JP4815104B2 - Hydrogen production method and apparatus - Google Patents

Description

  The present invention relates to a hydrogen extraction step for taking out high-purity product hydrogen by adsorbing impurities in a hydrogen-rich gas to the adsorbent while maintaining the inside of a hydrogen purifier containing the adsorbent in a pressurized state, and the hydrogen purifier A hydrogen production method for producing high-purity product hydrogen from a hydrogen-rich gas, and a direct use in the implementation of the method, while repeating the off-gas removal step of desorbing impurities from the adsorbent and removing the off-gas while maintaining the interior at a reduced pressure state The present invention relates to a hydrogen production apparatus.

Hydrogen is used for various applications such as fuel cell fuel and burner fuel, as well as for addition to unsaturated bonds, such as fuel gas transformation methods, liquid fuel gasification methods, and water electrolysis methods. They are produced by various methods such as coal and coke gasification methods, coke oven gas liquefaction separation methods, and methanol and ammonia decomposition methods.
However, if a large amount of impurities are contained in the hydrogen after production, it may become unusable depending on the application, so it is necessary to remove impurities contained in the hydrogen and purify it to high purity hydrogen. is there.

For example, when hydrogen is produced by a fuel gas conversion method using city gas or natural gas as a raw material, impurities such as CO and CO ₂ are contained in addition to hydrogen as a main component. Of the fuel cells, when hydrogen is used as a fuel for a phosphoric acid fuel cell (PAFC), the CO content is limited to 1%, which is used as a fuel for a polymer electrolyte fuel cell (PEFC). In this case, the limit is 100 ppm, and if it exceeds that, battery performance will be significantly degraded.
Also, when hydrogen is used for addition to an unsaturated bond, a purity of 5 N (N) or more is required, and therefore it is necessary to purify the hydrogen rich gas into high purity hydrogen by the hydrogen purification method described above. is there.

By the way, in the conventional hydrogen production method, high purity product hydrogen is produced from the hydrogen rich gas while repeating the hydrogen removal step and the off-gas removal step.
Specifically, in a hydrogen extraction process generally referred to as an adsorption process, the inside of a hydrogen purification apparatus that contains the adsorbent is maintained in a pressurized state, and impurities in the hydrogen-rich gas are adsorbed to the adsorbent to achieve high purity. The product hydrogen is taken out, and after passing through the pressure equalization step, the off-gas is taken out by maintaining the inside of the hydrogen purifier in a reduced pressure state and desorbing impurities from the adsorbent in the off-gas removal step called the decompression step and the washing step. Thereafter, product hydrogen was produced while performing the adsorption step again after going through the pressurization step (although it is actually carried out, there is no patent document or the like that specifically mentions this point).

As described above, in the conventional hydrogen production method, after completion of the hydrogen extraction process called the adsorption process, the process immediately proceeds to the off-gas extraction process while reducing the pressure in the hydrogen purifier. However, the production efficiency of hydrogen was problematic.
In other words, when the present inventors repeatedly pursued various experiments, etc., after taking out high-purity product hydrogen from the hydrogen purifier, the hydrogen purification is performed even at the stage where the pressure in the hydrogen purifier is subsequently reduced. It was found that high-purity hydrogen that can be recovered as product hydrogen remained in the apparatus.
However, in the conventional hydrogen purification method, since such residual hydrogen was not recovered as product hydrogen, there was a drawback that the recovery rate of product hydrogen was low and the production efficiency was poor.

  The present invention eliminates such conventional drawbacks, and its purpose is to efficiently produce product hydrogen by improving the product hydrogen recovery rate when producing high-purity product hydrogen from hydrogen-rich gas. It is an object of the present invention to provide a hydrogen production method and an apparatus therefor.

The first characteristic configuration of the present invention is that a hydrogen purifier containing an adsorbent is maintained in a pressurized state so that impurities in the hydrogen-rich gas are adsorbed to the adsorbent to extract high-purity product hydrogen, and hydrogen is extracted. The hydrogen extraction process for storing in a hydrogen storage tank using a line and the off-gas extraction process for desorbing impurities from the adsorbent and maintaining the interior of the hydrogen purifier in a depressurized state to remove the off-gas are repeated. A hydrogen production method for producing a pure product hydrogen, the high purity product hydrogen remaining in the hydrogen purifier after the completion of the hydrogen removal step in the hydrogen purifier in the hydrogen storage tank. The hydrogen recovery step of recovering using the hydrogen take-out line is executed, and after the hydrogen recovery step is completed, the process proceeds to the off-gas take-off step A plurality of the hydrogen purification devices are provided, and when one of the plurality of hydrogen purification devices is executing the hydrogen extraction step, another hydrogen purification device executes the hydrogen recovery step, and the product hydrogen extracted in extraction step, as well as stored prior Symbol hydrogen storage tank, there is to the storage of the product hydrogen recovered in the hydrogen recovery step simultaneously the hydrogen storage tank.

According to the first characteristic configuration of the present invention, the hydrogen purifier is maintained in a pressurized state so that impurities in the hydrogen-rich gas are adsorbed by the adsorbent and the hydrogen extraction step for extracting high-purity product hydrogen is completed. After performing a hydrogen recovery process that recovers high-purity product hydrogen remaining in the hydrogen purifier along with the pressure reduction in the purifier, the hydrogen purifier is maintained in a vacuum state to desorb impurities from the adsorbent. Since the process moves to an off-gas removal process for removing off-gas, high-purity residual hydrogen that has not been recovered by conventional methods can be reliably recovered as product hydrogen, and as a result, the product hydrogen recovery rate is improved. Product hydrogen can be produced efficiently .

  The second characteristic configuration of the present invention is that in the hydrogen production method described above, the hydrogen recovery step is completed when the pressure in the hydrogen purifier is reduced to a predetermined set pressure.

According to the second characteristic configuration of the present invention, since the hydrogen recovery step is completed when the pressure in the hydrogen purifier is reduced to a predetermined set pressure, the remaining hydrogen that has not been recovered is recovered. In this case, high purity product hydrogen can be recovered more reliably.
That is, to complete the hydrogen recovery process, for example, it can be completed after a predetermined time elapses after the hydrogen removal process is completed, but if the time is too short, the pressure in the hydrogen purifier is high and the product is still highly pure. Despite being able to recover hydrogen, it may end up being unrecovered. Conversely, if the time is too long, the pressure in the hydrogen purifier will decrease and impurities will desorb from the adsorbent, and the purity of the recovered hydrogen May be reduced.
In that respect, if the hydrogen recovery step is completed based on the pressure in the hydrogen purifier, high purity hydrogen as desired can be recovered efficiently.

A third characteristic configuration of the present invention is a hydrogen purifier that contains an adsorbent, a hydrogen storage tank that stores high-purity product hydrogen, and product hydrogen that is extracted from the hydrogen purifier and transported to the hydrogen storage tank. A hydrogen take-out line is provided, and the inside of the hydrogen purifier is maintained in a pressurized state so that impurities in the hydrogen-rich gas are adsorbed on the adsorbent to be purified into high-purity product hydrogen. A hydrogen production apparatus configured to remove the off-gas by desorbing impurities from the adsorbent while maintaining the reduced pressure in the hydrogen purification tank and removing the off-gas from the adsorbent. high purity product hydrogen with a reduced pressure in the apparatus remains in the hydrogen purifier was collected Ri Ah provided hydrogen recovery line for transporting to said hydrogen storage tank, the hydrogen purifier is double Each of the plurality of hydrogen purifiers is arranged in parallel in the hydrogen extraction line having a hydrogen extraction pressure adjusting mechanism for maintaining the inside of the hydrogen purification apparatus in a predetermined pressurized state and a hydrogen extraction opening / closing mechanism. The hydrogen recovery tank is connected in parallel to the hydrogen recovery line having a hydrogen recovery pressure adjusting mechanism for reducing the pressure inside the hydrogen purifier and a hydrogen recovery opening / closing mechanism, and the hydrogen recovery line is connected to the hydrogen recovery tank. At the position closer to the hydrogen storage tank than the pressure regulating mechanism for removal, it is connected to the hydrogen removal line .

  According to the third characteristic configuration of the present invention, the hydrogen purifier is maintained in a pressurized state so that the impurities in the hydrogen-rich gas are adsorbed by the adsorbent to be purified into high-purity product hydrogen. A hydrogen production apparatus configured to transport to a hydrogen storage tank via a take-out line, maintain a reduced pressure inside the hydrogen purification apparatus, desorb impurities from the adsorbent, and take off gas. A hydrogen recovery line is provided for recovering high-purity product hydrogen remaining in the hydrogen purifier as the pressure is reduced and transporting it to the hydrogen storage tank. In addition, after completing the hydrogen removal process, before proceeding to the off-gas removal process, a hydrogen recovery process for recovering high-purity product hydrogen remaining in the hydrogen purifier is performed, and the recovered product hydrogen is recovered in the hydrogen recovery line. It makes it possible to convey to the hydrogen storage tank can be produced efficiently product hydrogen to improve the product hydrogen recovery.

Furthermore, according to the third characteristic configuration of the present invention, the hydrogen take-out line includes a hydrogen take-out pressure adjusting mechanism for maintaining the inside of the hydrogen purifier in a predetermined pressurized state and a hydrogen take-off opening / closing mechanism. However, since the pressure recovery mechanism for recovering hydrogen and the opening / closing mechanism for hydrogen recovery are provided to reduce the pressure in the hydrogen purifier, the opening / closing mechanism for removing hydrogen and the opening / closing mechanism for recovering hydrogen can be appropriately opened and closed. The transition to the hydrogen recovery process can be performed smoothly.
Then, the inside of the hydrogen purifier is maintained at a desired pressure state by the pressure adjustment mechanism for hydrogen removal, and the hydrogen removal step is reliably executed, and the inside of the hydrogen purification apparatus is performed as desired by the pressure recovery mechanism for hydrogen recovery. The hydrogen recovery step can be executed while reducing the pressure, and as a result, the product hydrogen recovery rate can be further improved.

Furthermore, according to the third characteristic configuration of the present invention, a plurality of hydrogen purifiers are provided, and each of the plurality of hydrogen purifiers is provided with a hydrogen extraction opening / closing mechanism and connected in parallel to the hydrogen extraction line, and Since a hydrogen recovery opening / closing mechanism is connected in parallel to the hydrogen recovery line, a plurality of hydrogen purification devices can be operated by sequentially opening / closing the hydrogen extraction opening / closing mechanism and the hydrogen recovery opening / closing mechanism of each hydrogen purification device. It becomes possible to produce product hydrogen efficiently and continuously using.

Furthermore, according to the third characteristic configuration of the present invention, since the hydrogen recovery line is connected to the hydrogen extraction line by bypassing the pressure adjustment mechanism for hydrogen extraction, the hydrogen recovery line and the hydrogen extraction line can be shared. As described above, product hydrogen can be produced efficiently and continuously, and in addition, the cost of the hydrogen production apparatus can be reduced by sharing the line. In addition, since the hydrogen recovery line is connected to the hydrogen extraction line, bypassing the hydrogen extraction pressure adjustment mechanism, after adjusting the hydrogen flowing through the hydrogen extraction line, the hydrogen recovery line is mixed with the hydrogen flowing through the hydrogen recovery line Can do .

A fourth characteristic configuration of the present invention is that, in the above-described hydrogen production apparatus, a part of the hydrogen recovery line is also used as a pressure equalizing line for equalizing the pressure in each hydrogen purifier.

According to the fourth characteristic configuration of the present invention, a part of the hydrogen recovery line is also used as a pressure equalizing line for equalizing the pressure in each hydrogen purifier. In addition to sharing the line, the hydrogen recovery line and the pressure equalization line can also be shared, making it possible to further reduce the cost of the hydrogen production apparatus.

Embodiments of a hydrogen production method and apparatus according to the present invention will be described with reference to the drawings.
This hydrogen production method, for example, produces high-purity hydrogen using a city gas such as 13A as a hydrocarbon as a raw material, and the apparatus therefor includes a compressor 1, a first one as shown in FIG. Heat exchanger 2a, desulfurizer 3, second heat exchanger 2b, reformer 4 having burner 4a, transformer 5, third heat exchanger 2c, gas-liquid separator 6, hydrogen purifier 7, hydrogen storage tank 8 and an off-gas tank 9 are provided.
The compressor 1 compresses and raises the pressure of hydrocarbon gas as a raw material supplied from the first piping line L1. For example, when the gas from the medium pressure line in city gas is used as the raw material, The pressure of the hydrocarbon gas having a pressure of 1 MPa or higher is increased to about 0.98 MPa, and the pressurized hydrocarbon gas is sent to the desulfurizer 3 through the second piping line L2 having the first heat exchanger 2a. It is done.

The desulfurizer 3 removes the sulfur content from the pressurized hydrocarbon gas to the ppb level, and the hydrocarbon gas after the sulfur content removal is reformed through the third piping line L3 having the second heat exchanger 2b. The reformer 4 is supplied with steam (steam) or pure water that becomes steam in the reformer 4 from the fourth piping line L4.
The reformer 4 is maintained at a high temperature of about 750 ° C. by the combustion of the burner 4a, and the steam is reacted with the hydrocarbon gas by the steam reforming catalyst under a pressure of about 0.85 MPa to improve the gas to a hydrogen-rich gas. The reformed hydrogen-rich gas passes through the fifth piping line L5 and is preheated with the first and second heat exchangers 2a and 2b to be sent to the transformer 5.
The transformer 5 transforms carbon monoxide (CO) in the hydrogen-rich gas into carbon dioxide (CO ₂ ) by the catalyst for the transformation, and the hydrogen-rich gas after the transformation is the sixth piping line having the third heat exchanger 2c. The gas-liquid separator 6 is sent to the gas-liquid separator 6 through L6, and the gas-liquid separator 6 cools the hydrogen-rich gas to room temperature to condense and remove excess water, and then the hydrogen-rich gas passes through the first electromagnetic valve V1. It is sent to the hydrogen purifier 7 through the seventh piping line L7.

The hydrogen purifier 7 is a pressure swing-type hydrogen purifier that contains an adsorbent such as activated alumina, carbon molecular sieve (CMS), zeolite, and the like. From a hydrogen rich gas to water, carbon dioxide (CO ₂ ) under pressure. , Carbon monoxide (CO), methane (CH ₄ ), nitrogen (N ₂ ) and other impurities are adsorbed and removed to purify to high purity product hydrogen, and the adsorbed impurities are desorbed from the adsorbent under reduced pressure. Is.
As shown in detail in FIG. 2, the hydrogen purifier 7 includes, for example, a three-column hydrogen purifier 7, that is, a first hydrogen purifier 7a, a second hydrogen purifier 7b, and a third hydrogen purifier 7c. The first to third hydrogen purifiers 7a to 7c are connected in parallel. As will be described in detail later, in each hydrogen purifier 7a to 7c, adsorption (hydrogen extraction step), pressure equalization (hydrogen Recovery process), pressure equalization (1), pressure reduction (1) and (2), washing, pressure equalization (2), and pressure increase are repeated in order to continuously produce high purity product hydrogen from hydrogen rich gas. Is configured to do.

High-purity hydrogen from each of the hydrogen purifiers 7a to 7c is conveyed to the hydrogen storage tank 8 through an eighth piping line L8 as a hydrogen extraction line provided with a hydrogen extraction pressure adjusting mechanism PV1, and is supplied to the supply side and the demand side. Is stored in the hydrogen storage tank 8 so that it can be supplied as a constant amount of product hydrogen at all times, and is supplied from the ninth piping line L9 according to demand.
Therefore, each of the hydrogen purifiers 7a to 7c is connected in parallel to the eighth piping line L8 via the eighth auxiliary piping lines L8a to L8c provided with the second electromagnetic valves V2a to V2c as the hydrogen extraction opening / closing mechanism. ing.
Further, each of the hydrogen purifiers 7a to 7c has a tenth piping line L10 as a hydrogen recovery line via a tenth auxiliary piping line L10a to L10c provided with third electromagnetic valves V3a to V3c as a hydrogen recovery opening / closing mechanism. Connected in parallel.

The tenth piping line L10 includes a hydrogen recovery pressure regulating mechanism PV2 and a fourth electromagnetic valve V4, and is connected to the eighth piping line L8 on the lower side than the hydrogen extracting pressure regulating mechanism PV1, in other words, The tenth piping line L10 as the hydrogen recovery line is connected to the eighth piping line L8 as the hydrogen extraction line, bypassing the pressure adjustment mechanism PV1 for hydrogen extraction.
In the middle of the tenth piping line L10, an eleventh auxiliary piping line L11a provided with a pressure equalizing pressure regulating mechanism PV3 is branched and connected, and the eleventh auxiliary piping line L11a is located on the upper side of the hydrogen extracting pressure regulating mechanism PV1. Connected to the eighth piping line L8, the eleventh auxiliary piping line L11a, a part of the tenth piping line L10, and the tenth auxiliary piping lines L10a to L10c equalize the pressure in the hydrogen purifiers 7a to 7c. An eleventh piping line L11 is configured as a pressure equalizing line to be compressed. In other words, a part of the tenth piping line L10 as the hydrogen recovery line is also used as the pressure equalizing line L11.

Further, the off-gas from each of the hydrogen purifiers 7a to 7c is configured to be sent to the burner 4a side for the reformer 4 through the twelfth piping line L12. Therefore, each of the hydrogen purifiers 7a to 7c is The twelfth auxiliary pipe lines L12a to L12c having the fifth electromagnetic valves V5a to V5c are connected to the twelfth pipe line L12, respectively, and the off-gas tank 9 is interposed in the twelfth pipe line L12. The seventh piping line L7 is connected to the auxiliary piping lines L12a to L12c via seventh auxiliary piping lines L7a to L7c having the electromagnetic valves V1a to V1c constituting the first electromagnetic valve V1, respectively.
Off-gas from each of the hydrogen purification apparatuses 7a to 7c is supplied to the burner 4a, and the exhaust gas after combustion is discharged out of the apparatus through the fourteenth piping line L14.

The off gas tank 9 interposed in the twelfth piping line L12 is for temporarily storing off gas supplied from the hydrogen purifiers 7a to 7c and supplying a constant amount of off gas to the burner 4a at all times. Before and after the off-gas tank 9, a sixth electromagnetic valve V6 and a first flow rate adjustment valve FV1 are disposed.
In the twelfth piping line L12, a fifteenth piping line L15 including the off-gas tank 9 and bypassing the front and rear sixth electromagnetic valves V6 and the fourth pressure regulating valve PV4 is provided, and the fifteenth piping line L15 includes A seventh electromagnetic valve V7 and a fifth pressure adjustment valve PV5 are disposed, and a flow meter F is disposed in a twelfth piping line L12 on the lower side of the fifteenth piping line L15.
Then, on the upper side of the first electromagnetic valve V1 in the seventh piping line L7, a part of the hydrogen-rich gas from the gas-liquid separator 6 and the sixteenth piping line L16 for purge provided with the eighth electromagnetic valve V8. A seventeenth piping line L17 returning to the first piping line L1 is connected.

Next, the operation of the hydrogen production apparatus will be described and a hydrogen production method will be referred to.
First, after performing a start-up operation that raises the entire circulation system of the apparatus to a predetermined temperature, a hydrogen purification operation is performed to produce product hydrogen. In the hydrogen purification operation, the hydrocarbon gas that is a raw material is After being introduced from the first piping line L1, the pressure is increased to a predetermined pressure by the compressor 1, and after passing through the first heat exchanger 2a, sulfur is removed in the desulfurizer 3, and then the second heat exchanger 2b is In the reformer 4, it reacts with steam by the steam reforming catalyst at a high temperature due to combustion of the burner 4a to be reformed into a hydrogen rich gas.
The reformed hydrogen-rich gas passes through the first and second heat exchangers 2a and 2b and preheats the hydrocarbon gas as a raw material, and the carbon monoxide contained in the transformer 5 is transformed into carbon dioxide. After excess water is removed by the separator 6, impurities are adsorbed and removed in any one of the three towers of hydrogen purifiers 7 a to 7 c to be purified to high purity hydrogen.

For example, as shown in the upper part of FIG. 3, if the hydrogen-rich gas is purified in the first hydrogen purifier 7a, as shown in the lower part of FIG. 3, between steps 1 to 5 (time t1 to t5). By opening the first electromagnetic valve V1a, the hydrogen-rich gas is supplied to the first hydrogen purification device 7a, and the first hydrogen purification device 7a is maintained in a predetermined pressurized state, and is contained in the hydrogen-rich gas in the adsorbent. An adsorption step of adsorbing impurities such as water, carbon dioxide, carbon monoxide, methane, nitrogen, etc., and extracting the high-purity product hydrogen by opening the second electromagnetic valve V2a, that is, a hydrogen extraction step is executed.
During this hydrogen extraction process, the inside of the first hydrogen purification device 7a is maintained at a predetermined pressure of about 0.85 MPa by a hydrogen extraction pressure adjustment mechanism PV1 including a pressure adjustment valve, for example. It is transported and stored in the hydrogen storage tank 8 via an eighth piping line L8 as a take-out line.

At that time, the second hydrogen purification device 7b is in the pressure equalization (2) step immediately after the cleaning step is completed, and the third hydrogen purification device 7c is the pressure equalization step immediately after the adsorption step (hydrogen extraction step) is completed. That is, in the hydrogen recovery process for recovering high-purity product hydrogen remaining in the third hydrogen purification device 7c, the third electromagnetic valves V3c, V4b, and V10 are opened during step 1 (time t1). The pressure in the second and third hydrogen purification devices 7b and 7c is equalized, and at the same time, the high-purity product hydrogen remaining in the third hydrogen purification device 7c is reduced with the pressure reduction in the third hydrogen purification device 7c. The recovered product hydrogen is transported to the hydrogen storage tank 8 and stored through a tenth piping line L10 as a hydrogen recovery line.
Prior to the hydrogen recovery step, the inside of the third hydrogen purifier 7c is composed of, for example, a pressure adjustment valve when the set pressure of the pressure adjustment valve PV9 for adjusting the pressure of the hydrogen storage tank 8 is 0.65 MPa. The hydrogen recovery step is completed when the pressure is maintained at a predetermined pressure of 0.65 MPa or more by the hydrogen recovery pressure adjustment mechanism PV2 and reduced to a predetermined set pressure of 0.65 MPa.

Thereafter, in step 2 (time t2), the pressure of the second hydrogen purifier 7b is increased, and in step 3 and 4 (time t3 and t4), the pressure of the third hydrogen purifier 7c is reduced. Under the reduced pressure, the impurities adsorbed on the adsorbent are desorbed and the off-gas is discharged.
In the depressurization step of the third hydrogen purifier 7c, in the initial stage, as shown in FIG. 4A, the off-gas containing a relatively large amount of carbon monoxide is used for off-gas by opening the sixth electromagnetic valve V6. As shown in FIG. 4 (b), the sixth electromagnetic valve V6 is closed and the seventh electromagnetic valve V7 is opened to store off gas containing a relatively large amount of hydrogen. Passes through the bypass L15, is mixed with the offgas from the offgas tank 9, is supplied to the burner 4a of the reformer 4, and is burned.

Subsequently, in step 5 (time t5), the pressure of the second hydrogen purification device 7b is increased, and for example, hydrogen in the hydrogen storage tank 8 is supplied to the third hydrogen purification device 7c to be washed, as shown in FIG. ), The washed off-gas passes through the bypass L15, is mixed with the off-gas from the off-gas tank 9, is supplied to the burner 4a of the reformer 4, and is burned.
And in the 1st-3rd hydrogen refining apparatuses 7a-7c, high purity hydrogen is continuously refine | purified by repeating such a process sequentially, and product hydrogen is manufactured.

[Another embodiment]
(1) In the previous embodiment, an example was shown in which a hydrogen-rich gas was produced by a fuel gas transformation method, and product hydrogen was produced by purifying high-purity hydrogen from the hydrogen-rich gas. In addition to the fuel gas transformation method, it is manufactured by various methods such as liquid fuel gasification method, water electrolysis method, coal and coke gasification method, coke oven gas liquefaction separation method, and methanol and ammonia decomposition method. be able to.

(2) In the previous embodiment, an example in which the hydrogen purifier 7 was configured by connecting three towers of hydrogen purifiers 7a to 7c in parallel was shown. However, for example, a hydrogen production apparatus using two hydrogen purifiers In addition, the present invention can also be applied to a hydrogen production apparatus that uses four or more towers of hydrogen purifiers connected in parallel.

Schematic configuration diagram showing the entire hydrogen production system Schematic configuration diagram showing the main parts of the hydrogen production system Explanatory diagram showing the operation of the hydrogen purifier Explanatory diagram showing the operation of the hydrogen purifier

Explanation of symbols

7 (7a-7c) Hydrogen refining device 8 Hydrogen storage tank L8 Hydrogen removal line L10 Hydrogen recovery line L11 Pressure equalization line PV1 Hydrogen extraction pressure mechanism PV2 Hydrogen recovery pressure adjustment mechanism V2a-V2c Hydrogen extraction opening / closing mechanism V3a-V3c Open / close mechanism for hydrogen recovery

Claims (4)

Maintaining the inside of the hydrogen purifier that contains the adsorbent in a pressurized state, the impurities in the hydrogen-rich gas are adsorbed to the adsorbent to take out high-purity product hydrogen, and store it in a hydrogen storage tank using a hydrogen take-out line. A hydrogen production method for producing high-purity product hydrogen from a hydrogen-rich gas while repeating a hydrogen removal step and an off-gas removal step for removing off-gas by desorbing impurities from the adsorbent while maintaining the inside of the hydrogen purifier in a reduced pressure state Because
A hydrogen recovery step of recovering high-purity product hydrogen remaining in the hydrogen purifier with the reduced pressure in the hydrogen purifier after the hydrogen extraction step is completed, using the hydrogen extraction line in the hydrogen storage tank. And after the completion of the hydrogen recovery process, the process proceeds to the off-gas removal process,
A plurality of the hydrogen purification devices are provided, and when one of the plurality of hydrogen purification devices is executing the hydrogen extraction step, another hydrogen purification device executes the hydrogen recovery step;
The product hydrogen taken out by the hydrogen extraction step, as well as stored prior Symbol hydrogen storage tank, a hydrogen production method of storing simultaneously the hydrogen storage tank the product hydrogen recovered in the hydrogen recovery step.   The hydrogen production method according to claim 1, wherein the hydrogen recovery step is completed when the pressure in the hydrogen purifier is reduced to a predetermined set pressure. A hydrogen refining device for storing an adsorbent; a hydrogen storage tank for storing high-purity product hydrogen; and a hydrogen take-out line for taking out product hydrogen from the hydrogen refining device and transporting it to the hydrogen storage tank. Maintaining the inside in a pressurized state, the impurities in the hydrogen-rich gas are adsorbed on the adsorbent and purified into high-purity product hydrogen, and the product hydrogen is conveyed to the hydrogen storage tank via the hydrogen take-out line, A hydrogen production device configured to take off gas by desorbing impurities from the adsorbent while maintaining a reduced pressure inside the hydrogen purification device,
A hydrogen recovery line for recovering high-purity product hydrogen remaining in the hydrogen purifier along with the reduced pressure in the hydrogen purifier and transporting it to the hydrogen storage tank;
A plurality of the hydrogen purification devices are provided, and each of the plurality of hydrogen purification devices is
The hydrogen refining apparatus is connected to the hydrogen storage tank in parallel at the hydrogen take-out line provided with a hydrogen take-out pressure adjusting mechanism and a hydrogen take-off opening / closing mechanism for maintaining a predetermined pressurized state,
Connected in parallel to the hydrogen recovery line having a hydrogen recovery pressure adjustment mechanism for reducing the pressure inside the hydrogen purifier and a hydrogen recovery opening and closing mechanism;
The hydrogen production apparatus, wherein the hydrogen recovery line is connected to the hydrogen extraction line at a position closer to the hydrogen storage tank than the pressure adjustment mechanism for hydrogen extraction.   The hydrogen production apparatus according to claim 3, wherein a part of the hydrogen recovery line is also used as a pressure equalizing line for equalizing the pressure in each hydrogen purifier.

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