Hydrogen purification device and method

Abstract

The invention provides a hydrogen purification device and method. The device comprises a feed gas compressor unit and a desulfurization unit, the device further comprises a hydrogen purification unit; the input end of the hydrogen purification unit is connected with the output end of the feed gas compression unit through the desulfurization unit; one path of the output end of the hydrogen purification unit is connected with a downstream supply end; the other path of the output end of the hydrogen purification unit is connected with the input end of the feed gas compressor unit through a return pipe; wherein the hydrogen purification unit consists of a rotary valve, a packed bed group, a filter, a hydrogen buffer tank and a flow meter; the rotary valve controls the packed bed group to separate hydrogen from desulfurized feed gas, and the hydrogen is input into a supply end through the filter, the buffer tank and the flowmeter in sequence; when the supply end stops working, the separated hydrogen flows back to the feed gas compressor unit through the return pipeline; the technical problems that in the traditional hydrogen purification process, energy consumption is high, operation is complex, and purification efficiency is low are solved.

Description

Technical Field

[0001] The present invention relates to the field of chemical technology, and in particular to a hydrogen purification device and method thereof. Background Art

[0002] Hydrogen is colorless, odorless, non-toxic, has a high calorific value of 142.35KJ / g, and emits no carbon. Hydrogen burns to produce water, which can be electrolyzed to produce hydrogen. With the increasing severity of climate warming, air pollution and other issues, the global energy structure adjustment and energy efficiency improvement face higher challenges. As an efficient and clean secondary energy source, hydrogen energy has outstanding advantages in the energy market and is of great significance to promoting energy production and consumption.

[0003] For scenarios with various hydrogen-rich gas resources generated from oil refining, steelmaking or other chemical processes, directly using the pressure swing adsorption (PSA) process to directly recover and purify hydrogen from these rich gases will be the simplest and most economical technical solution. Summary of the invention

[0004] The purpose of the present invention is to provide a hydrogen purification device and method thereof, which solves the technical problems of high energy consumption, complex operation and low purification efficiency in the traditional hydrogen purification process; at the same time, the device is particularly suitable for purifying various hydrogen-rich gas resources generated in oil refining, steelmaking or other chemical processes, and realizes efficient and clean hydrogen purification by using PSA (pressure swing adsorption) molecular sieve technology.

[0005] In order to solve the problems existing in the prior art, the present invention adopts the following technical solutions to implement:

[0006] A hydrogen purification device, comprising a raw gas compressor unit and a desulfurization unit, wherein the raw gas compressor unit is used to pressurize the low-pressure hydrogen-containing raw gas to the pressure required for purification; the desulfurization unit is used to remove sulfides in the raw gas; the device is characterized in that the device also includes a hydrogen purification unit; the input end of the hydrogen purification unit is connected to the output end of the raw gas compression unit through the desulfurization unit; one path of the output end of the hydrogen purification unit is connected to the downstream supply end; the other path of the output end of the hydrogen purification unit is connected to the input end of the raw gas compression unit through a reflux pipeline; wherein: the hydrogen purification unit is composed of a rotary valve, a packed bed group, a filter, a hydrogen buffer tank and a flow meter; the rotary valve controls the packed bed group to separate hydrogen from the desulfurized raw gas, and sequentially inputs the hydrogen into the supply end through the filter, the hydrogen buffer tank and the flow meter; when the supply end stops working, the reflux pipeline refluxes the separated hydrogen to the raw gas compressor unit; wherein:

[0007] The packed bed group is composed of two groups of packed beds; each group of packed beds is provided with an adsorption layer; the adsorption layer is an adsorbent made of a mixture of octyl silica gel, activated carbon and molecular sieve; the rotary valve controls the packed bed group to separate hydrogen from the desulfurized raw gas, including:

[0008] In the adsorption step, the feed gas passes through the adsorbent bed, and the impurities are selectively adsorbed to separate the hydrogen;

[0009] In the desorption step, the impurities adsorbed on the adsorbent are desorbed by reducing the pressure, thereby achieving the regeneration of the adsorbent and preparing for the next round of adsorption;

[0010] The timing of the adsorption and desorption steps was controlled by a rotary valve, which was switched every four hours.

[0011] Furthermore, the raw gas compressor unit includes a raw gas filter, a compressor body, a cooler and a separator.

[0012] Furthermore, the desulfurization system is composed of a desulfurization tank and a desulfurization filter.

[0013] The device is integrated in the soundproof box.

[0014] The present invention also provides a technical solution for a hydrogen stripping method, comprising:

[0015] The raw gas passes through the raw gas filter and enters the raw gas compressor for pressurization. It then passes through the cooler to cool the compressed raw gas, and then enters the separator to separate the condensate. The gas phase enters the downstream desulfurization unit.

[0016] The pressurized raw gas enters the desulfurization tank for desulfurization, and then enters the desulfurization filter to filter the desulfurizer powder carried in the gas;

[0017] The desulfurized raw gas enters the packed bed group controlled by the rotary valve to separate the hydrogen, and then enters the hydrogen buffer tank through the filter, and then enters the gas supply end after being measured by the flow meter; wherein:

[0018] The rotary valve controls the packed bed group to separate hydrogen from the desulfurized raw gas, including:

[0019] In the adsorption step, the 0.9Mpa feed gas passes through the adsorbent bed, and the impurities are selectively adsorbed to separate the hydrogen;

[0020] In the desorption step, the impurities adsorbed on the adsorbent are desorbed by reducing the pressure to 0.1 MPa, thereby regenerating the adsorbent and preparing for the next round of adsorption;

[0021] The timing of the adsorption and desorption steps was controlled by a rotary valve, which was switched every four hours.

[0022] Beneficial Effects

[0023] 1. The present invention increases the pressure of low-pressure hydrogen-containing raw gas to the pressure required for purification through a raw gas compressor unit, thereby ensuring the smooth progress of the subsequent purification process and also ensuring the cleanliness and stability of the raw gas during the compression process.

[0024] 2. The present invention effectively removes sulfides in the raw gas through the desulfurization unit to avoid their influence on the subsequent purification process and improve the hydrogen purification effect.

[0025] 3. The hydrogen purification unit of the present invention adopts the PSA molecular sieve method to purify hydrogen; according to the different boiling points of the components in the mixed gas, and the properties that the volatile components are not easily adsorbed and the non-volatile components are easily adsorbed, when the raw gas passes through the adsorbent bed, the remaining components except hydrogen are selectively adsorbed by the adsorbent as impurities, while the hydrogen with a low boiling point and the highest volatility is basically not adsorbed and leaves the adsorption bed with high purity, thereby achieving the purpose of separation from other impurities.

[0026] 4. The present invention is based on modular design, that is, the raw gas compressor unit, the desulfurization unit and the hydrogen purification unit are integrated into a soundproof box, which not only improves the integrity of the device, but also reduces noise and vibration, making it easy to apply in various scenarios. BRIEF DESCRIPTION OF THE DRAWINGS

[0027] Figure 1 This is the process flow diagram of a hydrogen purification device of the present invention.

[0028] Reference numerals

[0029] 101 Raw gas compressor unit 102 Raw gas filter 103 Compressor body 104 Cooler

[0030] 105 separator 201 desulfurization unit 202 desulfurization tank 203 desulfurization filter 301 hydrogen purification unit 302 rotary valve 303 packed bed group 303a packed bed 303b packed bed 304 filter 305 hydrogen buffer tank 306 flow meter 307 adsorption layer 401 box 501 supply end 601 return line DETAILED DESCRIPTION

[0031] The following is combined with Figure 1 The present invention is described in detail:

[0032] The present invention provides a hydrogen purification device, comprising a raw gas compressor unit 101, a desulfurization unit 201 and a hydrogen purification unit 301. The device is integrated in a soundproof box 401. The raw gas compressor unit 101 is used to pressurize the low-pressure hydrogen-containing raw gas to the pressure required for purification; the desulfurization unit 201 is used to remove sulfides in the raw gas; wherein: the input end of the hydrogen purification unit 301 is connected to the output end of the raw gas compression unit 101 through the desulfurization unit 201; one end of the hydrogen purification unit 301 is connected to the downstream supply end 501; the other end of the hydrogen purification unit 301 is connected to the input end of the raw gas compressor unit 101 through a reflux pipeline 601; wherein:

[0033] The raw gas compressor unit 101 includes a raw gas filter 102, a compressor body 103, a cooler 104 and a separator 105. The raw gas source is various hydrogen-containing gases such as medium and low temperature shift gas, chlorosilane tail gas, methanol cracking gas, reforming hydrogen, alkane dehydrogenation tail gas, styrene tail gas, methanol pool offgas, refinery hydrogenation low-fraction gas, coal gas, membrane separation gas, catalytic dry gas, etc. The raw gas compressor in the present invention can be a screw compressor or a vane compressor.

[0034] The desulfurization unit 201 is composed of a desulfurization tank 202 and a desulfurization filter 203;

[0035] The hydrogen purification unit 301 is composed of a rotary valve 302, a packed bed group 303, a filter 304, a hydrogen buffer tank 305, a flow meter 306 and a reflux pipeline 307; the packed bed group 303 is composed of two groups of packed beds (303a, 303b); each group of packed beds (303a, 303b) is provided with an adsorption layer 308; the adsorption layer is an adsorbent made of a mixture of octyl silica gel, activated carbon and molecular sieve; wherein:

[0036] The raw gas first passes through the raw gas filter 102 and enters the raw gas compressor 103 to be pressurized to 0.9 MPa, and then passes through the cooler 104 to cool the compressed raw gas to 40°C, and then enters the separator 104 to separate the condensate, and the gas phase enters the downstream desulfurization unit 201. The pressurized raw gas enters the desulfurization tank 202 to remove the sulfide therein, and then enters the desulfurization filter 203 to filter the desulfurizer powder carried in the gas. After desulfurization, the raw gas enters the hydrogen purification unit 301. The desulfurized raw gas enters the packed bed group 303 controlled by the rotary valve 302. In the packed bed group 303, the impurity gas in the raw gas is adsorbed, and the hydrogen gas is discharged. When the impurity gas in the packed bed group 303 reaches a certain concentration, the rotary valve 302 is switched and the pressure is reduced, and the impurity gas is released for the regeneration process to prepare for the next adsorption. The hydrogen enters the filter 304 to filter out impurities, then enters the hydrogen buffer tank 305, and then enters the downstream user after being measured by the flow meter 306. The concentration of the hydrogen reaches 99.97%.

[0037] The principle of hydrogen PSA purification is based on the adsorption and desorption characteristics of adsorbents for gas molecules. In the PSA process, solid adsorbents such as octyl silica gel, activated carbon, molecular sieves, etc. installed in the packed bed group 303 selectively adsorb various impurities in the mixed gas. When the raw gas passes through the adsorbent bed, the remaining components other than hydrogen are selectively adsorbed by the adsorbent as impurities, while hydrogen with a low boiling point and the highest volatility is basically not adsorbed and leaves the adsorption bed with high purity, thereby achieving the purpose of separation from other impurities.

[0038] There are two groups of packed bed groups 303, which work alternately under a certain pressure. The working process mainly includes two processes: adsorption and desorption. In the adsorption step, the 0.9Mpa raw gas passes through the adsorbent bed, and the impurities are selectively adsorbed and separated into hydrogen; in the desorption step, the impurities adsorbed on the adsorbent are desorbed by reducing the pressure to 0.1MPa, thereby achieving the regeneration of the adsorbent and preparing for the next round of adsorption. The time of adsorption and desorption is controlled by a rotary valve, which is switched every four hours.

[0039] The reflux pipeline 601 is provided so that the machine can be kept running even when the downstream user temporarily cancels the use of gas, thereby maintaining the hydrogen purification efficiency and reducing the time required for restarting the machine.

[0040] By cyclically carrying out the above process, the hydrogen purification device of the present invention can realize continuous and efficient hydrogen purification. The entire device is integrated in a soundproof box, which not only reduces noise and vibration, but also improves the integrity and aesthetics of the device.

[0041] It should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit the scope of the present invention. For those skilled in the art, various modifications and changes can be made without departing from the principles of the present invention, and these modifications and changes should all fall within the scope of protection of the present invention.

Claims

1. A hydrogen purification device, comprising a raw gas compressor unit and a desulfurization unit, wherein the raw gas compressor unit is used to pressurize the low-pressure hydrogen-containing raw gas to the pressure required for purification; the desulfurization unit is used to remove sulfides in the raw gas; characterized in that: The device also includes a hydrogen purification unit; the input end of the hydrogen purification unit is connected to the output end of the raw gas compression unit through a desulfurization unit; one path of the output end of the hydrogen purification unit is connected to the downstream supply end; the other path of the output end of the hydrogen purification unit is connected to the input end of the raw gas compression unit through a reflux pipeline; wherein: the hydrogen purification unit is composed of a rotary valve, a packed bed group, a filter, a hydrogen buffer tank, a flow meter and a reflux pipeline; the rotary valve controls the packed bed group to separate hydrogen from the desulfurized raw gas, and sequentially inputs the hydrogen into the supply end through the filter, the hydrogen buffer tank and the flow meter; when the supply end stops working, the separated hydrogen is refluxed to the raw gas compressor unit through the reflux pipeline; wherein: The packed bed group is composed of two groups of packed beds; each group of packed beds is provided with an adsorption layer; the adsorption layer is an adsorbent made of a mixture of octyl silica gel, activated carbon and molecular sieve; the rotary valve controls the packed bed group to separate hydrogen from the desulfurized raw gas, including: In the adsorption step, the feed gas passes through the adsorbent bed, and the impurities are selectively adsorbed to separate the hydrogen; In the desorption step, the impurities adsorbed on the adsorbent are desorbed by reducing the pressure, thereby achieving the regeneration of the adsorbent and preparing for the next round of adsorption; The timing of the adsorption and desorption steps was controlled by a rotary valve, which was switched every four hours.

2. A hydrogen purification device according to claim 1, characterized in that: The raw gas compressor unit includes a raw gas filter, a compressor body, a cooler and a separator.

3. A hydrogen purification device according to claim 1, characterized in that: The desulfurization system is composed of a desulfurization tank and a desulfurization filter.

4. A hydrogen purification device according to claim 1, characterized in that: The device is integrated in the soundproof box.

5. A method for purifying hydrogen, characterized in that: The method is based on any one of claims 1 to 4 to realize a hydrogen purification process, comprising the following steps: The raw gas passes through the raw gas filter and enters the raw gas compressor for pressurization. It then passes through the cooler to cool the compressed raw gas, and then enters the separator to separate the condensate. The gas phase enters the downstream desulfurization unit. The pressurized raw gas enters the desulfurization tank for desulfurization, and then enters the desulfurization filter to filter the desulfurizer powder carried in the gas; The desulfurized raw gas enters the packed bed group controlled by the rotary valve to separate the hydrogen, and then enters the hydrogen buffer tank through the filter, and then enters the gas supply end after being measured by the flow meter; wherein: The rotary valve controls the packed bed group to separate hydrogen from the desulfurized raw gas, including: In the adsorption step, the 0.9Mpa feed gas passes through the adsorbent bed, and the impurities are selectively adsorbed to separate the hydrogen; In the desorption step, the impurities adsorbed on the adsorbent are desorbed by reducing the pressure to 0.1 MPa, thereby regenerating the adsorbent and preparing for the next round of adsorption; The timing of the adsorption and desorption steps was controlled by a rotary valve, which was switched every four hours.

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