JP2017032016A - Hydrogen gas supplying method and hydrogen station - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a hydrogen gas supplying method which reduces energy consumption and can improve a life of adsorbent.SOLUTION: A hydrogen gas supplying method includes: a process for performing dehydrogenation of an organic hydride by heating in existence of a catalyst in a reactor; a process for performing gas-liquid separation of a gas mixture of an aromatic compound and hydrogen discharged from the reactor into the aromatic compound and hydrogen gas in a separator; a process for refining hydrogen gas separated by the separator on an adsorption tower of a TSA type; a process for compressing the hydrogen gas refined on the adsorption tower on a compressor; and a process for supplying the hydrogen gas compressed on the compressor to an external part with a dispenser. Therein, on the supply process, the hydrogen gas is cooled by heat exchange with brine, on the separation process, gas to be circulated to a separator inner part is cooled by the brine to be used on the supply process and, on the refining process, the gas to be circulated to the adsorption tower inner part is cooled by the brine to be used on the supply process.SELECTED DRAWING: Figure 1

Description

  The present invention relates to a hydrogen gas supply method and a hydrogen station.

  Hydrogen stations for filling hydrogen into fuel cell vehicles (FCV), etc. include an on-site hydrogen station that produces hydrogen from fossil fuels such as natural gas locally, and hydrogen produced at other locations using compressed hydrogen. There are off-site hydrogen stations that are transported in form and used locally. As a form of compressed hydrogen transported at an off-site type hydrogen station, use of an organic hydride has been studied (for example, see JP 2013-87820 A).

  The organic hydride used for transportation in the off-site hydrogen station is an organic compound that reversibly releases hydrogen through a catalytic reaction, and releases hydrogen to become an aromatic compound. When the organic hydride is dehydrogenated, an aromatic compound corresponding to the vapor pressure remains. For example, when methylcyclohexane is used as the organic hydride, toluene corresponding to the vapor pressure remains in the gas upon dehydrogenation. In order to use hydrogen gas in FCV or the like, toluene remaining in this gas must be removed, and in particular for FCV, it is required to be removed on the order of ppm.

  As a general method for removing toluene remaining in the gas, a hydrogen supply system using an adsorbent has been proposed (see Japanese Patent Application Laid-Open No. 2014-73922). As described above, methods for removing toluene with an adsorbent include a TSA (Temperature Swing Adsorption) method and a PSA (Pressure Swing Adsorption) method, and the TSA method provides a higher hydrogen recovery rate. In this TSA method, the adsorbent regeneration method is to adsorb to the adsorbent at normal temperature at the time of adsorption, to release toluene adsorbed on the adsorbent by heating the adsorption tower at the time of regeneration, and again to the normal temperature at the time of adsorption after the regeneration. Cool down. In such a TSA method, in order to reduce the energy consumption of the entire system that supplies hydrogen gas obtained by dehydrogenating organic hydride to the outside and to reduce the operating cost, heating for regeneration of the adsorbent is performed. There is a need to reduce the required energy and extend the life of the adsorbent.

JP 2013-87820 A JP 2014-73922 A

  The present invention has been made based on the above-described circumstances, and an object thereof is to provide a hydrogen gas supply method and a hydrogen station that can reduce energy consumption and improve the life of an adsorbent.

  The invention made to solve the above-mentioned problems includes a step of performing a dehydrogenation reaction of an organic hydride in a reactor by heating in the presence of a catalyst, and a separator of a mixed gas of an aromatic compound and hydrogen discharged from the reactor. Gas-liquid separation into aromatic compound and hydrogen gas in step, step of purifying the hydrogen gas separated in the separator with a TSA type adsorption tower, and compression of the hydrogen gas purified in the adsorption tower with a compressor A hydrogen gas supply method in a hydrogen station comprising a step of supplying the hydrogen gas compressed by the compressor to the outside with a dispenser, wherein the hydrogen gas is cooled by heat exchange with brine in the supply step In the separation step, the gas circulating in the separator is cooled by the brine used in the supply step, and the gas flowing in the adsorption tower is purified in the purification step. A hydrogen gas supply method characterized by cooling the brine to be used.

  Since the hydrogen gas supply method cools the gas flowing through the separator in the separation step, the separation efficiency of the separator can be improved and the amount of the aromatic compound remaining in the separated gas can be reduced. In addition, since the hydrogen gas supply method cools the gas flowing inside the adsorption tower in the purification process, the effective adsorption amount of the aromatic compound by the adsorbent increases, so that the frequency of regeneration of the adsorbent can be reduced, and the adsorbent Can improve the service life. In addition, since the hydrogen gas supply method uses brine used in the supply step as a refrigerant in the separation step and the purification step, energy required for cooling the gas circulating in the separator and the adsorption tower can be reduced. The energy consumption of the station can be reduced and the equipment can be simplified.

  The method may further comprise a step of repurifying the hydrogen gas compressed in the compression step with a TSA type auxiliary adsorption tower, and in the repurification step, the gas circulating in the auxiliary adsorption tower may be cooled with brine used in the supply step. . Thus, the amount of the aromatic compound remaining in the gas can be more reliably reduced by repurifying the hydrogen gas compressed in the compression step by the auxiliary adsorption tower that cools the gas flowing inside.

  The cooling temperature of the brine is preferably −50 ° C. or higher and −13 ° C. or lower. Thus, by setting the cooling temperature of the brine within the above range, the separation efficiency in the separator is improved, the regeneration frequency of the adsorption tower is reduced, the temperature of the hydrogen gas supplied to the outside is adjusted, and the energy consumption is reduced. Reduction can be realized in a balanced manner.

  In the purification step, the adsorbent filled in the adsorption tower may be cooled by brine used in the supply step. Thus, by cooling the adsorbent filled in the adsorption tower, the effective adsorption amount of the aromatic compound by the adsorbent increases more effectively, and it is easier to reduce the regeneration frequency of the adsorbent.

  The method may further comprise storing a hydrogen gas compressed by the compressor in a reservoir, and supplying the hydrogen gas in the reservoir to the outside in the supplying step. As described above, the compressed hydrogen gas is stored in the reservoir, and the hydrogen gas in the reservoir is supplied to the outside, so that even when the supply amount of the hydrogen gas to the outside increases, the hydrogen gas can be stably supplied. Gas can be supplied.

  Another invention made in order to solve the above-mentioned problems is that a reactor for performing a dehydrogenation reaction of an organic hydride by heating in the presence of a catalyst, a mixed gas of an aromatic compound and hydrogen discharged from the reactor. A separator for gas-liquid separation into an aromatic compound and hydrogen gas, a TSA type adsorption tower for purifying the hydrogen gas separated by the separator, and a compressor for compressing the hydrogen gas purified by the adsorption tower; A hydrogen station comprising a dispenser for supplying hydrogen gas compressed by the compressor to the outside, wherein the dispenser has a cooler for cooling the supplied hydrogen gas by heat exchange with brine, and the separator Has a first cooling mechanism for cooling the gas flowing inside, and the adsorption tower has a second cooling mechanism for cooling the gas flowing inside, the first cooling mechanism and the second cooling machine. There is hydrogen station, which comprises using a brine of the cooler as a refrigerant.

  The hydrogen station cools the gas flowing through the separator by the first cooling mechanism, thereby improving the separation efficiency of the separator and reducing the amount of aromatic compounds remaining in the separated gas. In addition, since the hydrogen station cools the gas flowing inside the adsorption tower by the second cooling mechanism, the effective adsorption amount of the aromatic compound by the adsorbent increases, so that the frequency of regeneration of the adsorbent can be reduced. Lifetime can be improved. Further, the hydrogen station uses the brine used for cooling the hydrogen gas supplied by the dispenser by the first cooling mechanism and the second cooling mechanism, so that it is necessary for cooling by the first cooling mechanism and the second cooling mechanism. Energy can be reduced, energy consumption of the hydrogen station can be reduced, and equipment can be simplified.

  The adsorption tower may cool the adsorbent filled in the adsorption tower by the second cooling mechanism. Thus, by cooling the adsorbent filled in the adsorption tower by the second cooling mechanism, the effective adsorption amount of the aromatic compound by the adsorbent is more effectively increased, and the regeneration frequency of the adsorbent is further reduced. Easy to do.

  The apparatus may further include a reservoir that stores the hydrogen gas compressed by the compressor, and the dispenser may supply the hydrogen gas in the reservoir to the outside. As described above, the compressed hydrogen gas is stored in the reservoir, and the hydrogen gas in the reservoir is supplied to the outside by the dispenser, so that even when the supply amount of the hydrogen gas to the outside increases, the hydrogen gas is stabilized. Thus, hydrogen gas can be supplied.

  As described above, the hydrogen gas supply method and the hydrogen station of the present invention can reduce energy consumption and improve the life of the adsorbent.

It is a block diagram which shows the structure of the hydrogen station in one Embodiment of this invention.

  Hereinafter, embodiments of a hydrogen station and a hydrogen gas supply method according to the present invention will be described with reference to the drawings.

[Hydrogen station]
The hydrogen station in FIG. 1 includes a reactor 1 that performs a dehydrogenation reaction of organic hydride A by heating in the presence of a catalyst, and a mixed gas of an aromatic compound and hydrogen discharged from the reactor 1 as an aromatic compound and hydrogen gas. The separator 2 for gas-liquid separation, the adsorption tower 3 for purifying the hydrogen gas separated by the separator 2, the compressor 4 for compressing the hydrogen gas purified by the adsorption tower 3, and the compressor 4 And a dispenser 6 for supplying hydrogen gas to the outside. The hydrogen station includes an auxiliary adsorption tower 7 for purifying the hydrogen gas compressed by the compressor 4 and a cooler 8 for cooling the hydrogen gas B supplied by the dispenser 6 by heat exchange with the brine D. Prepare. In addition, the hydrogen station includes a reservoir 5 that stores the hydrogen gas compressed by the compressor 4, and the dispenser supplies the hydrogen gas B in the reservoir 5 to the outside. The separator 2 has a first cooling mechanism 11 that cools the gas flowing inside, and the adsorption tower 3 has a second cooling mechanism 12 that cools the gas flowing inside. The adsorption tower 7 has a third cooling mechanism 13 that cools the gas flowing inside. The hydrogen station also includes a brine supply line for supplying the cooled brine D to each cooling mechanism. In FIG. 1, the solid line indicates the flow of the organic hydride A, mixed gas, and hydrogen gas, the alternate long and short dash line indicates the flow of brine D, and the alternate long and two short dashes line indicates the flow of refrigerant E.

  Examples of the organic hydride A used in the hydrogen station include hydrogenated aromatic compounds such as methylcyclohexane (hereinafter also referred to as MCH), cyclohexane, dimethylcyclohexane, ethylcyclohexane, decalin, methyldecalin, dimethyldecalin, and ethyldecalin. For example, when MCH is used as the organic hydride A, it is converted to toluene which is an aromatic compound by a dehydrogenation reaction.

  The hydrogen station is used to supply hydrogen to hydrogen vehicles such as hydrogen automobiles and FCVs.

<Reactor>
The reactor 1 performs a dehydrogenation reaction of the organic hydride A by heating in the presence of a catalyst. Specifically, the reactor 1 has a dehydrogenation reaction catalyst that promotes the dehydrogenation reaction of the organic hydride A. The reactor 1 is heated from the organic hydride A and brought into contact with the dehydrogenation reaction catalyst to generate hydrogen from the organic hydride A. Causes an oxidation reaction to separate Thereby, a mixed gas of an aromatic compound and hydrogen is generated.

  Examples of the dehydrogenation reaction catalyst used in the dehydrogenation reactor 1 include sulfur and selenium.

  As a minimum of heating temperature of organic hydride A in reactor 1, 180 ° C is preferred and 200 ° C is more preferred. On the other hand, the upper limit of the heating temperature of the organic hydride A is preferably 400 ° C., more preferably 350 ° C. If the heating temperature of the organic hydride A is less than the lower limit, the reaction rate of the organic hydride A and the yield of hydrogen gas may be insufficient. Conversely, if the heating temperature of the organic hydride A exceeds the upper limit, the energy cost required for heating may be unnecessarily increased.

<Separator>
The separator 2 gas-liquid separates the mixed gas of the aromatic compound and hydrogen discharged from the reactor 1 into the aromatic compound and hydrogen gas. The separator 2 has a first cooling mechanism 11 that cools the gas flowing inside. By cooling the gas flowing through the separator 2, the aromatic compound and hydrogen are easily separated, and the concentration of the aromatic compound in the separated gas is reduced. The aromatic compound C separated as a liquid is discharged from the separator 2 as a drain.

(First cooling mechanism)
The first cooling mechanism 11 uses the brine D used as a refrigerant by the cooler 8 of the dispenser 6 to be described later as a refrigerant to cool the gas flowing inside the separator 2.

  As the 1st cooling mechanism 11, well-known heat exchangers, such as a shell and tube type heat exchanger, a fin tube type heat exchanger, a plate type heat exchanger, can be used.

  Note that a brine D supply line that branches from a brine D supply line used in a cooler 8 of the dispenser 6 described later and flows into the first cooling mechanism 11 is disposed, and a first flow rate is provided on the branched supply line. A control valve 21 is provided.

  As a minimum of the temperature of hydrogen gas in the exit of separator 2, -40 ° C is preferred and -35 ° C is more preferred. On the other hand, the upper limit of the temperature of the hydrogen gas at the outlet of the separator 2 is preferably −10 ° C., more preferably −15 ° C. If the temperature of the hydrogen gas at the outlet of the separator 2 is lower than the lower limit, the energy required for cooling the hydrogen gas increases, and the energy consumption of the hydrogen station may not be sufficiently reduced. Conversely, if the temperature of the hydrogen gas at the outlet of the separator 2 exceeds the above upper limit, the concentration of the aromatic compound in the gas after separation is not sufficiently reduced, and the adsorption load in the adsorption tower 3 described later increases. The life of the adsorbent may not be sufficiently improved. Note that the flow rate of the brine D supplied to the first cooling mechanism 11 is adjusted by the first flow rate adjustment valve 21, thereby adjusting the temperature of the hydrogen gas at the outlet of the separator 2.

  As a minimum of the concentration of an aromatic compound in hydrogen gas after separation with separator 2, 50 ppm is preferred and 100 ppm is more preferred. On the other hand, the upper limit of the concentration of the aromatic compound in the hydrogen gas is preferably 800 ppm, and more preferably 600 ppm. If the aromatic compound concentration in the hydrogen gas is less than the lower limit, it is necessary to lower the temperature of the brine D for cooling the hydrogen gas, which may increase the equipment cost and the operating cost. Conversely, if the concentration of the aromatic compound in the hydrogen gas exceeds the above upper limit, the amount of aromatic compound adsorbed by the adsorption tower 3 described later increases, so the adsorption load in the adsorption tower 3 increases and the adsorbent Life may not be improved sufficiently.

<Adsorption tower>
The adsorption tower 3 purifies the hydrogen gas separated by the separator 2. Specifically, the adsorption tower 3 is filled with an adsorbent, and the aromatic compound contained in the hydrogen gas separated by the separator 2 is adsorbed by the adsorbent so that the aromatic compound in the hydrogen gas is absorbed. The concentration is reduced.

  The adsorption tower 3 has the 2nd cooling mechanism 12 which cools the gas which distribute | circulates an inside. The adsorption tower 3 is adsorbed and regenerated by the TSA method, and at the time of adsorption, the second cooling mechanism 12 cools the gas flowing in the interior to a temperature lower than normal temperature. By making the temperature lower than room temperature during adsorption, the effective adsorption amount of the aromatic compound by the adsorbent increases, so that the frequency of regeneration of the adsorbent is reduced and the life of the adsorbent is improved.

  The adsorbent is not particularly limited as long as it can adsorb an aromatic compound, and examples thereof include activated carbon, zeolite, silica, and MOF (Metal Organic Frameworks). Among these, activated carbon is preferable in that it is relatively inexpensive and has a high specific surface area.

  The upper limit of the concentration of the aromatic compound in the hydrogen gas after adsorbing the aromatic compound by the adsorption tower 3 is preferably 2.0 ppm, and more preferably 1.5 ppm. If the concentration of the aromatic compound in the hydrogen gas exceeds the upper limit, the hydrogen gas may not be used as a fuel such as FVC having strict environmental standards.

  When the adsorption amount of the adsorbent reaches the effective adsorption amount, a regeneration process for releasing the aromatic compound adsorbed on the adsorbent is performed by heating the adsorption tower 3.

  As a minimum of the heating temperature at the time of adsorbent reproduction, 100 ° C is preferred and 150 ° C is more preferred. On the other hand, the upper limit of the heating temperature is preferably 300 ° C and more preferably 250 ° C. If the heating temperature is less than the lower limit, the time required for regeneration may be too long. On the other hand, when the heating temperature exceeds the upper limit, the energy required for heating for regeneration becomes too large, and there is a possibility that ignition is likely to occur due to local overheating.

(Second cooling mechanism)
The second cooling mechanism 12 uses the brine D used as a refrigerant by the cooler 8 of the dispenser 6 described later as a refrigerant, and cools the gas flowing inside the adsorption tower 3.

  As the 2nd cooling mechanism 12, well-known heat exchangers, such as a shell and tube type heat exchanger, a fin tube type heat exchanger, and a plate type heat exchanger, can be used.

  A brine D supply line branched from a brine D supply line used in a cooler 8 of the dispenser 6 described later and flowing into the second cooling mechanism 12 is disposed, and a second flow rate is provided on the branched supply line. A control valve 22 is provided.

  As a minimum of the temperature of hydrogen gas in the exit of adsorption tower 3, -40 ° C is preferred and -35 ° C is more preferred. On the other hand, the upper limit of the temperature of the hydrogen gas at the outlet of the adsorption tower 3 is preferably −10 ° C., more preferably −15 ° C. If the temperature of the hydrogen gas at the outlet of the adsorption tower 3 is below the lower limit, the energy required for cooling increases, and the energy consumption of the hydrogen station may not be sufficiently reduced. On the contrary, if the temperature of the hydrogen gas at the outlet of the adsorption tower 3 exceeds the upper limit, the effective adsorption amount of the aromatic compound by the adsorbent is not sufficiently increased, and the life of the adsorbent may not be sufficiently improved. Note that the flow rate of the brine D flowing into the second cooling mechanism 12 is adjusted by the second flow rate adjusting valve 22, and thereby the temperature of the hydrogen gas at the outlet of the adsorption tower 3 is adjusted.

  The second cooling mechanism 12 may cool the gas flowing inside the adsorption tower 3 and cool the adsorbent filled inside the gas when the adsorption tower 3 adsorbs the gas. By cooling the adsorbent, the effective adsorption amount of the aromatic compound by the adsorbent is more effectively increased. Therefore, the frequency of regeneration of the adsorbent can be easily reduced, and the life of the adsorbent can be further improved.

<Compressor>
The compressor 4 compresses the hydrogen gas purified by the adsorption tower 3 and supplies it to the auxiliary adsorption tower 7.

  As a minimum of the pressure of hydrogen gas after compression with compressor 4, 40MPa is preferred and 50MPa is more preferred. On the other hand, the upper limit of the pressure of the compressed hydrogen gas is preferably 95 MPa, and more preferably 87.5 MPa. If the pressure of the compressed hydrogen gas is less than the lower limit, the pressure of the hydrogen gas in the reservoir 5 may be too small, and the supply time of hydrogen to the outside such as FCV may be too long. Conversely, if the pressure of the compressed hydrogen gas exceeds the upper limit, the equipment cost may increase.

<Auxiliary adsorption tower>
The auxiliary adsorption tower 7 purifies the hydrogen gas compressed by the compressor 4. Since the effective adsorption amount of the adsorbent increases as the pressure of the processing gas increases, the auxiliary adsorption tower 7 can further reduce the concentration of the aromatic compound in the hydrogen gas.

  The auxiliary adsorption tower 7 has a third cooling mechanism 13 that cools the gas flowing inside. The auxiliary adsorption tower 7 is adsorbed and regenerated by the TSA method, and at the time of adsorption, the third cooling mechanism 13 is cooled so that the gas flowing inside becomes lower than normal temperature.

  As said adsorbent, the thing similar to what was mentioned by the adsorption tower 3, for example can be used. The auxiliary adsorption tower 7 may have the same configuration as the adsorption tower 3 or may have a different configuration.

(Third cooling mechanism)
The 3rd cooling mechanism 13 uses the brine D which the cooler 8 of the dispenser 6 mentioned later uses as a refrigerant | coolant, and cools the gas distribute | circulated inside the auxiliary adsorption tower 7. FIG.

  As the 3rd cooling mechanism 13, well-known heat exchangers, such as a shell and tube type heat exchanger, a fin tube type heat exchanger, a plate type heat exchanger, can be used.

  A brine D supply line branched from a brine D supply line used in a cooler 8 of the dispenser 6 described later and flowing into the third cooling mechanism 13 is disposed, and a third flow rate is provided on the branched supply line. A control valve 23 is provided.

  As a minimum of the temperature of hydrogen gas in the exit of auxiliary adsorption tower 7, -40 ° C is preferred and -35 ° C is more preferred. On the other hand, the upper limit of the temperature of the hydrogen gas at the outlet of the auxiliary adsorption tower 7 is preferably −10 ° C., more preferably −15 ° C. If the temperature of the hydrogen gas at the outlet of the auxiliary adsorption tower 7 is below the lower limit, the energy required for cooling the hydrogen gas increases, and the energy consumption of the hydrogen station may not be sufficiently reduced. Conversely, if the temperature of the hydrogen gas at the outlet of the auxiliary adsorption tower 7 exceeds the upper limit, the effective adsorption amount of the aromatic compound by the adsorbent does not increase sufficiently, and the adsorbent life may not be sufficiently improved. . Note that the flow rate of the brine D flowing into the third cooling mechanism 13 is adjusted by the third flow rate adjusting valve 23, thereby adjusting the temperature of the brine D at the outlet of the third cooling mechanism 13.

<Reservoir>
The storage 5 stores the hydrogen gas purified by the auxiliary adsorption tower 7, and the stored hydrogen gas B is supplied to the outside by the dispenser 6. The reservoir 5 has, for example, a plurality of pressure accumulators, and a pressure accumulator that stores hydrogen gas and a pressure accumulator that supplies hydrogen gas to the outside are switched according to the amount of hydrogen gas accumulated in each pressure accumulator.

<Dispenser>
The dispenser 6 supplies the hydrogen gas in the reservoir 5 to the outside, for example, FCV. The dispenser 6 has a cooler 8 that cools the supplied hydrogen gas so that the gas temperature in the container on the FCV side or the like does not rise excessively during the supply of the hydrogen gas to the outside.

(Cooler)
The cooler 8 cools the gas circulating in the adsorption tower 3 by heat exchange with the brine D cooled by heat exchange with the refrigerant E on the brine supply line. This cooling operation is performed only during the supply of the hydrogen gas B to the outside.

  The lower limit of the temperature of the hydrogen gas B at the outlet of the dispenser 6 is preferably −40 ° C., more preferably −35 ° C. On the other hand, the upper limit of the temperature of the hydrogen gas B at the outlet of the dispenser 6 is preferably −10 ° C., more preferably −15 ° C. When the temperature of the hydrogen gas B at the outlet of the dispenser 6 is lower than the lower limit, the energy required for cooling the hydrogen gas B increases, and the energy consumption of the hydrogen station may not be sufficiently reduced. On the contrary, if the temperature of the hydrogen gas B at the outlet of the dispenser 6 exceeds the upper limit, the gas temperature in an external container such as a container such as FCV may be excessively increased. By setting the temperature of the hydrogen gas B at the outlet of the dispenser 6 within the above range, the gas temperature in the external container can be suppressed to about 85 ° C. or less.

<Brine supply line>
The brine supply line includes a brine tank 14, a pump 15, and a heat exchanger 17.

  Brine D is stored in the brine tank 14 and sealed with, for example, nitrogen gas. The brine D in the brine tank 14 is circulated by a pump 15 to a circulation line having both ends connected to the brine tank 14.

  The brine supply line exchanges heat with the refrigerant circulation line through which the refrigerant E flows through the heat exchanger 17. The refrigerator 16 is connected to the refrigerant circulation line, and the refrigerant E flowing through the refrigerant circulation line is cooled by the refrigerator 16 by a pump or the like. Accordingly, the brine D flowing through the brine supply line is cooled by the refrigerant E by the heat exchanger 17.

  As a minimum of the to-be-cooled temperature of the brine D, -50 degreeC is preferable, -45 degreeC is more preferable, and -40 degreeC is further more preferable. On the other hand, the upper limit of the cooled temperature of brine D is preferably −13 ° C., more preferably −15 ° C., and further preferably −20 ° C. If the cooled temperature of the brine D is lower than the lower limit, the viscosity of the brine D tends to increase, the energy required for circulating the brine D increases, and the operating cost may increase. On the contrary, when the cooling temperature of the brine D exceeds the above upper limit, the temperature of the hydrogen gas B supplied from the dispenser 6 to the outside becomes high, and the rise in the gas temperature in the external container such as a container such as FCV is sufficiently increased. There is a possibility that it cannot be suppressed.

  As the brine D, any material that does not freeze within the above cooling temperature range may be used. For example, cold brine “FP40R” manufactured by Showa Co., Ltd., barrel fluid “E-60” manufactured by Matsumura Oil Co., Ltd., or the like can be used.

  As a minimum of the temperature of the refrigerant | coolant E which distribute | circulates to a refrigerant | coolant circulation line, -60 degreeC is preferable and -50 degreeC is more preferable. On the other hand, the upper limit of the temperature of the refrigerant E is preferably −18 ° C., more preferably −20 ° C. When the temperature of the refrigerant E is lower than the lower limit, the viscosity of the refrigerant E tends to be high, energy required for circulating the refrigerant E increases, and operation costs may increase. On the contrary, if the temperature of the refrigerant E exceeds the upper limit, the temperature of the brine D cannot be lowered sufficiently, and as a result, the temperature of the hydrogen gas B supplied from the dispenser 6 to the outside increases, and FCV or the like There is a possibility that an increase in gas temperature in an external container such as this container cannot be suppressed.

  As the refrigerant E, any refrigerant can be used as long as it can stably flow through the refrigerant circulation line in the above temperature range. For example, R410A, R404A, R407C, and the like can be used.

  As described above, the hydrogen station uses the brine D used as a refrigerant by the cooler 8 that cools the hydrogen gas B supplied by the dispenser 6, as the gas flowing through the separator 2, the adsorption tower 3, and the auxiliary adsorption tower 7. A line for supplying brine D is used in common as a cooling refrigerant. Thereby, the hydrogen station can simplify the cooling equipment for the gas flowing through the separator 2, the adsorption tower 3 and the auxiliary adsorption tower 7, and the entire hydrogen station can be configured relatively small. Further, by cooling the gas flowing through the separator 2, the adsorption tower 3 and the auxiliary adsorption tower 7, the separation efficiency of the separator 2 can be improved and the regeneration frequency of the adsorption tower 3 and the auxiliary adsorption tower 7 can be reduced. , Energy consumption can be reduced. Since the energy that can be reduced is larger than the energy used for cooling the separator 2, the adsorption tower 3, and the auxiliary adsorption tower 7, the hydrogen station can reduce the energy consumption as a whole.

[Hydrogen gas supply method]
The hydrogen gas supply method is a method of supplying hydrogen gas in the hydrogen station, and is a method of supplying hydrogen gas obtained by dehydrogenating organic hydride to the outside. The hydrogen gas supply method separates a process (reaction process) in which the dehydration reaction of the organic hydride A is performed in the reactor 1 by heating in the presence of a catalyst, and a mixed gas of the aromatic compound and hydrogen discharged from the reactor 1. A gas-liquid separation process into an aromatic compound and hydrogen gas in the vessel 2 (separation step), a step of purifying the hydrogen gas separated in the separator 2 with a TSA type adsorption tower 3 (purification step), and an adsorption tower 3 The step of compressing the hydrogen gas purified by the compressor 4 (compression step), the step of repurifying the hydrogen gas compressed in the compression step by the TSA type auxiliary adsorption tower 7 (repurification step), and the auxiliary adsorption A step of storing the hydrogen gas repurified in the tower 7 in the storage 5 (storage step) and a step of supplying the hydrogen gas B in the storage 5 to the outside by the dispenser 6 (supplying step) are provided.

<Reaction process>
In the reaction step, using the reactor 1, the organic hydride A is dehydrogenated by heating in the presence of a catalyst.

<Separation process>
In the separation step, the separator 2 is used to gas-liquid separate the mixed gas of the aromatic compound and hydrogen discharged from the reactor 1 into the aromatic compound and hydrogen gas. At this time, in the separation step, the gas-liquid separation is performed while cooling the gas flowing in the separator 2 by the brine D used in the supply step described later. Specifically, the brine D flows into the first cooling mechanism 11 from the supply line of the brine D used in the cooler 8 included in the dispenser 6, and the gas flowing into the separator 2 is cooled by the first cooling mechanism 11. The As described above, in the separation step, the gas flowing inside the separator 2 is cooled, so that the aromatic compound and hydrogen are easily separated, and the concentration of the aromatic compound in the separated gas is reduced.

<Purification process>
In the purification step, the hydrogen gas separated by the separator 2 is purified using the adsorption tower 3. At this time, in the purification step, the hydrogen gas is purified while being cooled by the brine D used in the supply step described later. Specifically, the brine D flows into the second cooling mechanism 11 from the supply line of the brine D used in the cooler 8 of the dispenser 6, and the gas circulating in the adsorption tower 3 is cooled by the second cooling mechanism 12. The Thereby, the aromatic compound concentration in hydrogen gas is reduced. As described above, in the purification step, the gas flowing inside the adsorption tower 3 is cooled at the time of adsorption, so that the effective adsorption amount of the aromatic compound by the adsorbent is increased and the regeneration frequency of the adsorbent is reduced. Thereby, the lifetime of the adsorbent is improved.

<Compression process>
In the compression step, the hydrogen gas purified by the adsorption tower 3 is compressed using the compressor 4.

<Repurification process>
In the repurification step, the hydrogen gas compressed by the compressor 4 is repurified using the auxiliary adsorption tower 7. At this time, in the re-purification process, the hydrogen gas is re-purified while being cooled by the brine D used in the supply process described later in the gas flowing through the auxiliary adsorption tower 7. Specifically, the brine D flows into the third cooling mechanism 13 from the supply line of the brine D used in the cooler 8 of the dispenser 6, and the gas flowing into the auxiliary adsorption tower 7 is cooled by the third cooling mechanism 13. Is done. Thereby, the concentration of the aromatic compound in the hydrogen gas is further reduced. Thus, in the re-purification step, the gas flowing through the auxiliary adsorption tower 7 during the adsorption is cooled, so that the effective adsorption amount of the aromatic compound by the adsorbent increases and the regeneration frequency of the adsorbent is reduced. Thereby, the lifetime of the adsorbent is improved.

<Storage process>
In the storage step, the hydrogen gas purified by the auxiliary adsorption tower 7 is stored in the storage 5.

<Supply process>
In the supply process, the dispenser 6 is used to supply the hydrogen gas in the reservoir 5 to the outside such as FCV. When supplying the hydrogen gas to the outside, the dispenser 6 cools the supplied hydrogen gas by heat exchange with the brine D sent from the cooler 8.

  Thus, since the hydrogen gas supply method uses the brine used for cooling the hydrogen gas supplied by the dispenser as a refrigerant in the separation step, the purification step, and the repurification step, the separator, the adsorption tower, and the auxiliary adsorption tower. The energy required for cooling the gas circulating inside can be reduced, the energy consumption of the hydrogen station can be reduced, and the equipment can be simplified.

[Other Embodiments]
The hydrogen gas supply method and the hydrogen station are not limited to the above embodiment.

  That is, in the above-described embodiment, the auxiliary adsorption tower has a cooling mechanism for cooling the gas flowing inside, but the auxiliary adsorption tower may not have such a cooling mechanism. Since the amount of the aromatic compound adsorbed by the auxiliary adsorption tower is smaller than the amount of the aromatic compound adsorbed by the adsorption tower, the regeneration frequency of the adsorbent is reduced even if the auxiliary adsorption tower does not have a cooling mechanism. small. Therefore, when the effect of improving the life of the adsorbent is small with respect to the amount of energy consumed by having the cooling mechanism, the auxiliary adsorption tower may not have the cooling mechanism.

  In addition, the reservoir is not an essential component of the hydrogen station. For example, when there is little increase / decrease in the supply amount of hydrogen gas to the outside and there is a margin in the purification amount of hydrogen gas with respect to the required supply amount of hydrogen gas, the storage unit may be omitted.

  The auxiliary adsorption tower is not an essential component of the hydrogen station. For example, when the aromatic compound concentration required for the hydrogen gas supplied to the outside is achieved by adsorption removal with an adsorption tower, the auxiliary adsorption tower may be omitted.

  Moreover, it is good also as a structure in which a compressor uses the brine of a cooler as a refrigerant | coolant, and is equipped with the cooling mechanism which cools the gas to compress inside. Thus, by cooling the gas inside the compressor, the power required for compression can be reduced, and the operating cost can be reduced.

  EXAMPLES Hereinafter, although an Example is given and this invention is demonstrated more concretely, this invention is not limited to these.

  The following verification was performed using the process simulation software “PRO / II” of Invensys.

[Example 1]
First, the hydrogen gas obtained by dehydrogenating MCH is cooled by heat exchange at a flow rate of 340 Nm ³ / h and an outside air temperature (30 ° C.), and then the hydrogen gas flowing through the separator is cooled to −20 ° C. by heat exchange. Gas-liquid separation. At this time, the amount of heat necessary for cooling the hydrogen gas was 8.22 kW. Further, the concentration of toluene remaining in the hydrogen gas separated by the separator was 574 ppm. Next, a single adsorption tower filled with 500 kg of activated carbon (Kuraray Chemical “GC10 / 20” from Kuraray Chemical Co., Ltd.) was prepared. When the adsorbent packed in the adsorption tower and the hydrogen gas flowing through the adsorption tower are cooled to −20 ° C. and toluene in the hydrogen gas is removed, the time that can be operated without regeneration is calculated. It was time. In addition, the amount of heat required to replace the adsorbent was 2565 kWh.

[Comparative Example 1]
First, hydrogen gas obtained by dehydrogenating MCH was cooled by heat exchange at a flow rate of 340 Nm ³ / h and an outside air temperature (30 ° C.). Next, two adsorption towers each filled with 250 kg of activated carbon (Kuraray Chemical Co., Ltd., Kuraray Coal “GG10 / 32”) were prepared, and the hydrogen removal was performed while switching between adsorption removal and heating regeneration with these two adsorption towers. The gas was removed by adsorption. The toluene concentration remaining in the hydrogen gas at 30 ° C. before being adsorbed by the adsorption tower was 1.22% by volume. Here, when the regeneration temperature was set to 180 ° C. and the adsorption cycle was 6 hours, the amount of heat necessary for regeneration under these conditions was 80.1 kWh per cycle. Therefore, the required heat amount under the 312 hour operation condition was 4165 kWh.

[inspection result]
From the results of Example 1 and Comparative Example 1, it was confirmed that the concentration of toluene remaining in the hydrogen gas can be significantly reduced by cooling and gas-liquid separating the hydrogen gas flowing inside the separator.

  Moreover, since Example 1 can be operated for 312 hours without regeneration, the regeneration interval is 312 hours or more. On the other hand, in Comparative Example 1, since the adsorption cycle is 6 hours, the regeneration interval is 6 hours. Therefore, it was confirmed that by cooling the hydrogen gas flowing through the adsorption tower as in Example 1, the regeneration frequency of the adsorbent was 1/50 or less that in Comparative Example 1 and could be significantly reduced. In addition, the required heat amount of Example 1 under the 312 hour operation condition is about 60% of the required heat amount of Comparative Example 1, and it has been confirmed that the energy consumption required for the operation of the hydrogen station can be significantly reduced.

  Note that Comparative Example 1 is an on-site type regeneration in which adsorption removal and heating regeneration are switched in a two-column adsorption tower, whereas in Example 1, when the adsorbent is regenerated, the adsorbent is removed from the installation location. This is off-site playback that moves to a location and plays. In the case of Example 1, when the adsorbent is regenerated, the adsorbent is moved to a place where the factory exhaust heat can be used, and the heat amount necessary for the regeneration of the adsorbent is generally 200 ° C. or less and generally difficult to use Since exhaust heat can be used, energy input for adsorbent regeneration can be minimized. On the other hand, in the case of on-site regeneration in Comparative Example 1, it is necessary to use 180 ° C. heat locally for regeneration of the adsorbent, and a part of product hydrogen is used to obtain this heat. Therefore, since the hydrogen recovery rate is reduced to about 90%, the energy efficiency is further reduced.

  As described above, the hydrogen supply method and the hydrogen station of the present invention can reduce energy consumption and improve the life of the adsorbent, so that it is suitable for an off-site type hydrogen station for filling FCV or the like with hydrogen. Can be used.

DESCRIPTION OF SYMBOLS 1 Reactor 2 Separator 3 Adsorption tower 4 Compressor 5 Storage 6 Dispenser 7 Auxiliary adsorption tower 8 Cooler 11 1st cooling mechanism 12 2nd cooling mechanism 13 3rd cooling mechanism 14 Brine tank 15 Pump 16 Refrigerator 17 Heat exchange 21 First flow control valve 22 Second flow control valve 23 Third flow control valve A Organic hydride B Hydrogen gas C Aromatic compound D Brine E Refrigerant

Claims (8)

A step of performing dehydrogenation of organic hydride in a reactor by heating in the presence of a catalyst;
Gas-liquid separation of a mixed gas of aromatic compound and hydrogen discharged from the reactor into an aromatic compound and hydrogen gas by a separator;
Refining the hydrogen gas separated by the separator with a TSA type adsorption tower;
Compressing hydrogen gas purified by the adsorption tower with a compressor;
A hydrogen gas supply method in a hydrogen station comprising: supplying hydrogen gas compressed by the compressor to the outside with a dispenser,
In the above supply step, the hydrogen gas is cooled by heat exchange with brine,
In the separation step, the gas flowing inside the separator is cooled by the brine used in the supply step,
A hydrogen gas supply method characterized in that, in the purification step, the gas flowing inside the adsorption tower is cooled by the brine used in the supply step. The method further comprises the step of re-purifying the hydrogen gas compressed in the compression step with a TSA type auxiliary adsorption tower,
The hydrogen gas supply method according to claim 1, wherein in the re-purification step, the gas flowing inside the auxiliary adsorption tower is cooled by brine used in the supply step.   The hydrogen gas supply method according to claim 1 or 2, wherein a temperature to be cooled of the brine is -50 ° C or higher and -13 ° C or lower.   The method for supplying hydrogen gas according to claim 1, 2 or 3, wherein the adsorbent packed in the adsorption tower is cooled by the brine used in the supply step in the purification step. Further comprising storing the hydrogen gas compressed by the compressor in a reservoir;
The hydrogen gas supply method according to any one of claims 1 to 4, wherein in the supply step, hydrogen gas in the reservoir is supplied to the outside. A reactor for dehydrogenation of organic hydride by heating in the presence of a catalyst;
A separator for gas-liquid separation of a mixed gas of an aromatic compound and hydrogen discharged from the reactor into an aromatic compound and hydrogen gas;
A TSA type adsorption tower for purifying the hydrogen gas separated by the separator;
A compressor for compressing hydrogen gas purified by the adsorption tower;
A hydrogen station comprising a dispenser for supplying hydrogen gas compressed by the compressor to the outside,
The dispenser has a cooler that cools the supplied hydrogen gas by heat exchange with brine,
The separator has a first cooling mechanism for cooling the gas flowing inside,
The adsorption tower has a second cooling mechanism for cooling the gas flowing inside,
The hydrogen station, wherein the first cooling mechanism and the second cooling mechanism use brine of the cooler as a refrigerant.   The hydrogen station according to claim 6, wherein the adsorption tower cools the adsorbent filled in the adsorption tower by the second cooling mechanism. A reservoir for storing hydrogen gas compressed by the compressor;
The hydrogen station according to claim 6 or 7, wherein the dispenser supplies hydrogen gas in the reservoir to the outside.

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