Self-heating type hydrogen deoxidation and purification system for hydrolysis hydrogen production process

Abstract

The utility model relates to a gas purification system, in particular to a self-heating type hydrogen deoxidation purification system for a hydrolysis hydrogen production process, and aims to solve the problems of high operation difficulty and higher energy consumption of the conventional hydrogen purification system. The deoxidization device comprises an alkali liquor filter, a deoxidization heat recoverer, a heater, a deoxidization tower, a deoxidization cooler and a deoxidization separation filter, a first output end pipeline of the alkali liquor filter is connected with a first input end of the deoxidation heat recoverer, and a second output end pipeline is connected with an input end of the heater; an output end pipeline of the heater is connected with an input end of the deoxidation tower, and an output end pipeline of the deoxidation tower is connected with a second input end of the deoxidation heat recoverer; a first output end pipeline of the deoxidation heat recoverer is connected with the input end of the heater, a second output end pipeline of the deoxidation heat recoverer is connected with the input end of the deoxidation cooler, and an output end pipeline of the deoxidation cooler is connected with the input end of the deoxidation separation filter.

Description

Technical Field

[0001] This utility model relates to a gas purification system, specifically a self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process. Background Technology

[0002] Hydrogen is a widely used raw material, serving industrially as a feed gas, reducing gas, cooling gas, protective gas, or combustion gas. It also has extensive applications in scientific research fields such as chemical engineering, petrochemicals, metallurgy, machining, power generation, and medicine. Water electrolysis is a common industrial method for producing hydrogen. The reaction takes place in an electrolytic cell containing a dilute hydroxide solution (e.g., KOH or NaOH solution). The reduction reaction at the cathode is: 4H₂O + 4e⁻ - = 2H2↑ + 4OH - The oxidation reaction that occurs at the anode is: 4OH⁻ - -4e - = 2H₂O + O₂↑, where +e - Represents the gain of electrons, -e - Representing the loss of electrons, the overall reaction formula is: The raw gas prepared by this method usually contains impurities such as O2, H2O(g), trace amounts of hydroxide solution, and other impurities, which need to be removed. (g) represents the gaseous state.

[0003] In response, Chinese patent CN108910824A discloses a high-purity hydrogen purification system and method. The system includes a main PSA hydrogen extraction unit and an auxiliary PSA hydrogen extraction unit. The main PSA hydrogen extraction unit includes an adsorption unit A, a feed gas buffer tank A, a product gas buffer tank A, a forward-release gas tank, a reverse-release gas tank, and a desorption gas tank. The auxiliary PSA hydrogen extraction unit includes an adsorption unit B, a feed gas buffer tank B, a product gas buffer tank B, and a tail gas tank. The desorption gas tank is connected to the feed gas buffer tank B, and the feed gas buffer tank A is connected to the product gas buffer tank B. The tail gas from the main PSA hydrogen extraction unit is compressed and used as the feed gas for the auxiliary PSA hydrogen extraction unit. The product gas from the auxiliary PSA hydrogen extraction unit is used as the feed gas for the main PSA hydrogen extraction unit, improving the hydrogen yield and effectively removing substances such as carbon monoxide, carbon dioxide, methane, nitrogen, water vapor, and nitrogen from the crude hydrogen, thereby improving product purity. However, this patent has shortcomings: it uses a large number of tanks, has a complex structure, is difficult to operate, and has high energy consumption. Utility Model Content

[0004] The purpose of this invention is to solve the problems of high operational difficulty and high energy consumption in existing hydrogen purification systems, and to provide a self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process.

[0005] To achieve the above objectives, the technical solution provided by this utility model is as follows:

[0006] A self-heating hydrogen deoxygenation and purification system for hydrogen production by hydrolysis is used to remove hydroxide solution and O2 impurities from the feed gas and to dehydrate it to obtain the finished gas. Its special feature is that:

[0007] It includes an alkaline filter for removing impurities from hydroxide solution, a deoxygenation heat recovery unit, a heater, a deoxygenation tower for removing O2 impurities, a deoxygenation cooler, and a deoxygenation separation filter for dehydration; wherein the deoxygenation heat recovery unit includes two sets of input terminals and output terminals;

[0008] The input end of the alkali filter is connected to the raw material gas input pipeline, and the output pipeline is divided into two lines. The first output pipeline is connected to the first input end of the deoxygenation heat recovery unit, and the second output pipeline is connected to the input end of the heater. The raw material gas input pipeline is used to input the raw material gas to be purified. The output end pipeline of the heater is connected to the input end of the deoxygenation tower, and the output end pipeline of the deoxygenation tower is connected to the second input end of the deoxygenation heat recovery unit. The first output end pipeline of the deoxygenation heat recovery unit is connected to the input end of the heater, and the second output end pipeline of the deoxygenation heat recovery unit is connected to the input end of the deoxygenation cooler. The output end pipeline of the deoxygenation cooler is connected to the input end of the deoxygenation separation filter, and the output end of the deoxygenation separation filter is connected to the finished product gas output pipeline, which is used to output the obtained finished product gas.

[0009] Furthermore, a second valve is installed on the first output pipeline, and a third valve is installed on the second output pipeline.

[0010] Furthermore, a temperature sensor is installed at the output end of the deoxygenation tower. The temperature sensor, the second valve, and the third valve are all electrically connected to an external control device. The second valve and the third valve are both automatic control valves.

[0011] Furthermore, the self-heating hydrogen deoxygenation and purification system used in the hydrolysis hydrogen production process also includes a condensate tank; the deoxygenation separation filter has a drain outlet, which is connected to the inlet of the condensate tank.

[0012] Furthermore, the deoxygenation heat recovery unit is a plate heat exchanger comprising two sets of input and output ends.

[0013] Furthermore, a first valve is installed on the raw material gas input pipeline.

[0014] Furthermore, the catalyst in the deoxygenation tower is a palladium catalyst.

[0015] Compared with the prior art, the beneficial effects of this utility model are:

[0016] 1. The self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process provided by this utility model is equipped with a deoxygenation heat recovery unit. The first intermediate gas after dealkalization is directed to the appropriate path based on the output temperature of the deoxygenation tower. Initially, the first intermediate gas directly enters the heater for direct heating. When the output temperature of the deoxygenation tower is high enough, the first intermediate gas can be preheated using the second intermediate gas before entering the heater for further heating. This fully utilizes the heat generated during the reaction of hydrogen and oxygen, reduces the power consumption of the heater, minimizes energy consumption, achieves heat self-sufficiency in the deoxygenation catalytic process, and has a simple system structure.

[0017] 2. The self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process provided by this utility model can save more than 30% of heat and more than 20% of circulating water. At the same time, the deoxygenation tower and heater are set up independently, which can greatly reduce the structural complexity of the tower and effectively solve the problems of local overheating in the tower, large tower volume, uneven heat transfer, many failure points and high energy consumption.

[0018] 3. The self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process provided by this utility model can be a plate heat exchanger, which has high heat exchange efficiency and small footprint. In actual application scenarios, the type of heat exchanger can also be changed according to different needs and environments, such as changing it to a shell and tube heat exchanger.

[0019] 4. The self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process provided by this utility model has a temperature sensor, a second valve, and a third valve that are all electrically connected to the control module. The second valve and the third valve are both automatic control valves. The automatic control method can save manpower and greatly reduce the difficulty of operation.

[0020] 5. The self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process provided by this utility model uses palladium catalyst in the deoxygenation tower, which has the advantages of low activation temperature and long life.

[0021] 6. The self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process provided by this utility model is equipped with a condensate tank, which can meet the drainage volume for several hours under maximum load conditions and ensure the timely removal of condensate. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of an embodiment of the self-heating hydrogen deoxygenation and purification system for hydrogen production by hydrolysis according to this utility model.

[0023] Explanation of reference numerals in the attached figures:

[0024] 11-Raw material gas, 12-Finished product gas, 2-Alkali filter, 3-Deoxygenation heat recovery unit, 4-Heater, 5-Deoxygenation tower, 6-Deoxygenation cooler, 7-Deoxygenation separation filter, 8-Condensate tank, 91-First valve, 92-Second valve, 93-Third valve. Detailed Implementation

[0025] The present invention will be further described below with reference to the accompanying drawings and specific embodiments.

[0026] A self-heating hydrogen deoxygenation and purification system for hydrogen production through hydrolysis, see [link to documentation]. Figure 1 Its function is to remove hydroxide solution and O2 impurities from raw material gas 11 and to dehydrate it to obtain finished product gas 12.

[0027] This embodiment includes an alkaline filter 2 for removing impurities from the hydroxide solution, a deoxygenation heat recovery unit 3, a heater 4, a deoxygenation tower 5 for removing O2 impurities, a deoxygenation cooler 6, a deoxygenation separation filter 7 for dehydration, and a condensate tank 8 connected to the drain outlet of the deoxygenation separation filter 7. The deoxygenation heat recovery unit 3 includes two sets of input and output ends. In this embodiment, the deoxygenation heat recovery unit 3 employs a plate heat exchanger with two sets of input and output ends. A plate heat exchanger can also be a shell-and-tube heat exchanger. The removed hydroxide solution is typically in droplet form. The alkaline filter 2 contains a filter element. The special coalescing material in the filter element coalesces and separates any trace amounts of hydroxide aqueous solution droplets that may be present in the raw gas 11, protecting the downstream catalyst as much as possible.

[0028] The input end of the alkali filter 2 is connected to the raw material gas input pipeline, and the output pipeline is divided into two lines. The first output pipeline is connected to the first input end of the deoxygenation heat recovery unit 3, and the second output pipeline is connected to the input end of the heater 4. The raw material gas input pipeline is used to input the raw material gas 11 to be purified. The output pipeline of the heater 4 is connected to the input end of the deoxygenation tower 5, and the output pipeline of the deoxygenation tower 5 is connected to the second input end of the deoxygenation heat recovery unit 3. The first output pipeline of the deoxygenation heat recovery unit 3 is connected to the input end of the heater 4, and the second output pipeline of the deoxygenation heat recovery unit 3 is connected to the input end of the deoxygenation cooler 6. The output pipeline of the deoxygenation cooler 6 is connected to the input end of the deoxygenation separation filter 7, and the output end of the deoxygenation separation filter 7 is connected to the finished product gas output pipeline, which is used to output the obtained finished product gas 12. The heating element of the heater 4 is usually made of stainless steel.

[0029] A first valve 91 is installed on the raw gas input pipeline, a second valve 92 is installed on the first output pipeline, and a third valve 93 is installed on the second output pipeline. A temperature sensor is installed at the output end of the deoxygenation tower 5. The temperature sensor, the second valve 92, and the third valve 93 are all electrically connected to an external control device. The second valve 92 and the third valve 93 are both electrically controlled valves. In practice, the valves can also be pneumatic valves; different choices can be made depending on the actual application scenario.

[0030] The reaction that occurs in deoxygenation tower 5 is as follows: That is, a small amount of O2 reacts with H2 to produce H2O under the catalytic action of a catalyst. The catalyst can be a palladium catalyst, which has the advantages of low activation temperature and long life. In practical applications, the design pressure of the condensate tank 8 is designed according to the maximum load pressure of the entire system. The condensate tank is equipped with a safety valve and a flame arrester to ensure that it does not operate under overpressure. The condensate tank is also equipped with a level transmitter, an automatic drain valve, and a condensate drain pump to ensure timely removal of cooling water.

[0031] The above-mentioned self-heating hydrogen deoxygenation and purification system for the hydrolysis hydrogen production process includes the following steps:

[0032] Step 1.1: Open the first valve 91. The raw material gas 11 containing O2, H2O(g) and a trace amount of hydroxide solution enters the alkaline filter 2. The alkaline filter 2 removes the trace amount of hydroxide solution from the raw material gas 11, and obtains the first intermediate gas containing impurities of O2 and H2O(g).

[0033] Step 1.2: Open the third valve 93 and heater 4. The first intermediate gas enters the heater 4 through the second output pipe of the alkali filter 2. The heater 4 heats the first intermediate gas to the first preset temperature T1. The first intermediate gas enters the deoxygenation tower 5, where O2 is removed from the first intermediate gas, resulting in a second intermediate gas containing H2O(g) impurities. This second intermediate gas then enters the second input of the deoxygenation heat recovery unit 3. Simultaneously, the temperature sensor at the output of the deoxygenation tower 5 is activated to monitor the temperature T at the output of the deoxygenation tower 5. out When T out When the third preset temperature T3 is reached, proceed to step 1.4; when T... out When T3 is greater than or equal to T3, proceed to step 1.3;

[0034] Step 1.3: Open the second valve 92 and close the third valve 93. The first intermediate gas enters from the first input end of the deoxygenation heat recovery unit 3 and flows out from the first output end of the deoxygenation heat recovery unit 3. Then, the first intermediate gas enters the heater 4, and the heater 4 heats the first intermediate gas to the first preset temperature T1. When flowing through the interior of the deoxygenation heat recovery unit 3, the multiple heat exchange plates of the deoxygenation heat recovery unit 3 transfer heat energy to the first intermediate gas. The first intermediate gas enters the deoxygenation tower 5, and the deoxygenation tower 5 removes O2 from the first intermediate gas, resulting in a second intermediate gas with H2O(g) impurities. This second intermediate gas enters the second input end of the deoxygenation heat recovery unit 3, and then step 1.4 is executed.

[0035] Step 1.4: After the second intermediate gas undergoes heat exchange in the deoxygenation heat recovery unit 3, it flows out from the second output end of the deoxygenation heat recovery unit 3; while flowing through the interior of the deoxygenation heat recovery unit 3, the second intermediate gas transfers heat energy to multiple heat exchange plates of the deoxygenation heat recovery unit 3.

[0036] Step 1.5: Turn on the deoxygenator 6. The second intermediate gas enters the deoxygenator 6 and is cooled to the second preset temperature T2. Then it flows into the deoxygenator separation filter 7. The deoxygenator separation filter 7 performs preliminary dehydration on the H2O(g) in the second intermediate gas. After dehydration, the finished product gas 12 is obtained, and the deoxygenation and purification of hydrogen is completed.

[0037] In this embodiment, the first preset temperature T1 = 100℃, the second preset temperature T2 = 30℃, and the third preset temperature T3 = 140℃~160℃.

[0038] It should be noted that when T out After T3, the operating power of heater 4 is greatly reduced, and it is basically in a shutdown state. The heating task of the first intermediate gas is largely completed by the heat transfer of multiple heat exchange plates, which saves the energy consumption of heater 4 and realizes "self-heating".

[0039] After the raw gas passes through the system of this embodiment, the removal of hydroxide solution and O2 impurities from H2, as well as the removal of H2O(g), can meet the H2 purity requirements of most application scenarios.

Claims

1. A self-heating hydrogen deoxygenation and purification system for a hydrolysis hydrogen production process, used to remove hydroxide solution and O2 impurities from the raw material gas (11) and to dehydrate it to obtain the finished product gas (12), characterized in that: It includes an alkaline filter (2) for removing impurities from hydroxide solution, a deoxygenation heat recovery unit (3), a heater (4), a deoxygenation tower (5) for removing O2 impurities, a deoxygenation cooler (6), and a deoxygenation separation filter (7) for dehydration; wherein the deoxygenation heat recovery unit (3) includes two sets of input and output terminals; The input end of the alkali filter (2) is connected to the raw material gas input pipeline, and the output end pipeline is divided into two paths. The first output end pipeline is connected to the first input end of the deoxygenation heat recovery unit (3), and the second output end pipeline is connected to the input end of the heater (4). The raw material gas input pipeline is used to input the raw material gas (11) to be purified. The output end pipeline of the heater (4) is connected to the input end of the deoxygenation tower (5), and the output end pipeline of the deoxygenation tower (5) is connected to the second input end of the deoxygenation heat recovery unit (3). The first output end pipeline of the deoxygenation heat recovery unit (3) is connected to the input end of the heater (4), and the second output end pipeline of the deoxygenation heat recovery unit (3) is connected to the input end of the deoxygenation cooler (6). The output end pipeline of the deoxygenation cooler (6) is connected to the input end of the deoxygenation separation filter (7), and the output end of the deoxygenation separation filter (7) is connected to the finished product gas output pipeline. The finished product gas output pipeline is used to output the obtained finished product gas (12).

2. The self-heating hydrogen deoxygenation and purification system for hydrogen production by hydrolysis according to claim 1, characterized in that: A second valve (92) is installed on the first output end pipeline, and a third valve (93) is installed on the second output end pipeline.

3. The self-heating hydrogen deoxygenation and purification system for hydrogen production by hydrolysis according to claim 2, characterized in that: The output end of the deoxygenation tower (5) is equipped with a temperature sensor. The temperature sensor, the second valve (92) and the third valve (93) are all electrically connected to an external control device. The second valve (92) and the third valve (93) are both automatic control valves.

4. A self-heating hydrogen deoxygenation and purification system for a hydrolysis hydrogen production process according to claim 3, characterized in that: It also includes a condensate tank (8); The deoxygenation separation filter (7) has a drain outlet, which is connected to the inlet of the condensate tank (8).

5. A self-heating hydrogen deoxygenation and purification system for a hydrolysis hydrogen production process according to any one of claims 1 to 4, characterized in that: The deoxygenation heat recovery unit (3) is a plate heat exchanger consisting of two sets of input and output ends.

6. A self-heating hydrogen deoxygenation and purification system for a hydrolysis hydrogen production process according to claim 1, characterized in that: The raw material gas input pipeline is equipped with a first valve (91).

7. A self-heating hydrogen deoxygenation and purification system for a hydrolysis hydrogen production process according to claim 1, characterized in that: The catalyst in the deoxygenation tower (5) is a palladium catalyst.

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