Methanol hydrogen production system capable of recycling tail gas

Abstract

The utility model discloses a methanol hydrogen production system capable of recycling tail gas. The methanol hydrogen production system comprises a reformer, a hydrogen purifier, a methanol water pipeline, a reformed gas pipeline, a tail gas pipeline, an air pipeline and a burner discharge pipeline, the reformer is provided with an upper chamber and a lower chamber; a combustion cavity is formed in the lower cavity; the methanol water pipeline is connected with the evaporator, and the gas outlet of the second reforming hydrogen production reaction module is communicated with the gas inlet of the hydrogen purifier through the reformed gas pipeline; the tail gas outlet of the hydrogen purifier is communicated with the gas inlet of the combustion cavity through the tail gas pipeline; the air pipeline is communicated with the combustion cavity; and the burner discharge pipeline is arranged on the cavity body of the upper cavity. By means of the technical scheme, tail energy is recycled, fuel consumption is reduced, meanwhile, the equipment size is reduced, and the tail energy recycling device can be better applied to mobile hydrogen production equipment.

Description

Technical Field

[0001] The utility model relates to the field of methanol hydrogen production, in particular to a methanol hydrogen production system for tail gas recycling. Background Art

[0002] In order to reduce energy consumption and lower costs in chemical production, the technology of hydrogen production by methanol steam reforming has gradually developed to replace the process of "hydrogen production by water electrolysis" which is known as an "electricity guzzler". However, the hydrogen purification technology in the existing methanol hydrogen production technology cannot completely purify the hydrogen-rich gas generated by the reforming reaction, thereby generating tail gas in the hydrogen production process. The content of hydrogen and carbon monoxide in the tail gas can reach 35% to 40%. If it is directly discharged without treatment, it will pollute the environment. In addition, the tail gas is a high-temperature gas and carries a lot of heat. Both hydrogen and carbon monoxide have high calorific values. Direct discharge will cause energy waste. Utility Model Content

[0003] In view of the deficiencies of the prior art, the present invention provides the following technical solutions:

[0004] Provided is a methanol hydrogen production system for tail gas recycling, comprising a reformer, a hydrogen purifier, a methanol water pipeline, a reformed gas pipeline, a tail gas pipeline, an air pipeline and a burner exhaust pipeline;

[0005] The reformer is provided with an upper chamber and a lower chamber, wherein the upper chamber is provided with an evaporator, a first reforming hydrogen production reaction module and a second reforming hydrogen production reaction module connected in series in sequence; the lower chamber is provided with a combustion chamber; the methanol-water pipeline is connected to the evaporator, one end of the reforming gas pipeline is connected to the gas outlet of the second reforming hydrogen production reaction module, and the other end of the reforming gas pipeline is connected to the air inlet of the hydrogen purifier; one end of the tail gas pipeline is connected to the tail gas outlet of the hydrogen purifier, and the other end of the tail gas pipeline is connected to the air inlet of the combustion chamber; the air pipeline is connected to the combustion chamber; the burner exhaust pipeline is arranged on the cavity body of the upper chamber.

[0006] Preferably, heat exchange elements are provided in both the first reforming hydrogen production reaction module and the second reforming hydrogen production reaction module.

[0007] Preferably, the evaporator includes a first evaporator, a second evaporator and a third evaporator, the first and second evaporators are arranged at the upper part of the upper chamber, and the third evaporator is arranged at the lower part of the upper chamber.

[0008] Preferably, the system further comprises a blower, and the air duct is connected to the combustion chamber via the blower.

[0009] Preferably, the system further comprises a combustion-supporting system.

[0010] Preferably, the combustion-supporting system comprises a fuel pipeline, and the fuel pipeline is connected to the exhaust gas pipeline.

[0011] Preferably, the fuel used in the combustion-supporting system is at least one of hydrogen or methanol.

[0012] Preferably, the combustion-supporting system includes a first gas pipeline and a second gas pipeline; one end of the first gas pipeline is connected to the heat outlet of the combustion chamber, and the other end is connected to the heat inlet of the purifier; one end of the second gas pipeline is connected to the heat outlet of the purifier, and the other end is connected to the burner exhaust pipe.

[0013] Preferably, the combustion-supporting system further comprises a nitrogen purge pipeline, and the nitrogen purge pipeline is connected to the combustion chamber through the blower.

[0014] Preferably, the hydrogen purifier is a metal palladium membrane group purifier.

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

[0016] By burning the tail gas produced by methanol hydrogen production, on the one hand, the heat energy of the tail gas is recovered and reused, thereby achieving the purpose of energy saving and consumption reduction, reducing fuel consumption and tail gas emissions; on the other hand, the tail gas discharged after combustion can meet the tail gas emission standards required by environmental protection; at the same time, this technical solution reduces the number of pipelines in the hydrogen production system by combining the burner with the reforming reactor, thereby reducing the volume of the hydrogen production system, so that it can be better applied to mobile hydrogen production equipment. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the utility model's tail gas recycling methanol hydrogen production system

[0018] Figure 2 This is a schematic diagram of the combustion system flow of the utility model's tail gas recycling methanol hydrogen production system DETAILED DESCRIPTION

[0019] 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.

[0020] Embodiment 1:

[0021] like Figure 1As shown, a methanol hydrogen production system with tail gas recycling includes a reformer 16, a hydrogen purifier 17, a methanol water pipeline 1, a reformed gas pipeline 7, a tail gas pipeline 9, an air pipeline 10 and a burner exhaust pipeline 13.

[0022] The reformer 16 has two chambers, namely an upper chamber 16.1 and a lower chamber 16.2. The upper chamber 16.1 is provided with an evaporator, a first reforming hydrogen production reaction module 5 and a second reforming hydrogen production reaction module 6 connected in series, wherein both reforming hydrogen production reaction modules are provided with heat exchange elements, and the lower chamber 16.2 is provided with a combustion chamber 12; a methanol water pipeline 1 is connected to the evaporator, one end of the reforming gas pipeline 7 is connected to the gas outlet of the second reforming hydrogen production reaction module 6, and the other end is connected to the inlet of the hydrogen purifier 17; one end of the tail gas pipeline 9 is connected to the tail gas outlet of the hydrogen purifier 17, and the other end is connected to the inlet of the combustion chamber 12; a burner exhaust pipeline 13 is provided on the cavity body of the upper chamber 16.1; an air pipeline 10 is connected to the combustion chamber 12, and its function is to provide air to the combustion chamber 12 to make the tail gas burn more fully; the burner exhaust pipeline 13 is provided on the cavity body of the upper chamber.

[0023] Furthermore, the hydrogen production system is also provided with a blower 11, and the air duct 10 provides air to the combustion chamber 12 through the blower 11. Adding the blower 11 to the system can ensure the flow rate and flow of the air, so that the exhaust gas can be burned more completely.

[0024] During operation, the methanol-water mixture flows into the evaporator through the methanol-water pipeline 1 for heat exchange, and then flows into the first reforming hydrogen production reaction module 5 for reforming reaction. In order to fully react the raw materials, a second reforming hydrogen production reaction module 6 is also added in this scheme. Therefore, the mixed gas generated by the first reforming hydrogen production reaction module 5 flows into the second reforming hydrogen production reaction module 6 again. The reformed reaction mixed gas obtained after further reaction in the second reforming hydrogen production reaction module 6 flows into the hydrogen purifier 17 through the reformer pipeline 7. The reformed reaction mixed gas is purified here. The obtained hydrogen flows out of the hydrogen production system through the hydrogen pipeline 8; the remaining tail gas flows into the combustion chamber 12 through the tail gas pipeline 9, and the tail gas flowing into the combustion chamber 12 is mixed with the air flowing in from the air pipeline 10 and burned. After the combustion, the gas carrying a large amount of heat flows from the lower chamber 16.2 into the upper chamber 16.1, and fully exchanges heat with the evaporator, the first reforming hydrogen production reaction module 5, and the second reforming hydrogen production reaction module 6 arranged in the upper chamber 16.1; the combustion gas after heat exchange is discharged from the methanol hydrogen production system through the burner exhaust pipeline 13.

[0025] The methanol hydrogen production system achieves full utilization of the tail gas in terms of material and heat through the combination of the reforming reaction hydrogen production module and the combustion chamber, and reduces fuel consumption through the evaporator arranged in the upper chamber and the heat exchange element in the reforming reaction hydrogen production module, thereby achieving the purpose of energy saving and consumption reduction; at the same time, the combination of the burner and the reforming reactor also reduces the use of pipelines in the system and reduces the size of the equipment, so that the hydrogen production system can be better applied to mobile hydrogen production equipment.

[0026] Embodiment 2:

[0027] The difference between this embodiment and embodiment 1 is that the methanol hydrogen production system further includes a combustion-supporting system, which includes a fuel pipeline 14 and a nitrogen purge pipeline 15; the nitrogen purge pipeline 15 is connected to the combustion chamber 12 through a blower 11; the methanol fuel pipeline 14 is connected to the combustion chamber 12 through an exhaust pipeline 9 to achieve the purpose of providing fuel to the combustion chamber 12. The fuel used in the combustion-supporting system is preferably methanol or hydrogen used or generated by the system to reduce the storage space of the fuel.

[0028] In the methanol-to-hydrogen system, when external fuel is needed to provide heat for the reaction due to insufficient tail gas, the combustion-supporting system can be activated to provide additional heat for the methanol-to-hydrogen system.

[0029] Furthermore, the combustion-supporting system also includes a first gas pipeline 18 and a second gas pipeline 19 to simultaneously provide startup heat for the purifier 17. One end of the first combustion gas pipeline 18 is connected to the combustion gas outlet of the combustion chamber 12, and the other end is connected to the heat inlet of the hydrogen purifier 17 in the methanol hydrogen production system; one end of the second combustion gas pipeline 19 is connected to the combustion gas outlet of the hydrogen purifier 17, and the other end is connected to the combustion gas exhaust pipeline 13 to discharge the combusted gas out of the methanol hydrogen production system.

[0030] When the combustion-supporting system is used to provide startup heat for the methanol-to-hydrogen reaction, a two-stage slow heating method is adopted to ensure that the evaporation rate of water in the reforming reaction catalyst is moderate to ensure the integrity of the reforming reaction catalytic tube.

[0031] Specifically, nitrogen is first introduced into the nitrogen purge pipeline, and the nitrogen flows into the combustion chamber 12 under the action of the blower 11, and the combustion chamber 12 is purged to discharge the impurities in the combustion chamber 12, and then the fuel flows into the combustion chamber 12 through the fuel pipeline 14 and the tail gas pipeline 9, and is fully burned in the combustion chamber 12 under the action of the ignition device, thereby providing sufficient startup heat for the methanol hydrogen production system. The first stage of heating is first performed, the fuel flows into the combustion chamber 12 from the fuel pipeline 14 through the tail gas pipeline 9, and the air enters the combustion chamber 12 from the air pipeline 10. The high-temperature gas generated after the fuel and air are mixed and burned in the combustion chamber 12 heats the reformer 16, and part of it flows into the hydrogen purifier 17 through the first burner pipeline 18 to heat it, so that the temperature of the reformer 16 and the hydrogen purifier 17 slowly rises to 110°C.

[0032] Then the second stage of heating is carried out, and the fuel and air continue to burn in the combustion chamber 12. The high-temperature gas generated by the combustion continues to heat the reformer 16 and the hydrogen purifier 17 to slowly rise to 410°C; after the temperature rises to 410°C, the machine can be started to first carry out low-load production and then further increase the production load until full-load production. That is, after reaching the required temperature of the system, the flow valve arranged on the methanol water pipeline 1 makes the methanol water flow rate 10% of the full-load flow rate for reforming reaction and hydrogen production, and the tail gas obtained after the mixed gas generated in the reformer 16 is purified by the hydrogen purifier 17 enters the combustion chamber 12 through the tail gas pipeline 9 for combustion, and the heat obtained by the combustion in the combustion chamber 12 continues to provide heat for the reformer 16 and the hydrogen purifier 17; then the flow valve is gradually adjusted to increase the methanol water flow rate so that it can meet the production target. With the increase of the generation load, the increase of tail gas generation can gradually reduce the input of fuel hydrogen, until sufficient heat can be provided for the methanol hydrogen production system only by the combustion of tail gas and air without the addition of fuel.

[0033] Embodiment 3:

[0034] The difference between this embodiment and embodiment 1 or 2 is that the reformer 16 is provided with a first evaporator 2, a second evaporator 3 and a fourth evaporator 4 which are connected in series in sequence. The first and second evaporators are arranged at the upper part of the upper chamber 16.1, and the third evaporator 4 is arranged at the lower part of the upper chamber 16.1; in this embodiment, the first and second reforming hydrogen production reaction modules 5 and 6 are located in the middle of the upper chamber 16.1, that is, in the middle of the evaporator. This position design enables heat to be exchanged simultaneously in the upper, middle and lower parts of the upper chamber 16.1, thereby improving the heat exchange efficiency.

[0035] Furthermore, the hydrogen purifier 17 used in the hydrogen production system is a metal palladium membrane group purifier.

[0036] It should be noted that the technical features in the above-mentioned embodiments 1 to 3 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.

[0037] 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 methanol hydrogen production system with tail gas recycling, characterized in that: The system includes a reformer, a hydrogen purifier, a methanol-water pipeline, a reformed gas pipeline, an exhaust gas pipeline, an air pipeline, and a burner exhaust pipeline; The reformer is provided with an upper chamber and a lower chamber, wherein the upper chamber is provided with an evaporator, a first reforming hydrogen production reaction module and a second reforming hydrogen production reaction module connected in series in sequence; the lower chamber is provided with a combustion chamber; the methanol-water pipeline is connected to the evaporator, one end of the reforming gas pipeline is connected to the gas outlet of the second reforming hydrogen production reaction module, and the other end of the reforming gas pipeline is connected to the air inlet of the hydrogen purifier; one end of the tail gas pipeline is connected to the tail gas outlet of the hydrogen purifier, and the other end of the tail gas pipeline is connected to the air inlet of the combustion chamber; the air pipeline is connected to the combustion chamber; the burner exhaust pipeline is arranged on the cavity body of the upper chamber.

2. The methanol-to-hydrogen system according to claim 1, characterized in that: Heat exchange elements are provided in the first reforming hydrogen production reaction module and the second reforming hydrogen production reaction module.

3. The methanol to hydrogen system according to claim 1 or 2, characterized in that: The evaporator includes a first evaporator, a second evaporator and a third evaporator. The first and second evaporators are arranged at the upper part of the upper chamber, and the third evaporator is arranged at the lower part of the upper chamber.

4. The methanol-to-hydrogen system according to claim 1, characterized in that: The system further includes a blower, and the air duct is communicated with the combustion chamber through the blower.

5. The methanol-to-hydrogen system according to claim 4, characterized in that: The system also includes a combustion support system.

6. The methanol-to-hydrogen system according to claim 5, characterized in that: The combustion-supporting system comprises a fuel pipeline, and the fuel pipeline is communicated with the exhaust gas pipeline.

7. The methanol-to-hydrogen system according to claim 6, characterized in that: The fuel used by the combustion-supporting system is at least one of hydrogen and methanol.

8. The methanol-to-hydrogen system according to claim 6, characterized in that: The combustion-supporting system includes a first gas pipeline and a second gas pipeline; one end of the first gas pipeline is connected to the heat outlet of the combustion chamber, and the other end is connected to the heat inlet of the purifier; one end of the second gas pipeline is connected to the heat outlet of the purifier, and the other end is connected to the burner exhaust pipeline.

9. The methanol-to-hydrogen system according to claim 6, characterized in that: The combustion-supporting system further comprises a nitrogen purge pipeline, and the nitrogen purge pipeline is connected to the combustion chamber through the blower.

10. The methanol-to-hydrogen system according to claim 1, characterized in that: The hydrogen purifier is a metal palladium membrane group purification.

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