WO2015029543A1

WO2015029543A1 - Hydrogen production method

Info

Publication number: WO2015029543A1
Application number: PCT/JP2014/065802
Authority: WO
Inventors: 光利中谷; 瓏尤; 康一志摩
Original assignee: 住友精化株式会社
Priority date: 2013-08-26
Filing date: 2014-06-13
Publication date: 2015-03-05
Also published as: JPWO2015029543A1; TW201507971A; PH12016500321A1

Abstract

The present invention is a hydrogen production method in which a partial oxidation reaction and a steam reforming reaction of a hydrocarbon-type compound such as methanol are allowed to proceed to produce hydrogen, wherein the life of a catalyst can be prolonged and hydrogen can be produced steadily for a long period. A liquid raw material comprising methanol and water is vaporized in a raw material vaporizing section (1), a vaporized fluid gas and an oxygen-containing gaseous raw material are supplied to a reactor (2A), and a partial oxidation reaction and a steam reforming reaction (a decomposition reaction) of methanol proceed in the reactor (2A) to produce hydrogen. As a heat source for vaporizing the liquid raw material in the vaporizer (2A), combustion heat generated in a gas combustion section (9) can be used. The combustion heat generated in the gas combustion section (9) is generated by the combustion using, as a combustion gas, a detached gas that is detached from a hydrogen gas separation section (3) in multiple steps. In the hydrogen gas separation section (3), the detached gas is allowed to flow while altering the amount of outflow of the detached gas.

Description

Method for producing hydrogen

The present invention relates to a method for producing hydrogen. More specifically, the present invention relates to a method for producing hydrogen in which hydrogen is produced by reacting a hydrocarbon compound with water and oxygen in the presence of a catalyst.

Hydrocarbon compounds such as methanol are energy sources that can be easily transported and stored, and are used as raw materials for generating hydrogen gas on-site. As a method for producing hydrogen gas from a hydrocarbon-based compound such as methanol, a steam reforming method, a partial oxidation method, and a partial oxidation-steam reforming reaction method are generally known.

The steam reforming method is a method for producing hydrogen gas by bringing methanol vapor into contact with steam in the presence of a catalyst. Since this steam reforming reaction involves a relatively large endotherm, there is a drawback that the heat supply system such as a heat exchanger has a heavy load and takes a long time to start.

The partial oxidation method is a method for producing hydrogen gas by bringing methanol vapor into contact with oxygen gas in the presence of a catalyst. Since this partial oxidation method is a reaction with a relatively large exotherm, there is a drawback that it is likely to cause a decrease in the activity of the catalyst.

On the other hand, the partial oxidation-steam reforming reaction method is a method for producing hydrogen gas by bringing methanol vapor into contact with steam and oxygen in the presence of a catalyst. In this partial oxidation-steam reforming reaction method, the heat generated when methanol is partially oxidized (partial oxidation reaction) to form carbon dioxide and hydrogen is converted into carbon dioxide by steam reforming in which methanol vapor and steam are brought into contact. Therefore, there is an advantage that the load of a heat supply system such as a heat exchanger can be reduced.

However, in the partial oxidation-steam reforming reaction method, the partial oxidation reaction, which is an exothermic reaction, and the steam reforming reaction (decomposition reaction), which is an endothermic reaction, do not proceed at the same time, but are slightly delayed from the partial oxidation reaction. Since the steam reforming reaction (decomposition reaction) proceeds, there is a problem that it is difficult to control the temperature in the reactor.

This point will be described in detail. A raw material gas containing methanol, water and oxygen is supplied to a reactor filled with a catalyst. When the raw material gas is supplied to the reactor, a partial oxidation reaction with a high reaction rate proceeds in a portion upstream of the raw material gas in the flow direction, and a steam reforming with a low reaction rate occurs in a portion downstream of the raw material gas in the flow direction. The quality reaction (decomposition reaction) proceeds. As a result, the catalyst existing in the upstream portion of the reactor in the flow direction of the raw material gas becomes high temperature under the influence of the partial oxidation reaction accompanied by heat generation. Thus, the catalyst which became high temperature will generate | occur | produce a sintering, will deteriorate, and activity will fall.

Various methods for solving the above problems have been proposed in the method for producing hydrogen by the partial oxidation-steam reforming reaction method.

For example, Patent Document 1 discloses a method of temporarily stopping the supply of oxygen-containing gas to the catalyst. Copper which is a catalyst is oxidized by a partial oxidation reaction to become copper oxide. Further, copper oxide is reduced to copper by reducing gas generated by the steam reforming reaction. In the method for producing hydrogen disclosed in Patent Document 1, only the steam reforming reaction is performed by temporarily stopping the supply of the oxygen-containing gas, and the copper oxide produced by the partial oxidation reaction is reduced to copper to produce steam. The activity of the reforming reaction is increased again, and the temperature rise of the catalyst is suppressed.

Further, Patent Document 2 discloses a CuPdO ₂ / ZnO-based catalyst as a catalyst used when producing hydrogen. The technique disclosed in Patent Document 2 aims to suppress partial oxidation reaction accompanied by heat generation and catalyst deterioration.

International Publication WO2012 / 105355 JP 2003-117396 A

However, in the method disclosed in Patent Document 1, the difference in reaction rate between the partial oxidation reaction with exotherm and the steam reforming reaction (decomposition reaction) with endotherm is not sufficiently small, and the partial oxidation with high reaction rate is performed. The reaction proceeds in the upstream portion of the reactor in the flow direction of the raw material gas, and the decomposition reaction having a slow reaction rate proceeds in the downstream portion of the reactor in the flow direction of the raw material gas.

Patent Document 2 has problems such as an increase in the amount of catalyst used, an increase in unreacted methanol, and a decrease in the amount of hydrogen generated.

An object of the present invention is to increase the catalyst life in a hydrogen production method in which hydrogen is produced by a partial oxidation reaction and a steam reforming reaction (decomposition reaction) of a hydrocarbon compound such as methanol. It is providing the manufacturing method which can be manufactured stably over a long period of time.

The present invention includes a combustion process in which a combustion gas flows into a combustor and burns,
A vaporizer is heated by combustion heat generated by combustion of combustion gas in the combustor, and a liquid raw material containing a hydrocarbon compound and water is caused to flow into the heated vaporizer to vaporize the liquid raw material. A vaporization step of obtaining a gas fluid;
The gas fluid obtained in the vaporization step is mixed with a gas raw material containing oxygen, and the mixed gas fluid is caused to flow into a reactor filled with a catalyst, thereby partially oxidizing the hydrocarbon-based compound and steam. A hydrogen generation step in which a reforming reaction proceeds to obtain a reaction product mainly composed of hydrogen;
The reaction product obtained in the hydrogen generation step is allowed to flow into the adsorption tower filled with the adsorbent under the pressure of the adsorption start pressure, and adsorbent removes the secondary component in the reaction product. An adsorption step for flowing out hydrogen, which is a main component in the reaction product, from the adsorption tower to the recovery device;
After outflow of hydrogen from the adsorption tower in the adsorption step, the pressure in the adsorption tower is changed to a desorption start pressure lower than the adsorption start pressure, and the adsorbent component including the subcomponent adsorbed on the adsorbent is adsorbed. A desorption step of desorbing the desorbed gas containing the desorbed adsorbing component from the adsorbing tower and changing the flow rate to the outside of the adsorption tower;
A desorption gas supply step of supplying the desorption gas that has flowed out of the adsorption tower in the desorption step into the combustor as the combustion gas.

In the hydrogen production method of the present invention, in the desorption step, the pressure in the adsorption tower is changed from the adsorption start pressure to the desorption start pressure, and then in multiple stages from the desorption start pressure to the desorption end pressure. It is preferable to change the flow rate of the desorption gas flowing out of the adsorption tower by reducing the pressure.

The method of manufacturing a hydrogen present invention, the desorption step, the adsorption tower when depressurizing in multiple steps, represented the first stage of the pressure reduction rate P _A is not more than 35% by the following formula (I) Preferably there is.
Decompression rate P _A (%) = [(P _S −P _E ) / P _S ] × 100 (I)
(Wherein, _{P S} represents a desorption start pressure (kPaG), _{P E} represents the first stage of the desorption completion pressure (kPaG).)

According to the present invention, the method for producing hydrogen includes a combustion process, a vaporization process, a hydrogen generation process, an adsorption process, a desorption process, and a desorption gas supply process. In the combustion process, combustion gas flows into the combustor and burns. In the vaporization step, a liquid raw material containing a hydrocarbon-based compound and water is caused to flow into a vaporizer heated by combustion heat generated by combustion in the combustor, whereby the liquid raw material is vaporized to generate a gas fluid (vaporization). Fluid). In the hydrogen generation process, the gas fluid obtained in the vaporization process and the gas raw material containing oxygen are allowed to flow into a reactor filled with a catalyst, thereby performing a partial oxidation reaction and a steam reforming reaction of a hydrocarbon compound. Proceed to generate hydrogen to obtain a reaction product containing hydrogen as a main component. In the adsorption step, the reaction product obtained in the hydrogen production step is caused to flow into the adsorption tower filled with the adsorbent under the pressure of the adsorption start pressure. Next, in the adsorption step, subcomponents in the reaction product are adsorbed on the adsorbent, and the purified hydrogen flows out of the adsorption tower. In the desorption process, after purifying the hydrogen purified from the adsorption tower in the adsorption process, the pressure in the adsorption tower is changed to a desorption start pressure lower than the adsorption start pressure. Next, in the desorption process, the pressure in the adsorption tower is changed from the desorption start pressure to multiple stages, the adsorbed components including the adsorbent adsorbed on the adsorbent are desorbed from the adsorbent, and the desorbed gas including the desorbed adsorbed component is adsorbed. It flows out while changing the flow rate outside the tower. In the desorption gas supply step, the desorption gas that has flowed out of the adsorption tower in the desorption step is supplied into the combustor as the combustion gas. In the desorption gas supply step, the desorption gas supplied into the combustor as the combustion gas contains subcomponents and hydrogen in the reaction product.

In the method for producing hydrogen according to the present invention, first, a liquid raw material containing a hydrocarbon compound and water is vaporized by a vaporizer. Next, the vaporized gas fluid and a gas raw material containing oxygen are supplied to the reactor, and hydrogen is generated by the partial oxidation reaction and steam reforming reaction (decomposition reaction) of the hydrocarbon compound in the reactor. The As a heat source for vaporizing the liquid raw material in the vaporizer, combustion heat generated in the combustor is used. The combustion heat generated in the combustor is generated by burning the desorption gas (mixed gas containing subcomponents and hydrogen) discharged from the adsorption tower and desorbed from the adsorbent in the adsorption tower as a combustion gas. is there. In the method for producing hydrogen of the present invention, the desorption gas desorbed from the adsorbent is caused to flow out of the adsorption tower while changing the flow rate, and the desorption gas flowing out of the adsorption tower is supplied to the combustor as a combustion gas. For this reason, the calorie | heat amount of the combustion heat which generate | occur | produces in a combustor changes with the change of the flow volume of the desorption gas which flows out out of an adsorption tower. As a result, the heating amount for vaporizing the liquid raw material in the vaporizer changes. Thus, when the heating amount for vaporizing the liquid raw material in the vaporizer changes, the gas fluid whose temperature has changed flows into the reactor.

In the reactor, the partial oxidation reaction and steam reforming reaction (decomposition reaction) of hydrocarbon compounds with different reaction rates proceed, and the effect of partial oxidation reaction with exotherm on the catalyst filled in the reactor. The part where the temperature rises most (hot spot) is generated. In the method for producing hydrogen of the present invention, as described above, the gas fluid whose temperature has changed flows into the reactor, so that the position of the hot spot in the reactor can be changed. For this reason, it can prevent that the same area | region always becomes the highest temperature in the catalyst filling part in a reactor. The position of the hot spot in the reactor moves to the downstream side when the temperature of the catalyst decreases with respect to the flow direction in which the gas fluid flows in the reactor, and moves to the upstream side when the temperature of the catalyst increases.

This point will be described in detail. When the catalyst is deteriorated by exposure to a high temperature, the reaction selectivity decreases and a large amount of impurities are produced as a by-product. In order to obtain hydrogen with a predetermined purity and a predetermined acquisition amount per time in a situation where the catalyst has deteriorated, it is necessary to change settings such as pressure conditions of the adsorption tower. When the deterioration of the catalyst further progresses, even if hydrogen having a predetermined purity is obtained, hydrogen cannot be obtained gradually in a predetermined amount per time. This makes it impossible to produce stable hydrogen. Therefore, in the present invention, the amount of heat for vaporizing the liquid raw material containing the hydrocarbon compound and water is increased or decreased by changing the outflow amount of the desorption gas desorbed from the adsorbent and flowing out from the adsorption tower. For this reason, the calorie | heat amount of the combustion heat generate | occur | produced by combustion of the combustion gas is increased / decreased, and the temperature of the gas fluid heated externally raises / lowers. When the temperature of the gas fluid increases and decreases, the temperature of the catalyst surface with which the gas fluid contacts in the reactor increases and decreases. Along with this, the position of the hot spot generated by the partial oxidation reaction varies up and down in the flow direction of the gas fluid. As described above, by changing the position of the hot spot in the reactor, it is possible to prevent the same region from always becoming the highest temperature in the catalyst filling portion in the reactor. Accordingly, deterioration due to sintering can be suppressed and the catalyst life can be extended, and hydrogen can be stably produced over a long period of time.

According to the present invention, in the desorption step, the pressure in the adsorption tower is reduced in multiple stages from the desorption start pressure to the desorption end pressure. As a result, the flow rate of the desorption gas flowing out of the adsorption tower can be varied. As a result, the amount of combustion heat generated in the combustor changes, and the amount of heating for vaporizing the liquid raw material in the vaporizer can be changed. For this reason, the gas fluid whose temperature has changed can be caused to flow into the reactor, and the position of the hot spot in the reactor can be changed. As a result, it is possible to prevent the same region from always reaching the highest temperature in the catalyst packed portion in the reactor, and to prevent catalyst deterioration.

According to the invention, the desorption step, when to reduce the pressure in the adsorption tower in multiple stages, pressure reduction rate P _A in the first stage of the formula (I) is 35% or less. As a result, the flow rate of the desorption gas flowing out of the adsorption tower can be varied. As a result, the amount of combustion heat generated in the combustor changes, and the amount of heating for vaporizing the liquid raw material in the vaporizer can be changed. For this reason, the gas fluid whose temperature has changed can be caused to flow into the reactor, and the position of the hot spot in the reactor can be changed. As a result, it is possible to prevent the same region from always reaching the highest temperature in the catalyst packed portion in the reactor, and to prevent catalyst deterioration.

Objects, features, and advantages of the present invention will become more apparent from the following detailed description and drawings.
It is process drawing which shows the manufacturing method of hydrogen which concerns on one Embodiment of this invention. It is the schematic which shows the structure of the hydrogen production apparatus 100 for implement | achieving the manufacturing method of hydrogen which concerns on this invention. FIG. 3 is a diagram showing a configuration of a hydrogen gas separation unit 3. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. 4 is a diagram for explaining the operation of the hydrogen gas separation unit 3. FIG. It is a graph which shows the temperature change in the heat retention part 4 of each Example and a comparative example. It is a graph which shows the temperature change in the reactive gas production | generation part 2 of each Example and a comparative example.

Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the drawings.
FIG. 1 is a process diagram showing a method for producing hydrogen according to an embodiment of the present invention. FIG. 2 is a schematic diagram showing the configuration of a hydrogen production apparatus 100 for realizing the method for producing hydrogen according to the present invention. FIG. 3 is a diagram illustrating a configuration of the hydrogen gas separation unit 3.

The method for producing hydrogen according to the present embodiment is a method for producing hydrogen by reacting a hydrocarbon compound such as methanol with water and oxygen in the presence of a catalyst. The hydrogen production apparatus shown in FIG. 100. The hydrogen production apparatus 100 includes a raw material vaporization unit 1 that functions as a vaporizer, a reaction gas generation unit 2 having a reactor 2A, a hydrogen gas separation unit 3 having an adsorption tower, and a heat retaining unit 4. Below, the case where methanol is used as a hydrocarbon compound is demonstrated.

The hydrogen production method according to this embodiment includes a vaporization step s1, a hydrogen generation step s2, a hydrogen gas separation step s3, a recovery step s4, a desorption gas supply step s5, and a desorption gas combustion step corresponding to the combustion step. and s6.

The vaporization step s1 is a step for vaporizing a liquid raw material containing at least methanol and water by combustion heat generated by the gas combustion unit 9 in a desorption gas combustion step s6 described later, and is performed by the raw material vaporization unit 1. .

In the vaporization step s1, a mixed gas containing methanol vapor and water vapor is generated by vaporizing methanol and water. As shown in FIG. 2, methanol and water are sent from the pump 5 to the raw material vaporization unit 1 via the first pipe 6, for example. The first pipe 6 is provided with a first valve 7 a and a second valve 7 b that open or close a flow path in the first pipe 6. Methanol and water flow through the first pipe 6 from the pump 5 toward the raw material vaporization unit 1 with the first valve 7a and the second valve 7b being opened, and are supplied to the raw material vaporization unit 1.

A heat exchanger 8 may be disposed between the pump 5 and the raw material vaporization unit 1 as necessary. When the heat exchanger 8 is provided, methanol and water are heated by the heat exchanger 8 by exchanging heat with a reaction product gas obtained in the reaction gas generation unit 2 described later. The resulting reaction product gas is cooled by exchanging heat with methanol and water. Thereby, since methanol and water are previously heated before being sent to the raw material vaporization part 1, methanol and water can be efficiently vaporized.

The amount of water per mole of methanol is preferably 1.2 mol or more, more preferably from the viewpoint of efficiently generating hydrogen gas and increasing the yield of hydrogen gas by reducing the residual amount of carbon monoxide gas. Is 1.5 mol or more. In addition, even if the amount of water becomes too large, the yield of hydrogen gas does not improve so much, and from the viewpoint of increasing energy efficiency by reducing the amount of water with a large latent heat of evaporation, preferably 2.5 mol or less, more Preferably it is 2.0 mol or less.

In addition, the liquid temperature of methanol and water sent to the raw material vaporization unit 1 is not particularly limited, and may be room temperature or higher than room temperature. The liquid temperatures of methanol and water are preferably as high as possible from the viewpoint of improving the yield of hydrogen gas. The upper limit temperature of the liquid temperature is preferably not more than the boiling point of methanol from the viewpoint of increasing energy efficiency.

Further, it is not always necessary to heat and vaporize methanol and water at the same time, and the vaporization of methanol and the vaporization of water may be performed separately, or methanol and water are mixed, and the methanol mixed solution May be vaporized.

As the raw material vaporization unit 1, for example, as shown in FIG. 2, a metal tube having a spiral shape may be mentioned, but it is not limited to such an example. Examples of the metal used for the metal tube include stainless steel and copper, brass and the like because of excellent thermal conductivity. The raw material vaporization unit 1 is disposed in a container-like heat retaining unit 4 so that heat generated by burning a desorption gas described later in the gas combustion unit 9 can be efficiently transmitted.

In the raw material vaporization unit 1, a mixed gas (gas fluid) containing methanol vapor and water vapor obtained by vaporizing methanol and water flows through the second pipe 10 toward the reaction gas generation unit 2. It is aired.

In the present embodiment, oxygen as a raw material for generating hydrogen gas is used as an oxygen-containing gas (gas raw material). For example, air or oxygen gas is used as the oxygen-containing gas.

In this embodiment, a mixed gas containing methanol vapor and water vapor and flowing in the second pipe 10 is mixed with an oxygen-containing gas to prepare a raw material gas containing at least methanol, water, and oxygen. Note that the oxygen-containing gas does not necessarily have to be heated because it has a smaller heat capacity than methanol and water.

The amount of oxygen gas contained in the oxygen-containing gas per mole of methanol is preferably 0.05 moles or more, more preferably 0.08 moles or more, from the viewpoint of reducing the remaining amount of unreacted methanol. It is. The amount of oxygen gas contained in the oxygen-containing gas per mole of methanol avoids an increase in reaction temperature due to the reaction between the hydrogen gas generated from methanol and the introduced oxygen gas, and the generated hydrogen gas From the viewpoint of avoiding consumption by reaction with oxygen gas, the amount is preferably 0.20 mol or less, more preferably 0.15 mol or less.

The oxygen-containing gas is sent toward the reaction gas generation unit 2 through the third pipe 11 provided with the third valve 13. The oxygen-containing gas flows through the third pipe 11 in a state where the third valve 13 is opened, and is sent toward the reaction gas generation unit 2.

A second pipe 10 through which a mixed gas containing methanol vapor and water vapor flows and a third pipe 11 through which an oxygen-containing gas flows are connected to a fourth pipe 12. The fourth pipe 12 is connected to a reactor 2 </ b> A provided in the reaction gas generator 2. The mixed gas flowing in the second pipe 10 and the oxygen-containing gas flowing in the third pipe 11 are mixed in the fourth pipe 12, thereby preparing a raw material gas containing at least methanol, water, and oxygen. The The raw material gas thus prepared flows through the fourth pipe 12 and is supplied to the reactor 2A.

In the hydrogen generation step s2, the raw material gas that flows in the fourth pipe 12 and is supplied to the reactor 2A of the reaction gas generation unit 2 is subjected to partial oxidation reaction of methanol and steam reforming reaction (decomposition reaction) in the presence of a catalyst. ) To generate a reaction product gas (reaction product) containing hydrogen, which is performed by the reaction gas generation unit 2. In the present embodiment, the reactive gas generation unit 2 is disposed in the heat retaining unit 4. By being arranged in this way, the steam reforming reaction (decomposition reaction) of methanol accompanied by endotherm by the heat generated by burning the desorption gas in the gas combustion unit 9 installed in the heat retaining unit 4 The temperature decrease due to the reaction is suppressed, and hydrogen gas can be generated efficiently.

The raw material gas supplied to the reaction gas generation unit 2 via the fourth pipe 12 is adjusted to a reaction possible temperature before flowing into the reactor 2A. The temperature of the raw material gas is adjusted such that the temperature immediately before flowing into the reactor 2A (the inlet temperature of the reactor 2A) is the reaction possible temperature. The temperature of the raw material gas immediately before flowing into the reactor 2A is preferably 200 ° C. or higher, more preferably 220 ° C. or higher, from the viewpoint of promoting the partial oxidation reaction of methanol and reducing the remaining amount of unreacted methanol. is there. From the viewpoint of the heat resistant temperature of the catalyst, it is preferably 300 ° C. or lower, more preferably 260 ° C. or lower.

In the reactor 2A, for example, a granular or columnar catalyst is filled to form a catalyst layer. As the catalyst, a catalyst in which a copper compound is supported on aluminum oxide can be used. Specifically, a catalyst in which copper is supported on aluminum oxide and a catalyst in which copper and zinc oxide are supported on aluminum oxide are used.

The mass ratio of copper (Cu) to aluminum oxide (Al ₂ O ₃ ) [copper (Cu) / aluminum oxide (Al ₂ O ₃ )] exhibits sufficient catalytic activity of copper (Cu) as an additive. From the viewpoint of making it possible, it is preferably 0.1 or more, and from the viewpoint of imparting sufficient mechanical strength to the added copper (Cu) and increasing the catalytic activity, it is preferably 1 or less.

A commercially available catalyst in which copper is supported on aluminum oxide or a catalyst in which copper and zinc oxide are supported on aluminum oxide is present in a state of copper oxide when purchased. In this state, since it does not show catalytic activity, it is preferably used after being reduced to copper. Examples of the method of reducing copper oxide include a method of bringing a catalyst containing copper oxide into contact with a reducing gas. Examples of the reducing gas include hydrogen gas, mixed gas of hydrogen gas and nitrogen gas, and inert gas such as hydrogen gas and argon gas.

The particle diameter of the catalyst in which copper is supported on aluminum oxide or the catalyst in which copper and zinc oxide are supported on aluminum oxide is preferably 1 mm or more, more preferably 3 mm or more, from the viewpoint of reducing the pressure loss of the catalyst layer. is there. From the viewpoint of increasing the contact efficiency between the catalyst and the methanol vapor, water vapor and oxygen-containing gas, it is preferably 20 mm or less, more preferably 10 mm or less. The filling amount of the catalyst in which copper is supported on aluminum oxide, or the catalyst in which copper and zinc oxide are supported on aluminum oxide is usually 35 ml or more per 1 g / min of methanol fed to the raw material vaporization section 1. It is preferable.

The reactor 2A is a cylindrical body having a circular cross section as shown in FIG. The upper part (the inlet side into which the raw material gas flows) of the reactor 2A is configured such that the cylindrical body is filled with a catalyst to form a columnar catalyst layer, and the lower part (the outlet side from which the reaction product gas flows out). ) Is formed by concentrically overlapping two cylindrical bodies having a circular cross-sectional shape, and filling a gap between the cylindrical bodies to form a cylindrical catalyst layer. That is, the reactor 2A is formed in a cylindrical shape, and its internal space is filled with a catalyst. The reactor 2A has the same inner diameter at one end in the axial direction and the other end, and has a shape extending longer in the axial direction than the inner diameter.

The surface temperature (maximum temperature) of the catalyst charged in the reactor 2A is preferably 250 ° C. or higher from the viewpoint of efficiently reforming methanol into hydrogen. Further, the surface temperature of the catalyst is preferably 300 ° C. or less from the viewpoints of preventing deterioration of the catalyst, suppressing the generation of reaction byproducts, and suppressing the reaction between hydrogen and oxygen. The pressure in the reactor 2A is not particularly limited, but usually it is preferably 0.2 to 1.5 MPaG in terms of gauge pressure.

When the source gas containing at least methanol, water and oxygen adjusted to the reaction possible temperature is supplied to the reaction gas generation unit 2 through the fourth pipe 12, the source gas is supplied from the upper part in the reactor 2A. It flows toward the bottom. Thus, when the source gas flows through the reactor 2A and comes into contact with the catalyst, the partial oxidation reaction represented by the following formula (1) proceeds, in which methanol is partially oxidized to generate hydrogen and carbon dioxide. In addition, a decomposition reaction represented by the following formula (2), in which methanol is decomposed into carbon monoxide and hydrogen as a side reaction, also proceeds. Furthermore, a steam reforming reaction represented by the following formula (3) in which methanol is decomposed into carbon dioxide and hydrogen also proceeds.
CH ₃ OH + 1 / 2O ₂ → CO ₂ + 2H ₂ (1)
CH ₃ OH → CO + 2H ₂ ... (2)
CH ₃ OH + H ₂ O → CO ₂ + 3H ₂ (3)

In the above reaction, the partial oxidation reaction represented by the formula (1) is an exothermic reaction, and the decomposition reaction and the steam reforming reaction represented by the formulas (2) and (3) are endothermic reactions.

In the reaction product gas generated by the partial oxidation reaction, steam reforming reaction and decomposition reaction of methanol in the reactor 2A, in addition to hydrogen gas as a main component, unreacted methanol vapor, carbon dioxide gas, Impurity gases (subcomponents) such as carbon monoxide gas, water vapor, and dimethyl ether are contained. The reaction product gas generated in the reactor 2 </ b> A is supplied to the hydrogen gas separation unit 3 through the fifth pipe 14 and the sixth pipe 15.

A heat exchanger 8 is disposed between the fifth pipe 14 and the sixth pipe 15. In this heat exchanger 8, the reaction product gas generated in the reactor 2 </ b> A and the raw material methanol and water exchange heat, whereby the methanol and water can be efficiently heated. The reaction product gas can be efficiently cooled by exchanging heat with methanol and water.

The hydrogen gas separation step s3 is a step of separating hydrogen gas from an impurity gas from a reaction product gas supplied to the hydrogen gas separation unit 3 through the fifth pipe 14 and the sixth pipe 15, and the hydrogen gas separation unit 3 Is implemented.

As the hydrogen gas separation unit 3, for example, a pressure fluctuation adsorption device (PSA device) including an adsorption tower is used. From the viewpoint of efficiently producing high-purity hydrogen gas, it is preferable to use a plurality of adsorption towers of about 2 to 5 adsorption towers. In the present embodiment, the hydrogen gas separation unit 3 includes three adsorption towers, a first adsorption tower 3A, a second adsorption tower 3B, and a third adsorption tower 3C, as shown in FIG.

As the adsorbent filled in the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C, a carbon-based adsorbent or the like is used when removing carbon dioxide, methanol, dimethyl ether, or the like. In the case of removing carbon monoxide, zeolite or the like is used. Further, when removing water vapor or the like, alumina or the like is used. Usually, these adsorbents are used in a mixed manner in order to adsorb and remove many kinds of impurity gases such as unreacted methanol vapor, carbon dioxide gas, carbon monoxide gas, water vapor, dimethyl ether and the like.

In this embodiment, the hydrogen gas separation unit 3 is a pressure fluctuation adsorption device (PSA device) shown in FIG. The hydrogen gas separation unit 3 uses the reaction product gas obtained in the reactor 2A of the reaction gas generation unit 2 as one of the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C. The impurity gas in the reaction product gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the adsorption tower. The purified hydrogen gas flowing out from the adsorption tower is stored in the hydrogen gas storage tank 17 through the seventh pipe 16.

Further, after hydrogen gas is flowed out from the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C, the pressure in the adsorption tower is changed to a desorption start pressure lower than the adsorption start pressure. Then, the adsorbing component containing the impurity gas adsorbed on the adsorbent is desorbed from the adsorbent, and the desorbed gas containing the desorbed adsorbing component is discharged out of the adsorption tower while changing the flow rate. The desorption gas flowing out from the adsorption tower is sent as a combustion gas to the gas combustion unit 9 disposed in the heat retaining unit 4 through the eighth pipe 18. In addition, impurity gas and hydrogen are contained in the desorption gas sent to the gas combustion part 9 as combustion gas.

The hydrogen gas separation unit 3 will be described in detail. The hydrogen gas separation unit 3 includes a first adsorption tower 3A, a second adsorption tower 3B, and a third adsorption tower 3C, a reaction product gas supply pipe d, an offgas outflow pipe e, a hydrogen gas outflow pipe f, It includes a gas introduction pipe g and a tower gas extraction pipe h. Note that the reaction product gas supply pipe d of the hydrogen gas separation unit 3 is connected to the sixth pipe 15 shown in FIG. 2, and the hydrogen gas outlet pipe f is connected to the seventh pipe 16 shown in FIG. e is connected to the eighth pipe 18 shown in FIG.

Between the first adsorption tower 3A and the reaction product gas supply pipe d, there is a pipe through which the reaction product gas flowing through the reaction product gas supply pipe d via the sixth pipe 15 flows into the first adsorption tower 3A. It is connected. The pipe is provided with an automatic opening / closing valve a1 for opening and closing the flow path. Further, between the first adsorption tower 3A and the off-gas outflow pipe e, a pipe for allowing desorption gas (off-gas) flowing out from the first adsorption tower 3A to flow into the off-gas outflow pipe e is connected. The pipe is provided with an automatic opening / closing valve a2 for opening and closing the flow path. Further, between the first adsorption tower 3A and the gas extraction pipe h in the tower, the gas in the tower (cleaning gas including desorption gas) flowing out from the first adsorption tower 3A is converted into the gas extraction pipe h in the tower. A pipe for flowing into the pipe is connected. The pipe is provided with an automatic opening / closing valve a3 for opening and closing the flow path. Further, between the first adsorption tower 3A and the gas introduction pipe g in the tower, the gas is introduced from the second adsorption tower 3B or the third adsorption tower 3C other than the first adsorption tower 3A and introduced into the tower. A pipe for allowing the in-tower gas (cleaning gas including desorption gas) flowing through the pipe for piping g to flow into the first adsorption tower 3A is connected. The pipe is provided with an automatic opening / closing valve a4 for opening and closing the flow path. A pipe for allowing the hydrogen gas flowing out from the first adsorption tower 3A to flow into the hydrogen gas outflow pipe f is connected between the first adsorption tower 3A and the hydrogen gas outflow pipe f. The pipe is provided with an automatic opening / closing valve a5 for opening and closing the flow path.

Between the second adsorption tower 3B and the reaction product gas supply pipe d, there is a pipe through which the reaction product gas flowing through the reaction product gas supply pipe d via the sixth pipe 15 flows into the second adsorption tower 3B. It is connected. The pipe is provided with an automatic opening / closing valve b1 for opening and closing the flow path. In addition, a pipe for allowing desorption gas (off gas) flowing out from the second adsorption tower 3B to flow into the off gas outflow pipe e is connected between the second adsorption tower 3B and the off gas outflow pipe e. The pipe is provided with an automatic opening / closing valve b2 for opening and closing the flow path. In addition, between the second adsorption tower 3B and the gas extraction pipe h in the tower, the gas in the tower (cleaning gas including desorption gas) flowing out from the second adsorption tower 3B is converted into the gas extraction pipe h in the tower. A pipe for flowing into the pipe is connected. The pipe is provided with an automatic opening / closing valve b3 for opening and closing the flow path. Further, between the second adsorption tower 3B and the gas introduction pipe g in the tower, the gas is introduced from the first adsorption tower 3A or the third adsorption tower 3C other than the second adsorption tower 3B and introduced into the tower. A pipe for allowing the gas in the tower (the cleaning gas including the desorption gas) flowing through the pipe g to flow into the second adsorption tower 3B is connected. The pipe is provided with an automatic opening / closing valve b4 for opening and closing the flow path. A pipe for allowing the hydrogen gas flowing out from the second adsorption tower 3B to flow into the hydrogen gas outflow pipe f is connected between the second adsorption tower 3B and the hydrogen gas outflow pipe f. The pipe is provided with an automatic open / close valve b5 for opening and closing the flow path.

Between the third adsorption tower 3C and the reaction product gas supply pipe d, there is a pipe through which the reaction product gas flowing through the reaction product gas supply pipe d through the sixth pipe 15 flows into the third adsorption tower 3C. It is connected. The pipe is provided with an automatic opening / closing valve c1 for opening and closing the flow path. In addition, between the third adsorption tower 3C and the off-gas outflow pipe e, a pipe for connecting the desorption gas (off-gas) flowing out from the third adsorption tower 3C into the off-gas outflow pipe e is connected. The pipe is provided with an automatic opening / closing valve c2 for opening and closing the flow path. Further, between the third adsorption tower 3C and the gas extraction pipe h in the tower, the tower gas (cleaning gas including desorption gas) that has flowed out of the third adsorption tower 3C is converted into the gas extraction pipe h in the tower. A pipe for flowing into the pipe is connected. The pipe is provided with an automatic opening / closing valve c3 for opening and closing the flow path. Further, between the third adsorption tower 3C and the gas introduction pipe g in the tower, it flows out from the first adsorption tower 3A or the second adsorption tower 3B other than the third adsorption tower 3C and introduces the gas in the tower. A pipe for allowing the in-tower gas (cleaning gas including desorption gas) flowing through the pipe g to flow into the third adsorption tower 3C is connected. The pipe is provided with an automatic opening / closing valve c4 for opening and closing the flow path. Further, a pipe for allowing the hydrogen gas flowing out from the third adsorption tower 3C to flow into the hydrogen gas outflow pipe f is connected between the third adsorption tower 3C and the hydrogen gas outflow pipe f. The pipe is provided with an automatic opening / closing valve c5 for opening and closing the flow path.

The off-gas outflow pipe e is provided with an off-gas flow rate adjusting valve e1 for adjusting the flow rate of desorption gas (off-gas) flowing out from the hydrogen gas separation unit 3 toward the gas combustion unit 9. Furthermore, the gas extraction pipe h in the tower and the gas introduction pipe g in the tower are connected via a cleaning gas flow rate adjustment valve h1, and the opening degree of the cleaning gas flow rate adjustment valve h1 is adjusted. The supply flow rate of the gas in the tower (cleaning gas) flowing through the gas extraction pipe h in the tower to the gas introduction pipe g in the tower is adjusted.

As shown in FIG. 1, the hydrogen gas separation step s3 executed by the respective adsorption towers of the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C includes an adsorption process s31 and a cleaning gas outflow process. s32, a pressure equalizing gas outflow step s33, a first desorption step s34, a second desorption step s35, a cleaning gas inflow step s36, a pressure equalizing gas inflow step s37, and a pressure increasing step s38. The hydrogen gas separation step s3 executed by each of the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C will be described with reference to FIGS. 4A to 4I. 4A to 4I are diagrams for explaining the operation of the hydrogen gas separation unit 3. FIG.

In the hydrogen gas separation step s3, first, as shown in FIG. 4A, the adsorption step s31 is performed in the first adsorption tower 3A, the cleaning gas inflow step s36 is performed in the second adsorption tower 3B, and the third adsorption tower 3C. The cleaning gas outflow step s32 is performed in FIG. Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is opened, the automatic open / close valve a2 is closed, the automatic open / close valve a3 is closed, the automatic open / close valve a4 is closed, and the automatic open / close valve a5 is opened. Opened, the adsorption step s31 is performed in the first adsorption tower 3A. In the second adsorption tower 3B, the automatic on-off valve b1 is closed, the automatic on-off valve b2 is opened, the automatic on-off valve b3 is closed, the automatic on-off valve b4 is opened, and the automatic on-off valve b5 is closed. The cleaning gas inflow step s36 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2, the automatic open / close valve c3 are opened, the automatic open / close valve c4 is closed, and the automatic open / close valve c5 is closed. The cleaning gas outflow step s32 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the off gas flow rate adjustment valve e1 is opened so that the opening degree becomes 100%.

In the hydrogen gas separation step s3 shown in FIG. 4A, the reaction product gas is introduced into the first adsorption tower 3A through the reaction product gas supply pipe d and the automatic opening / closing valve a1. In the first adsorption tower 3A, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the first adsorption tower 3A flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve a5, and flows through the seventh pipe 16 to pass through the hydrogen gas storage tank (collector). ) 17 (collection step s4).

In the hydrogen gas separation step s3 shown in FIG. 4A, the second adsorption tower 3B includes an automatic on-off valve c3, a gas extraction pipe h in the tower, a cleaning gas flow rate adjustment valve h1, and a gas introduction pipe in the tower. The gas in the tower (cleaning gas) flowing out from the third adsorption tower 3C is introduced through g and the automatic opening / closing valve b4. Here, when the pressures in the second adsorption tower 3B and the third adsorption tower 3C are compared, the third adsorption tower 3C has a higher pressure than the second adsorption tower 3B. Therefore, by introducing the gas (cleaning gas) in the third adsorption tower 3C into the second adsorption tower 3B, the inside of the third adsorption tower 3C is depressurized and remains in the tower from the second adsorption tower 3B. The gas inside the tower (cleaning gas) is discharged. The gas in the second adsorption tower 3B (cleaning gas including desorption gas) flows into the eighth pipe 18 via the automatic on-off valve b2, the off-gas outflow pipe e, and the off-gas flow rate adjustment valve e1. The gas flows through the eight pipes 18 and is supplied to the gas combustion unit 9 as combustion gas (desorption gas supply step s5). In this way, when the tower gas containing the desorption gas is supplied to the gas combustion unit 9 as the off gas, the supplied off gas is burned (desorption gas combustion step s6). When off-gas is combusted in the gas combustion unit 9, the temperature of the heat retaining unit 4 rises according to the amount of off-gas due to combustion heat corresponding to the amount of off-gas supplied to the gas combustion unit 9. When the temperature of the heat retaining unit 4 rises, the raw material vaporizing unit 1 disposed in the heat retaining unit 4 is heated, and a liquid raw material containing methanol and water is vaporized.

The desorption gas combustion step s6 is a step of burning off-gas (desorption gas), and is performed by the gas combustion unit 9. In the present embodiment, the off gas is not disposed as exhaust gas, but is effectively used by burning in the gas combustion unit 9 disposed in the heat retaining unit 4 as described above.

If methanol and water are heated using combustion heat generated when off-gas is burned, methanol vapor and water vapor can be produced efficiently. At the same time, heat can be supplied to the steam reforming reaction and decomposition reaction of methanol accompanied by endotherm represented by the above formulas (2) and (3) by the combustion heat of the off-gas. Can be generated.

It is preferable to use a catalyst when burning off-gas. Among the catalysts, a platinum catalyst is preferable because of its high catalytic activity and excellent heat resistance. As the shape of the catalyst, a catalyst in which platinum is supported on a carrier having a honeycomb structure is preferable. Metal honeycombs and ceramic honeycombs are used. The platinum catalyst may be platinum particles, or may be one in which platinum is supported on a carrier such as alumina particles. As a catalyst for burning off-gas, in addition to platinum, noble metals such as palladium, rhodium and silver, compounds of these metals, and the like are used.

When burning off-gas, it is preferable to add air in order to burn off-gas. The amount of air is not particularly limited as long as hydrogen gas contained in the off-gas is sufficiently combusted. The heating temperature of methanol vapor and water vapor, which are reaction gases due to combustion heat generated when off-gas is burned, is preferably 250 ° C. from the viewpoint of increasing the amount of hydrogen gas generated by reducing the amount of unreacted methanol remaining. From the viewpoint of suppressing the deterioration of the catalyst, the temperature is preferably 600 ° C. or lower.

The air for burning off gas is blown by the blower 19 and heated by the heater 20. The temperature to be heated is preferably 150 ° C. or higher from the viewpoint of increasing the amount of hydrogen gas generated by reducing the remaining amount of unreacted methanol, and preferably 300 ° C. or lower from the viewpoint of suppressing catalyst deterioration. is there.

The heated air is sent to the gas combustion unit 9 through the pipe 21. The air sent to the gas combustion unit 9 is mixed with the off gas (desorption gas) sent via the eighth pipe 18, and the off gas burns on the platinum catalyst.

After combustion, the gas after combustion is used as a heat source for vaporizing methanol and water. Further, the post-combustion gas exchanges heat in order to facilitate the reaction by supplying heat from the outside to the reaction involving the endothermic reaction in the reaction equations (2) and (3) of the reaction gas generation unit 2. The post-combustion gas subjected to heat exchange is purged from the pipe 22.

Next, in the hydrogen gas separation step s3, as shown in FIG. 4B, the adsorption step s31 is performed in the first adsorption tower 3A, the pressure equalizing gas inflow step s37 is performed in the second adsorption tower 3B, and the third adsorption. A pressure equalizing gas outflow step s33 is performed in the tower 3C. Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is opened, the automatic open / close valve a2 is closed, the automatic open / close valve a3 is closed, the automatic open / close valve a4 is closed, and the automatic open / close valve a5 is opened. Opened, the adsorption step s31 is performed in the first adsorption tower 3A. In the second adsorption tower 3B, the automatic open / close valve b1, the automatic open / close valve b2, the automatic open / close valve b3, the automatic open / close valve b4, and the automatic open / close valve b5 are closed. The equalized gas inflow step s37 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2, the automatic open / close valve c3 are opened, the automatic open / close valve c4 is closed, and the automatic open / close valve c5 is closed. The equalized gas outflow step s33 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the off gas flow rate adjustment valve e1 is closed.

In the hydrogen gas separation step s3 shown in FIG. 4B above, the reaction product gas is introduced into the first adsorption tower 3A via the reaction product gas supply pipe d and the automatic opening / closing valve a1. In the first adsorption tower 3A, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the first adsorption tower 3A flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve a5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4).

In the hydrogen gas separation step s3 shown in FIG. 4B, the tower gas (cleaning gas) that has flowed out of the third adsorption tower 3C through the tower gas extraction pipe h is supplied with the automatic open / close valve c3 and the cleaning gas. The gas is introduced into the second adsorption tower 3B through the flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic opening / closing valve b4. In the hydrogen gas separation step s3 shown in FIG. 4A described above, the gas in the tower (cleaning gas) is turned off gas from the second adsorption tower 3B via the automatic opening / closing valve b2, the off gas outflow pipe e, and the off gas flow rate adjusting valve e1. Spill. In the hydrogen gas separation step s3 shown in FIG. 4B, the pressure in the tower is equalized between the second adsorption tower 3B and the third adsorption tower 3C by closing the automatic opening / closing valve b2. As a result, the pressure in the third adsorption tower 3C is further reduced, and the pressure in the second adsorption tower 3B is increased.

In the hydrogen gas separation step s3 shown in FIG. 4B, since the automatic on-off valve e1 for opening and closing the flow path of the off-gas outflow pipe e is closed, to the eighth pipe 18 connected to the off-gas outflow pipe e. Inflow of off gas is stopped. For this reason, the supply of off-gas to the gas combustion unit 9 connected to the eighth pipe 18 is stopped. Thus, when the supply of the off gas to the gas combustion unit 9 is stopped, the off gas combustion operation in the gas combustion unit 9 is stopped. As a result, the temperature of the heat retaining unit 4 decreases. When the temperature of the heat retaining unit 4 is lowered, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 is lowered, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water is lowered. .

Next, in the hydrogen gas separation step s3, as shown in FIG. 4C, the adsorption step s31 is performed in the first adsorption tower 3A, the pressurization step s38 is performed in the second adsorption tower 3B, and the third adsorption tower 3C is performed. A desorption process (a first desorption process s34 in the first stage and a second desorption process s35 in the second stage when depressurizing each adsorption tower in multiple stages) is performed. When the first desorption step s34 in the first stage is performed in the third adsorption tower 3C, the automatic opening / closing valve a1 is opened, the automatic opening / closing valve a2 is closed, and the automatic opening / closing valve a3 is opened in the first adsorption tower 3A. Then, the automatic open / close valve a4 is closed, the automatic open / close valve a5 is opened, and the adsorption step s31 is performed in the first adsorption tower 3A. In the second adsorption tower 3B, the automatic open / close valve b1, the automatic open / close valve b2 are closed, the automatic open / close valve b3 is closed, the automatic open / close valve b4 is opened, and the automatic open / close valve b5 is closed. The pressure increasing step s38 is performed in the second adsorption tower 3B.

In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2 are opened, the automatic open / close valve c3 is closed, the automatic open / close valve c4 is closed, and the automatic open / close valve c5 is closed. The first desorption step s34 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the opening degree of the off gas flow rate adjustment valve e1 is expressed by the following formula (I) in the third adsorption tower 3C in which the desorption operation is performed in multiple stages (two stages). as first stage of the pressure reduction rate P _a to be of 35% or less, it is adjusted.
Decompression rate P _A (%) = [(P _S −P _E ) / P _S ] × 100 (I)
(Wherein, _{P S} represents a desorption start pressure (kPaG), _{P E} represents the first stage of the desorption completion pressure (kPaG).)

In the hydrogen gas separation step s3 shown in FIG. 4C above, the reaction product gas is introduced into the first adsorption tower 3A through the reaction product gas supply pipe d and the automatic opening / closing valve a1. In the first adsorption tower 3A, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the first adsorption tower 3A flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve a5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4). Part of the hydrogen gas flowing out from the first adsorption tower 3A passes through the automatic open / close valve a3, the gas extraction pipe h in the tower, the cleaning gas flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic open / close valve b4. Is introduced into the second adsorption tower 3B, and the pressure in the second adsorption tower 3B is increased.

On the other hand, in the third adsorption tower 3C, the pressure in the tower is reduced to a desorption start pressure that is lower than the adsorption start pressure, which is the pressure in the first adsorption tower 3A in which the adsorption step s31 is performed. At the same time, the automatic open / close valves c1, c3, c4, and c5 are closed, and the automatic open / close valve c2 is opened. As a result, the adsorbing component including the impurity gas adsorbed by the adsorbent in the third adsorption tower 3C is desorbed from the adsorbent, and the desorbed desorption gas (off-gas) flows out from the third adsorption tower 3C. The desorption gas flowing out from the third adsorption tower 3C flows into the eighth pipe 18 through the automatic opening / closing valve c2, the off-gas outflow pipe e, and the off-gas flow rate adjusting valve e1, and flows through the eighth pipe 18 for gas combustion. It is supplied to the part 9 as a combustion gas (desorption gas supply step s5). However, the opening degree of the off-gas flow rate adjusting valve e1 is, since pressure reduction rate P _A represented by the formula (I) is adjusted to be 35% or less, is supplied as the off gas to the gas combustion unit 9 desorption The amount of gas will be reduced, and the temperature of the heat retaining unit 4 will continue to fall further than in the case of FIG. 4B. When the temperature of the heat retaining unit 4 is lowered, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 is lowered, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water is lowered. .

Next, in the hydrogen gas separation step s3, the second desorption step s35 (second desorption step when each adsorption tower is depressurized in multiple stages) is performed in the third adsorption tower 3C. When the second desorption process s35 is performed in the third adsorption tower 3C, as shown in FIG. 4C, the adsorption process s31 is performed in the first adsorption tower 3A, and the pressure increasing process s38 is performed in the second adsorption tower 3B. The Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is opened, the automatic open / close valve a2 is closed, the automatic open / close valve a3 is opened, the automatic open / close valve a4 is closed, and the automatic open / close valve a5 is opened. Thus, the adsorption step s31 is performed in the first adsorption tower 3A. In the second adsorption tower 3B, the automatic open / close valve b1, the automatic open / close valve b2 are closed, the automatic open / close valve b3 is closed, the automatic open / close valve b4 is opened, and the automatic open / close valve b5 is closed. The pressure increasing step s38 is performed in the second adsorption tower 3B.

In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2 are opened, the automatic open / close valve c3 is closed, the automatic open / close valve c4 is closed, and the automatic open / close valve c5 is closed. The first desorption step s34 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the opening degree of the off gas flow rate adjustment valve e1 is expressed by the following formula (II) in the third adsorption tower 3C in which the desorption operation is performed in multiple stages (two stages). The second stage pressure reduction rate _PA2 is adjusted to be 65% or more.
Decompression rate P _A2 (%) = [(P _S −P _E2 ) / P _S ] × 100 (II)
(Wherein, _{P S} represents a desorption start pressure _{(kPaG), P E2} indicates the second stage of desorption completion pressure (kPaG).)

In the hydrogen gas separation step s3 in which the second desorption step s35 is performed in the third adsorption tower 3C, as shown in FIG. 4C, the first adsorption tower 3A is provided with a reaction product gas supply pipe d and an automatic on-off valve a1. Through which reaction product gas is introduced. In the first adsorption tower 3A, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the first adsorption tower 3A flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve a5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4). Part of the hydrogen gas flowing out from the first adsorption tower 3A passes through the automatic open / close valve a3, the gas extraction pipe h in the tower, the cleaning gas flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic open / close valve b4. Is introduced into the second adsorption tower 3B, and the pressure in the second adsorption tower 3B is increased.

On the other hand, in the third adsorption tower 3C, the pressure in the tower is further reduced than in the first desorption step s34, the automatic open / close valves c1, c3, c4, and c5 are closed, and the automatic open / close valve c2 is opened. Yes. As a result, the adsorbing component including the impurity gas adsorbed by the adsorbent in the third adsorption tower 3C is desorbed from the adsorbent, and the desorbed desorption gas (off-gas) flows out from the third adsorption tower 3C. The desorption gas flowing out from the third adsorption tower 3C flows into the eighth pipe 18 through the automatic opening / closing valve c2, the off-gas outflow pipe e, and the off-gas flow rate adjusting valve e1, and flows through the eighth pipe 18 for gas combustion. It is supplied to the part 9 as a combustion gas (desorption gas supply step s5). Here, since the opening degree of the off-gas flow rate adjusting valve e1 is adjusted so that the pressure reduction rate _PA2 expressed by the above formula (II) is 65% or more, it is supplied to the gas combustion unit 9 as off-gas. The amount of desorption gas will increase more than the 1st desorption process s34, and the temperature of the heat retention part 4 will rise. When the temperature of the heat retaining unit 4 increases, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 increases, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water increases. .

Next, in the hydrogen gas separation step s3, as shown in FIG. 4D, the cleaning gas outflow step s32 is performed in the first adsorption tower 3A, the adsorption step s31 is performed in the second adsorption tower 3B, and the third adsorption tower is performed. In 3C, the cleaning gas inflow step s36 is performed. Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is closed, the automatic open / close valve a2 is closed, the automatic open / close valve a3 is opened, the automatic open / close valve a4 is closed, and the automatic open / close valve a5 is closed. Then, the cleaning gas outflow step s32 is performed in the first adsorption tower 3A. Further, in the second adsorption tower 3B, the automatic opening / closing valve b1 is opened, the automatic opening / closing valve b2 is closed, the automatic opening / closing valve b3 is closed, the automatic opening / closing valve b4 is closed, and the automatic opening / closing valve b5 is opened, An adsorption step s31 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2 are opened, the automatic open / close valve c3 is closed, the automatic open / close valve c4 is opened, and the automatic open / close valve c5 is closed. A cleaning gas inflow step s36 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the off gas flow rate adjustment valve e1 is opened so that the opening degree becomes 100%.

In the hydrogen gas separation step s3 shown in FIG. 4D above, the reaction product gas is introduced into the second adsorption tower 3B through the reaction product gas supply pipe d and the automatic opening / closing valve b1. In the second adsorption tower 3B, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the second adsorption tower 3B flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve b5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4).

In the hydrogen gas separation step s3 shown in FIG. 4D, the third adsorption tower 3C includes an automatic opening / closing valve a3, a gas extraction pipe h in the tower, a cleaning gas flow rate adjustment valve h1, and a gas introduction pipe in the tower. The gas in the tower (cleaning gas) flowing out from the first adsorption tower 3A is introduced through g and the automatic opening / closing valve c4. Here, when the pressures in the first adsorption tower 3A and the third adsorption tower 3C are compared, the first adsorption tower 3A has a higher pressure than the third adsorption tower 3C. Therefore, by introducing the gas (cleaning gas) in the first adsorption tower 3A into the third adsorption tower 3C, the inside of the first adsorption tower 3A is depressurized and remains in the tower from the third adsorption tower 3C. The gas inside the tower (cleaning gas) is discharged. The gas in the tower (cleaning gas including desorption gas) in the third adsorption tower 3C flows into the eighth pipe 18 via the automatic open / close valve c2, the off-gas outflow pipe e, and the off-gas flow rate adjusting valve e1. The gas flows through the eight pipes 18 and is supplied to the gas combustion unit 9 as a combustion gas (desorption gas supply step s5). In this way, when the tower gas containing the desorption gas is supplied to the gas combustion unit 9 as the off gas, the supplied off gas is burned (desorption gas combustion step s6). When off-gas is combusted in the gas combustion unit 9, the temperature of the heat retaining unit 4 rises according to the amount of off-gas due to combustion heat corresponding to the amount of off-gas supplied to the gas combustion unit 9. When the temperature of the heat retaining unit 4 increases, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 increases, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water increases. .

Next, in the hydrogen gas separation step s3, as shown in FIG. 4E, the pressure equalizing gas outflow step s33 is performed in the first adsorption tower 3A, the adsorption step s31 is performed in the second adsorption tower 3B, and the third adsorption is performed. A pressure equalizing gas inflow step s37 is performed in the tower 3C. Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is closed, the automatic open / close valve a2 is closed, the automatic open / close valve a3 is opened, the automatic open / close valve a4 is closed, and the automatic open / close valve a5 is closed. Then, the pressure equalizing gas outflow step s33 is performed in the first adsorption tower 3A. Further, in the second adsorption tower 3B, the automatic opening / closing valve b1 is opened, the automatic opening / closing valve b2 is closed, the automatic opening / closing valve b3 is closed, the automatic opening / closing valve b4 is closed, and the automatic opening / closing valve b5 is opened, An adsorption step s31 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2, the automatic open / close valve c3 are closed, the automatic open / close valve c4 is opened, and the automatic open / close valve c5 is closed. A pressure equalizing gas inflow step s37 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the off gas flow rate adjustment valve e1 is closed.

In the hydrogen gas separation step s3 shown in FIG. 4E above, the reaction product gas is introduced into the second adsorption tower 3B through the reaction product gas supply pipe d and the automatic opening / closing valve b1. In the second adsorption tower 3B, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the second adsorption tower 3B flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve b5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4).

Also, in the hydrogen gas separation step s3 shown in FIG. 4E, the tower gas (cleaning gas) that has flowed out from the first adsorption tower 3A through the tower gas extraction pipe h is converted into the automatic opening / closing valve a3, the cleaning gas. The gas is introduced into the third adsorption tower 3C through the flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic opening / closing valve c4. In the hydrogen gas separation step s3 shown in FIG. 4D described above, the gas in the column (cleaning gas) is turned off gas from the third adsorption tower 3C via the automatic opening / closing valve c2, the off gas outflow pipe e, and the off gas flow rate adjusting valve e1. Spill. In the hydrogen gas separation step s3 shown in FIG. 4E, the pressure in the tower is equalized between the first adsorption tower 3A and the third adsorption tower 3C by closing the automatic opening / closing valve c2. As a result, the pressure in the first adsorption tower 3A is further reduced, and the pressure in the third adsorption tower 3C is increased.

In the hydrogen gas separation step s3 shown in FIG. 4E, since the automatic on-off valve e1 for opening and closing the flow path of the off-gas outflow pipe e is closed, to the eighth pipe 18 connected to the off-gas outflow pipe e. Inflow of off gas is stopped. For this reason, the supply of off-gas to the gas combustion unit 9 connected to the eighth pipe 18 is stopped. Thus, when the supply of the off gas to the gas combustion unit 9 is stopped, the off gas combustion operation in the gas combustion unit 9 is stopped. As a result, the temperature of the heat retaining unit 4 decreases. When the temperature of the heat retaining unit 4 is lowered, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 is lowered, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water is lowered. .

Next, in the hydrogen gas separation step s3, as shown in FIG. 4F, in the first adsorption tower 3A, a desorption process (the first desorption process s34 in the first stage when each adsorption tower is decompressed in multiple stages and The second desorption step s35) of the second stage is performed, the adsorption step s31 is performed in the second adsorption tower 3B, and the pressure increasing step s38 is performed in the third adsorption tower 3C. When the first desorption step s34 in the first stage is performed in the first adsorption tower 3A, the automatic opening / closing valve a1 is closed, the automatic opening / closing valve a2 is opened, and the automatic opening / closing valve a3 is closed in the first adsorption tower 3A. Then, the automatic open / close valve a4 is closed, the automatic open / close valve a5 is closed, and the first desorption step s34 is performed in the first adsorption tower 3A. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the opening degree of the off gas flow rate adjustment valve e1 is expressed by the above formula (I) in the first adsorption tower 3A in which the desorption operation is performed in multiple stages (two stages). as first stage of the pressure reduction rate P _a to be of 35% or less, it is adjusted. In the second adsorption tower 3B, the automatic opening / closing valve b1 is opened, the automatic opening / closing valve b2 is closed, the automatic opening / closing valve b3 is opened, the automatic opening / closing valve b4 is closed, and the automatic opening / closing valve b5 is opened. An adsorption step s31 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2, the automatic open / close valve c3 are closed, the automatic open / close valve c4 is opened, and the automatic open / close valve c5 is closed. The pressure increasing step s38 is performed in the third adsorption tower 3C.

In the hydrogen gas separation step s3 shown in FIG. 4F above, the reaction product gas is introduced into the second adsorption tower 3B through the reaction product gas supply pipe d and the automatic on-off valve b1. In the second adsorption tower 3B, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the second adsorption tower 3B flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve b5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4). A part of the hydrogen gas flowing out from the second adsorption tower 3B passes through the automatic opening / closing valve b3, the gas extraction pipe h in the tower, the cleaning gas flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic opening / closing valve c4. Are introduced into the third adsorption tower 3C, and the pressure in the third adsorption tower 3C is increased.

On the other hand, in the first adsorption tower 3A, the pressure in the tower is reduced to a desorption start pressure that is lower than the adsorption start pressure that is the pressure in the second adsorption tower 3B in which the adsorption step s31 is performed. At the same time, the automatic open / close valves a1, a3, a4, a5 are closed, and the automatic open / close valve a2 is opened. As a result, the adsorbing component containing the impurity gas adsorbed by the adsorbent in the first adsorption tower 3A is desorbed from the adsorbent, and the desorbed desorbed gas (off-gas) flows out from the first adsorption tower 3A. The desorption gas flowing out from the first adsorption tower 3A flows into the eighth pipe 18 through the automatic opening / closing valve a2, the off-gas outflow pipe e, and the off-gas flow rate adjusting valve e1, and flows through the eighth pipe 18 for gas combustion. It is supplied to the part 9 as a combustion gas (desorption gas supply step s5). However, the opening degree of the off-gas flow rate adjusting valve e1 is, since pressure reduction rate P _A represented by the formula (I) is adjusted to be 35% or less, is supplied as the off gas to the gas combustion unit 9 desorption The amount of gas will be reduced, and the temperature of the heat retaining section 4 will continue to fall further than in the case of FIG. 4E. When the temperature of the heat retaining unit 4 is lowered, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 is lowered, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water is lowered. .

Next, in the hydrogen gas separation step s3, the second desorption step s35 is performed in the first adsorption tower 3A. When the second desorption process s35 is performed in the first adsorption tower 3A, as shown in FIG. 4F, the adsorption process s31 is performed in the second adsorption tower 3B, and the pressure increasing process s38 is performed in the third adsorption tower 3C. The Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is closed, the automatic open / close valve a2 is opened, the automatic open / close valve a3 is closed, the automatic open / close valve a4 is closed, and the automatic open / close valve a5 is closed. Thus, the second desorption step s35 is performed in the first adsorption tower 3A. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the opening degree of the off gas flow rate adjustment valve e1 is expressed by the above formula (II) in the first adsorption tower 3A in which the desorption operation is performed in multiple stages (two stages). The second stage pressure reduction rate _PA2 is adjusted to be 65% or more. In the second adsorption tower 3B, the automatic opening / closing valve b1 is opened, the automatic opening / closing valve b2 is closed, the automatic opening / closing valve b3 is opened, the automatic opening / closing valve b4 is closed, and the automatic opening / closing valve b5 is opened. An adsorption step s31 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic open / close valve c1, the automatic open / close valve c2, the automatic open / close valve c3 are closed, the automatic open / close valve c4 is opened, and the automatic open / close valve c5 is closed. The pressure increasing step s38 is performed in the third adsorption tower 3C.

In the hydrogen gas separation step s3 in which the second desorption step s35 is performed in the first adsorption tower 3A, as shown in FIG. 4F, the second adsorption tower 3B is provided with a reaction product gas supply pipe d and an automatic on-off valve b1. Through which reaction product gas is introduced. In the second adsorption tower 3B, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the second adsorption tower 3B flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve b5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4). A part of the hydrogen gas flowing out from the second adsorption tower 3B passes through the automatic opening / closing valve b3, the gas extraction pipe h in the tower, the cleaning gas flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic opening / closing valve c4. Are introduced into the third adsorption tower 3C, and the pressure in the third adsorption tower 3C is increased.

On the other hand, in the first adsorption tower 3A, the pressure in the tower is further reduced than in the first desorption step s34, the automatic open / close valves a1, a3, a4, and a5 are closed, and the automatic open / close valve a2 is opened. Yes. As a result, the adsorbing component containing the impurity gas adsorbed by the adsorbent in the first adsorption tower 3A is desorbed from the adsorbent, and the desorbed desorbed gas (off-gas) flows out from the first adsorption tower 3A. The desorption gas flowing out from the first adsorption tower 3A flows into the eighth pipe 18 through the automatic opening / closing valve a2, the off-gas outflow pipe e, and the off-gas flow rate adjusting valve e1, and flows through the eighth pipe 18 for gas combustion. It is supplied to the part 9 as a combustion gas (desorption gas supply step s5). Here, since the opening degree of the off-gas flow rate adjusting valve e1 is adjusted so that the pressure reduction rate _PA2 expressed by the above formula (II) is 65% or more, it is supplied to the gas combustion unit 9 as off-gas. The amount of desorption gas will increase more than the 1st desorption process s34, and the temperature of the heat retention part 4 will rise. When the temperature of the heat retaining unit 4 increases, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 increases, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water increases. .

Next, in the hydrogen gas separation step s3, as shown in FIG. 4G, the cleaning gas inflow step s36 is performed in the first adsorption tower 3A, and the cleaning gas outflow step s32 is performed in the second adsorption tower 3B. An adsorption step s31 is performed in the adsorption tower 3C. Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is closed, the automatic open / close valve a2 is opened, the automatic open / close valve a3 is closed, the automatic open / close valve a4 is opened, and the automatic open / close valve a5 is closed. Then, the cleaning gas inflow step s36 is performed in the first adsorption tower 3A. Further, in the second adsorption tower 3B, the automatic open / close valve b1, the automatic open / close valve b2, the automatic open / close valve b3, the automatic open / close valve b4, and the automatic open / close valve b5 are closed, A cleaning gas outflow step s32 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic opening / closing valve c1 is opened, the automatic opening / closing valve c2 is closed, the automatic opening / closing valve c3 is closed, the automatic opening / closing valve c4 is closed, and the automatic opening / closing valve c5 is opened, An adsorption step s31 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the off gas flow rate adjustment valve e1 is opened so that the opening degree becomes 100%.

In the hydrogen gas separation step s3 shown in FIG. 4G above, the reaction product gas is introduced into the third adsorption tower 3C through the reaction product gas supply pipe d and the automatic opening / closing valve c1. In the third adsorption tower 3C, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the third adsorption tower 3C flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve c5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4).

In the hydrogen gas separation step s3 shown in FIG. 4G, the first adsorption tower 3A includes an automatic on-off valve b3, a tower gas extraction pipe h, a cleaning gas flow rate adjustment valve h1, and a tower gas introduction pipe. The gas in the tower (cleaning gas) flowing out from the second adsorption tower 3B is introduced through g and the automatic opening / closing valve a4. Here, when the pressures in the first adsorption tower 3A and the second adsorption tower 3B are compared, the second adsorption tower 3B has a higher pressure than the first adsorption tower 3A. Therefore, by introducing the gas (cleaning gas) in the second adsorption tower 3B into the first adsorption tower 3A, the inside of the second adsorption tower 3B is depressurized and remains in the tower from the first adsorption tower 3A. The gas inside the tower (cleaning gas) is discharged. The gas in the first adsorption tower 3A (cleaning gas including desorption gas) flows into the eighth pipe 18 via the automatic open / close valve a2, the off-gas outflow pipe e, and the off-gas flow rate adjustment valve e1, The gas flows through the eight pipes 18 and is supplied to the gas combustion unit 9 as combustion gas (desorption gas supply step s5). In this way, when the tower gas containing the desorption gas is supplied to the gas combustion unit 9 as the off gas, the supplied off gas is burned (desorption gas combustion step s6). When off-gas is combusted in the gas combustion unit 9, the temperature of the heat retaining unit 4 rises according to the amount of off-gas due to combustion heat corresponding to the amount of off-gas supplied to the gas combustion unit 9. When the temperature of the heat retaining unit 4 increases, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 increases, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water increases. .

Next, in the hydrogen gas separation step s3, as shown in FIG. 4H, a pressure equalizing gas inflow step s37 is performed in the first adsorption tower 3A, and a pressure equalizing gas outflow step s33 is performed in the second adsorption tower 3B. An adsorption step s31 is performed in the third adsorption tower 3C. Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is closed, the automatic open / close valve a2 is closed, the automatic open / close valve a3 is closed, the automatic open / close valve a4 is opened, and the automatic open / close valve a5 is closed. Thus, the pressure equalizing step s37 is performed in the first adsorption tower 3A. Further, in the second adsorption tower 3B, the automatic open / close valve b1, the automatic open / close valve b2, the automatic open / close valve b3, the automatic open / close valve b4, and the automatic open / close valve b5 are closed, A pressure equalizing step s33 is performed in the second adsorption tower 3B. In the third adsorption tower 3C, the automatic opening / closing valve c1 is opened, the automatic opening / closing valve c2 is closed, the automatic opening / closing valve c3 is closed, the automatic opening / closing valve c4 is closed, and the automatic opening / closing valve c5 is opened, An adsorption step s31 is performed in the third adsorption tower 3C. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the off gas flow rate adjustment valve e1 is closed.

In the hydrogen gas separation step s3 shown in FIG. 4H above, the reaction product gas is introduced into the third adsorption tower 3C via the reaction product gas supply pipe d and the automatic opening / closing valve c1. In the third adsorption tower 3C, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the third adsorption tower 3C flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve c5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4).

In the hydrogen gas separation step s3 shown in FIG. 4H, the tower gas (cleaning gas) that has flowed out of the second adsorption tower 3B through the tower gas extraction pipe h is converted into the automatic on-off valve b3, the cleaning gas. The gas is introduced into the first adsorption tower 3A through the flow rate adjustment valve h1, the gas introduction pipe g in the tower, and the automatic opening / closing valve a4. In the hydrogen gas separation step s3 shown in FIG. 4G described above, the gas in the tower (cleaning gas) is turned off gas from the first adsorption tower 3A via the automatic open / close valve a2, the off gas outflow pipe e, and the off gas flow rate adjusting valve e1. Spill. In the hydrogen gas separation step s3 shown in FIG. 4H, the pressure in the tower is equalized between the first adsorption tower 3A and the second adsorption tower 3B by closing the automatic opening / closing valve a2. As a result, the pressure in the second adsorption tower 3B is further reduced, and the pressure in the first adsorption tower 3A is increased.

In the hydrogen gas separation step s3 shown in FIG. 4H, since the automatic on-off valve e1 for opening and closing the flow path of the off-gas outflow pipe e is closed, to the eighth pipe 18 connected to the off-gas outflow pipe e. Inflow of off gas is stopped. For this reason, the supply of off-gas to the gas combustion unit 9 connected to the eighth pipe 18 is stopped. Thus, when the supply of the off gas to the gas combustion unit 9 is stopped, the off gas combustion operation in the gas combustion unit 9 is stopped. As a result, the temperature of the heat retaining unit 4 decreases. When the temperature of the heat retaining unit 4 is lowered, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 is lowered, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water is lowered. .

Next, in the hydrogen gas separation step s3, as shown in FIG. 4I, the pressure increasing step s38 is performed in the first adsorption tower 3A, and the desorption step (when depressurizing each adsorption tower in multiple stages) is performed in the second adsorption tower 3B. The first desorption step s34 of the first stage and the second desorption step s35) of the second stage are performed, and the adsorption step s31 is performed in the third adsorption tower 3C. When the first desorption step s34 of the first stage is performed in the second adsorption tower 3B, the automatic opening / closing valve a1 is closed, the automatic opening / closing valve a2 is closed, and the automatic opening / closing valve a3 is closed in the first adsorption tower 3A. Then, the automatic open / close valve a4 is opened, the automatic open / close valve a5 is closed, and the pressure increasing step s38 is performed in the first adsorption tower 3A. In the second adsorption tower 3B, the automatic open / close valve b1, the automatic open / close valve b2 are opened, the automatic open / close valve b3 is closed, the automatic open / close valve b4 is closed, and the automatic open / close valve b5 is closed, The first desorption step s34 is performed in the second adsorption tower 3B. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the opening degree of the off gas flow rate adjustment valve e1 is expressed by the above formula (I) in the second adsorption tower 3B in which the desorption operation is performed in multiple stages (two stages). as first stage of the pressure reduction rate P _a to be of 35% or less, they are adjusted. Further, in the third adsorption tower 3C, the automatic open / close valve c1 is opened, the automatic open / close valve c2 is closed, the automatic open / close valve c3 is opened, the automatic open / close valve c4 is closed, and the automatic open / close valve c5 is opened. An adsorption step s31 is performed in the third adsorption tower 3C.

In the hydrogen gas separation step s3 shown in FIG. 4I above, the reaction product gas is introduced into the third adsorption tower 3C through the reaction product gas supply pipe d and the automatic opening / closing valve c1. In the third adsorption tower 3C, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the third adsorption tower 3C flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve c5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4). A part of the hydrogen gas flowing out from the third adsorption tower 3C passes through the automatic opening / closing valve c3, the gas extraction pipe h in the tower h, the cleaning gas flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic opening / closing valve a4. Are introduced into the first adsorption tower 3A, and the pressure in the first adsorption tower 3A is increased.

On the other hand, in the second adsorption tower 3B, the pressure in the tower is reduced to a desorption start pressure that is lower than the adsorption start pressure, which is the pressure in the third adsorption tower 3C in which the adsorption step s31 is performed. At the same time, the automatic open / close valves b1, b3, b4, and b5 are closed, and the automatic open / close valve b2 is opened. As a result, the adsorbed component containing the impurity gas adsorbed by the adsorbent in the second adsorption tower 3B is desorbed from the desorbent, and the desorbed desorbed gas (off-gas) flows out from the second adsorption tower 3B. The desorption gas that has flowed out of the second adsorption tower 3B flows into the eighth pipe 18 through the automatic on-off valve b2, the off-gas outflow pipe e, and the off-gas flow rate adjusting valve e1, and flows through the eighth pipe 18 for gas combustion. It is supplied to the part 9 as a combustion gas (desorption gas supply step s5). However, the opening degree of the off-gas flow rate adjusting valve e1 is, since pressure reduction rate P _A represented by the formula (I) is adjusted to be 35% or less, of the desorption gas supplied to the gas combustion section 9 The amount will be reduced, and the temperature of the heat retaining section 4 will continue to fall further than in the case of FIG. 4H. When the temperature of the heat retaining unit 4 is lowered, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 is lowered, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water is lowered. .

Next, in the hydrogen gas separation step s3, the second desorption step s35 is performed in the second adsorption tower 3B. When the second desorption process s35 is performed in the second adsorption tower 3B, as shown in FIG. 4I, the adsorption process s31 is performed in the third adsorption tower 3C, and the pressure increasing process s38 is performed in the first adsorption tower 3A. The Specifically, in the first adsorption tower 3A, the automatic open / close valve a1 is closed, the automatic open / close valve a2 is closed, the automatic open / close valve a3 is closed, the automatic open / close valve a4 is opened, and the automatic open / close valve a5 is closed. Thus, the pressure increasing step s38 is performed in the first adsorption tower 3A. In the second adsorption tower 3B, the automatic open / close valve b1, the automatic open / close valve b2 are opened, the automatic open / close valve b3 is closed, the automatic open / close valve b4 is closed, and the automatic open / close valve b5 is closed, The second desorption step s35 is performed in the second adsorption tower 3B. Here, the cleaning gas flow rate adjustment valve h1 is opened, and the opening degree of the off gas flow rate adjustment valve e1 is expressed by the above formula (II) in the second adsorption tower 3B in which the desorption operation is performed in multiple stages (two stages). The second stage pressure reduction rate _PA2 is adjusted to be 65% or more. Further, in the third adsorption tower 3C, the automatic open / close valve c1 is opened, the automatic open / close valve c2 is closed, the automatic open / close valve c3 is opened, the automatic open / close valve c4 is closed, and the automatic open / close valve c5 is opened. An adsorption step s31 is performed in the third adsorption tower 3C.

In the hydrogen gas separation step s3 in which the second desorption step s35 is performed in the second adsorption tower 3B, as shown in FIG. 4I, the third adsorption tower 3C is provided with a reaction product gas supply pipe d and an automatic opening / closing valve c1. Through which reaction product gas is introduced. In the third adsorption tower 3C, the impurity gas is adsorbed and removed by the adsorbent, and the purified hydrogen gas flows out of the tower. The hydrogen gas flowing out from the third adsorption tower 3C flows into the seventh pipe 16 through the hydrogen gas outflow pipe f and the automatic opening / closing valve c5, flows through the seventh pipe 16 and is collected in the hydrogen gas storage tank 17. (Collection step s4). A part of the hydrogen gas flowing out from the third adsorption tower 3C passes through the automatic opening / closing valve c3, the gas extraction pipe h in the tower h, the cleaning gas flow rate adjusting valve h1, the gas introduction pipe g in the tower, and the automatic opening / closing valve a4. Are introduced into the first adsorption tower 3A, and the pressure in the first adsorption tower 3A is increased.

On the other hand, in the second adsorption tower 3B, the pressure in the tower is further reduced than in the first desorption step s34, the automatic open / close valves b1, b3, b4, and b5 are closed, and the automatic open / close valve b2 is opened. Yes. As a result, the adsorbing component including the impurity gas adsorbed by the adsorbent in the second adsorption tower 3B is desorbed from the adsorbent, and the desorbed desorption gas (off-gas) flows out from the second adsorption tower 3B. The desorption gas that has flowed out of the second adsorption tower 3B flows into the eighth pipe 18 through the automatic on-off valve b2, the off-gas outflow pipe e, and the off-gas flow rate adjusting valve e1, and flows through the eighth pipe 18 for gas combustion. It is supplied to the part 9 as a combustion gas (desorption gas supply step s5). Here, since the opening degree of the off-gas flow rate adjusting valve e1 is adjusted so that the pressure reduction rate _PA2 expressed by the above formula (II) is 65% or more, it is supplied to the gas combustion unit 9 as off-gas. The amount of desorption gas will increase more than the 1st desorption process s34, and the temperature of the heat retention part 4 will rise. When the temperature of the heat retaining unit 4 increases, the temperature of the raw material vaporizing unit 1 disposed in the heat retaining unit 4 increases, and the temperature of the gas fluid obtained by vaporizing the liquid raw material containing methanol and water increases. .

In the hydrogen gas separation step s3, in the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C, the adsorption step s31, the cleaning gas outflow step s32, the pressure equalizing gas outflow step s33, the first desorption step s34, The second desorption process s35, the cleaning gas inflow process s36, the pressure equalizing gas inflow process s37, and the pressure increasing process s38 are repeatedly performed.

In the method for producing hydrogen according to the present embodiment, a liquid raw material containing methanol and water is vaporized in the raw material vaporization unit 1. Next, the vaporized gas fluid and the gas raw material containing oxygen are supplied to the reactor 2A of the reaction gas generation unit 2, and the partial oxidation reaction of methanol and the steam reforming reaction (decomposition reaction) proceed in the reactor 2A. As a result, hydrogen is generated. As a heat source for vaporizing the liquid raw material in the raw material vaporization unit 1, combustion heat generated in the gas combustion unit 9 is used. The combustion heat generated in the gas combustion unit 9 is discharged from the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C of the hydrogen gas separation unit 3, and the first adsorption tower 3A and the second adsorption tower. It is generated by burning the desorption gas (mixed gas containing impurity gas and hydrogen) desorbed from the adsorbent in 3B and the third adsorption tower 3C as a combustion gas.

In the method for producing hydrogen according to the present embodiment, the desorption gas flowing out from the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C and the flow rate of the gas in the tower (cleaning gas) including the desorption gas are changed. The desorption gas and the tower interior gas (cleaning gas) flowing out from the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C are supplied to the gas combustion section 9 as a combustion gas. For this reason, the combustion generated in the gas combustion section 9 with the change in the flow rate of the desorption gas and the gas in the tower (cleaning gas) flowing out from the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C The amount of heat changes. As a result, the heating amount for vaporizing the liquid raw material in the raw material vaporization unit 1 changes. Thus, when the heating amount for vaporizing the liquid raw material in the raw material vaporization section 1 changes, the gas fluid whose temperature has changed flows into the reactor 2A.

In the reactor 2A, the partial oxidation reaction of methanol and the steam reforming reaction (decomposition reaction) with different reaction rates proceed, and the catalyst charged in the reactor 2A is affected by the partial oxidation reaction with exotherm. A part (hot spot) where the temperature rises the most is generated. In the hydrogen production method of the present embodiment, as described above, the gas fluid whose temperature has changed flows into the reactor 2A, so that the position of the hot spot in the reactor 2A can be changed. For this reason, it can prevent that the same area | region always becomes the highest temperature in the catalyst filling part in the reactor 2A. The position of the hot spot in the reactor 2A moves to the downstream side when the temperature of the catalyst decreases, and moves to the upstream side when the temperature of the catalyst rises, with respect to the flow direction in which the gas fluid flows in the reactor 2A.

Thus, it is possible to prevent the same region from always reaching the maximum temperature by changing the position of the hot spot in the reactor 2A. Accordingly, deterioration due to sintering can be suppressed and the catalyst life can be extended, and hydrogen can be stably produced over a long period of time.

Further, in the desorption process performed in the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C, the pressure in the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C is changed. The pressure is reduced in multiple stages from the desorption start pressure. Thereby, the flow rate of the desorption gas flowing out from the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C can be varied. As a result, the amount of heat of combustion heat generated in the gas combustion unit 9 changes, and the amount of heating for vaporizing the liquid raw material in the raw material vaporization unit 1 can be changed. For this reason, the gas fluid whose temperature has changed can be caused to flow into the reactor 2A, and the position of the hot spot in the reactor 2A can be changed.

Further, in the desorption process performed in the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C, the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C are multistaged. in time for decompressing, decompression rate P _a in the first stage of the formula (I) is 35% or less. Thereby, the flow rate of the desorption gas flowing out from the first adsorption tower 3A, the second adsorption tower 3B, and the third adsorption tower 3C can be varied. As a result, the amount of heat of combustion heat generated in the gas combustion unit 9 changes, and the amount of heating for vaporizing the liquid raw material in the raw material vaporization unit 1 can be changed. For this reason, the gas fluid whose temperature has changed can be caused to flow into the reactor 2A, and the position of the hot spot in the reactor 2A can be changed. As a result, it is possible to prevent the same region from always reaching the maximum temperature in the catalyst packed portion in the reactor 2A.

Next, the present invention will be described in more detail based on examples. However, the present invention is not limited to such examples.

Example 1
Methanol and water were vaporized by heating the methanol and water to about 240 ° C. using the raw material vaporization section 1 for vaporizing methanol and water. Methanol vapor and water vapor connected to the raw material vaporization unit 1 and obtained in the raw material vaporization unit 1 were mixed with air to prepare a raw material gas.

The reactive gas generator 2 is composed of the following two parts. A catalyst (a copper oxide / alumina-supported catalyst manufactured by Sigma-Aldrich Japan Co., Ltd.) is located on the upstream side of the reaction gas generation unit 2 and the partial oxidation reaction unit in which the oxidation reaction represented mainly by the reaction formula (1) occurs. A reaction tube having an inner diameter of 8.5 cm and a length of 20 cm was used. The steam reforming reaction part (decomposition reaction part), which is located downstream of the reaction gas generation part 2 and in which the reactions mainly represented by the reaction formulas (2) and (3) occur, has an inner diameter of 14 cm and a length. A cylindrical tube having 95 cm and a cylindrical tube having an inner diameter of 21 cm and a length of 95 cm are overlapped, and a catalyst (copper oxide-zinc oxide / alumina, manufactured by Mitsubishi Gas Chemical Co., Ltd.) is formed in the gap (equivalent diameter: 6.9 cm) between them. A reaction tube filled with (supported catalyst) was used.

The reaction gas generation unit 2 was aerated so as to have a flow rate of methanol vapor 214 g / min, water vapor 194 g / min, and air 69 N liter / min (average value) obtained in the raw material vaporization unit 1. After aeration of air for 92 seconds at a flow rate of 79 Nl / min, the operation of stopping the ventilation of air for 8 seconds was repeated periodically. When the raw material gas and air were vented, the water / methanol molar ratio was 2.2 / 1 and the oxygen gas / methanol molar ratio was 0.28 / 1.

The hydrogen gas separation unit 3 shown in FIG. 3 is connected to the reaction gas generation unit 2 and separates hydrogen gas contained in the reaction product gas from the reaction product gas obtained by the reaction gas generation unit 2. The hydrogen gas contained in the reaction product gas was separated from the reaction product gas using (pressure fluctuation adsorption device: PSA device).

The moisture generated from the reaction product gas obtained in the reaction gas generation unit 2 was removed by condensation. This reaction product gas is packed with zeolite molecular sieve (Ca5A type, 5AHP made by UOP) and carbon molecular sieve (G2-X made by Nippon Enviro) as adsorbents in a volume ratio of 1: 1.3 in a total volume of 50 liters. In addition, purification was performed using a hydrogen gas separation unit 3 of a three-column type (a configuration including three adsorption towers) to obtain high-purity hydrogen gas.

4A to 4I, the separation comprising the adsorption process, the cleaning gas outflow process, the pressure equalizing gas outflow process, the first desorption process, the second desorption process, the cleaning gas inflow process, the pressure equalizing gas inflow process, and the pressure increasing process. According to the method, hydrogen gas was separated from the reaction product gas. As a result, hydrogen gas having a purity of 99.0% by volume or more was obtained at a rate of 19.7 Nm ³ / hour.

Using the heat retaining section 4 connected to the hydrogen gas separation section 3 and having a gas combustion section 9 for burning a desorption gas (off gas) in which hydrogen gas is separated from a reaction product gas in the hydrogen gas separation section 3, The desorption gas discharged after the hydrogen gas was separated was burned.

The desorption start pressure in the desorption process in which the hydrogen gas is separated from the reaction product gas in the hydrogen gas separation unit 3 is 250 kPaG. The desorption end pressure in the first desorption step was 170 kPaG (decompression rate 32%). The desorption gas and air that flowed out from the hydrogen gas separation unit 3 were mixed at a flow rate of air 108 Nm ³ / hour, and the resulting mixed gas was passed through a metal honeycomb platinum catalyst and burned in the gas combustion unit 9. The temperature of the heat retaining unit 4 at that time is shown in FIG. Moreover, the temperature of the reaction gas production | generation part 2 at that time was shown in FIG. FIG. 5 is a graph showing a temperature change in the heat retaining section 4 of each example and comparative example. FIG. 6 is a graph showing a temperature change in the reaction gas generation unit 2 of each example and comparative example.

(Example 2)
In Example 2, the desorption start pressure in the desorption step was set to 160 kPaG, and the desorption end pressure in the first desorption step was set to 130 kPaG (decompression rate 19%). Separation. The temperature of the heat retaining unit 4 at that time is shown in FIG. Moreover, the temperature of the reaction gas production | generation part 2 at that time was shown in FIG.

(Comparative Example 1)
In Comparative Example 1, hydrogen gas was separated from the reaction product gas in the same manner as in Example 1 except that the desorption end pressure in the first desorption step was set to 100 kPaG (pressure reduction rate 60%). The temperature of the heat retaining unit 4 at that time is shown in FIG. Moreover, the temperature of the reaction gas production | generation part 2 at that time was shown in FIG.

(Comparative Example 2)
In Comparative Example 2, hydrogen gas was separated from the reaction product gas in the same manner as in Example 1 except that the desorption end pressure in the first desorption step was 40 kPaG (pressure reduction rate: 85%). The temperature of the heat retaining unit 4 at that time is shown in FIG. Moreover, the temperature of the reaction gas production | generation part 2 at that time was shown in FIG.

As is clear from the results shown in FIG. 5, it can be seen that the temperature of the heat retaining section 4 in Examples 1 and 2 varies greatly as compared with Comparative Examples 1 and 2. That is, in Examples 1 and 2, the flow rate of the impurity gas flowing out from the hydrogen gas separation unit 3 is greatly changed, and the desorption gas is supplied to the gas combustion unit 9 in a state where the flow rate is greatly changed. The amount of heat of combustion generated in the gas combustion unit 9 changes with the change in the flow rate. As a result, the temperature of the heat retaining unit 4 varies greatly. Therefore, in Examples 1 and 2, since the heating amount for vaporizing methanol and water in the raw material vaporization unit 1 changes, methanol vapor and water vapor whose temperature has changed flow into the reaction gas generation unit 2.

In Examples 1 and 2, since the methanol vapor and the water vapor whose temperature has changed flow into the reaction gas generation unit 2, the position of the hot spot in the reaction gas generation unit 2 can be changed, and the same region is always present. As a result, it is possible to prevent the temperature from reaching the maximum temperature (dispersion of heat bias), and as a result, the temperature of the reaction gas generation unit 2 can be suppressed to 380 ° C. or lower as shown in FIG.

The present invention can be implemented in various other forms without departing from the spirit or main features thereof. Therefore, the above-described embodiment is merely an example in all points, and the scope of the present invention is shown in the scope of claims, and is not restricted by the text of the specification. Further, all modifications and changes belonging to the claims are within the scope of the present invention.

DESCRIPTION OF SYMBOLS 1 Raw material vaporization part 2 Reaction gas production | generation part 3 Hydrogen gas separation part 4 Heat insulation part 9 Gas combustion part

Claims

A combustion process in which combustion gas flows into the combustor and burns;
A vaporizer is heated by combustion heat generated by combustion of combustion gas in the combustor, and a liquid raw material containing a hydrocarbon compound and water is caused to flow into the heated vaporizer to vaporize the liquid raw material. A vaporization step of obtaining a gas fluid;
The gas fluid obtained in the vaporization step is mixed with a gas raw material containing oxygen, and the mixed gas fluid is caused to flow into a reactor filled with a catalyst, thereby partially oxidizing the hydrocarbon-based compound and steam. A hydrogen generation step in which a reforming reaction proceeds to obtain a reaction product mainly composed of hydrogen;
The reaction product obtained in the hydrogen generation step is allowed to flow into the adsorption tower filled with the adsorbent under the pressure of the adsorption start pressure, and adsorbent removes the secondary component in the reaction product. An adsorption step for flowing out hydrogen, which is a main component in the reaction product, from the adsorption tower to the recovery device;
After outflow of hydrogen from the adsorption tower in the adsorption step, the pressure in the adsorption tower is changed to a desorption start pressure lower than the adsorption start pressure, and the adsorbent component including the subcomponent adsorbed on the adsorbent is adsorbed. A desorption step of desorbing the desorbed gas containing the desorbed adsorbing component from the adsorbing tower and changing the flow rate to the outside of the adsorption tower;
A desorption gas supply step of supplying the desorption gas that has flowed out of the adsorption tower in the desorption step into the combustor as the combustion gas.
In the desorption step, the pressure in the adsorption tower is changed from the adsorption start pressure to the desorption start pressure, and then depressurized in multiple stages from the desorption start pressure to the desorption end pressure. The method for producing hydrogen according to claim 1, wherein the flow rate of the desorption gas to be changed is changed.
The desorption step is operated to vacuum the suction tower in multiple stages, in claim 2 in which pressure reduction rate P A in the first stage is represented by the following formula (I) is characterized in that 35% or less The manufacturing method of hydrogen of description.
Decompression rate P A (%) = [(P S −P E ) / P S ] × 100 (I)
(Wherein, P S represents a desorption start pressure (kPaG), P E represents the first stage of the desorption completion pressure (kPaG).)