Hydrogen purification system based on methanol hydrogen production

Abstract

The utility model discloses a hydrogen purification system based on methanol hydrogen production, which comprises a heat supply system, a reforming hydrogen production system, a first hydrogen purification system and a tail gas recovery system which are connected in sequence, the tail gas recovery system comprises a carbon monoxide converter and a second hydrogen purifier which are sequentially connected, the first hydrogen purifier comprises a first hydrogen outlet and a purified tail gas outlet, and a gas inlet of the carbon monoxide converter is connected with the purified tail gas outlet; and a gas outlet of the carbon monoxide converter is connected with a gas inlet of the second hydrogen purifier. According to the technical scheme, open fire combustion of purified tail gas is reduced, the hydrogen yield of a methanol hydrogen production system is increased, the recovery rate of carbon dioxide is increased, the production cost is reduced, and environmental pollution is reduced; and the production safety is also improved.

Description

Technical Field

[0001] The utility model relates to the technical field of methanol hydrogen production, in particular to a hydrogen purification system based on methanol hydrogen production. Background Art

[0002] Existing methanol hydrogen production and natural gas hydrogen production equipment produce hydrogen through the conversion of methanol, methane, carbon, carbon monoxide and other substances with water vapor. CO2 and H2 are generated in this process, of which the CO2 content is about 45% or higher. After the mixed gas is purified, hydrogen is output as a product, and the remaining tail gas is mostly discharged directly. These tail gases contain a large amount of CO2 and a relatively high concentration of H2 and CO and other gases, which not only cause serious environmental pollution, but also waste precious carbon resources.

[0003] At the same time, the use of methanol to produce hydrogen is an endothermic reaction, which requires a large amount of heat source. Most traditional industries use the combustion of methane or further combustion of purified exhaust gas to provide heat, but the use of open flames brings many safety hazards. Utility Model Content

[0004] In view of the deficiencies of the prior art, the present invention provides the following technical solutions:

[0005] Provided is a hydrogen purification system based on methanol hydrogen production, comprising a heat supply system, a reforming hydrogen production system, a first hydrogen purification system and a tail gas recovery system connected in sequence, wherein the first hydrogen purification system comprises a first hydrogen purifier, characterized in that the tail gas recovery system comprises a carbon monoxide converter and a second hydrogen purifier connected in sequence, the first hydrogen purifier comprises a first hydrogen outlet and a purified tail gas outlet, the gas inlet of the carbon monoxide converter is connected to the purified tail gas outlet, and the gas outlet of the carbon monoxide converter is connected to the gas inlet of the second hydrogen purifier.

[0006] Preferably, the tail gas recovery system further comprises a carbon dioxide collector, and the second hydrogen purifier comprises a second hydrogen outlet and a waste gas outlet, and the waste gas outlet is connected to the gas inlet of the carbon dioxide collector.

[0007] Preferably, the tail gas recovery system further comprises a gas-liquid separator, a gas inlet of the gas-liquid separator is connected to a gas outlet of the carbon monoxide converter, and a gas outlet of the gas-liquid separator is connected to a gas inlet of the second hydrogen purifier.

[0008] Preferably, the first hydrogen purifier is an alloy membrane purifier.

[0009] Preferably, the second hydrogen purifier is an adsorption tower device.

[0010] Preferably, the heating system comprises a first heat exchanger, a heat medium inlet of the first heat exchanger is connected to the purified tail gas outlet, and a heat medium outlet of the first heat exchanger is connected to a gas inlet of the carbon monoxide converter.

[0011] Preferably, the heat supply system further comprises an external exothermic reactor, the periphery of which is provided with a heat exchange tube; the reforming hydrogen production system comprises a reforming reactor, the outlet of the heat exchange tube is connected to the heat medium inlet of the reforming reactor.

[0012] Preferably, the heat supply system further comprises a second heat exchanger, a heat medium inlet of the second heat exchanger is connected to a heat medium outlet of the reforming reactor, and a heat medium outlet of the second heat exchanger is connected to an inlet of the heat exchange tube.

[0013] Preferably, the material inlet of the first heat exchanger is connected to a methanol water supply device, the material outlet of the first heat exchanger is connected to the material inlet of the second heat exchanger, and the material outlet of the second heat exchanger is connected to the material inlet of the reforming reactor.

[0014] Preferably, the external exothermic reactor is an ironmaking furnace.

[0015] Compared with the prior art, the utility model has the following beneficial effects:

[0016] 1) The CO and H2O in the purified tail gas are reused to improve the hydrogen yield, and the carbon dioxide produced in the methanol hydrogen production process is recovered, which further improves the carbon dioxide recovery rate, not only saving resources but also reducing environmental pollution;

[0017] 2) By introducing external high-exothermic reaction equipment to provide reaction heat energy for the methanol-to-hydrogen system, open flame heating is eliminated, the process is simplified, energy consumption is reduced, and the safety of the system is greatly improved. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the process of Example 1 of the present application;

[0019] Figure 2 This is a flow chart of Example 2 of the present application. DETAILED DESCRIPTION

[0020] The following will be combined with the drawings in the embodiments of the utility model to clearly and completely describe the technical solutions in the embodiments of the utility model. Obviously, the described embodiments are only part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments in the utility model, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the utility model.

[0021] Embodiment 1:

[0022] A hydrogen purification system based on methanol hydrogen production, such as Figure 1 As shown, it includes a heating system 1, a reforming hydrogen production system 2, a first hydrogen purification system 3, and a tail gas recovery system 4 which are connected in sequence; the heating system 1 is used to heat methanol water so that the methanol water reaches the temperature required for the reforming reaction; the reforming hydrogen production system 2 is used to catalyze the methanol water to obtain a mixed gas containing a large amount of hydrogen; the first hydrogen purifier 3 is used to purify the mixed gas obtained by the methanol hydrogen production system 2 to obtain high-concentration hydrogen; the tail gas recovery system 4 is used to recycle the purified tail gas generated by the first hydrogen purifier 3.

[0023] The first hydrogen purification system comprises a first hydrogen purifier 3 (attached Figure 1 Only the first hydrogen purifier 3 is identified in the figure, and the first hydrogen purifier 3 is provided with a first hydrogen outlet 31 and a purified tail gas outlet 32; the purified tail gas outlet 32 ​​is connected to the inlet of the tail gas recovery system 4; the first hydrogen outlet 31 is connected to the hydrogen storage device. Preferably, the first hydrogen purifier 3 is preferably an alloy membrane purifier.

[0024] The tail gas recovery system 4 includes a carbon monoxide converter 41 and a second hydrogen purifier 42; the purified tail gas outlet 32 ​​is connected to the gas inlet of the carbon monoxide converter 41, and the gas outlet of the carbon monoxide converter 42 is connected to the inlet of the second hydrogen purifier 42. In order to reduce tail gas emissions and maximize resource utilization, the tail gas recovery system also includes a carbon dioxide collector 44, and the exhaust gas outlet 422 of the second hydrogen purifier 42 is connected to the gas inlet of the carbon dioxide collector 44; in order to save storage space and production costs, the second hydrogen outlet 421 of the second hydrogen purifier 42 can be connected to the hydrogen storage device connected to the first hydrogen outlet 31.

[0025] Furthermore, in order to improve the working efficiency of the second hydrogen purifier 42, the tail gas recovery system 4 further includes a gas-liquid separator 43, the gas inlet of the gas-liquid separator 43 is connected to the gas outlet of the carbon monoxide converter 41; the gas outlet of the gas-liquid separator 43 is connected to the gas inlet of the second hydrogen purifier 42. After adding the gas-liquid separator 43, from the perspective of thermal energy, the purifier in the second hydrogen purifier 42 is preferably an adsorption tower device.

[0026] During operation, after the methanol aqueous solution is heated to the required temperature by the heating system 1, it enters the reforming reaction system 2 for reforming reaction to obtain a mixed gas. The reformed mixed gas containing H2, CO2, CO, H2O, etc. flows into the first hydrogen purifier 3 through the connecting pipeline. After being purified by the first hydrogen purifier 3, the product hydrogen and the purified tail gas (H2, CO2, CO, H2O mixed gas) are separated. The obtained product hydrogen flows out from the first hydrogen outlet 31 and enters the hydrogen storage device. The remaining tail gas after purification flows from the purified tail gas outlet 32 ​​to the tail gas recovery system 4. The purified tail gas passes through the carbon monoxide converter 41. The gas inlet flows into the carbon monoxide converter 41, and the CO and H2O in the purified tail gas are converted into H2 and CO2 under the action of the catalyst; the mixed gas after the conversion reaction flows into the gas-liquid separator 43, and after the saturated water is separated out in the gas-liquid separator 43, the remaining gas continues to flow into the second hydrogen purifier 42 for a second purification, and the obtained product hydrogen is stored together with the product hydrogen obtained by the first purification system 3; the waste gas with a high carbon dioxide content generated flows into the carbon dioxide collector 44 through the waste gas outlet 422, and high-purity product carbon dioxide is obtained in the device for use as gas.

[0027] This technical solution not only eliminates the need for combustion of purified tail gas, but also further transforms CO in the tail gas, recovers the residual hydrogen in the tail gas, and improves the hydrogen yield of methanol hydrogen production through secondary purification, further reducing the cost of hydrogen production. At the same time, it also increases the concentration of carbon dioxide in the exhaust gas, greatly improves the tail gas recovery rate, reduces environmental pollution, and reduces production costs.

[0028] Embodiment 2:

[0029] In the process of producing hydrogen from methanol, both the temperature rise of methanol water and the reforming reaction require a large amount of heat. In order to make the methanol hydrogen production technology more environmentally friendly and green, the heating system in the hydrogen purification system mainly provides heating by recovering thermal energy.

[0030] Therefore, the difference between this embodiment and embodiment 1 is that the heat exchange system includes a first heat exchanger 11, a second heat exchanger 12, and an external exothermic reactor 13; each heat exchanger is provided with a material inlet, a material outlet and a heat medium inlet, a heat medium outlet, and a heat exchange tube 131 is wound around the outer periphery of the external exothermic reactor 13, and a heat exchange medium is passed through the heat exchange tube 131.

[0031] The material outlet of the first heat exchanger 11 is connected to the material inlet of the second heat exchanger 12 , and the material outlet of the second heat exchanger 12 is connected to the methanol water vapor inlet of the reforming hydrogen production system 2 .

[0032] like Figure 2As shown, the heat medium inlet of the first heat exchanger 11 is connected to the purified tail gas outlet 32 ​​of the first hydrogen purifier 3; the heat medium outlet of the first heat exchanger 11 is connected to the gas inlet of the carbon monoxide converter 41. At this time, the heat exchange medium in the first heat exchanger is the purified tail gas, and the heat of the purified tail gas is recovered in this way, and the heat can be used to preheat the methanol water.

[0033] The reforming hydrogen production system 2 includes a reforming reactor 21, the heat medium inlet of the reforming reactor 21 is connected to the outlet of the heat exchange tube 131, the heat medium outlet of the reforming reactor 21 is connected to the heat medium inlet of the second heat exchanger 12, and the heat medium outlet of the second heat exchanger 12 is connected to the inlet of the heat exchange tube 132. Since the reforming reaction is an endothermic reaction, in order to provide more environmentally friendly heat for the reforming reaction, an external exothermic reactor 13 is introduced in this technical solution. The exothermic reaction carried out in the reactor 13 provides continuous heat energy for the methanol hydrogen production system. This heat energy is not only more environmentally friendly but also improves the thermal energy utilization rate of the entire system. The external exothermic reactor 13 can be a steelmaking furnace, an ironmaking furnace, etc. used for exothermic reactions such as steelmaking and ironmaking. In this technical solution, the external exothermic reactor 13 is preferably an ironmaking furnace.

[0034] During operation, methanol water first flows into the first heat exchanger 11 for preheating, and then flows into the second heat exchanger 12 for vaporization treatment; during preheating, methanol water exchanges heat with purified tail gas; during vaporization treatment, methanol water exchanges heat with the heat medium in the heat exchange tube 131. The heat medium in the heat exchange tube 131 flows into the shell side of the reforming reactor 21 after heating, providing heat to the tube side in the reforming reactor 21, and the heat medium passing through the reforming reactor enters the second heat exchanger 12 again. The methanol water flowing into the second heat exchanger 12 is heated to 380-450°C by heat exchange vaporization.

[0035] Preferably, the heat medium in the heat exchange tube 131 is water, and the heat medium pressure therein is maintained at 2-3 MPa.

[0036] It can be seen that in this technical solution, open flame combustion heating is eliminated, and medium-pressure steam is used instead of combustion heating to provide heat for methanol steam reforming, which simplifies the process, saves energy, reduces energy consumption, and greatly improves safety.

[0037] It should be noted that the technical features in the above-mentioned embodiments 1 to 2 can be combined arbitrarily, and the combined technical solutions all belong to the protection scope of the present application. And in this article, terms such as "including", "comprising" or any other variants thereof are intended to cover non-exclusive inclusion, so that the process, method, article or equipment including a series of elements includes not only those elements, but also other elements not explicitly listed, or also includes elements inherent to such process, method, article or equipment. In the absence of further restrictions, the elements defined by the sentence "including one..." do not exclude the existence of other identical elements in the process, method, article or equipment including the elements.

[0038] Although embodiments of the present invention have been shown and described, it will be appreciated by those skilled in the art that various changes, modifications, substitutions and variations may be made to the embodiments without departing from the principles and spirit of the present invention, and that the scope of the present invention is defined by the appended claims and their equivalents.

Claims

1. A hydrogen purification system based on methanol hydrogen production, comprising a heating system, a reforming hydrogen production system, a first hydrogen purification system and a tail gas recovery system connected in sequence, wherein the first hydrogen purification system comprises a first hydrogen purifier, characterized in that: The tail gas recovery system includes a carbon monoxide converter and a second hydrogen purifier connected in sequence, the first hydrogen purifier includes a first hydrogen outlet and a purified tail gas outlet, the gas inlet of the carbon monoxide converter is connected to the purified tail gas outlet, and the gas outlet of the carbon monoxide converter is connected to the gas inlet of the second hydrogen purifier.

2. The hydrogen purification system according to claim 1, characterized in that: The tail gas recovery system further comprises a carbon dioxide collector, and the second hydrogen purifier comprises a second hydrogen outlet and a waste gas outlet, and the waste gas outlet is connected to the gas inlet of the carbon dioxide collector.

3. The hydrogen purification system according to claim 2, characterized in that: The tail gas recovery system further comprises a gas-liquid separator, a gas inlet of the gas-liquid separator is connected to a gas outlet of the carbon monoxide converter, and a gas outlet of the gas-liquid separator is connected to a gas inlet of the second hydrogen purifier.

4. The hydrogen purification system according to claim 2, characterized in that: The first hydrogen purifier is an alloy membrane purifier.

5. The hydrogen purification system according to claim 2, characterized in that: The second hydrogen purifier is an adsorption tower device.

6. The hydrogen purification system according to any one of claims 1 to 5, characterized in that: The heating system comprises a first heat exchanger, a heat medium inlet of the first heat exchanger is connected to the purified tail gas outlet, and a heat medium outlet of the first heat exchanger is connected to a gas inlet of the carbon monoxide converter.

7. The hydrogen purification system according to claim 6, characterized in that: The heat supply system also includes an external heat release reactor, and a heat exchange tube is arranged on the periphery of the external heat release reactor; the reforming hydrogen production system includes a reforming reactor, and the outlet of the heat exchange tube is connected to the heat medium inlet of the reforming reactor.

8. The hydrogen purification system according to claim 7, characterized in that: The heat supply system further comprises a second heat exchanger, wherein a heat medium inlet of the second heat exchanger is connected to a heat medium outlet of the reforming reactor, and a heat medium outlet of the second heat exchanger is connected to an inlet of the heat exchange tube.

9. The hydrogen purification system according to claim 8, characterized in that: The material inlet of the first heat exchanger is connected to a methanol water supply device, the material outlet of the first heat exchanger is connected to the material inlet of the second heat exchanger, and the material outlet of the second heat exchanger is connected to the material inlet of the reforming reactor.

10. The hydrogen purification system according to claim 8, characterized in that: The external exothermic reactor is an ironmaking furnace.

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