Biomass in-situ catalytic gasification hydrogen production method based on sealed reactor

Abstract

The invention relates to a biomass in-situ catalytic gasification hydrogen production method based on a sealed reactor. The sealed reactor comprises a pipeline system, a gas control system, a U-shaped tube reactor, a lifting heating system, a detection device and a water adding device. The method specifically comprises the following steps: uniformly mixing reactants and a catalyst in proportion, and feeding the mixture into the bottom of the U-shaped tube reactor; the U-shaped tube reactor is fixedly connected with the pipeline system, inert gas is introduced to exhaust air, and after exhaust, a valve is closed to enable the U-shaped tube reactor to be in a closed state; and heating the U-shaped tube reactor to carry out catalytic gasification hydrogen production reaction. When biomass is subjected to an in-situ catalytic gasification hydrogen production reaction in the U-shaped tube reactor, high-yield and high-selectivity preparation of hydrogen from the biomass can be realized at the same time under a relatively mild gasification condition, the hydrogen selectivity can reach the highest level in the biomass hydrogen production industry, and the hydrogen yield is also in the front of the industry; the method has great potential in industrial application of biomass catalytic gasification hydrogen production.

Description

Technical Field

[0001] The invention belongs to the technical field of biomass gasification hydrogen production, and specifically relates to a method for in-situ catalytic gasification of biomass hydrogen production based on a sealed reactor. Background Art

[0002] Hydrogen energy has the advantages of high calorific value, cleanliness and no pollution, and is an important part of the modern energy system. Among the many hydrogen production technologies, biomass catalytic gasification hydrogen production technology has attracted widespread attention due to its effective utilization of renewable resources and environmental friendliness. However, how to improve the yield and selectivity of hydrogen is the core issue that needs to be solved in the development of biomass catalytic gasification hydrogen production technology. At the same time, how to reduce the energy consumption of hydrogen production and the complexity of the device are also issues that need to be considered for industrial applications.

[0003] At present, nickel-based catalysts are widely used in biomass catalytic gasification hydrogen production technology due to their good dehydrogenation effect and low cost. At the same time, the most commonly used devices for biomass catalytic gasification are fixed bed reactors and fluidized bed reactors. However, in the available literature on biomass catalytic gasification hydrogen production based on nickel-based catalysts, the comprehensive performance of fixed bed reactors and fluidized bed reactors in hydrogen production efficiency and selectivity is not good enough: (1) In the report of biomass catalytic gasification experiments using fixed bed reactors, the highest hydrogen yield can reach 60.0 mmol / g-biomass, but the selectivity is only 62.5 vol.% (Li et al. Fuel, 2023, 334, 126842-126848); (2) In the report of biomass catalytic gasification hydrogen production experiments using fluidized bed reactors, the highest hydrogen yield can reach 63.6 mmol / g-biomass, but the selectivity is only 75.0 vol.% (Inayat et al. Int. J. Hydrogen Energ., 2021, 46, 30581-30591). In addition, in the above two reports, the gasification reaction conditions that can achieve the highest hydrogen production efficiency are relatively harsh, such as the gasification time needs to reach 30min, and the gasification temperature is higher than 600℃, so the energy consumption of hydrogen production is relatively high. If at a relatively mild gasification temperature, such as 600℃, the hydrogen production rate of the fluidized bed reactor in the above-mentioned literature report by Inayat et al. will drop to about 20mmol / g-biomass, and the selectivity will drop to about 60%. Furthermore, in contrast, patent CN201910137452.7 discloses a device for preparing hydrogen by pyrolysis and gasification of biomass in a dual fluidized bed, which uses the circulation of CO2 absorbent in the furnace to carry CO2 in the gasifier to the combustion furnace for release, and finally obtains a synthesis gas with a hydrogen concentration of 49.0%. It can be seen that its hydrogen selectivity is also at a low level, and the product contains more by-products such as CH4, CO, and CO2, which hinders the subsequent hydrogen purification process and the overall hydrogen production cost is higher.

[0004] The main reasons why fixed bed reactors and fluidized bed reactors perform poorly in experiments on biomass gasification and hydrogen production using nickel-based catalysts are: (1) The contact time between the pyrolysis gas and the catalyst is relatively short, resulting in low utilization of the active sites of the nickel-based catalyst; (2) The degree of secondary reaction of the biomass gaseous pyrolysis products is low, which affects the gasification rate and hydrogen production efficiency. In addition, when using a fluidized bed reactor for gasification and hydrogen production experiments, the catalyst surface will wear during the collision with the biomass particles, resulting in a decrease in catalytic activity, which will also affect the hydrogen production effect of biomass gasification to a certain extent. Therefore, it is crucial to develop a reaction device for high-yield and high-selectivity hydrogen production from biomass catalytic gasification. Summary of the invention

[0005] The purpose of the present invention is to provide a method for producing hydrogen by in-situ catalytic gasification of biomass based on a sealed reactor in order to solve the above problems.

[0006] The present invention achieves the above-mentioned purpose through the following technical solutions:

[0007] A method for producing hydrogen by in-situ catalytic gasification of biomass based on a sealed reactor, wherein the sealed reactor comprises a pipeline system, a gas control system, a U-tube reactor, a lifting and heating system, a detection device, and a water adding device;

[0008] The method for producing hydrogen by in-situ catalytic gasification of biomass comprises the following specific steps:

[0009] Step 1: preheat the lifting and lowering heating system to the reaction temperature, mix the reactants and catalysts in proportion and then feed them into the bottom of the U-tube reactor;

[0010] Step 2: Connect and fix the U-tube reactor to the pipeline system, use the gas control system to adjust the gas flow, introduce inert gas to exhaust air, and after the exhaust is completed, close the valve to make the U-tube reactor in a closed state;

[0011] Step 3: Use the lifting and heating system to heat the U-tube reactor for catalytic gasification hydrogen production reaction. The catalytic gasification time is 10 minutes. After completion, it is naturally cooled for 10 minutes. After cooling is completed, a carrier gas is introduced, and the cooled gasified gas is collected and tested.

[0012] As a further optimization scheme of the present invention, the U-shaped tube reactor comprises a U-shaped quartz tube and quartz wool, and the quartz wool is respectively loaded into both sides of the reactants at the bottom of the U-shaped quartz tube.

[0013] As a further optimization scheme of the present invention, the piping system includes a total intake pipe and an exhaust pipe connected to the U-shaped pipe, a first intake pipe, a second intake pipe, a third intake pipe connected to the total intake pipe, and an air collecting device connected to the exhaust pipe, the second intake pipe is connected to the first intake pipe and the third intake pipe, and the total intake pipe is connected to the first intake pipe and the second intake pipe.

[0014] As a further optimization scheme of the present invention, the gas control system includes a plurality of gas mass flow meters and ball valves 2 respectively arranged on the first intake pipe, the second intake pipe, and the third intake pipe, a needle valve 1 arranged on the main intake pipe, and a needle valve 2 arranged on the exhaust pipe.

[0015] As a further optimization scheme of the present invention, the lifting and heating system includes a lifting mechanism, a heating furnace arranged at the top of the telescopic end of the lifting mechanism, a temperature controller connected to the heating furnace, a fixing frame for detachably connecting and fixing the U-shaped tube, and a thermocouple extending to the inside of the U-shaped tube;

[0016] The water adding device comprises a water inlet pipe extending to the inside of the U-shaped tube and a sample injection pump connected to the water inlet pipe.

[0017] As a further optimization scheme of the present invention, two through-plate joints are provided on the fixing frame, the two ends of the U-shaped tube are respectively connected and fixed to the lower parts of the two through-plate joints by means of two nuts, and two fluororubber rings are provided between the connecting gaps, the thermocouple and the water inlet pipe are respectively connected and fixed to the upper parts of the two through-plate joints by means of one nut, and one fluororubber ring is provided between the connecting gaps.

[0018] As a further optimization scheme of the present invention, the detection device includes a pressure gauge and a gas detection instrument connected to the gas collecting device. The pressure gauge is arranged between needle valve 1 and the U-shaped tube, and a ball valve 1 is provided on the input pipeline of the pressure gauge.

[0019] As a further optimization scheme of the present invention, in step 1, the reaction temperature is in the range of 600-750°C.

[0020] As a further optimization scheme of the present invention, in step 2, the U-tube reactor is connected and fixed to the pipeline system, and the water adding device can be opened to introduce liquid water into the U-tube reactor, and then the gas is exhausted.

[0021] As a further optimization scheme of the present invention, the mass ratio of the reactant to the catalyst is 1:3, the reactant is biomass, and the catalyst is Ni / CaO; the biomass is poplar, pine, bamboo or corn cob.

[0022] The beneficial effects of the present invention are:

[0023] 1) In the present invention, when biomass is subjected to in-situ catalytic gasification hydrogen production reaction inside a U-tube reactor, high yield and high selectivity of hydrogen production from biomass can be achieved under relatively mild gasification conditions (i.e., gasification temperature of 600°C, gasification time of 10 min). The hydrogen selectivity can reach the highest level (93.1 vol.%) in the biomass hydrogen production industry, and the hydrogen yield is also at the forefront of the industry (39.6 mmol / g-biomass).

[0024] 2) The sealed catalytic gasification reaction device provided by the present invention has the advantages of simple structure and low cost, and has great potential for industrial application in biomass catalytic gasification to produce hydrogen. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a schematic diagram of the overall structure of the sealed reactor of Example 1 of the present invention.

[0026] Figure 2 For the present invention Figure 1 Schematic diagram of part of the structure.

[0027] Figure 3 1 is a comparison chart of hydrogen production capacity of different reactants in the sealed reactor of Example 1 by the method of Example 1 for in-situ catalytic gasification hydrogen production reaction.

[0028] Figure 4 This is a comparison diagram of hydrogen production effects of in-situ catalytic gasification of poplar wood in the sealed reactor of Example 1 using the method of Example 2.

[0029] Figure 5 It is a comparison chart of hydrogen production effects of catalytic gasification hydrogen production reaction of poplar wood in existing common hydrogen production reactors (fixed bed in-situ gasification reactor, two-stage fixed bed non-in-situ gasification reactor, fluidized bed reactor) and the sealed reactor of Example 1 of the present application.

[0030] In the figure: 1. ball valve 1; 2. gas mass flow meter; 3. ball valve 2; 4. first air inlet pipe; 5. second air inlet pipe; 6. third air inlet pipe; 7. main air inlet pipe; 8. three-way joint; 9. two-way joint; 10. needle valve 1; 11. pressure gauge; 12. exhaust pipe; 13. gas collecting device; 14. needle valve 2; 15. fixing bracket; 16. through-plate joint; 17. thermocouple; 18. U-shaped tube; 19. heating furnace; 20. quartz wool; 21. mixture of catalyst and biomass; 22. lifting mechanism; 23. temperature controller; 24. water inlet pipe; 25. sample pump; 26. controller; 27. nut 1; 28. fluororubber ring 1; 29. ​​fluororubber ring 2; 30. nut 2. DETAILED DESCRIPTION

[0031] The present application is further described in detail below in conjunction with the accompanying drawings. It is necessary to point out here that the following specific implementation methods are only used to further illustrate the present application and cannot be understood as limiting the scope of protection of the present application. Technical personnel in this field can make some non-essential improvements and adjustments to the present application based on the above application content.

[0032] Example 1

[0033] like Figure 1-2 As shown, a sealed reactor includes a pipeline system, a gas control system, a U-tube reactor, a lifting and heating system, a detection device, and a water adding device;

[0034] The pipeline system is used to supply, exhaust and collect gas for the U-tube reactor;

[0035] The gas control system is used to control the gas flow of the pipeline system;

[0036] The U-shaped tube reactor is used for reactants and catalysts to carry out in-situ catalytic gasification hydrogen production reaction inside the reactor;

[0037] The lifting and heating system is used to heat the U-tube reactor;

[0038] The detection device is used to monitor the pressure change in the U-tube reactor;

[0039] The water adding device is used to introduce liquid water into the U-tube reactor.

[0040] Preferably, the U-shaped tube reactor comprises a U-shaped tube 18 and quartz wool 20, wherein the quartz wool 20 is respectively loaded into both sides of the reactants at the bottom of the U-shaped tube to prevent the reactant particles from being too small or too light and being carried away by the carrier gas. The transparent U-shaped tube 18 is an integrated design without splicing and has good air tightness.

[0041] Preferably, the piping system includes a total air intake pipe 7 and an exhaust pipe 12 connected to the U-shaped tube 18, a first air intake pipe 4, a second air intake pipe 5, a third air intake pipe 6 connected to the total air intake pipe 7, and an air collecting device 13 connected to the exhaust pipe 12, the second air intake pipe 5 is connected to the first air intake pipe 4 and the third air intake pipe 6, and the total air intake pipe 7 is connected to the first air intake pipe 4 and the second air intake pipe 5, which is convenient for the introduction of a variety of different carrier gases, and three different carrier gases can be introduced at the same time to meet certain specific experimental conditions.

[0042] It should be noted that, in this embodiment, the output ends of the first air intake pipe 4 and the second air intake pipe 5 are both provided with three-way joints 8, and the output end of the third air intake pipe 6 is provided with a two-way joint 9 for easy connection.

[0043] In this embodiment, the main air intake pipe 7 and the exhaust pipe 12 are both 3 mm stainless steel pipes;

[0044] In this embodiment, the gas collecting device 13 is any one of an air bag and a gas cylinder.

[0045] Preferably, the gas control system includes a plurality of gas mass flow meters 2 and ball valves 3 respectively arranged on the first air inlet pipe 4, the second air inlet pipe 5, and the third air inlet pipe 6, a needle valve 10 arranged on the main air inlet pipe 7, and a needle valve 14 arranged on the exhaust pipe 12. The needle valve has a better sealing effect here, and the needle valve can adjust the flow rate. The air supply or exhaust starts slowly, and the needle valve can prevent the carrier gas flow from being too large to blow away the reactants and catalysts in the U-shaped tube 18.

[0046] It should be noted that the range of the gas mass flow meter 2 is 0-1000 mL / min.

[0047] Preferably, the lifting and heating system comprises a lifting mechanism 22, a heating furnace 19 disposed at the top of the telescopic end of the lifting mechanism 22, a temperature controller 23 connected to the heating furnace 19, a fixing frame 15 for detachably connecting and fixing the U-shaped tube 18, and a thermocouple 17 extending into the interior of the U-shaped tube 18 to monitor the temperature inside the U-shaped tube 18 in real time;

[0048] The water adding device includes a water inlet pipe 24 extending into the interior of the U-shaped tube 18 and a sample injection pump 25 connected to the water inlet pipe 24 .

[0049] Preferably, two through-plate joints 16 are provided on the fixing frame 15, and the two ends of the U-shaped tube 18 are respectively connected and fixed to the lower parts of the two through-plate joints 16 by nuts 2 30, and a fluororubber ring 29 is provided between the connecting gaps, and the thermocouple 17 and the water inlet pipe 24 are respectively connected and fixed to the upper parts of the two through-plate joints 16 by nuts 1 27, and a fluororubber ring 28 is provided between the connecting gaps.

[0050] It should be noted that, in this embodiment, the diameter of the lower part of the through-plate joint 16 is 8 mm, and the diameter of the upper part is 3 mm, and the nut 2 30 and the nut 1 27 are matched with the upper and lower parts of the through-plate joint 16;

[0051] In this embodiment, the specifications of the fluororubber ring 1 28 are 4 mm in outer diameter, 2 mm in inner diameter, and 1 mm in wire diameter, and the specifications of the fluororubber ring 2 29 are 12 mm in outer diameter, 8 mm in inner diameter, and 2 mm in wire diameter;

[0052] The bottom of the thermocouple 17 is 5 mm away from the bottom of the U-shaped tube, and the bottom of the water inlet pipe 24 is 1 cm away from the bottom of the U-shaped tube.

[0053] Preferably, the detection device includes a pressure gauge 11 and a gas detection instrument connected to the gas collecting device 13, the gas detection instrument is used to detect the gas composition inside the gas collecting device 13, and perform qualitative and quantitative analysis, the pressure gauge 11 is arranged between the needle valve 10 and the U-tube 18, and a ball valve 1 is arranged on the input pipeline of the pressure gauge 11, the range of the pressure gauge 11 is 0-0.6MPa, while closing the needle valve 10 and the needle valve 14, the ball valve 1 at the pressure gauge 11 is also opened, and the pressure change in the U-tube 18 during the catalytic gasification reaction is monitored by the pressure gauge 11, and the system pressure range in the closed state is maintained between 0.14-0.20MPa. In the following embodiments 1-2 and comparative example 1, the system pressure is 0.14MPa.

[0054] A method for producing hydrogen by in-situ catalytic gasification based on the sealed reactor, the specific steps are as follows:

[0055] Step 1: preheat the heating furnace 19 to 600°C, weigh 10 mg of reactants and 30 mg of catalysts so that the mass ratio of catalyst to reactants is 3:1, and feed them into the bottom of the U-shaped tube 18. After mixing evenly, a little quartz wool 20 is stuffed on both sides of the mixture 21 of reactants and catalysts at the bottom of the U-shaped tube 18;

[0056] Step 2: Install the nut 2 30 and the fluororubber ring 29 on the upper part of the U-shaped tube 18 in sequence, then tighten the U-shaped tube 18 to the through-plate joint 16 through the nut 2 30, open the ball valve 2 3, the needle valve 10 and the needle valve 2 14, close the ball valve 1, control the gas mass flow meter 2 to adjust the gas flow, blow in several types of gas for exhaust, and after the exhaust is completed, close the needle valve 10 and the needle valve 2 14, and connect the gas collecting device 13 to the exhaust pipe 12. At this time, the U-shaped tube 18 is in a closed state, and the system pressure is 0.14MPa;

[0057] Step 3: Raise the heating furnace 19 to heat the U-shaped tube 18 for catalytic gasification hydrogen production reaction. The catalytic gasification time is 10 minutes. After completion, lower the heating furnace 19 to allow the U-shaped tube 18 to cool naturally for 10 minutes. After cooling, first open the needle valve 2 14, then open the needle valve 1 10 to allow the carrier gas to prevent the excessive gas pressure in the U-shaped tube from rushing into the air inlet pipe, blow the cooled gasified gas into the gas collecting device 13, and send the gas in the gas collecting device 13 to the micro chromatograph (Agilent, MicroGC-990) for detection.

[0058] It should be noted that, in this embodiment, the mass ratio of the reactant to the catalyst is 1:3, the selected reactant is biomass or plastic, and the catalyst is Ni / CaO; the biomass is poplar, pine, bamboo or corn cob, and the plastic is polyethylene.

[0059] The experimental results are as follows Figure 3As shown: when the mass ratio of catalyst to biomass is 3:1, the gasification temperature is 600℃, and the gasification time is 10min, different types of biomass all show excellent hydrogen production capacity, the hydrogen yield is above 24.6mmol / g-biomass, and the selectivity of hydrogen in non-condensable gas is about 90vol.%. Compared with biomass, when polyethylene is used as a raw material, its hydrogen yield increases (polyethylene has a higher hydrogen content), but the selectivity of hydrogen is only 62.0vol.%, resulting in a high cost for its secondary purification. Therefore, the sealed reaction system proposed in the present invention is more suitable for various biomass catalytic gasification hydrogen production reactions. The biomass gasification product contains a large amount of oxygen-containing compounds. Under a closed state, the thermal motion of the oxygen-containing compound molecules is restricted in a limited space. Therefore, the yield and selectivity of hydrogen can be improved from the following two dimensions: First, it will increase the number of effective collisions between gaseous molecules, promote the occurrence of secondary pyrolysis reactions of the gaseous products themselves, and improve the gasification rate of condensable products; second, the gaseous pyrolysis product molecules form turbulence in the U-tube 18, which can repeatedly and multiple times contact the catalyst, thereby effectively improving the efficiency of the catalytic gasification reaction; third, the closed environment (the system pressure range is 0.14-0.20MPa, preferably 0.14MPa) can promote the adsorption of CO2 by the catalyst, thereby promoting the occurrence of secondary reactions such as water gas, and increasing the proportion and purity of hydrogen in the synthesis gas.

[0060] Example 2

[0061] A method for producing hydrogen by in-situ catalytic gasification based on the sealed reactor, the specific steps are as follows:

[0062] Step 1: preheat the heating furnace 19 to 600°C or 750°C, weigh 10 mg of poplar wood and 30 mg of Ni / CaO catalyst, mix them, and feed them into the bottom of the U-shaped tube 18, and then plug a little quartz wool 20 on both sides of the mixture 21 of the catalyst and biomass at the bottom of the U-shaped tube 18;

[0063] Step 2: Install the nut 2 30 and the fluororubber ring 2 29 on the upper part of the U-shaped tube 18 in sequence, then tighten the U-shaped tube 18 to the through-plate joint 16 through the nut 2 30, open the water adding device to introduce liquid water into the U-shaped tube 18, then open the ball valve 2 3, the needle valve 10 and the needle valve 2 14, close the ball valve 1, control the gas mass flow meter 2 to adjust the gas flow, blow in several types of inert gas for exhaust, after the exhaust is completed, close the needle valve 10 and the needle valve 2 14, and connect the gas collecting device 13 to the exhaust pipe 12. At this time, the U-shaped tube 18 is in a closed state, and the system pressure is 0.14MPa;

[0064] Step 3: Raise the heating furnace 19 to heat the U-tube 18 for catalytic gasification hydrogen production reaction. The catalytic gasification time is 10 minutes. After completion, lower the heating furnace 19 to allow the U-tube 18 to cool naturally for 10 minutes. After cooling, first open the needle valve 2 14, then open the needle valve 1 10 to allow the carrier gas to prevent the excessive gas pressure in the U-tube from rushing into the air inlet pipe, blow the cooled gasified gas into the gas collecting device 13, and send the gas in the gas collecting device 13 to the micro chromatograph (MircoGC-990) for detection.

[0065] The experimental results are as follows Figure 4 As shown, the results show that the addition of liquid water can improve the effect of hydrogen production by biomass catalytic gasification. When the mass ratio of catalyst to biomass is 3:1, the gasification temperature is 600°C, the gasification time is 10 min, and the amount of water added is 20 μL, the hydrogen yield can reach 39.6 mmol / g-biomass, and the selectivity can reach more than 93.0 vol.%; when the gasification temperature is increased to 750°C, the hydrogen yield and selectivity are further improved: the hydrogen yield is 47.5 mmol / g-biomass, and the selectivity is higher than 94.0 vol.%, which indicates that the sealed reactor of the present application can achieve high-yield and high-selectivity hydrogen production by in-situ catalytic gasification of biomass, thereby improving the economy and environmental protection of the reaction.

[0066] Comparative Example 1

[0067] The existing fixed bed and fluidized bed reactors were used to carry out experiments on biomass catalytic gasification for hydrogen production. The biomass was poplar wood, the catalyst was Ni / CaO, the mass ratio of the catalyst to the biomass was 3:1, the gasification temperature was 600°C, the system pressure was 0.14MPa, and no liquid water was added.

[0068] The experimental results are as follows Figure 5 As shown, when the two-stage fixed bed reactor is used for non-in-situ catalytic gasification, the hydrogen yield is only 14.7mmol / g-biomass, and the hydrogen selectivity is 44.1vol.%. When the fixed bed reactor is used for in-situ catalytic gasification, the hydrogen yield is 23.1mmol / g-biomass, and the hydrogen selectivity in the gasification gas is 64.6vol.%. Subsequently, the fluidized bed reactor is used for biomass catalytic gasification experiments. The results show that the hydrogen yield is 19.3mmol / g-biomass, and the hydrogen selectivity in the gasification gas is 67.9vol.%. It should be noted that the fixed bed and fluidized bed reactors used for biomass catalytic gasification are both hydrogen production reactors disclosed in the literature. When the sealed reactor of the present application is used for in-situ catalytic gasification of biomass to produce hydrogen, the hydrogen yield at 600°C is 30.2mmol / g-biomass, and the selectivity can be as high as 91.1vol.%, which shows that the sealed reactor of the present application is more effective in the catalytic gasification of biomass to produce hydrogen.

[0069] Result analysis: Figure 5It can be seen from the data that the currently commonly used fixed bed and fluidized bed reactors have the problem of high CO2 and CO content. When the method of Example 1 of the present application is used to carry out the biomass catalytic gasification experiment, the closed environment it provides (when the pyrolysis temperature is 600°C, the system pressure is 0.14MPa) can not only make the pyrolysis gas repeatedly contact the catalyst, improve the utilization rate of the active sites in the catalyst, but also promote the adsorption of CO2 by the catalyst, thereby effectively promoting the water gas reaction and methane reforming reaction The forward direction is achieved, thereby improving the hydrogen yield and selectivity.

[0070] Experimental conclusion: Compared with the prior art, the yield and selectivity of preparing hydrogen using the closed reaction system provided in the embodiment of the present application and Ni / CaO as a catalyst for poplar wood are the highest.

[0071] The above-mentioned embodiments only express several implementation methods of the present invention, and the description thereof is relatively specific and detailed, but it cannot be understood as limiting the scope of the present invention. It should be pointed out that, for ordinary technicians in this field, several variations and improvements can be made without departing from the concept of the present invention, which all belong to the protection scope of the present invention.

Claims

1. A method for producing hydrogen by in-situ catalytic gasification of biomass based on a sealed reactor, characterized in that: The sealed reactor includes a pipeline system, a gas control system, a U-shaped tube reactor, a lifting and heating system, a detection device, and a water adding device; The method for producing hydrogen by in-situ catalytic gasification of biomass comprises the following specific steps: Step 1: preheat the lifting and lowering heating system to the reaction temperature, mix the reactants and catalysts in proportion and then feed them into the bottom of the U-tube reactor; Step 2: Connect and fix the U-tube reactor to the pipeline system, use the gas control system to adjust the gas flow, introduce inert gas to exhaust the air, and after the exhaust is completed, put the U-tube reactor in a closed state; Step 3: Use the lifting and heating system to heat the U-tube reactor for catalytic gasification hydrogen production reaction. The catalytic gasification time is 10 minutes. After completion, it is naturally cooled for 10 minutes. After cooling is completed, a carrier gas is introduced, and the cooled gasified gas is collected and tested.

2. The method according to claim 1, characterized in that: The U-shaped tube reactor comprises a U-shaped tube (18) and quartz wool (20), wherein the quartz wool (20) is respectively loaded on both sides of the reactant at the bottom of the U-shaped tube.

3. The method according to claim 2, characterized in that: The pipeline system comprises a main intake pipe (7) and an exhaust pipe (12) connected to the U-shaped pipe (18), a first intake pipe (4) connected to the main intake pipe (7), a second intake pipe (5), a third intake pipe (6) and an air collecting device (13) connected to the exhaust pipe (12), the second intake pipe (5) being connected to the first intake pipe (4) and the third intake pipe (6), and the main intake pipe (7) being connected to the first intake pipe (4) and the second intake pipe (5).

4. The method according to claim 3, characterized in that: The gas control system comprises a plurality of gas mass flow meters (2) and ball valves (3) respectively arranged on a first intake pipe (4), a second intake pipe (5), and a third intake pipe (6), a needle valve (10) arranged on a main intake pipe (7), and a needle valve (14) arranged on an exhaust pipe (12).

5. The method according to claim 1, characterized in that: The lifting and heating system comprises a lifting mechanism (22), a heating furnace (19) arranged at the top of the telescopic end of the lifting mechanism (22), a temperature controller (23) connected to the heating furnace (19), a fixing frame (15) for detachably connecting and fixing the U-shaped tube (18), and a thermocouple (17) extending into the interior of the U-shaped tube (18); The water adding device comprises a water inlet pipe (24) extending to the inside of the U-shaped tube (18) and a sample injection pump (25) connected to the water inlet pipe (24).

6. The method according to claim 5, characterized in that: The fixing frame (15) is provided with two through-plate joints (16), the two ends of the U-shaped tube (18) are respectively connected and fixed to the lower parts of the two through-plate joints (16) by means of two nuts (30), and a two fluororubber ring (29) is provided between the connection gaps, and the thermocouple (17) and the water inlet pipe (24) are respectively connected and fixed to the upper parts of the two through-plate joints (16) by means of one nut (27), and a one fluororubber ring (28) is provided between the connection gaps.

7. The method according to claim 1, characterized in that: The detection device comprises a pressure gauge (11) and a gas detection instrument connected to a gas collecting device (13); the pressure gauge (11) is arranged between a needle valve (10) and a U-shaped tube (18); a ball valve (1) is arranged on an input pipeline of the pressure gauge (11).

8. The method according to claim 1, characterized in that: In step 1, the reaction temperature is 600-750°C.

9. The method according to claim 1, characterized in that: In step 2, the U-tube reactor is connected and fixed to the pipeline system, and the water adding device can be opened to introduce liquid water into the U-tube reactor, and then the gas is exhausted.

10. The method according to claim 1, characterized in that: The mass ratio of the reactant to the catalyst is 1:3, the reactant is biomass, the catalyst is Ni / CaO; the biomass is poplar, pine, bamboo or corn cob.

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