JP5357465B2 - High purity hydrogen production method - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a lower-cost method for producing high purity hydrogen which achieves further compacting of a production apparatus while achieving improvement in the energy efficiency of the whole process. <P>SOLUTION: High purity hydrogen F is obtained by pressurizing liquid hydrocarbon fuel A and water B as being liquid, thereafter reforming and converting them with a reformer 1 and a converter 2 to form a high pressure hydrogen-enriched gas D, bringing the high pressure hydrogen-enriched gas D into contact with a copper halide-supporting CO adsorbing agent filled in a CO remover 5 as it is without being subjected to pressure reduction, storing hydrogen in a hydrogen storing material in a hydrogen separation/recover unit 6 as being in a high pressure state, and discharging the stored hydrogen from the storing material. <P>COPYRIGHT: (C)2010,JPO&amp;INPIT

Description

  The present invention relates to a method for producing high-purity hydrogen used in proton-conducting fuel cells such as phosphoric acid type and solid polymer type, and more specifically, in the production of hydrogen which is energy (fuel) of a fuel cell. The present invention relates to a method for efficiently producing high-purity hydrogen by removing produced carbon monoxide, carbon dioxide, water, unreacted methane, and the like.

In recent years, there is an increasing expectation for hydrogen as a fuel for fuel cells that leads to improvement of the global environment. In general, hydrogen is obtained by reforming and reforming a hydrocarbon-containing fuel such as natural gas, naphtha, kerosene, or methanol and steam in the presence of a metal catalyst. The gas after modification (metamorphic gas) contains carbon monoxide (CO), carbon dioxide (CO ₂ ), methane (CH ₄ ), water (H ₂ O), etc. in addition to hydrogen. In order to reduce the voltage output by adsorbing to the electrode of a low temperature fuel cell such as a polymer electrolyte fuel cell, it is necessary to remove it to the ppm level.

A typical method for obtaining high purity hydrogen is a hydrogen PSA method. The hydrogen PSA method is a method of separating by utilizing the difference in adsorption / desorption behavior of each gas component to the adsorbent, and adsorbs impurities such as CO, CO ₂ , CH ₄ , H ₂ O under high pressure. This is a method of recovering only H ₂ having a lower adsorption affinity than the above gas. The adsorbed impurity gas component is desorbed by reduced pressure and released out of the system. The hydrogen PSA apparatus according to this method is composed of a plurality of adsorption towers. In each adsorption tower, an operation combining the adsorption process, the pressure equalization process, the pressure reduction process, the purge process and the pressure increase process is repeated. (See, for example, Non-Patent Document 1). The adsorption tower is filled with activated carbon, zeolite and activated alumina as adsorbents alone or in layers, and can produce 99.999% by volume or more of high-purity hydrogen. However, in order to remove CO to the ppm level with these adsorbents, a large amount of adsorbent is required, which causes the problem that the adsorption tower becomes larger and the yield of H ₂ is lowered.

Further, for the purpose of producing a hydrogen-rich fuel gas suitable for a fuel cell, a method for removing CO by passing the reformed / modified gas through a copper halide adsorbent is disclosed (Patent Literature). 1). However, although this method can remove CO, but cannot remove other gases such as CO ₂ , there is a problem that power generation efficiency decreases when fuel gas is supplied to the fuel cell. Also, the case of supplying the long-term fuel gas, the effect of gases other than H ₂ and CO are supplied to the electrode of the fuel cell is still another problem that it is unclear at present.

Further, a method of removing CO ₂ , CH ₄ , and H ₂ O using hydrogen PSA after removing CO with a CO selective oxidation catalyst has been studied (see Non-Patent Document 2). This method removes CO, which is the main cause of the increase in the size of the adsorption tower in the hydrogen PSA method, leading to downsizing of the adsorption tower. However, when introducing air to oxidize CO, CO oxidation, etc. since it is necessary to supply oxygen or the amount of oxygen which does not react with the CO together reduces the recovery efficiency of H ₂ consumed and H ₂ react with H _2, methanation occurs as a side reaction, PSA There is a problem that CH _{4 that} is difficult to remove by the formation of nitrogen and that nitrogen (N ₂ ) that is also difficult to remove by PSA is mixed in the system.

  In addition, a method for producing high-purity hydrogen using hydrogen storage alloys from various hydrogen-containing gases generated from waste silicon, biomass, and waste aluminum has been studied (see Non-Patent Document 3). This method can produce high-purity hydrogen by selectively storing only hydrogen in a hydrogen-containing gas in a hydrogen storage alloy, but the problem with respect to impurity gases, particularly CO, has been sufficiently solved. Absent.

  Therefore, the present inventors removed CO from a hydrogen-rich gas obtained by reforming and transforming a hydrocarbon-containing fuel with a CO adsorbent that carries copper halide having excellent adsorption characteristics. Later, a method for obtaining high purity hydrogen by selectively storing hydrogen in the hydrogen storage material was proposed (see Patent Document 2). This method solves the problem for CO and makes it possible to obtain high-purity hydrogen with high efficiency. As a result, the production apparatus can be greatly downsized, and high-purity hydrogen can be obtained at low cost. became.

However, in this method, in order to further reduce the size of the production apparatus, it is preferable to increase the CO adsorption capacity by the CO adsorbent and the hydrogen storage capacity by the hydrogen storage material by pressurizing the hydrogen rich gas (Patent Document). Although the paragraph [0038] of FIG. 2 (see FIG. 3), there is a problem that the energy efficiency of the whole process is lowered due to the energy required for pressurization of the hydrogen-rich gas, and there remains room for improvement in this respect.
Supervised by Atsushi Takeuchi, "Handbook of latest adsorption technology", NTS Corporation, January 1999, p. 86 NEDO 2001 Report, Development of Hydrogen Production Technology by New PSA Method, 2002 Masafumi Katsuta, Chemical Engineering, October 2005, p. 737-744 JP 2002-201005 A JP 2006-342014 A

  Accordingly, an object of the present invention is to provide a method for producing high-purity hydrogen at a lower cost that can realize further downsizing of the production apparatus while improving the energy efficiency of the entire process.

According to the first aspect of the present invention, there is provided a liquid reforming raw material pressurizing step for pressurizing a liquid reforming raw material composed of a liquid hydrocarbon fuel and water to a predetermined pressure in a liquid state, and the pressurization. A hydrogen-rich gas production process for reforming or reforming and reforming a liquid reforming raw material to obtain a hydrogen-rich gas containing CO, and contact with a CO adsorbent without depressurizing the hydrogen-rich gas containing CO A CO adsorption / removal step for absorbing and removing CO to obtain a CO removal gas, a hydrogen occlusion step for occluding hydrogen contained in the CO removal gas in the hydrogen occlusion material without reducing the CO removal gas, and the occlusion a method of producing a high-purity hydrogen and a hydrogen separation and recovery step and a hydrogen release step for releasing hydrogen from the storage material, the predetermined pressure is ambient pressure in said hydrogen absorbing step From the atmospheric pressure, the atmospheric gas pressure loss in the hydrogen-rich gas production step and the CO removal step is such that the counter pressure is 0.60133 to 5.1133 MPa (gauge pressure is 0.5 to 5.0 MPa). In addition, the CO adsorbent is silica, alumina, activated carbon, graphite, and polystyrene . However, the predetermined pressure excludes a range of 5.0 MPa or more in absolute pressure. A method for producing high-purity hydrogen, characterized in that it is a material in which copper (I) halide and / or copper (II) halide is supported on one or more carriers selected from the group consisting of resin based resins. .

  The invention according to claim 2 is the high purity according to claim 1, wherein a hydrogen storage alloy, a surface-treated hydrogen storage alloy, a chemical hydride, a carbon nanotube, or any two or more thereof is used as the hydrogen storage material. This is a hydrogen production method.

  The invention according to claim 3 is the method for producing high purity hydrogen according to claim 1 or 2, wherein the reaction temperature in the hydrogen storage step is 80 ° C. or less and the atmospheric pressure is 0.2 to 35 MPa in terms of gauge pressure. .

  The invention according to claim 4 is the high purity according to any one of claims 1 to 3, wherein the reaction temperature in the hydrogen releasing step is 250 ° C. or lower and the atmospheric pressure is lower than the atmospheric pressure in the hydrogen storage step. This is a hydrogen production method.

  The invention according to claim 5 is any one of claims 1 to 4, wherein the CO adsorption removing step includes a CO adsorption step for adsorbing and removing CO, and a CO adsorbent regeneration step for regenerating the CO adsorbent. The high-purity hydrogen production method described in the item.

  According to a sixth aspect of the present invention, the heat generated when the hydrogen storage material stores hydrogen in the hydrogen storage step is used to increase the temperature of the CO adsorbent and / or release the hydrogen in the CO adsorbent regeneration step. The high-purity hydrogen production method according to claim 5, which is used for raising the temperature of the hydrogen storage material in the step.

In order to obtain the reaction temperature in the hydrogen releasing step , the invention according to claim 7 includes the latent heat of water vapor contained in the hydrogen-rich gas containing CO, the sensible heat of the hydrogen-rich gas, and the step of performing the reforming. 6. The hydrogen storage material is heated using sensible heat of combustion exhaust gas, combustion heat of a liquid hydrocarbon fuel different from that used for the reforming raw material, or any two or more thereof. 6. The method for producing high-purity hydrogen according to 6.

  The invention according to claim 8 is the liquid crystal fuel according to any one of claims 1 to 7, wherein the liquid hydrocarbon fuel is at least one fuel selected from the group consisting of kerosene, methanol, gasoline, and dimethyl ether. This is a high-purity hydrogen production method.

  According to the present invention, a liquid reforming raw material composed of a liquid hydrocarbon fuel and water is reformed after being pressurized while being in a liquid state, which is much larger than in the case where gas is pressurized in the conventional manner. As a result, the energy required for pressurization was reduced, and as a result, the energy efficiency of the entire process was improved, and the production apparatus could be made more compact, and high-purity hydrogen could be obtained at a lower cost.

  Hereinafter, embodiments of the present invention will be described in detail with reference to the flowcharts of FIGS.

Embodiment 1
An example of the embodiment is shown in the flowchart of FIG. In the present embodiment, an example is shown in which the switching operation between the adsorption / regeneration of the CO adsorbent and the hydrogen occlusion / hydrogen release of the hydrogen occlusion material is performed mainly by raising and lowering the reaction pressure (that is, pressure swing).

(Liquid reforming raw material pressurization process)
The present invention is characterized in that reforming is performed after pressurizing a liquid reforming raw material in a liquid state at room temperature. That is, as the hydrocarbon fuel, kerosene, methanol, gasoline, methyl ether or the like, or liquid hydrocarbon fuel A in which two or more of these are mixed is used. Moreover, water is used instead of water vapor as H ₂ O as a modifier.

  Then, a liquid reforming raw material C composed of such a liquid hydrocarbon fuel A and water B is pressurized using a booster 1 such as a diaphragm pump, a piston pump, a plunger pump, etc., and the pressure is increased to a predetermined pressure. . The predetermined pressure is 0.2 to about the atmospheric pressure in the hydrogen storage step of the hydrogen separation and recovery process through the subsequent hydrogen rich gas production process and the CO removal process, in terms of gauge pressure (hereinafter, the unit of pressure is gauge pressure). In view of the pressure loss of the atmospheric gas in the hydrogen rich gas production process and the CO removal process, the pressure may be set slightly higher than the atmospheric pressure in the hydrogen storage step of the hydrogen separation and recovery process so that the pressure becomes 35 MPa.

  Here, the reason why the atmospheric pressure in the hydrogen storage step of the hydrogen separation and recovery process is set to 0.2 to 35 MPa is as follows. That is, when the pressure is 0.2 MPa or less, the amount of heat necessary for releasing hydrogen from the hydrogen storage material in the hydrogen separation and recovery process increases and energy efficiency decreases. On the other hand, when the pressure exceeds 35 MPa, the liquid hydrocarbon fuel is pressurized. This is because the required energy becomes excessive and the energy efficiency is lowered. More preferably, it is 0.5-5.0 MPa.

(Hydrogen rich gas production process)
In the hydrogen rich gas production process for producing the modified gas D as the hydrogen rich gas containing CO, for example, a combination of the steam reformer 2 and the transformer 3 that are usually used may be used. The reformer 2 is supplied with a liquid reforming raw material C in a pressurized state, promotes a reforming reaction with a reforming catalyst to be a reformed gas mainly composed of H ₂ and CO, and then is transformed. In the vessel 3, the reformed gas is further transformed by adding steam to produce a high-pressure transformed gas D containing H ₂ as a main component (rich in hydrogen). In this high-pressure modified gas D, in addition to H ₂ , about 15% by volume (hereinafter simply referred to as “%”) CO ₂ , a small amount of CH ₄ , H ₂ O, etc., 0.5% Some degree of CO remains.

(CO adsorption removal process)
In the CO adsorption removal process of the present embodiment, a CO remover 5 comprising two CO adsorption towers (5a, 5b) filled with a CO adsorbent is used. Hereinafter, the CO adsorption removal step and the CO adsorbent regeneration step will be described separately, and the switching operation of those steps will be described.

  [CO adsorption removal step]: The high-pressure modified gas D obtained in the hydrogen-rich gas production process is passed through the CO remover 5 filled with the CO adsorbent as it is without depressurization, and the CO in the modified gas D Is selectively removed. The reason why the pressure reduction operation is not performed is that the CO adsorption reaction by the CO adsorbent is promoted as the pressure increases.

  As the CO adsorbent, a material in which copper (I) halide or copper (II) halide is supported on one or more carriers selected from the group consisting of silica, alumina, activated carbon, graphite, and polystyrene resin. Use. Since the CO adsorbent carrying such a copper halide exhibits adsorption performance several to tens of times that of conventional adsorbents such as zeolite molecular sieves, carbon molecular sieves, activated carbon, or activated alumina. The remover 5 can be greatly downsized.

  Further, since the CO adsorption reaction by the CO adsorbent is promoted as the temperature is lower, the heat exchanger 4 is provided upstream of the CO remover 5 in order to cool the high temperature modified gas D, and the modified gas D after cooling is provided. It is preferable to lower the temperature of the reaction to 80 ° C. or less, and further to 60 ° C. or less, and to set the reaction temperature in this step within these temperature ranges.

  The CO concentration of the CO removal gas E after CO adsorption removal is preferably 100 ppm or less, and more preferably 10 ppm or less, in order to suppress poisoning of the hydrogen storage material in the next step.

  [CO adsorbent regeneration step]: In order to maintain the adsorption performance of the CO adsorbent, the CO concentration on the outlet side of the CO remover 5 increases to a predetermined concentration after the predetermined time elapses in the CO adsorption removal step (breakdown). It is necessary to regenerate the CO adsorbent. The regeneration of the CO adsorbent is performed by reducing the pressure below the atmospheric pressure in the CO adsorption removal step, preferably below the atmospheric pressure, in order to desorb CO adsorbed at the adsorption site.

  In order to efficiently remove the desorbed CO without re-adsorption, the above depressurization operation may be performed while circulating a gas substantially free of CO as a carrier gas.

  In addition, since the CO desorption reaction is accelerated as the temperature increases, the reaction temperature in the CO adsorbent regeneration step may be higher than the reaction temperature in the CO adsorption removal step.

  In order to satisfy such conditions, as the gas that does not substantially contain CO used as the carrier gas, for example, a part G ′ of the off-gas G that has not been occluded by the hydrogen separation and recovery device 6 described later is used. This may be used by exchanging heat with the modified gas (hydrogen-rich gas) D in the heat exchanger 4 described above and heating. However, when heated above 250 ° C., the active species carried on the adsorbent is irreversibly damaged, and the performance of the CO adsorbent is lowered. A particularly recommended temperature range is 80-150 ° C.

  The gas G ″ after the regeneration of the CO adsorbent contains CO at a high concentration, so that it can be effectively used instead of a part of the heating fuel H of the reformer 2, for example.

  [Switching operation between CO adsorption removal step and CO adsorbent regeneration step]: It is necessary to alternately switch the CO adsorption removal step and the CO adsorbent regeneration step for each of the CO adsorption towers 5a and 5b. In order to produce high-purity hydrogen (that is, in order to obtain CO removal gas E continuously), one of the two towers (5a in this example) is always set as the CO adsorption removal step. Another tower (5b in this example) is preferably used as the CO adsorbent regeneration step.

(Hydrogen separation and recovery process)
In the hydrogen separation / recovery process of the present invention, a hydrogen separation / recovery device 6 comprising two hydrogen storage material containers (6a, 6b) filled with a hydrogen storage material is used. Hereinafter, the hydrogen storage step and the hydrogen release step will be described separately, and the switching operation of these steps will be described.

[Hydrogen storage step]: The high-pressure CO removal gas E obtained in the CO adsorption removal step is passed through the hydrogen separation and recovery device 6 filled with the hydrogen storage material without being decompressed, and the CO removal gas E Of H ₂ selectively. The reason why the depressurization operation is not performed is that the hydrogen absorption reaction by the hydrogen storage material is accelerated as the pressure increases, as in the CO adsorption reaction by the CO adsorbent. As described in the description of the liquid reforming raw material pressurizing step, the atmospheric pressure in this step is preferably 0.2 to 35 MPa, more preferably 0.5 to 5.0 MPa.

As the hydrogen storage material, a hydrogen storage alloy is suitable, and a material obtained by subjecting the hydrogen storage alloy to surface treatment is more preferable because poisoning by CO can be sufficiently suppressed. The surface treatment of the hydrogen storage alloy is not particularly limited as long as it has durability against CO ₂ , H ₂ O, and CO. For example, fluorination treatment, electroless plating treatment, resin coating treatment Etc.

  Further, since the hydrogen absorption reaction by the hydrogen storage material is promoted as the temperature is lower, the CO removal gas E discharged from the previous step may be introduced by cooling with a water cooling jacket or the like, if necessary. The reaction temperature in this step is preferably 80 ° C. or lower, more preferably 60 ° C. or lower.

Gases other than H ₂ (CO ₂ , CH ₄ , H ₂ O, etc.) that have not been absorbed by the hydrogen storage material may be washed out as off-gas F and discharged outside the system as necessary.

  [Hydrogen desorption step]: Since the reaction for desorbing hydrogen from the hydrogen occlusion material that occludes hydrogen is promoted as the pressure is lower, the atmospheric pressure in the hydrogen desorption step is the same as in the hydrogen occlusion step. Lower than atmospheric pressure.

In contrast to the hydrogen absorption reaction, the higher the temperature, the more accelerated the reaction. Therefore, the reaction temperature in the hydrogen release step may be higher than the reaction temperature in the hydrogen storage step. In order to satisfy such conditions, for example, the sensible heat of the combustion exhaust gas J of the reformer may be used to indirectly raise the temperature of the hydrogen storage material using the heat exchanger 4 . In addition, when the temperature of the hydrogen storage material cannot be sufficiently raised only by the sensible heat of the combustion exhaust gas J of the reformer 2, the shortage is exhausted from the fuel cell (heat generated when the hydrogen storage material stores hydrogen). It is also possible to utilize fuel for reforming. However, if the temperature exceeds 250 ° C., the temperature difference from the time of occlusion increases, and the hydrogen occlusion material is pulverized by cycle thermal stress. Further, when the heating temperature is increased, the performance of the hydrogen storage material is lowered due to an increase in heat loss, and therefore, the temperature is preferably set to 250 ° C. or lower. The particularly recommended temperature range is from room temperature to 200 ° C.

  [Switching operation between hydrogen storage step and hydrogen release step]: For each of the hydrogen storage material containers 6a and 6b, it is necessary to alternately switch between the hydrogen storage step and the hydrogen release step, but one hydrogen storage material is always provided. The container (6a in this example) is preferably a hydrogen storage step, and the other hydrogen storage material container (6b in this example) is preferably a hydrogen release step. As a result, the high purity hydrogen F can be continuously supplied to the subsequent fuel cell or the like, so that the buffer tank for temporarily storing the high purity hydrogen can be omitted or downsized.

[Embodiment 2]
Another embodiment is shown in the flow diagram of FIG. In the first embodiment, the combination of the reformer 1 and the transformer 2 is exemplified as the hydrogen rich gas production process. However, in the second embodiment, the transformer 2 is omitted and only the reformer 1 is used. A reformed gas having a CO concentration of about 15% is used as the hydrogen rich gas D, and this is circulated through the CO adsorption remover 5. Since the CO concentration in the hydrogen-rich gas D increases, the load on the CO remover 5 increases, but the CO adsorbent can adsorb CO at a higher capacity as the CO partial pressure is higher due to its characteristics, so the CO adsorption tower expands much. There is no need. Therefore, since the effect of greatly reducing the size of the hydrogen-rich gas production process by omitting the transformer 2 is greater, it is possible to construct a more efficient process.

(Modification)
In the first and second embodiments, an example is shown in which the two CO adsorption towers 5a and 5b are alternately switched as the CO adsorption removal step. However, three or more CO adsorption towers may be sequentially switched and used.

  Moreover, in the said Embodiment 1, 2, although the example which uses two hydrogen storage material containers 6a and 6b by switching alternately as a hydrogen separation-and-recovery process was shown, it switches and uses three or more hydrogen storage material containers sequentially. May be. In addition, a single hydrogen storage material container and a buffer tank are combined, and high purity hydrogen is continuously supplied from the buffer tank to a subsequent fuel cell or the like, while hydrogen is stored by the hydrogen storage material in the single hydrogen storage material container. It is also possible to store hydrogen in the buffer tank only during the release while repeating the occlusion and release.

  In the first and second embodiments, the hydrogen storage material and the surface-treated hydrogen storage alloy are exemplified as the hydrogen storage material. However, chemical hydride, carbon nanotube, or any two or more of these may be used.

  In the first and second embodiments, the off-gas G from the hydrogen separation / recovery device 6 is exemplified as a gas substantially free of CO used for regeneration of the CO adsorbent. However, the high purity hydrogen from the hydrogen separation / recovery device 6 is exemplified. F, the heating fuel H for the reformer 2, or any two or more of these may be mixed and used.

  Further, in the first and second embodiments, the example in which the sensible heat of the modified gas (hydrogen rich gas) D is used to obtain the reaction temperature in the CO adsorption step has been described, but it is included in the modified gas (hydrogen rich gas) D. The latent heat of water vapor, the sensible heat of the combustion exhaust gas from the reformer 2 (from the reforming step), or any two or more of these may be used.

  In the first and second embodiments, the liquid hydrocarbon fuel A and the water B are mixed and boosted together. However, the pressure may be increased separately without mixing.

  In order to confirm the effect of the present invention, examination was performed by steady process simulation calculation.

(Invention example)
The process of omitting the transformer and using only the reformer as the hydrogen rich gas production process described in the second embodiment was considered. The process flow is shown in FIG.

(Comparative Example 1)
Unlike the above invention example, a process in which a booster was installed not at the front stage but at the rear stage of the reformer and the reformed gas obtained by the reformer was boosted by the booster was studied. The process flow is shown in FIG.

(Comparative Example 2)
Unlike the above invention example and comparative example 1, an atmospheric pressure process not using a booster was considered. The process flow is shown in FIG.

[Prerequisites for simulation calculation]
-Liquid hydrocarbon fuel: methanol-Fuel flow rate: 10.008 g-mol / h
・ Reforming temperature: 250 ℃
-Reformer steam / carbon ratio (S / C): 2.0
・ Utilization efficiency of reformer burner combustion heat: 90%
・ Hydrogen purification efficiency with hydrogen storage materials: 90%
・ CO adsorbent: Copper (I) chloride supported alumina ・ Adsorption temperature of CO adsorbent: 40 ° C.
・ Regeneration temperature of CO adsorbent: 90 ° C
・ Power efficiency of booster: 50% (Invention example, Comparative example 1)
CO removal / hydrogen separation operating pressure: 0.9 MPa (invention example, comparative example 1), 0.12 MPa (comparative example 2)

〔Calculation result〕
The calculation results are shown in Table 1 below. The energy efficiency of the entire process is defined by the following formula (1). The amount of heat was based on the higher heating value (HHV).

  [Energy efficiency of entire process (%)] = [calorie of purified high-purity hydrogen] / ([calorie of methanol for reforming raw material] + [calorie of methanol for burner fuel] + [power of booster]) × 100 ... Formula (1)

  As shown in Table 1 below, in the inventive example, the power of the booster is greatly reduced as compared with Comparative Example 1, and the thermal energy efficiency of the entire process is increased from 82.1% to 88.5%. An improvement effect of 4 points is recognized.

  In addition, although the inventive example requires extra booster power compared to Comparative Example 2, the energy required for the boosting is very small. Therefore, the effect of reducing the fuel required for heating to regenerate the CO adsorbent is greater, and as a result, the thermal energy efficiency of the entire process is increased from 85.4% to 88.5% by 3.1 points. Improvement effect is recognized.

From the above results, it was confirmed that the present invention can realize further downsizing of the manufacturing apparatus while improving the energy efficiency of the entire process.

1 is a flowchart showing a high-purity hydrogen production process according to Embodiment 1. FIG. FIG. 5 is a flowchart showing a high-purity hydrogen production process according to Embodiment 2. It is a flowchart which shows the high-purity hydrogen production process of the example of an invention. 6 is a flowchart showing a high-purity hydrogen production process of Comparative Example 1. FIG. 6 is a flowchart showing a high-purity hydrogen production process of Comparative Example 2. FIG.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 ... Booster 2 ... Reformer 3 ... Transformer 4 ... Heat exchanger 5 ... CO remover 5a, 5b ... CO adsorption tower 6 ... Hydrogen separation collection | recovery apparatus 6a, 6b ... Hydrogen storage material container A ... Liquid hydrocarbon Fuel B ... Water C ... Liquid reforming raw material D ... Hydrogen-rich gas E containing CO ... CO removal gas F ... High purity hydrogen G ... Off-gas H ... Fuel for heating reformer J ... Combustion exhaust gas of reformer

Claims (8)

A liquid reforming raw material pressurizing step of pressurizing a liquid reforming raw material composed of a liquid hydrocarbon fuel and water to a predetermined pressure while being in a liquid state;
A hydrogen-rich gas production process for reforming the pressurized liquid reforming raw material, or reforming and reforming to obtain a hydrogen-rich gas containing CO;
A CO adsorption / removal step in which the hydrogen-rich gas containing CO is brought into contact with a CO adsorbent without depressurization to adsorb and remove CO to obtain a CO removal gas;
A hydrogen separation and recovery process comprising a hydrogen storage step for storing hydrogen contained in the CO removal gas into the hydrogen storage material without reducing the pressure of the CO removal gas, and a hydrogen release step for releasing the stored hydrogen from the storage material. When,
A method for producing high-purity hydrogen comprising:
The predetermined pressure is such that the atmospheric pressure in the hydrogen storage step is 0.60133 to 5.1133 MPa in absolute pressure (0.5 to 5.0 MPa in gauge pressure). It is set higher in consideration of the pressure loss of the atmospheric gas in the manufacturing process and the CO removal process (however, the predetermined pressure excludes the range of 5.0 MPa or more in absolute pressure), and
The CO adsorbent has copper (I) halide and / or copper (II) halide supported on one or more carriers selected from the group consisting of silica, alumina, activated carbon, graphite and polystyrene resin. A high-purity hydrogen production method characterized by being a material.   The high-purity hydrogen production method according to claim 1, wherein a hydrogen storage alloy, a surface-treated hydrogen storage alloy, a chemical hydride, a carbon nanotube, or any two or more thereof is used as the hydrogen storage material.   The high-purity hydrogen production method according to claim 1 or 2, wherein in the hydrogen storage step, the reaction temperature is 80 ° C or lower and the atmospheric pressure is 0.2 to 35 MPa in terms of gauge pressure.   The high-purity hydrogen production method according to any one of claims 1 to 3, wherein a reaction temperature in the hydrogen releasing step is 250 ° C or lower and an atmospheric pressure is lower than an atmospheric pressure in the hydrogen storage step.   The high-purity hydrogen production method according to any one of claims 1 to 4, wherein the CO adsorption removal step includes a CO adsorption step for adsorbing and removing CO, and a CO adsorbent regeneration step for regenerating the CO adsorbent. .   Heat generated when the hydrogen storage material stores hydrogen in the hydrogen storage step is used to increase the temperature of the CO adsorbent in the CO adsorbent regeneration step and / or the temperature increase of the hydrogen storage material in the hydrogen release step. The method for producing high-purity hydrogen according to claim 5, which is used in the method. In order to obtain the reaction temperature in the hydrogen releasing step, the latent heat of water vapor contained in the hydrogen-rich gas containing CO, the sensible heat of the hydrogen-rich gas, the sensible heat of the combustion exhaust gas from the reforming step, the reforming The method for producing high-purity hydrogen according to claim 5 or 6, wherein the hydrogen storage material is heated using combustion heat of a liquid hydrocarbon fuel different from that used for the raw material, or any two or more thereof. .   The high-purity hydrogen production method according to any one of claims 1 to 7, wherein the liquid hydrocarbon fuel is one or more fuels selected from the group consisting of kerosene, methanol, gasoline, and dimethyl ether.

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