A biogas hydrogen production prying device
By introducing a carbon dioxide removal system and waste heat cascade utilization into the biogas hydrogen production unit, the problem of carbon dioxide covering the active sites of the catalyst was solved, which improved the methane conversion rate and catalyst life and reduced the cost.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- SHANGHAI REZEL KEHUA ENG DESIGN CO LTD
- Filing Date
- 2025-07-10
- Publication Date
- 2026-07-03
AI Technical Summary
In existing biogas steam reforming processes, carbon dioxide occupies the active sites of the reforming catalyst, resulting in low methane conversion rates and short catalyst lifespans.
Before biogas enters the converter, carbon dioxide is removed by a carbon dioxide removal system to prevent it from covering the active sites of the catalyst. An integrated skid-mounted unit design is adopted, which includes modules for desulfurization, decarbonization, conversion, shift conversion and hydrogen purification, and utilizes waste heat for cascaded heat utilization.
It improved methane conversion rate, extended catalyst life, reduced equipment cost, improved heat utilization rate, and simplified on-site assembly and transportation.
Smart Images
Figure CN224442574U_ABST
Abstract
Description
Technical Field
[0001] This utility model belongs to the field of hydrogen production technology, specifically to a biogas-to-hydrogen skid device. Background Technology
[0002] Against the backdrop of the global energy structure accelerating its transformation towards low-carbon and clean energy, hydrogen, as a highly efficient energy carrier with zero carbon emissions, is widely regarded as an important component of the future energy system. Biogas, a product of anaerobic fermentation of organic waste, has methane as its main component, which has a high calorific value. Through proper conversion, it can achieve the dual goals of waste resource utilization and clean energy production; therefore, the technological route for producing hydrogen from biogas has attracted widespread attention.
[0003] The current mainstream process for hydrogen production from biogas is steam reforming. Its principle is that, under high temperature (600-900℃) and the action of a catalyst, methane in biogas reacts with water vapor to produce hydrogen and carbon monoxide. This method has advantages such as fast reaction rate and mature technology. However, biogas steam reforming hydrogen production devices have certain drawbacks: the large amount of carbon dioxide in biogas partially occupies the active sites of the conversion catalyst, inhibiting the methane conversion reaction and resulting in a low methane conversion rate in biogas. Utility Model Content
[0004] To address the aforementioned problems, the purpose of this utility model is to provide a biogas-to-hydrogen skid device. Before the biogas enters the converter, the carbon dioxide in the biogas is removed by a carbon dioxide removal system to prevent carbon dioxide from covering the active sites of the conversion catalyst, thereby improving the methane conversion rate and extending the life of the conversion catalyst.
[0005] The technical solution adopted in this utility model is as follows:
[0006] A biogas-to-hydrogen skid-mounted device includes a reactor skid, on which a desulfurization tank is installed. The top of the desulfurization tank is connected to a biogas delivery pipe, and the bottom of the desulfurization tank is connected to a carbon dioxide removal system via a pipe. The top of the carbon dioxide removal system is connected to a converter via a pipe, and the bottom of the converter is connected to a shift reactor via a pipe. The bottom of the shift reactor is connected to a gas-liquid separator via a pipe, and the top of the gas-liquid separator is connected to a hydrogen purification system via a pipe. The top of the hydrogen purification system is connected to a product hydrogen delivery pipe.
[0007] Preferably, the lower sidewall of the converter is connected to an air / flue gas heat exchanger via a pipe, the air / flue gas heat exchanger is connected to an air delivery pipe, the upper sidewall of the converter is connected to the heat source inlet of the air / flue gas heat exchanger via a pipe, and the heat source outlet of the air / flue gas heat exchanger is connected to a cold flue gas delivery pipe.
[0008] Preferably, a steam superheater is installed on the pipe connecting the upper side wall of the converter to the air / flue gas heat exchanger, a steam generator is installed on the pipe connecting the converter to the shift reactor, the cold source inlet of the steam generator is connected to a demineralized water delivery pipe, the cold source outlet of the steam generator is connected to the heat source inlet of the steam superheater, and the heat source outlet of the steam superheater is connected to the top of the converter through a pipe.
[0009] Preferably, the shift reactor is provided with a first catalyst bed and a second catalyst bed located below the first catalyst bed. The first catalyst bed is connected to a demineralized water primary preheater through a pipeline. The demineralized water primary preheater is connected to the second catalyst bed through a pipeline. The cold source inlet of the demineralized water primary preheater is connected to the demineralized water conveying pipe. The cold source outlet of the demineralized water primary preheater is connected to the cold source inlet of the steam generator.
[0010] Preferably, a secondary demineralized water preheater is installed on the pipeline between the shift reactor and the gas-liquid separator, and a water cooler is installed on the pipeline between the secondary demineralized water preheater and the gas-liquid separator. The cold source inlet of the secondary demineralized water preheater is connected to the cold source outlet of the primary demineralized water preheater, and the cold source outlet of the secondary demineralized water preheater is connected to the cold source inlet of the steam generator.
[0011] Preferably, the bottom of the hydrogen purification system is connected to the lower side wall of the conversion furnace via a pipe.
[0012] Preferably, it also includes a pressure swing adsorption skid and a compressor skid. The carbon dioxide removal system and the hydrogen purification system are installed on the pressure swing adsorption skid. The compressor skid is equipped with a biogas compressor, a desorbed gas compressor and a blower. The biogas compressor is located on the pipeline connecting the desulfurization tank and the carbon dioxide removal system. The desorbed gas compressor is located on the pipeline connecting the hydrogen purification system and the converter. The blower is located on the air delivery pipe.
[0013] Preferably, a biogas / converted gas heat exchanger is installed on the pipeline connecting the converter and the shift reactor, and the cold source inlet and cold source outlet of the biogas / converted gas heat exchanger are connected to the pipeline between the carbon dioxide removal system and the converter.
[0014] Preferably, the bottom of the carbon dioxide removal system is connected to a coarse carbon dioxide delivery pipe.
[0015] Preferably, the bottom of the gas-liquid separator is connected to a process condensate conveying pipe.
[0016] In summary, due to the adoption of the above technical solution, the beneficial effects of this utility model are:
[0017] Before biogas enters the converter, carbon dioxide is removed from the biogas through a carbon dioxide removal system to prevent carbon dioxide from covering the active sites of the conversion catalyst, thereby improving the methane conversion rate and extending the life of the conversion catalyst. Attached Figure Description
[0018] To more clearly illustrate the technical solutions of the embodiments of this utility model, the drawings used in the embodiments will be briefly introduced below. It should be understood that the following drawings only show some embodiments of this utility model and should not be regarded as a limitation on the scope. For those skilled in the art, other related drawings can be obtained based on these drawings without creative effort.
[0019] Figure 1 Schematic diagrams of the reactor skid, pressure swing adsorption skid, and compressor skid provided in the embodiments of this utility model;
[0020] Figure 2 A flowchart illustrating an embodiment of this utility model.
[0021] Figure reference numerals: 101-Reactor skid; 102-Pressure swing adsorption skid; 103-Compressor skid; 1-Desulfurization tank; 2-Biogas compressor; 3-Carbon dioxide removal system; 4-Biogas / converted gas heat exchanger; 5-Converter; 6-Steam generator; 7-Shift reactor; 8-Demineralized water primary preheater; 9-Demineralized water secondary preheater; 10-Water cooler; 11-Gas-liquid separator; 12-Hydrogen purification system; 13-Desorbed gas compressor; 14-Steam superheater; 1 5-Air / flue gas heat exchanger; 16-Blower; 21-Biogas delivery pipe; 22-Pretreated biogas; 23-Crude carbon dioxide delivery pipe; 24-Mixed feedstock gas; 25-Converted gas; 26-Shifted gas; 27-Crude hydrogen; 28-Process condensate delivery pipe; 29-Product hydrogen delivery pipe; 30-Desorbed gas; 31-Air delivery pipe; 32-Hot flue gas; 33-Cold flue gas delivery pipe; 34-Demineralized water delivery pipe; 35-Saturated steam; 36-Superheated steam. Detailed Implementation
[0022] To make the objectives, technical solutions, and advantages of the embodiments of this utility model clearer, the technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. The components of the embodiments of this utility model described and shown in the accompanying drawings can generally be arranged and designed in various different configurations.
[0023] Therefore, the following detailed description of the embodiments of the present invention provided in the accompanying drawings is not intended to limit the scope of the claimed invention, but merely to illustrate selected embodiments of the invention. All other embodiments obtained by those skilled in the art based on the embodiments of the present invention without inventive effort are within the scope of protection of the present invention.
[0024] In the description of this utility model, it should be noted that if terms such as "center", "upper", "lower", "left", "right", "vertical", "horizontal", "inner", "outer" appear to indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings, or the orientation or positional relationship commonly used when the product is in use, they are only for the convenience of describing this utility model and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation, and therefore should not be construed as a limitation of this utility model.
[0025] The following is combined Figure 1 and Figure 2 This utility model will be described in detail.
[0026] Example
[0027] A biogas-to-hydrogen skid-mounted device includes a reactor skid 101, a desulfurization tank 1 mounted on the reactor skid 101, a biogas delivery pipe 21 connected to the top of the desulfurization tank 1, a carbon dioxide removal system 3 connected to the bottom of the desulfurization tank 1 via a pipe, a converter 5 connected to the top of the carbon dioxide removal system 3 via a pipe, a shift reactor 7 connected to the bottom of the shift reactor 5 via a pipe, a gas-liquid separator 11 connected to the bottom of the shift reactor 7 via a pipe, a hydrogen purification system 12 connected to the top of the gas-liquid separator 11 via a pipe, and a product hydrogen delivery pipe 29 connected to the top of the hydrogen purification system 12.
[0028] The desulfurization tank 1 is filled with iron oxide desulfurizing agent, which is cylindrical with a diameter of 2-10 mm, a length of 2-20 mm, and a bulk density of 0.4-0.8 kg / L. It can reduce the hydrogen sulfide content in biogas to below 0.5 ppm under normal temperature and pressure conditions, thereby avoiding the deactivation of conversion catalyst and shift catalyst due to sulfur poisoning. The furnace tube of the converter 5 is filled with nickel-based conversion catalyst, which is cylindrical with a diameter of 10-30 mm, a length of 5-25 mm, and a bulk density of 0.6-1.5 kg / L. The reaction pressure is 0.1-3.5 MPa, and the reaction temperature is 650-900℃. The carbon dioxide removal system 3 and the hydrogen purification system 12 are both dual-tower pressure swing adsorption systems, and can also be set as dual-tower pressure swing adsorption systems with more towers according to actual needs.
[0029] Before biogas enters the converter 5, carbon dioxide is removed from the biogas through the carbon dioxide removal system 3 to prevent carbon dioxide from covering the active sites of the conversion catalyst, thereby improving the methane conversion rate and extending the life of the conversion catalyst.
[0030] An air / flue gas heat exchanger 15 is connected to the lower side wall of the converter 5 via a pipe. The air / flue gas heat exchanger 15 is connected to an air delivery pipe 31. The upper side wall of the converter 5 is connected to the heat source inlet of the air / flue gas heat exchanger 15 via a pipe. The heat source outlet of the air / flue gas heat exchanger 15 is connected to a cold flue gas delivery pipe 33. The hot flue gas 32 generated by the converter 5 can transfer heat to the air through the air / flue gas heat exchanger 15, thereby preheating the air and increasing the utilization rate of heat.
[0031] A steam superheater 14 is installed on the pipe connecting the upper side wall of the converter 5 to the air / flue gas heat exchanger 15. A steam generator 6 is installed on the pipe connecting the converter 5 to the shift reactor 7. The cold source inlet of the steam generator 6 is connected to a demineralized water delivery pipe 34, and the cold source outlet of the steam generator 6 is connected to the heat source inlet of the steam superheater 14. The heat source outlet of the steam superheater 14 is connected to the top of the converter 5 through a pipe. The converted gas 25 generated by the converter 5 heats the demineralized water through the steam generator 6 to obtain saturated steam 35. The hot flue gas 32 generated by the converter 5 further heats the saturated steam 35 through the steam superheater 14, turning the saturated steam 35 into superheated steam 36, which is then mixed with the pretreated biogas 22 to obtain mixed feed gas 24, improving the utilization rate of heat.
[0032] The shift reactor 7 contains a first catalyst bed and a second catalyst bed located below the first catalyst bed. The first catalyst bed is connected to a demineralized water primary preheater 8 via a pipeline. The demineralized water primary preheater 8 is connected to the second catalyst bed via a pipeline. The cold source inlet of the demineralized water primary preheater 8 is connected to the demineralized water delivery pipe 34, and the cold source outlet of the demineralized water primary preheater 8 is connected to the cold source inlet of the steam generator 6. The shift reactor 7 has two catalyst beds, filled with the same iron-based shift catalyst. The catalyst beds are cylindrical in shape, with a diameter of approximately 3-16 mm, a length of 4-30 mm, a bulk density of 1.1-1.8 g / mL, a reaction pressure of 0.1-3.5 MPa, and a reaction temperature of 260-510℃. The shift reactor 7 adopts a two-stage catalyst bed layout. The reaction gas drawn from the bottom of the first-stage catalyst bed is cooled by demineralized water and then enters the top of the second-stage catalyst bed. This can effectively avoid the sintering and deactivation of the shift catalyst caused by excessively high catalyst bed temperature in the shift reactor 7. At the same time, the removed heat is used to preheat the demineralized water, making full use of the reaction heat.
[0033] A secondary demineralized water preheater 9 is installed on the pipeline between the shift reactor 7 and the gas-liquid separator 11. A water cooler 10 is installed on the pipeline between the secondary demineralized water preheater 9 and the gas-liquid separator 11. The cold source inlet of the secondary demineralized water preheater 9 is connected to the cold source outlet of the primary demineralized water preheater 8, and the cold source outlet of the secondary demineralized water preheater 9 is connected to the cold source inlet of the steam generator 6. The shift gas 26 output from the bottom of the shift reactor 7 further heats the demineralized water through the secondary demineralized water preheater 9, improving the utilization rate of heat. The temperature of the demineralized water is heated to near saturation temperature, which facilitates the heating by the steam generator 6 to obtain saturated steam 35.
[0034] This application requires no external steam supply. The steam needed for the conversion reaction is obtained as follows: the demineralized water is heated by the waste heat of the shift gas 26, and then the preheated demineralized water is converted into saturated steam 35 by the waste heat of the shift gas 25. The saturated steam 35 is then heated by the hot flue gas 32 to become superheated steam 36 that meets the process requirements. This process uses a temperature gradient configuration, which can effectively utilize waste heat.
[0035] The bottom of the hydrogen purification system 12 is connected to the lower side wall of the converter 5 via a pipe. The desorbed gas 30 (mainly containing carbon monoxide, carbon dioxide, methane and a small amount of hydrogen) discharged from the bottom of the hydrogen purification system 12 is transported to the converter 5 for use as fuel, thereby reducing fuel consumption.
[0036] It also includes a pressure swing adsorption (PSA) skid 102 and a compressor skid 103. The carbon dioxide removal system 3 and the hydrogen purification system 12 are installed on the PSA skid 102. The compressor skid 103 is equipped with a biogas compressor 2, a desorbed gas compressor 13, and a blower 16. The biogas compressor 2, the desorbed gas compressor 13, and the blower 16 are used to pressurize the biogas, the desorbed gas 30, and the air, respectively. The biogas compressor 2 is located on the pipeline connecting the desulfurization tank 1 and the carbon dioxide removal system 3. The desorbed gas compressor 13 is located on the pipeline connecting the hydrogen purification system 12 and the converter 5. The blower 16 is located on the air delivery pipe 31. The desulfurization tank 1, the gas-liquid separator 11, the converter 5, the shift reactor 7, the water cooler 10, the primary preheater of demineralized water 8, the secondary preheater of demineralized water 9, the steam generator 6, the biogas / converted gas heat exchanger 4, the steam superheater 14, and the air / flue gas heat exchanger 15 are all installed on the reactor skid 101. The reactor skid 101, pressure swing adsorption skid 102, and compressor skid 103 are connected by pipelines, as are the internal equipment of the skids. This can effectively utilize space and save floor space. At the same time, the use of highly integrated skid-mounted facilities facilitates transportation, reduces equipment costs, and shortens on-site assembly time, which can significantly save construction time.
[0037] A biogas / converted gas heat exchanger 4 is installed on the pipeline connecting the converter 5 and the shift reactor 7. The cold source inlet and cold source outlet of the biogas / converted gas heat exchanger 4 are connected to the pipeline between the carbon dioxide removal system 3 and the converter 5. The converted gas 25 produced by the converter 5 preheats the pretreated biogas 22 through the biogas / converted gas heat exchanger 4, which facilitates subsequent reactions and improves the utilization rate of heat.
[0038] The bottom of the carbon dioxide removal system 3 is connected to a coarse carbon dioxide conveying pipe 23. The coarse carbon dioxide conveying pipe 23 can output coarse carbon dioxide, which is then transported outside the device for purification to obtain food-grade carbon dioxide.
[0039] The bottom of the gas-liquid separator 11 is connected to a process condensate delivery pipe 28. The process condensate delivery pipe 28 can output process condensate, which is discharged to the wastewater treatment system.
[0040] The specific implementation process of this application:
[0041] Biogas, used as feedstock, enters desulfurization tank 1 at normal temperature and pressure to remove hydrogen sulfide. It is then pressurized by biogas compressor 2 and transported to carbon dioxide removal system 3. The pretreated biogas 22 obtained from carbon dioxide removal system 3 contains <1 mol of carbon dioxide. The crude carbon dioxide discharged from carbon dioxide removal system 3 is transported outside the equipment for purification to obtain food-grade carbon dioxide.
[0042] After pretreatment, biogas 22 is preheated to 500-650°C by converted gas 25 in biogas / converter heat exchanger 4, and then mixed with superheated steam 36 from steam superheater 14 to obtain mixed feed gas 24, which then enters converter 5 for conversion reaction. The methane conversion rate is higher than 95%. The converted gas 25 obtained after the reaction passes through biogas / converter heat exchanger 4 and steam generator 6 in sequence, is cooled to 260-420°C, and then enters shift reactor 7 for shift reaction.
[0043] The shift reactor 7 has two catalyst beds from top to bottom. The reaction gas flowing out from the bottom of the first catalyst bed enters the demineralized water primary preheater 8 for cooling, and then enters the second catalyst bed from the top to continue the reaction. The shift gas 26 discharged from the bottom of the shift reactor 7 passes through the demineralized water secondary preheater 9 and the water cooler 10 in sequence, and is cooled to 40~45℃ before entering the gas-liquid separator 11 for gas-liquid separation. The process condensate 28 discharged from the bottom of the gas-liquid separator 11 is discharged to the external wastewater treatment system, and the crude hydrogen 27 discharged from the top of the gas-liquid separator 11 enters the hydrogen purification system 12.
[0044] The hydrogen obtained from the hydrogen purification system 12 has a hydrogen content greater than 99.95 mol; the desorbed gas 30 discharged from the hydrogen purification system 12 mainly contains carbon monoxide, carbon dioxide, methane and a small amount of hydrogen. After being pressurized by the desorbed gas compressor 13, it is sent to the furnace of the converter 5 for use as fuel gas.
[0045] After being pressurized by blower 16, the air enters air / flue gas heat exchanger 15 for preheating, and then enters the furnace of converter 5. There, it undergoes a combustion reaction with the desorbed gas from self-desorbed gas compressor 13, and the released heat energy serves as the heat source for converter 5. The hot flue gas 32 discharged from the furnace of converter 5 still has a high temperature. After being cooled by steam superheater 14 and air / flue gas heat exchanger 15 in sequence, it is discharged as cold flue gas.
[0046] The above are merely preferred embodiments of this utility model and are not intended to limit the scope of this utility model. Various modifications and variations can be made to this utility model by those skilled in the art. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of this utility model should be included within the protection scope of this utility model.
Claims
1. A biogas to hydrogen prying device comprising a reactor pry (101), characterized in that, The reactor skid (101) is equipped with a desulfurization tank (1), the top of the desulfurization tank (1) is connected to a biogas delivery pipe (21), the bottom of the desulfurization tank (1) is connected to a carbon dioxide removal system (3) through a pipe, the top of the carbon dioxide removal system (3) is connected to a converter (5) through a pipe, the bottom of the converter (5) is connected to a shift reactor (7) through a pipe, the bottom of the shift reactor (7) is connected to a gas-liquid separator (11) through a pipe, the top of the gas-liquid separator (11) is connected to a hydrogen purification system (12) through a pipe, and the top of the hydrogen purification system (12) is connected to a product hydrogen delivery pipe (29).
2. The biogas-to-hydrogen skid device according to claim 1, characterized in that, The lower side wall of the converter (5) is connected to an air / flue gas heat exchanger (15) via a pipe. The air / flue gas heat exchanger (15) is connected to an air delivery pipe (31). The upper side wall of the converter (5) is connected to the heat source inlet of the air / flue gas heat exchanger (15) via a pipe. The heat source outlet of the air / flue gas heat exchanger (15) is connected to a cold flue gas delivery pipe (33).
3. A biogas to hydrogen prizing device according to claim 2, wherein, A steam superheater (14) is installed on the pipe connecting the upper side wall of the converter (5) to the air / flue gas heat exchanger (15). A steam generator (6) is installed on the pipe connecting the converter (5) to the shift reactor (7). The cold source inlet of the steam generator (6) is connected to a demineralized water delivery pipe (34). The cold source outlet of the steam generator (6) is connected to the heat source inlet of the steam superheater (14). The heat source outlet of the steam superheater (14) is connected to the top of the converter (5) through a pipe.
4. A biogas to hydrogen prizing device according to claim 3, wherein, The shift reactor (7) is provided with a catalyst bed and a second catalyst bed located below the first catalyst bed. The first catalyst bed is connected to a demineralized water primary preheater (8) through a pipe. The demineralized water primary preheater (8) is connected to the second catalyst bed through a pipe. The cold source inlet of the demineralized water primary preheater (8) is connected to the demineralized water conveying pipe (34). The cold source outlet of the demineralized water primary preheater (8) is connected to the cold source inlet of the steam generator (6).
5. A biogas to hydrogen prizing device according to claim 4, wherein, A secondary demineralized water preheater (9) is installed on the pipeline between the shift reactor (7) and the gas-liquid separator (11). A water cooler (10) is installed on the pipeline between the secondary demineralized water preheater (9) and the gas-liquid separator (11). The cold source inlet of the secondary demineralized water preheater (9) is connected to the cold source outlet of the primary demineralized water preheater (8). The cold source outlet of the secondary demineralized water preheater (9) is connected to the cold source inlet of the steam generator (6).
6. A biogas to hydrogen prizing device according to claim 2, wherein, The bottom of the hydrogen purification system (12) is connected to the lower side wall of the converter (5) via a pipe.
7. A biogas to hydrogen prizing device according to claim 6, wherein, It also includes a pressure swing adsorption skid (102) and a compressor skid (103). The carbon dioxide removal system (3) and the hydrogen purification system (12) are installed on the pressure swing adsorption skid (102). The compressor skid (103) is equipped with a biogas compressor (2), a desorbed gas compressor (13) and a blower (16). The biogas compressor (2) is located on the pipeline connecting the desulfurization tank (1) and the carbon dioxide removal system (3). The desorbed gas compressor (13) is located on the pipeline connecting the hydrogen purification system (12) and the converter (5). The blower (16) is located on the air delivery pipe (31).
8. The biogas to hydrogen prizing device of claim 1, wherein, A biogas / converted gas heat exchanger (4) is installed on the pipeline connecting the converter (5) and the conversion reactor (7). The cold source inlet and cold source outlet of the biogas / converted gas heat exchanger (4) are connected to the pipeline between the carbon dioxide removal system (3) and the converter (5).
9. The biogas to hydrogen prizing device of claim 1, wherein, The bottom of the carbon dioxide removal system (3) is connected to a coarse carbon dioxide delivery pipe (23).
10. The biogas to hydrogen prizing device of claim 1, wherein, The bottom of the gas-liquid separator (11) is connected to a process condensate delivery pipe (28).