System for comprehensively utilizing electrochemical byproduct hydrogen and co-producing high-purity hydrogen

Abstract

The utility model provides an electrochemical by-product hydrogen comprehensive utilization and high-purity hydrogen co-production system, which relates to the technical field of by-product hydrogen recovery, and comprises an inlet separator, a compressor, a PSA (pressure swing adsorption) purification device and a hydraulic drive piston type hydrogen compressor, an exhaust port of the compressor is connected with a gas inlet of the PSA purification device through a pipeline, high-purity hydrogen purified by the PSA purification device is shunted to a gas inlet of the liquid-driven piston type hydrogen compressor and an ethylene glycol hydrogen header pipe through pipelines, and tail gas of the PSA purification device is discharged to a hydrogen boiler. According to the utility model, by-product hydrogen is recovered and high-purity hydrogen is sold through one set of system, so that the production cost of a company is saved, when the bus does not need to be inflated at night, the high-purity gas is conveyed to the ethylene glycol system to be used as raw material gas, a hydrogen storage device is not needed, the comprehensive utilization rate of hydrogen is improved, and the production cost of the enterprise is reduced; and meanwhile, the safety risk is also reduced.

Description

Technical Field

[0001] The utility model relates to the technical field of by-product hydrogen recovery, and in particular to a system for comprehensive utilization and co-production of high-purity hydrogen by-product hydrogen from electrochemical processes. Background Art

[0002] As a clean and renewable energy source, hydrogen has high energy density and combustion efficiency. Hydrogen can be used as a raw material for synthesizing chemicals such as ammonia, organic compounds, alcohols, and can also be used in metal smelting, glass manufacturing, ceramics and other fields. In recent years, with the continuous development of fuel cell technology, the application of hydrogen energy in the energy field has gradually attracted attention. Hydrogen can be converted into electrical energy and thermal energy through fuel cells and used for heating, cooling and lighting in industrial production processes. It has the advantages of high efficiency and environmental protection. Moreover, hydrogen energy also has broad application prospects in the fields of transportation, electricity, construction, etc.

[0003] At present, with the rapid development of the caustic soda industry, by-product hydrogen has become an important energy resource with wide applications in industry. There are still some problems in the energy utilization of caustic soda by-product hydrogen. The existing by-product hydrogen is usually burned as waste heat boilers, with a low comprehensive utilization rate. At the same time, due to production load restrictions, a part of the hydrogen is discharged to the flare or requires a specially built hydrogen storage device for storage, which has high safety risks and low economic benefits.

[0004] Therefore, how to recycle and process the by-product hydrogen, improve its comprehensive utilization rate, reduce the safety risks of by-product hydrogen and reduce the company's production costs is an urgent problem to be solved. Utility Model Content

[0005] 1. Technical issues to be resolved

[0006] In view of the deficiencies in the prior art, the utility model provides a system for the comprehensive utilization of electrochemical by-product hydrogen to produce high-purity hydrogen, which solves the technical problems that the direct utilization of the existing by-product hydrogen leads to high safety risks and low comprehensive utilization rate.

[0007] (II) Technical solution

[0008] In order to achieve the above objectives, the present invention is implemented through the following technical solutions:

[0009] A system for co-producing high-purity hydrogen by comprehensive utilization of electrochemical by-product hydrogen includes an imported separator, a compressor, a PSA purification device and a liquid-driven piston hydrogen compressor, wherein the air inlet of the imported separator is connected to the by-product hydrogen, the exhaust port of the imported separator is connected to the air inlet of the compressor through a pipeline, the exhaust port of the compressor is connected to the air inlet of the purification device through a pipeline, the high-purity hydrogen purified by the PSA purification device is diverted through a pipeline, and is compressed by the liquid-driven piston hydrogen compressor during the day and then introduced into a high-purity hydrogen filling station as a hydrogen energy source for a bus company. At night, when the high-purity hydrogen filling station is no longer working, it is introduced into an ethylene glycol hydrogen main pipe as a feed gas for an ethylene glycol production system, and the tail gas of the PSA purification device is discharged to a hydrogen boiler.

[0010] Preferably, a first program-controlled valve is provided at the air inlet of the PSA purification device, a second program-controlled valve is provided at the air outlet, a first shock absorber is provided adjacent to the first program-controlled valve, and a second shock absorber is provided adjacent to the second program-controlled valve.

[0011] Preferably, the pressure of the by-product hydrogen when entering the inlet separator is 80 kPa.

[0012] Preferably, the number of the compressors is not less than one, and the flow rate of the by-product hydrogen entering each compressor is the same.

[0013] Preferably, the by-product hydrogen is pressurized to 3.6 MPa before entering the PSA purification device.

[0014] Preferably, the outlet pressure of the PSA purification device is 3.5 MPa.

[0015] Preferably, the purity of the hydrogen purified by the PSA purification device is not less than 99.999%.

[0016] Preferably, the ratio of high-purity hydrogen to tail gas at the outlet of the PSA purification device is 9:1.

[0017] Preferably, the air intake ratio of the liquid-driven piston hydrogen compressor to the ethylene glycol hydrogen main pipe is 1:2.6.

[0018] Preferably, the gas outlet of the liquid-driven piston type hydrogen compressor is connected to a high-purity hydrogen filling station, and the hydrogen pressure of the high-purity hydrogen filling station is 20 MPa.

[0019] (III) Beneficial effects

[0020] The utility model provides a system for comprehensive utilization of electrochemical byproduct hydrogen and co-production of high-purity hydrogen. Compared with the prior art, it has the following beneficial effects:

[0021] 1. The utility model removes oxygen, chlorine and water from the by-product hydrogen through an imported separator, pressurizes it through a compressor, and transports it to a PSA purification device for further purification to remove impurities and control the outlet pressure of the purified hydrogen. The purity of the purified hydrogen is not less than 99.999%. A small portion of the high-purity hydrogen is transported to the ethylene glycol hydrogen main for reuse in a certain proportion, and most of it is transported to a high-purity hydrogen filling station and sold to bus companies for hydrogen energy utilization.

[0022] 2. The utility model realizes the recovery of by-product hydrogen and sells high-purity hydrogen through a system to save the company's production costs. When the bus does not need to be inflated at night, the high-purity gas is transmitted to the ethylene glycol preparation system for use as raw gas. No hydrogen storage device is required, which improves the comprehensive utilization rate of hydrogen, reduces the company's production costs, and also reduces safety risks. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] In order to more clearly illustrate the embodiments of the utility model or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0024] Figure 1 The utility model is a process flow chart of an embodiment of the present invention.

[0025] Among them, 1. Import separator; 11. Air inlet; 12. Exhaust port; 2. Compressor; 3. PSA purification device; 31. First program-controlled valve; 32. Second program-controlled valve; 33. First shock absorber; 34. Second shock absorber; 4. Liquid-driven piston hydrogen compressor; 5. High-purity hydrogen charging station; 6. Ethylene glycol hydrogen main; 7. Hydrogen boiler; 8. Pipeline. DETAILED DESCRIPTION

[0026] In order to make the purpose, technical solution and advantages of the embodiments of the utility model clearer, the technical solution in the embodiments of the utility model is described clearly and completely. Obviously, the described embodiments are part of the embodiments of the utility model, not all of the embodiments. Based on the embodiments of 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.

[0027] The embodiment of the utility model solves the technical problems that the direct utilization of the existing by-product hydrogen leads to high safety risks and low comprehensive utilization rate by providing a system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen. The hydrogen treated by the system of the utility model has a safe source, high purity, wide application, high comprehensive utilization rate, and no need for storage, which effectively reduces the production cost of the enterprise and improves the economic benefits of the enterprise.

[0028] Example:

[0029] like Figure 1 As shown, the system for co-producing high-purity hydrogen by comprehensive utilization of electrochemical by-product hydrogen includes an imported separator 1, a compressor 2, a PSA purification device 3 and a liquid-driven piston hydrogen compressor 4.

[0030] The flow rate of byproduct hydrogen entering the inlet separator 1 is 4000Nm 3 / h, and the pressure is 80 kPa. The function of the inlet separator 1 is to separate the gas from the liquid in the by-product hydrogen, and the separated condensed water is discharged through the pipeline 8.

[0031] The exhaust port 12 of the inlet separator 1 is connected to the air inlet 11 of the compressor 2 through the pipeline 8. The compressor 2 uses a four-stage compressor 2, the number of which is not less than 1. According to the actual working conditions, 1, 2, 3, etc. can be set. The flow rate of the byproduct hydrogen entering each compressor 2 is the same. For example, if there is one compressor 2, the flow rate of the byproduct hydrogen entering the compressor 2 is 4000Nm 3 / h; if there are two compressors 2, the flow rate of byproduct hydrogen entering each compressor 2 is 2000Nm 3 / h, Figure 1 The figure is a schematic diagram of the process flow in which two compressors 2 are set. The purpose of the by-product hydrogen passing through the compressor 2 is to pressurize the gas so that its outlet pressure reaches 3.6Mpa.

[0032] The exhaust port 12 of the compressor 2 is connected to the air inlet of the PSA purification device 3 through the pipeline 8. The PSA purification device 3 is mainly composed of an adsorption tower, a compression mechanism, and a control mechanism. When the by-product hydrogen passes through the adsorption tower, the impurities are adsorbed by the adsorption material in the adsorption tower, and the hydrogen is filled in the tower. In this way, the hydrogen and the impurities are separated, thereby purifying high-purity hydrogen. The function of the compression mechanism is to change the pressure in the PSA purification device 3 so that the impurities are adsorbed or released. The released impurities are discharged through the extrusion of hydrogen and lead to the hydrogen boiler 7. The flow rate of this part of the gas leading to the hydrogen boiler 7 is 400Nm 3 / h. The purity of the hydrogen purified by the PSA purification device 3 is not less than 99.999%. The pressure of the high-purity gas discharged from the PSA purification device 3 is 3.5Mpa, and the total flow rate is 3600Nm 3 / h.

[0033] A first program-controlled valve 31 is provided at the air inlet of the PSA purification device 3, and a first shock absorber 33 is provided adjacent to the first program-controlled valve 31. The first shock absorber 33 is located at one end of the first program-controlled valve 31 away from the PSA purification device 3. The purpose of providing the first program-controlled valve 31 is to accurately control the flow rate, temperature, pressure and other parameters of the gas entering the PSA purification device 3 to ensure the purification effect. During long-term use, the first program-controlled valve 31 will be affected by the vibration of the system components. The purpose of providing the first shock absorber 33 is to reduce the impact of the vibration on the first program-controlled valve 31, so as to improve the long-term use safety of the system.

[0034] A second program-controlled valve 32 is provided at the gas outlet of the PSA purification device 3, and a second shock absorber 34 is provided adjacent to the second program-controlled valve 32. The second shock absorber 34 is located at one end of the second program-controlled valve 32 away from the PSA purification device 3. The purpose of providing the second program-controlled valve 32 is to accurately control the flow rate, temperature, pressure and other parameters of the gas discharged from the PSA purification device 3. The purpose of providing the second shock absorber 34 is the same as that of the first shock absorber 32, which is to protect the second program-controlled valve 32.

[0035] The high-purity hydrogen is split into two places through pipeline 8, which is transmitted to the liquid-driven piston hydrogen compressor 4 during the day and to the glycol hydrogen main pipe 6 at night. The air inlet of the liquid-driven piston hydrogen compressor 4 is connected to the exhaust port of the PSA purification device 3 through pipeline 8. The flow rate of the high-purity hydrogen entering the liquid-driven piston hydrogen compressor 4 is 1000Nm 3 / h. During the day, high-purity hydrogen is pressurized to 20.0Mpa by a liquid-driven piston hydrogen compressor 4 and then delivered to a high-purity hydrogen filling station 5. The high-purity hydrogen filling station 5 is connected to a long-tube trailer and sold to bus companies, supplying hydrogen to no less than 6 buses at the same time. This not only improves the comprehensive utilization rate of high-purity hydrogen, but also earns extra income for the company and reduces the company's production costs.

[0036] When the bus company does not need to fill hydrogen at night, it does not store or process the high-purity hydrogen, but directly transmits it to the glycol hydrogen main 6, with a hydrogen flow rate of 2600Nm 3 / h, and the pressure remains at 3.5Mpa. This part of high-purity hydrogen is used as raw material gas for the production of ethylene glycol production line, which effectively improves the comprehensive utilization rate and recycling rate of high-purity hydrogen. The company can reduce the amount of high-purity hydrogen purchased from outside, thereby saving production costs, and there is no need to set up storage devices, which greatly reduces safety risks.

[0037] In summary, compared with the prior art, the present invention has the following beneficial effects:

[0038] 1. The utility model removes water, oxygen and chlorine from the by-product hydrogen through an imported separator, pressurizes it through a compressor, and transports it to a PSA purification device for further purification to remove impurities and control the outlet pressure of the purified hydrogen. The purity of the purified hydrogen is not less than 99.999%. A small portion of the high-purity hydrogen is transported to the ethylene glycol hydrogen main for reuse in a certain proportion, and most of it is transported to a high-purity hydrogen filling station and sold to bus companies for hydrogen energy utilization. The utility model uses a set of systems to recover by-product hydrogen and sell high-purity hydrogen to save the company's production costs. When the bus does not need to be inflated at night, the high-purity gas is transported to the ethylene glycol preparation system for use as raw gas. No hydrogen storage device is required, which improves the comprehensive utilization rate of hydrogen, reduces the company's production costs, and also reduces safety risks.

[0039] 2. The system of the utility model can effectively reduce the production costs of enterprises, as follows:

[0040] Byproduct hydrogen 4000Nm 3 / h, after passing through a set of systems of the present invention, the hydrogen recovery rate is calculated as 90%, and 3600Nm 3 / h (4000 × 0.9 = 3600) hydrogen, which is equivalent to reducing the coal input into the gasifier by 3.0 tons / h (3600 / 1200 = 3.0) coal slurry (1m 3 Coal slurry produces effective gas 1200Nm 3 ), equivalent to 1.8 (3.0×0.6=1.8) tons of coal / h (coal slurry concentration is 60%), calculated based on 8,000 hours per year, saving 8,600 tons of raw coal per year. The coal price is 1,150 yuan / ton at the site, and the annual coal saving benefit is 9.89 million yuan (0.86×1150=9.89 million).

[0041] If calculated based on the manufacturing cost of delivering ethylene glycol hydrogen, the manufacturing cost of ethylene glycol hydrogen is 1.3 yuan / Nm 3 , all the recovered hydrogen is sent to ethylene glycol, then the annual operation is calculated as 8,000 hours, the project investment is 16 million yuan, the investment payback period is calculated as 2 years (excluding the residual value of the equipment), the power load is 700KW / h, the electricity price including tax is 0.70 yuan / KWh, the hydrogen boiler produces 4.0 tons / h of by-product steam, and the steam is 150 yuan / ton. The annual hydrogen recovery benefit is: (3600×1.3-700×0.7-4×150-1600×10000 / 8000 / 2)×8000 / 10000=25.9 million yuan.

[0042] If high-purity hydrogen is sold externally, the external selling price is 2.3 yuan / Nm 3 , 200Nm per hour 3 / h for sale, and calculated as 8,000 hours per year, the economic benefit is: 200×(2.3-1.3)×0.8-30×0.7×0.8=1.432 million yuan.

[0043] Annual benefit of hydrogen: 2590+143.2=27.332 million yuan.

[0044] From this we can see that this system saves a lot of production costs for the enterprise and has excellent practical value.

[0045] It should be noted that, in this article, relational terms such as first and second, etc. are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between these entities or operations. Moreover, the terms "include", "comprise" or any other variants thereof are intended to cover non-exclusive inclusion, so that a process, method, article or device 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 device. In the absence of further restrictions, the elements defined by the sentence "comprise a ..." do not exclude the existence of other identical elements in the process, method, article or device including the elements.

[0046] The above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the same. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that the technical solutions described in the aforementioned embodiments may still be modified, or some of the technical features may be replaced by equivalents. However, these modifications or replacements do not deviate the essence of the corresponding technical solutions from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. A system for comprehensive utilization of electrochemical by-product hydrogen to produce high-purity hydrogen, characterized in that: The invention comprises an inlet separator (1), a compressor (2), a PSA purification device (3) and a liquid-driven piston hydrogen compressor (4), wherein the air inlet (11) of the inlet separator (1) is connected to the by-product hydrogen, the exhaust port (12) of the inlet separator (1) is connected to the air inlet of the compressor (2) through a pipeline (8), the exhaust port of the compressor (2) is connected to the air inlet of the PSA purification device (3) through a pipeline (8), the high-purity hydrogen purified by the PSA purification device (3) is diverted through the pipeline (8), compressed by the liquid-driven piston hydrogen compressor (4), and then introduced into a high-purity hydrogen filling station (5), when the high-purity hydrogen filling station (5) is no longer in operation, it is introduced into an ethylene glycol hydrogen main pipe (6), and the tail gas of the PSA purification device (3) is discharged to a hydrogen boiler (7).

2. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The pressure of the by-product hydrogen when entering the inlet separator (1) is 80 kPa.

3. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The number of the compressor (2) is no less than one, and the flow rate of the by-product hydrogen entering each compressor (2) is the same.

4. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The by-product hydrogen is pressurized to 3.6 MPa and then enters the PSA purification device (3).

5. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The PSA purification device (3) is provided with a first program-controlled valve (31) at the air inlet, and a second program-controlled valve (32) at the air outlet. A first shock absorber (33) is also provided adjacent to the first program-controlled valve (31), and a second shock absorber (34) is also provided adjacent to the second program-controlled valve (32).

6. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The outlet pressure of the PSA purification device (3) is 3.5 MPa.

7. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The purity of the hydrogen purified by the PSA purification device (3) is not less than 99.999%.

8. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The flow ratio of high-purity hydrogen to tail gas at the outlet of the PSA purification device (3) is 9:

1.

9. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The air intake ratio of the liquid-driven piston hydrogen compressor (4) and the ethylene glycol hydrogen main pipe (6) is 1:2.

6.

10. The system for comprehensive utilization of electrochemical by-product hydrogen and co-production of high-purity hydrogen as claimed in claim 1, characterized in that: The hydrogen pressure of the high-purity hydrogen filling station (5) is 20 MPa. The high-purity hydrogen filling station (5) is connected to a long tube trailer to supply hydrogen to no less than 6 buses at the same time.

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