A method for producing hydrogen from water vapor of alcohols by alkaline gas-solid phase photothermal catalytic reforming
By using alkaline gas-solid phase photothermal catalysis method in alcohol steam reforming reaction and using light source to irradiate the catalyst for reaction, the problems of catalyst poisoning and energy consumption in alcohol steam reforming process were solved, and further High hydrogen production and lower production costs.
Patent Information
- Application Number
- CN202410269809.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2024-03-11
- Publication Date
- 2024-12-10
- Estimated Expiration
- 2044-03-11
AI Technical Summary
The existing methods of alcohol-based steam reforming hydrogen production consume a large amount of electrical energy or fossil energy under thermal catalysis, and the catalyst is easily poisoned and inactivated under alkaline conditions, affecting hydrogen production.
Using alkaline gas-solid phase photothermal catalysis method, by setting up light windows and porous support frames in the reactor, using light sources to irradiate the catalyst to carry out alcohol steam reforming reaction, avoiding direct contact between the catalyst and the alkaline solution, and increasing hydrogen production .
Maintain catalyst activity under alkaline conditions, significantly improve hydrogen production, reduce electricity or fossil fuel consumption, and reduce production costs.
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Figure CN118145597B_ABST
Abstract
Description
Technical Field
[0001] The invention relates to the field of chemical production, and in particular to a method for producing hydrogen from water vapor of alcohols by alkaline gas-solid phase photothermal catalytic reforming. Background Art
[0002] Due to the large consumption of fossil fuels and the environmental problems caused by their combustion, hydrogen is considered to be a clean energy source that is expected to replace fossil fuels. However, the promotion and use of hydrogen faces many challenges due to its high risk and low volumetric energy density, especially the transportation and storage of hydrogen. Compared with gaseous hydrogen storage, hydrogen production from liquid fuels such as alcohols such as methanol, ethanol, and propanol not only eliminates the safety risks of high-pressure hydrogen storage, but also reduces transportation costs, providing another solution for the development and utilization of hydrogen. In addition, hydrogen production from alcohol steam reforming is considered to be an economical and effective method due to its simple process control, reasonable energy utilization, and relatively high hydrogen production under mild conditions. However, commercial hydrogen production from alcohol steam reforming currently relies heavily on thermal catalysis and consumes a large amount of electricity or fossil energy. Therefore, other methods need to be explored to increase the production of hydrogen in the alcohol steam reforming reaction.
[0003] Semiconductor materials synthesized based on TiO2, ZnO, CdS, CeO2, Al2O3, WO3, ZrO2, SnO2, CoO, In2O3, and C3N4 have good light responsiveness. Using them as catalyst carriers can utilize solar energy and reduce the reaction temperature of steam reforming of alcohols. At present, based on the above semiconductors, there have been studies on the use of Cu / TiO2, Pt / TiO2, Cu / ZnO / Al2O3, Ni / CdS, Pt / CeO2, and Cu / ZrO2 catalysts for hydrogen production from steam reforming of alcohols, among which Cu / ZnO / Al2O3 is a representative commercial catalyst.
[0004] Overcoming the thermodynamic barrier of the alcohol steam hydrogen production reaction from the energy perspective alone is still insufficient, and kinetic factors must also be considered. Alcohols are more easily activated under alkaline conditions, and the CO2 produced by the reaction can be absorbed by the alkaline solution, promoting the reaction. Therefore, alkaline reforming of alcohol steam hydrogen production can achieve a higher hydrogen yield. However, direct contact between the catalyst and the alkaline solution can easily lead to catalyst poisoning, structural damage and deactivation, which seriously affects the catalyst life. Summary of the invention
[0005] In order to solve the problems existing in the above-mentioned prior art, the present invention provides a method for producing hydrogen from water vapor of alcohols by alkaline gas-solid phase photothermal catalytic reforming, which can maintain the original activity of the catalyst under alkaline conditions and increase the hydrogen production.
[0006] In order to achieve the above object, the technical solution adopted by the present invention is:
[0007] The present invention provides a method for producing hydrogen by alkaline gas-solid phase photothermal catalytic reforming of alcohol water vapor, comprising the following steps:
[0008] S1. Take a reactor, one end of which is provided with a light window so that the light source outside the reactor can enter the reactor; a porous support frame is provided inside the reactor for supporting a glass sheet;
[0009] S2, adding an alkaline alcohol aqueous solution into a reaction kettle to serve as a reaction substrate, placing a porous support frame, and placing a glass sheet with a catalyst loaded on the surface on the porous support frame, wherein the glass sheet with a catalyst loaded on the surface is not immersed in the reaction substrate;
[0010] S3. After the reactor with the light window is installed, the air in the reactor is exhausted with inert gas, the reactor is heated, and a light source is used to illuminate the light window. The light passes through the light window to illuminate the catalyst, and the vaporized alcohol water vapor contacts the catalyst through the porous support frame, and a reforming reaction occurs to produce hydrogen.
[0011] Preferably, the porous support frame may be a porous metal sheet with supporting legs, or a porous metal sheet supported by a slot.
[0012] Preferably, the alcohol in the alkaline alcohol aqueous solution includes one or more of methanol, ethanol, propanol, n-butanol, isobutanol, pentanol, hexanol, heptanol, octanol, ethylene glycol, propylene glycol, butanediol, hexanediol, glycerol, and pentanetriol.
[0013] Preferably, the alkaline substance in the alkaline alcohol aqueous solution includes LiOH, NaOH, KOH, RbOH, CsOH, Be(OH)2, Ca(OH)2, Sr(OH)2, Ba(OH)2, Ra(OH)2, Li2CO3, LiHCO3, Na2CO3, NaHCO3, K2CO3, KHCO3, Rb2CO3, RbHCO3, Cs2CO3, CsHCO3, Li3PO4, Li2HPO4, Li One or more of H2PO4, Na3PO4, Na2HPO4, NaH2PO4, K3PO4, K2HPO4, KH2PO4, Rb3PO4, Rb2HPO4, RbH2PO4, Cs3PO4, Cs2HPO4, CsH2PO4, Li2SO3, LiHSO3, Na2SO3, NaHSO3, K2SO3, KHSO3, Rb2SO3, RbHSO3, Cs2SO3, and CsHSO3.
[0014] In the present invention, the salt, alcohol and water contained in the alkaline alcohol aqueous solution can be in any ratio.
[0015] In the present invention, the reactor is a batch reactor.
[0016] Preferably, the glass sheet with the catalyst loaded on the surface is prepared by the following steps: uniformly dispersing the catalyst in a solvent, dripping onto the glass sheet, drying, and evaporating the solvent to obtain the glass sheet with the catalyst loaded on the surface. In the present invention, there is no limitation on the specific solvent, as long as the catalyst can be uniformly dispersed.
[0017] Further preferably, the catalyst is at least one of photosensitive catalysts loaded with active metals.
[0018] Further preferably, the carrier of the catalyst is one or more of TiO2, ZnO, CdS, CeO2, Al2O3, WO3, ZrO2, SnO2, CoO, In2O3, MgO, and C3N4, and the supported metal of the catalyst is at least one of Pt, Pd, Ru, Ir, Au, Ag, La, Cu, Ni, Co, Fe, Ce, Zn, Al, Sm, Gd, Zr, and B.
[0019] Preferably, in step S3, the reactor is heated to 100-500°C; further preferably, in step S3, the reactor is heated to 150-250°C.
[0020] Preferably, in step S3, after the air in the kettle is exhausted by inert gas, the pressure is increased to 0-10 MPa using inert gas, and then the reactor is heated; further preferably, in step S3, after the air in the kettle is exhausted by inert gas, the pressure is increased to 1-10 MPa using inert gas, and then the reactor is heated.
[0021] In the present invention, the inert gas is at least one of N2, He, Ne, Ar, Kr, and Xe.
[0022] Preferably, in step S3, the optical power density of the light source is 0 to 1000 W / m 2 Further preferably, in step S3, the optical power density of the light source is 100 to 1000 W / m 2 .
[0023] In the present invention, the light source may be a xenon lamp, or other alternative light sources, which is not limited in the present invention.
[0024] Compared with the prior art, the present invention has the following beneficial effects:
[0025] The present invention separates the catalyst from the alkaline alcohol aqueous solution, can achieve a higher hydrogen yield under the same reaction conditions, reduces the consumption of electric energy or fossil fuels, and helps to reduce production costs. BRIEF DESCRIPTION OF THE DRAWINGS
[0026] Figure 1A diagram of a reactor model used in an embodiment of the present invention, in which a, b and c are respectively a light window, a porous metal sheet and a card slot;
[0027] Figure 2 The hydrogen production rate under different KOH concentrations in Example 1 of the present invention;
[0028] Figure 3 The hydrogen production rate under different K2CO3 concentrations in Example 2 of the present invention. DETAILED DESCRIPTION
[0029] The specific embodiments of the present invention are further described below. It should be noted that the description of these embodiments is used to help understand the present invention, but does not constitute a limitation of the present invention. In addition, the technical features involved in each embodiment of the present invention described below can be combined with each other as long as they do not conflict with each other.
[0030] The experimental methods in the following examples are conventional methods unless otherwise specified, and the experimental materials used in the following examples are commercially available unless otherwise specified.
[0031] Example 1
[0032] Dissolve 50mg of TiO2 catalyst loaded with 0.05wt% Pt in 1.5ml of methanol solution, ultrasonicate for 30min to make the catalyst evenly dispersed in the methanol solution, then use a pipette to evenly drop it on a round glass piece, and use a constant temperature heating table to dry at 70℃; use 0M, 2M, 4M, 6M, 8M, 14M, 20M potassium hydroxide solution and methanol to prepare methanol aqueous solution with a mass ratio of alcohol to water of 27:16; take 40ml of the prepared methanol aqueous solution, pour it into a high-pressure reactor with a light window, and put the glass piece with the catalyst dropped into the high-pressure reactor supported by a porous metal sheet in the reactor. After the reactor is installed, exhaust the air with nitrogen and pressurize it to 2Mpa; then put the installed reactor into the heating jacket and heat it to 190℃, use 500W / m 2 After 75 minutes of reaction, the reactor was cooled to room temperature and the gas was collected. The hydrogen content was detected by gas chromatography. The hydrogen yield was as follows: Figure 2 As shown, it can be seen that with the increase of potassium hydroxide concentration, that is, the increase of pH, the hydrogen production increases significantly.
[0033] Example 2
[0034] Dissolve 50mg of TiO2 catalyst loaded with 0.05wt% Pt in 1.5ml of methanol solution, ultrasonicate for 30min to make the catalyst evenly dispersed in the methanol solution, then use a pipette to evenly drop it on a round glass sheet, and use a constant temperature heating table to dry at 70℃; use 0M and 8M potassium carbonate solution and methanol to prepare a methanol aqueous solution with a mass ratio of 27:16; take 40ml of the prepared methanol aqueous solution, pour it into a high-pressure reactor with a light window, and put the glass sheet with the catalyst dropped into the high-pressure reactor supported by a porous metal sheet in the reactor. After the reactor is installed, exhaust the air with nitrogen and pressurize it to 2Mpa; then put the installed reactor into the heating jacket and heat it to 190℃, use 500W / m 2 After 75 minutes of reaction, the reactor was cooled to room temperature and the gas was collected. The hydrogen content was detected by gas chromatography. The hydrogen yield was as follows: Figure 3 As shown, it can be seen that with the increase of potassium carbonate concentration, that is, the increase of pH, the hydrogen production increases significantly.
[0035] The embodiments of the present invention are described in detail above, but the present invention is not limited to the described embodiments. For those skilled in the art, various changes, modifications, substitutions and variations of these embodiments are made without departing from the principles and spirit of the present invention, and still fall within the protection scope of the present invention.
Claims
1. A method for producing hydrogen from water vapor of alcohols by alkaline gas-solid phase photothermal catalytic reforming, It is characterized in that The following steps are involved: S1. Take a reactor, one end of which is provided with a light window so that the light source outside the reactor can enter the reactor; a porous support frame is provided inside the reactor for supporting a glass sheet; S2, adding an alkaline alcohol aqueous solution into a reactor to serve as a reaction substrate, placing a porous support frame, placing a glass sheet with a catalyst on the surface on the porous support frame, and the glass sheet with a catalyst on the surface is not immersed in the reaction substrate; the alcohol in the alkaline alcohol aqueous solution includes one or more of methanol, ethanol, n-butanol, isobutanol, ethylene glycol, and glycerol; the alkaline substance in the alkaline alcohol aqueous solution includes LiOH, NaOH, KOH, RbOH, CsOH, Ca(OH) 2 、Sr(OH) 2 、Ba(OH) 2 、Ra(OH) 2 , Li 2 CO 3 、LiHCO 3 、Na 2 CO 3 、NaHCO 3 , K 2 CO 3 , KHCO 3 , Rb 2 CO 3 , RbHCO 3 , Cs 2 CO 3 , CsHCO 3 , Li 3 PO 4 、Na 3 PO 4 , K 3 PO 4 , Rb 3 PO 4 , Cs 3 PO 4 , Li 2 SO 3 、Na 2 SO 3 , K 2 SO 3 , Rb 2 SO 3 , Cs 2 SO 3 One or more of the following; S3. After the reactor with the light window is installed, the air in the reactor is exhausted with an inert gas, the reactor is heated, and the light window is irradiated with a light source. The light passes through the light window and irradiates the catalyst. The vaporized alcohol water vapor contacts the catalyst through the porous support frame, and a reforming reaction occurs to produce hydrogen. The catalyst is at least one of the photosensitive catalysts loaded with active metals, and the catalyst carrier is TiO 2 、ZnO、CdS、CeO 2 、Al 2 O 3 , WO 3 、ZrO 2 SnO 2 、CoO、In 2 O 3 、MgO、C 3 N 4 The catalyst may be selected from the group consisting of one or more of Pt, Pd, Ru, Ir, Au, Ag, La, Cu, Ni, Co, Fe, Ce, Zn, Al, Sm, Gd, and Zr.
2. The method for producing hydrogen from alcohol water vapor by alkaline gas-solid phase photothermal catalytic reforming according to claim 1, It is characterized in that The porous support frame is a porous metal sheet with supporting feet, or a porous metal sheet supported by a slot.
3. The method for producing hydrogen from alcohol steam by alkaline gas-solid phase photothermal catalytic reforming according to claim 1, It is characterized in that The glass sheet with catalyst loaded on the surface is prepared by the following steps: uniformly dispersing the catalyst in a solvent, dripping the catalyst on the glass sheet, drying, and obtaining the glass sheet with catalyst loaded on the surface after the solvent evaporates.
4. The method for producing hydrogen from alcohol water vapor by alkaline gas-solid phase photothermal catalytic reforming according to claim 1, It is characterized in that In step S3, the reactor is heated to 100-500°C.
5. The method for producing hydrogen from alcohol water vapor by alkaline gas-solid phase photothermal catalytic reforming according to claim 1, It is characterized in that In step S3, after the air in the reactor is exhausted by the inert gas, the pressure is increased to 1-10 MPa by the inert gas, and then the reactor is heated.
6. The method for producing hydrogen from alcohol steam by alkaline gas-solid phase photothermal catalytic reforming according to claim 1, It is characterized in that In step S3, the optical power density of the light source is 100-1000 W / m 2 .