A low-consumption, zero-carbon emission methanol hydrogen production system and method

Abstract

The present application discloses a methanol hydrogen production system, comprising: a raw material storage unit, a heat exchange unit and a hydrogen production unit; the raw material liquid of the raw material storage unit is input into the heat exchange unit for temperature increase, and the obtained raw material gas is input into the hydrogen production unit to prepare hydrogen; the heat exchange unit comprises a heat exchanger and a gasification superheater connected in series, the heat exchanger is connected to the raw material storage unit, and the gasification superheater is connected to the hydrogen production unit. The present application also discloses a methanol hydrogen production method implemented by the methanol hydrogen production system. The methanol hydrogen production system and method of the present application can reduce the energy consumption of methanol hydrogen production and achieve zero carbon emissions.

Description

Technical Field

[0001] The present application relates to the technical field of methanol hydrogen production, and specifically to a low-consumption, zero-carbon emission methanol hydrogen production system and method. Background Art

[0002] Energy security and environmental pollution are real problems facing my country. The key to solving the problem is to develop green new energy. Hydrogen energy, as an efficient and environmentally friendly secondary energy source, is the most promising alternative energy source. However, hydrogen needs to be stored in high-pressure gaseous form, has low energy density, high cost, and certain safety hazards. Methanol, as a hydrogen storage carrier, has high energy density, safety and reliability, low storage and transportation costs, and relatively mild conditions for hydrogen production conversion and low toxicity, making it the first choice for hydrogen production raw materials.

[0003] Although methanol-to-hydrogen has a high hydrogen yield and simple process control, its high energy consumption and high intensity of CO2 emissions also restrict the further promotion and application of methanol-to-hydrogen technology.

[0004] Therefore, providing a low-consumption, zero-carbon emission methanol hydrogen production system and method is a technical problem that needs to be solved urgently. Summary of the invention

[0005] In order to solve all or part of the above problems, the present application aims to provide a methanol hydrogen production system and method so as to reduce the energy consumption of methanol hydrogen production and achieve zero carbon emissions.

[0006] In order to achieve the above technical objectives, this application adopts the following technical solutions:

[0007] A methanol hydrogen production system comprises: a raw material storage unit, a heat exchange unit and a hydrogen production unit; the raw material liquid in the raw material storage unit is input into the heat exchange unit for temperature increase, and the obtained raw material gas is input into the hydrogen production unit to prepare hydrogen; the heat exchange unit comprises a heat exchanger and a gasification superheater connected in series, the heat exchanger is connected to the raw material storage unit, and the gasification superheater is connected to the hydrogen production unit.

[0008] Optionally, the hydrogen production unit includes a reforming reactor, a catalytic burner and a gas separation device; the raw gas is input into the reforming reactor for reaction, the generated conversion gas is input into the heat exchange unit for cooling, and then input into the gas separation device to separate carbon dioxide, and then hydrogen is output to the outside; the catalytic burner provides heat to the reforming reactor.

[0009] Optionally, the raw material storage unit includes a methanol storage tank and a desalted water tank; the methanol output from the methanol storage tank and the desalted water output from the desalted water tank are mixed to form the raw material liquid; and the methanol storage tank is also connected to the catalytic burner.

[0010] Optionally, a preheater is also included. The combustion exhaust gas generated by the catalytic burner is cooled by the preheater and then input into the gasification superheater. The pipeline connecting the methanol storage tank to the catalytic burner passes through the preheater, and the methanol is heated by the preheater before being input into the catalytic burner.

[0011] Optionally, part of the hydrogen output by the methanol hydrogen production system is heated by the preheater and then input into the catalytic burner.

[0012] Optionally, the hydrogen production unit further comprises a decarbonization tower, and the decarbonization tower captures the carbon dioxide separated by the gas separation device; preferably, an alcohol amine solvent is sprayed inside the decarbonization tower to capture the carbon dioxide.

[0013] A method for producing hydrogen from methanol is implemented using the methanol hydrogen production system of the present application, and the method for producing hydrogen from methanol comprises:

[0014] The raw gas obtained by heating the raw liquid through the heat exchange unit is input into the reforming reactor;

[0015] The heat released by the catalytic oxidation of the catalytic burner is transmitted to the reforming reactor, so that the raw gas reacts to produce conversion gas;

[0016] The reformed gas is cooled by the heat exchange unit and then fed into a carbon dioxide separation device to remove carbon dioxide to obtain hydrogen.

[0017] Optionally, the methanol output from the methanol storage tank and the desalted water output from the desalted water tank are mixed in a mass ratio of 1:(1-1.5) to form the raw material liquid; the raw material liquid is heated to 100-130°C in a heat exchanger, and then heated to 220-290°C in a gasification superheater.

[0018] Optionally, the methanol in the methanol storage tank and a portion of the hydrogen are heated in a preheater and then input into the catalytic burner for catalytic oxidation reaction to release heat so that the temperature of the reforming reactor is maintained at 260-310°C.

[0019] Optionally, the combustion tail gas generated by the reforming reactor is cooled in a preheater and then cooled to 120-140° C. together with the conversion gas through a gasification superheater, and then cooled to 30-45° C. through a heat exchanger.

[0020] It can be seen from the above technical solution that the present application provides a methanol hydrogen production system and method, which has the following advantages:

[0021] (1) The methanol hydrogen production system of the present application is provided with a multi-stage heat exchanger, which utilizes heat in a gradient manner and can significantly reduce the energy consumption of the methanol hydrogen production system.

[0022] (2) The methanol-to-hydrogen system of the present application is equipped with carbon dioxide removal and capture equipment to ensure zero carbon emissions of the system and realize green methanol-to-hydrogen production.

[0023] (3) The heat source of the methanol hydrogen production system of the present application comes from the catalytic burner, which avoids flame combustion, further improves the safety of the system, and better meets the safety technical requirements of hydrogen production in hydrogen refueling stations. BRIEF DESCRIPTION OF THE DRAWINGS

[0024] Various other advantages and benefits will become apparent to those of ordinary skill in the art by reading the detailed description of the preferred embodiments below. The accompanying drawings are only for the purpose of illustrating the preferred embodiments and are not to be considered as limiting the present application. Also, the same reference symbols are used throughout the accompanying drawings to represent the same components. In the accompanying drawings:

[0025] Figure 1 It is a structural schematic diagram of the methanol hydrogen production system of an embodiment of the present application.

[0026] Explanation of the accompanying drawings: 1. Methanol storage tank; 2. Desalted water tank; 3. Heat exchanger; 4. Gasification superheater; 5. Reforming reactor; 6. Catalytic burner; 7. Gas separation device; 8. Preheater; 9. Decarbonization tower; 10. Raw liquid delivery pipeline; 11. First heat transfer oil delivery pipe; 12. Second heat transfer oil delivery pipe; 13. Methanol delivery pipeline; 14. First hydrogen delivery pipeline; 15. Second hydrogen delivery pipeline. DETAILED DESCRIPTION

[0027] The exemplary embodiments of the present application will be described in more detail below with reference to the accompanying drawings. Although the exemplary embodiments of the present application are shown in the accompanying drawings, it should be understood that the present application can be implemented in various forms and should not be limited by the embodiments set forth herein. On the contrary, these embodiments are provided in order to enable a more thorough understanding of the present application and to fully convey the scope of the present application to those skilled in the art.

[0028] Example 1

[0029] like Figure 1 As shown, it is a structural schematic diagram of a methanol hydrogen production system in Example 1 of the present application, including: a raw material storage unit, a heat exchange unit and a hydrogen production unit; the raw material liquid of the raw material storage unit is input into the heat exchange unit for heating, and the obtained raw material gas is input into the hydrogen production unit to prepare hydrogen; the heat exchange unit includes a heat exchanger 3 and a gasification superheater 4 connected in series, the heat exchanger 3 is connected to the raw material storage unit, and the gasification superheater 4 is connected to the hydrogen production unit.

[0030] The methanol hydrogen production system of this embodiment is designed based on methanol steam reforming-pressure swing adsorption technology, and the raw materials used are methanol and desalted water. Figure 1As shown, the raw material storage unit includes a methanol storage tank 1 and a desalted water tank 2. The methanol output from the methanol storage tank 1 and the desalted water output from the desalted water tank 2 are first mixed in proportion to form a raw material liquid, and then input into the heat exchange unit.

[0031] like Figure 1 As shown, the heat exchange unit includes a heat exchanger 3 and a gasification superheater 4. The heat exchanger 3 is connected to the raw material storage unit through a raw material liquid delivery pipeline 10. For example, the methanol outlet of the methanol storage tank 1 and the desalted water outlet of the desalted water tank 2 are respectively connected to the raw material liquid delivery pipeline 10, and the methanol in the methanol storage tank 1 and the desalted water in the desalted water tank 2 are respectively input into the raw material liquid delivery pipeline 10 and mixed in the raw material liquid delivery pipeline 10 to form a raw material liquid, and then input into the heat exchanger 3. After the raw material liquid undergoes the first heat exchange and temperature rise in the heat exchanger 3, it is input into the gasification superheater 4 for the second heat exchange and temperature rise to obtain the raw material gas. The specific structure of the heat exchanger 3 and the gasification superheater 4 of this embodiment can refer to the prior art.

[0032] like Figure 1 As shown, the hydrogen production unit includes a reforming reactor 5, a catalytic burner 6 and a gas separation device 7. The raw gas output from the gasification superheater 4 is input into the reforming reactor 5, and a methanol reforming hydrogen production reaction occurs in the reforming reactor 5 to produce a high-temperature conversion gas. The main components of the conversion gas are hydrogen and carbon dioxide. After being output from the reforming reactor 5, the conversion gas passes through the gasification superheater 4 and the heat exchanger 3 in sequence to cool down, and then is input into the gas separation device 7. In the process of passing through the gasification superheater 4 and the heat exchanger 3, the conversion gas exchanges heat with the raw material liquid, transfers heat to the raw material liquid, and converts the raw material liquid into raw gas, thereby realizing heat recovery and improving the heat utilization rate of the methanol hydrogen production system.

[0033] The reaction temperature in the reforming reactor 5 is 260-310°C, which is maintained by the catalytic burner 6. The catalytic burner 6 uses methanol and hydrogen as raw materials to release heat by flameless catalytic oxidation, and the released heat is sent to the reforming reactor 5 through heat transfer oil. The heat source of the methanol hydrogen production system of this embodiment comes from the catalytic burner 6, which avoids flame combustion, further improves the safety of the methanol hydrogen production system, and better meets the safety technical requirements of hydrogen production in hydrogen refueling stations.

[0034] like Figure 1 As shown, a first heat transfer oil delivery pipe 11 and a second heat transfer oil delivery pipe 12 are provided between the reforming reactor 5 and the catalytic burner 6. The heat transfer oil is delivered from the catalytic burner 6 to the reforming reactor 5 through the first heat transfer oil delivery pipe 11, thereby delivering heat to the reforming reactor 5. After releasing the heat, the heat transfer oil is delivered from the reforming reactor 5 to the catalytic burner 6 through the second heat transfer oil delivery pipe 12.

[0035] The methanol used by the catalytic burner 6 can be provided by the methanol storage tank 1, so, for example Figure 1As shown, the methanol storage tank 1 is connected to the catalytic burner 6 via a methanol delivery pipeline 13 so as to deliver methanol to the catalytic burner 6 .

[0036] The combustion tail gas produced by the flameless catalytic oxidation reaction in the catalytic burner 6 has carbon dioxide and water vapor as main components, and the temperature is as high as 420-560°C. In order to recover this part of heat, preferably, a preheater 8 is provided, and the second hydrogen delivery pipeline 15 for delivering hydrogen to the catalytic burner 6 and the methanol delivery pipeline 13 for delivering methanol to the catalytic burner 6 pass through the preheater 8. After the combustion tail gas is output from the catalytic burner 6, it first passes through the preheater 8, and exchanges heat with the methanol and hydrogen flowing through the preheater 8. The methanol and hydrogen exchange heat and heat up, and then enter the catalytic burner 6. The combustion tail gas output from the preheater 8 continues to cool down by passing through the gasification superheater 4 and the heat exchanger 3 in sequence. The combustion tail gas output from the preheater 8 can be directly transported to the gasification superheater 4 through a separate pipeline, and combined with the reformed gas in the gasification superheater 4 to form a mixed gas, or the combustion tail gas output from the preheater 8 can first be combined with the reformed gas output from the reforming reactor 5 to form a mixed gas, and then the mixed gas is sent to the gasification superheater 4. The mixed gas passes through the gasification superheater 4 and the heat exchanger 3 to exchange heat with the raw material liquid, transferring heat to the raw material liquid. By passing the combustion tail gas through the preheater 8, the gasification superheater 4 and the heat exchanger 3 for heat exchange, the heat of the combustion tail gas can be recovered, thereby further improving the heat utilization rate of the methanol hydrogen production system.

[0037] In this embodiment, the specific structures of the reforming reactor 5, the catalytic burner 6 and the preheater 8 may refer to the prior art.

[0038] The gas output from heat exchanger 3 is dried ( Figure 1 The gas separation device 7 (not shown) is transported to the gas separation device 7 to separate the carbon dioxide. In this embodiment, the gas separation device 7 uses pressure swing adsorption (PSA) to separate carbon dioxide and purify hydrogen. Specifically, the PSA process is based on the physical adsorption of gas molecules on the internal surface of a porous solid substance (adsorbent). It is a reversible physical adsorption process that works between two pressure states. It is based on the principle that the impurity components in the mixed gas have a larger adsorption capacity under high pressure and a smaller adsorption capacity under low pressure, while H2 has a smaller adsorption capacity regardless of high pressure or low pressure. Under high pressure, the impurity partial pressure is increased so that as much as possible is adsorbed on the adsorbent, thereby achieving a high product purity. The desorption or regeneration of the adsorbent is carried out under low pressure to minimize the residual amount of impurities on the adsorbent so as to facilitate the adsorption of impurities again in the next cycle. In this embodiment, the specific structure of the gas separation device 7 (PSA) can refer to the prior art.

[0039] like Figure 1As shown, a decarbonization tower 9 is provided, and a gas separation device 7 is connected to the decarbonization tower 9. The decarbonization tower 9 captures the carbon dioxide separated by the gas separation device 7. Preferably, an alcohol amine solvent is sprayed inside the decarbonization tower 9 to capture the carbon dioxide. By providing the decarbonization tower 9, zero carbon emissions of the methanol hydrogen production system of this embodiment can be ensured, and green methanol hydrogen production can be achieved.

[0040] In this embodiment, the specific structure of the decarbonization tower 9 and the alcoholamine solvent used therein can refer to the prior art.

[0041] The purified hydrogen is output from the gas separation device 7 and transported to the outside through the first hydrogen transport pipeline 14 for use. Preferably, part of the hydrogen output from the gas separation device 7 can be used in the catalytic burner 6. Figure 1 As shown, the second hydrogen delivery pipeline 15 is connected to the first hydrogen delivery pipeline 14 , so as to deliver a portion of the hydrogen generated by the methanol hydrogen production system of this embodiment to the catalytic burner 6 .

[0042] The working process of the methanol hydrogen production system of this embodiment is as follows:

[0043] The methanol output from the methanol storage tank 1 and the desalted water output from the desalted water tank 2 are mixed in a mass ratio of 1: (1-1.5) to form a raw liquid. The raw liquid is input into the heat exchanger 3 and heated to 100-130°C, and then input into the superheater 4 and heated to 220-290°C, and gasified to form a raw gas. The raw gas is input into the reforming reactor 5 for methanol reforming hydrogen production reaction, generating a conversion gas with hydrogen and carbon dioxide as the main components, and the reaction temperature is 260-310°C. The temperature of the reforming reactor 5 is maintained by the catalytic burner 6.

[0044] The catalytic burner 6 uses methanol and hydrogen as raw materials to perform flameless catalytic oxidation to release heat, and the released heat is sent to the reforming reactor 5 through the heat transfer oil to maintain the temperature of the reforming reactor 5. Specifically, the methanol in the methanol storage tank 1 and a small amount of hydrogen produced by the methanol hydrogen production system are respectively input into the catalytic burner 6 through the methanol delivery pipeline 13 and the second hydrogen delivery pipeline 15 after heat exchange and temperature increase in the preheater 8. The heat released by the flameless catalytic oxidation of the catalytic burner 6 is transferred to the reforming reactor 5 by the heat transfer oil through the first heat transfer oil delivery pipe 11, and then the heat transfer oil is transported back to the catalytic burner 6 by the second heat transfer oil delivery pipe 12.

[0045] The combustion tail gas mainly composed of carbon dioxide and water vapor produced by the catalytic burner 6 has a temperature of 420-560°C. After being output from the catalytic burner 6, it first passes through the preheater 8 to exchange heat with methanol and hydrogen, and transfers part of the heat of the combustion tail gas to methanol and hydrogen to achieve heat recovery. The combustion tail gas after heat exchange and cooling is mixed with the conversion gas output by the reforming reactor 5. The obtained mixed gas passes through the gasification superheater 4 and the heat exchanger 3 in turn to exchange heat with the raw material liquid, and the temperature of the mixed gas is reduced to 120-140°C and 30-45°C in turn.

[0046] The mixed gas after cooling and drying is sent to the gas separation device 7 (PSA) for gas separation, and the carbon dioxide enriched gas produced after separation is sent to the decarbonization tower 9 for carbon dioxide removal, wherein the decarbonization tower uses alcohol amine solvents to capture carbon dioxide; the qualified product hydrogen after separation can be directly supplied to the outside for use.

[0047] It should be noted that, unless otherwise specified, the technical terms or scientific terms used in this application should have the common meanings understood by technicians in the field to which this application belongs.

[0048] In addition, the terms "first", "second", etc. are used for descriptive purposes only and cannot be understood as indicating or implying relative importance or implicitly indicating the quantity of the indicated technical features.

[0049] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present application, rather than to limit them; although the present application has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein by equivalents; and these modifications or replacements do not make the essence of the corresponding technical solutions deviate from the scope of the technical solutions of the embodiments of the present application, and they should all be included in the scope of the claims and specification of the present application. In particular, as long as there is no structural conflict, the various technical features mentioned in the various embodiments can be combined in any way. The present application is not limited to the specific embodiments disclosed herein, but includes all technical solutions that fall within the scope of the claims.

Claims

1. A methanol hydrogen production system, characterized in that: include: A raw material storage unit, a heat exchange unit and a hydrogen production unit; the raw material liquid of the raw material storage unit is input into the heat exchange unit for temperature increase, and the obtained raw material gas is input into the hydrogen production unit to prepare hydrogen; the heat exchange unit includes a heat exchanger and a gasification superheater connected in series, the heat exchanger is connected to the raw material storage unit, and the gasification superheater is connected to the hydrogen production unit; The hydrogen production unit includes a reforming reactor, a catalytic burner and a gas separation device; the raw gas is input into the reforming reactor for reaction, the generated conversion gas is input into the gasification superheater and the heat exchanger for cooling, and then input into the gas separation device to separate carbon dioxide; The methanol hydrogen production system further includes a preheater, the combustion tail gas generated by the catalytic burner is cooled by the preheater and then fed into the gasification superheater together with the reformed gas, the pipeline connecting the methanol storage tank to the catalytic burner passes through the preheater, and the methanol is heated by the preheater and then fed into the catalytic burner; Part of the hydrogen output by the methanol hydrogen production system is heated by the preheater and then input into the catalytic burner.

2. The methanol to hydrogen system according to claim 1, characterized in that: The catalytic burner provides heat to the reforming reactor.

3. The methanol to hydrogen system according to claim 2, characterized in that: The raw material storage unit comprises a methanol storage tank and a desalted water tank; the methanol output from the methanol storage tank and the desalted water output from the desalted water tank are mixed to form the raw material liquid; the methanol storage tank is also connected to the catalytic burner.

4. The methanol to hydrogen system according to any one of claims 2 to 3, characterized in that: The hydrogen production unit further includes a decarbonization tower, which captures the carbon dioxide separated by the gas separation device.

5. The methanol to hydrogen system according to claim 4, characterized in that: The decarbonization tower is internally sprayed with an alcohol amine solvent to capture carbon dioxide.

6. A method for producing hydrogen from methanol, characterized in that: The methanol hydrogen production system according to any one of claims 1 to 5 is used for implementation, and the methanol hydrogen production method comprises: The raw liquid is heated by a series-connected heat exchanger and a gasification superheater to obtain a raw gas which is input into a reforming reactor; The heat released by the catalytic oxidation of the catalytic burner is transmitted to the reforming reactor, so that the raw gas reacts to produce conversion gas; The reformed gas is cooled by the gasification superheater and the heat exchanger and then fed into a carbon dioxide separation device to remove carbon dioxide and obtain hydrogen; The combustion tail gas generated by the catalytic burner is cooled by the preheater and then fed into the gasification superheater together with the conversion gas; the pipeline connecting the methanol storage tank to the catalytic burner passes through the preheater, and the methanol is heated by the preheater and then fed into the catalytic burner; Part of the hydrogen output by the methanol hydrogen production system is heated by the preheater and then input into the catalytic burner.

7. The method for producing hydrogen from methanol according to claim 6, characterized in that: The methanol output from the methanol storage tank and the desalted water output from the desalted water tank are mixed in a mass ratio of 1: (1-1.5) to form the raw material liquid; the raw material liquid is heated to 100-130° C. in a heat exchanger, and then heated to 220-290° C. in a gasification superheater.

8. The method for producing hydrogen from methanol according to claim 6, characterized in that: The methanol in the methanol storage tank and a portion of the hydrogen are heated in a preheater and then input into the catalytic burner for catalytic oxidation reaction to release heat so that the temperature of the reforming reactor is maintained at 260-310°C.

9. The method for producing hydrogen from methanol according to claim 6, characterized in that: The combustion tail gas generated by the reforming reactor is cooled by a preheater and then cooled to 120-140°C by a gasification superheater together with the conversion gas, and then cooled to 30-45°C by a heat exchanger.

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