification in the water washing unit (7) is sent to the desulfurization unit (8), and the hydrogen-containing clean synthesis gas after desulfurization treatment at the outlet of the desulfurization unit (8) is sent to the conversion unit (9); The hydrogen-containing synthesis gas after conversion and hydrogen extraction in the conversion unit (9) is sent to the pressure swing adsorption unit (10). The hydrogen outlet of the pressure swing adsorption unit (10) is the hydrogen product, and the other gas outlet is the by-product carbon dioxide.

6. The method for producing hydrogen by biomass gasification according to claim 5, characterized in that: The material return device comprises a material sealing valve (11) and a material return ejector (12); the solid fly ash separated by the primary cyclone separator (2) falls from the cone bottom of the primary cyclone separator (2) to the material sealing valve (11), and then passes through the material return ejector (12), using carbon dioxide as ejector gas, and is ejected to a local high-temperature area in the dense phase section of the gasifier.

7. The method for producing hydrogen by biomass gasification according to claim 6, characterized in that: The fly ash collected by the ash hopper I (14) and the cone section below the filter (6) is combined and transported to the local high temperature area in the dense phase section of the gasifier.

8. The method for producing hydrogen by biomass gasification according to claim 5, characterized in that: The return material device comprises an ash hopper II (15), a fly ash cooler (16) is arranged on the inlet pipeline of the ash hopper II (15), the cone bottom of the primary cyclone separator (2) is connected to the ash hopper II (15), and the bottom of the cone section of the ash hopper II (15) is connected to the position of the gasifying agent nozzle on the distribution plate of the gasifier (1); the fly ash collected by the ash hopper II (15), the ash hopper I (14) and the cone section below the filter (6) are combined and transported to the local high temperature area in the dense phase section of the gasifier.

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