阅读说明：本技术 氢制造装置的运转方法及氢制造装置 (Method for operating hydrogen production apparatus and hydrogen production apparatus ) 是由 松尾日向子 阿曾沼飞昂 池田耕一郎 于 2020-03-27 设计创作，主要内容包括：提供一种氢制造装置的运转方法,抑制产品气体的消耗且抑制原料气体的无用的消耗的同时能够开始产品气体制造运转,并且能够实现至开始产品气体制造运转的时间的缩短。停止产品气体制造运转时,进行待机运转,前述待机运转中,关于压力变动吸附部(BS),使吸附塔(1)的吸附剂维持成已将吸附对象成分脱附的状态,且关于改质处理部(AK),在将由加热燃烧器(N)进行的改质器(2)的加热继续的状态下,进行使填充至改质处理部(AK)的产品气体(H)循环,停止待机运转来开始产品气体制造运转时,进行产品气体制造运转,前述产品气体制造运转中,刚开始后执行初始运转处理,前述初始运转处理为,将原料气体(G)及水蒸气供给至改质器(2),生成改质气体(K),将来自改质处理部(AK)的改质气体(K)供给至吸附塔(1)来制造产品气体(H),之后,将产品气体(H)回收至产品气体罐(U)。(Provided is a method for operating a hydrogen production apparatus, which can start a product gas production operation while suppressing the consumption of a product gas and the wasteful consumption of a raw material gas, and which can shorten the time until the start of the product gas production operation. When the product gas production operation is stopped, a standby operation is performed in which the adsorbent of the adsorption tower (1) is maintained in a state in which the component to be adsorbed is desorbed in the pressure swing adsorption unit (BS), and the product gas (H) filled in the reforming treatment unit (AK) is circulated in a state in which the heating of the reformer (2) by the heating burner (N) is continued in the reforming treatment unit (AK), and when the product gas production operation is started by stopping the standby operation, the product gas production operation is performed in which an initial operation process is performed immediately after the start of the product gas production operation, the initial operation process is performed in which the raw material gas (G) and the steam are supplied to the reformer (2) to generate the reformed gas (K), and the reformed gas (K) from the reforming treatment unit (AK) is supplied to the adsorption tower (1) to produce the product gas (H), thereafter, the product gas (H) is recycled to the product gas tank (U).)

1. A method for operating a hydrogen production apparatus provided with a reforming treatment section, a pressure fluctuation adsorption section, a product gas tank, and an exhaust gas supply passage,

the reforming unit comprises a compressor for supplying a raw material gas containing a hydrogen component, and a reformer for performing steam reforming treatment on the raw material gas while the raw material gas is heated to a reforming temperature by a heating burner to generate a reformed gas containing a large amount of hydrogen components,

the pressure swing adsorption unit includes a plurality of adsorption columns that perform a pressure swing adsorption operation for adsorbing adsorption target components other than the hydrogen component from the reformed gas to an adsorbent to produce a product gas and discharging the adsorption target components as an exhaust gas,

the product gas tank recovers the product gas,

the exhaust gas supply path supplies the exhaust gas as a fuel for combustion to the heating burner,

the hydrogen production apparatus is configured to perform a product gas production operation for supplying the raw material gas and steam to the reformer to produce the reformed gas, supplying the reformed gas from the reforming unit to the adsorption tower to produce the product gas,

the method for operating the hydrogen production apparatus is characterized in that,

performing a standby operation in which the adsorbent of the adsorption tower is maintained in a state in which the adsorbent is desorbed from the component to be adsorbed in the pressure swing adsorption unit while the gas supply line from the reforming treatment unit to the pressure swing adsorption unit is cut off, and the product gas filled in the reforming treatment unit is circulated through the return line to the compressor while the supply of the steam is stopped and the heating of the reformer by the heating burner is continued in the reforming treatment unit,

when the standby operation is stopped and the product gas production operation is started, an initial operation process is executed immediately after the start, the initial operation process is performed in which the raw material gas and the steam are supplied to the reformer to generate the reformed gas, the reformed gas from the reforming unit is supplied to the adsorption tower to produce the product gas, and the product gas is discarded when the concentration of the hydrogen component of the produced product gas is less than a set value, and then the product gas production operation is performed in which the product gas is recovered to the product gas tank when the concentration of the hydrogen component of the produced product gas is equal to or greater than the set value.

2. The method of operating a hydrogen generator according to claim 1,

when the product gas production operation is stopped, a purge operation is performed in which a steam purge process and a product gas purge process are sequentially performed, the steam purge process being performed in which the product gas from the product gas tank is supplied to the reformer by the compressor and the reformed gas from the reforming process section is supplied to the plurality of adsorption towers that perform the pressure swing adsorption operation, instead of the raw material gas, in a state in which the reformer is heated by the heating burner and the steam is supplied to the reformer is continued, the product gas purge process being performed in which the product gas from the product gas tank is supplied to the reformer by the compressor and the steam supply is stopped and the heating burner is continued, and the product gas from the reforming section is supplied to the adsorption tower.

3. The method of operating a hydrogen production apparatus according to claim 1 or 2,

the pressure swing adsorption operation is performed by repeating an operation cycle including an adsorption step of supplying the reformed gas to the adsorption column to generate the product gas, a pressure reduction step of discharging the gas inside the adsorption column, a regeneration step of regenerating the adsorbent in the adsorption column performing the pressure swing adsorption operation, and a pressure increase step of supplying the product gas to the inside of the adsorption column, with the operation phases of the adsorption columns being different from each other,

in the initial operation process, the time for performing the operation cycle with respect to the supply amount of the raw material gas supplied by the compressor is set to be shorter than the time for performing the product gas production operation.

4. A hydrogen production apparatus is provided with a reforming treatment unit, a pressure fluctuation adsorption unit, a product gas tank, an exhaust gas supply path, and an operation control unit,

the reforming unit comprises a compressor for supplying a raw material gas containing a hydrogen component, and a reformer for performing steam reforming treatment on the raw material gas while the raw material gas is heated to a reforming temperature by a heating burner to generate a reformed gas containing a large amount of hydrogen components,

the pressure swing adsorption unit includes a plurality of adsorption columns that perform a pressure swing adsorption operation for adsorbing adsorption target components other than the hydrogen component from the reformed gas to an adsorbent to produce a product gas and discharging the adsorption target components as an exhaust gas,

the product gas tank recovers the product gas,

the exhaust gas supply path supplies the exhaust gas as a fuel for combustion to the heating burner,

the hydrogen production apparatus is configured such that the operation control unit executes a product gas production operation for supplying the raw material gas and steam to the reformer to produce the reformed gas, supplying the reformed gas from the reforming unit to the adsorption tower to produce the product gas,

the aforementioned hydrogen production apparatus is characterized in that,

the operation control unit performs a standby operation in which the adsorbent of the adsorption tower is maintained in a state in which the adsorbent desorbs the component to be adsorbed in the pressure swing adsorption unit while a gas supply line from the reforming treatment unit to the pressure swing adsorption unit is cut off, and the product gas filled in the reforming treatment unit is circulated through a return line to the compressor while the supply of the steam is stopped and the heating of the reformer by the heating burner is continued in the reforming treatment unit,

and when the standby operation is stopped and the product gas production operation is started, an initial operation process is executed immediately after the start, the initial operation process is performed in which the raw material gas and the steam are supplied to the reformer to generate the reformed gas, the reformed gas from the reforming processing unit is supplied to the adsorption tower to produce the product gas, and the product gas is discarded when the concentration of the hydrogen component of the produced product gas is less than a set value, and then the product gas production operation is performed in which the product gas is recovered to the product gas tank when the concentration of the hydrogen component of the produced product gas is equal to or greater than the set value.

5. The hydrogen production apparatus according to claim 4,

the operation control unit performs a purge operation for sequentially performing a steam purge process and a product gas purge process when the product gas production operation is stopped, the steam purge process being a process in which the product gas from the product gas tank is supplied to the reformer by the compressor and the reformed gas from the reforming unit is supplied to the plurality of adsorption towers that perform the pressure swing adsorption operation, instead of the raw material gas, in a state in which the reformer is heated by the heating burner and the steam is supplied to the reformer, the product gas purge process being a process in which the product gas from the product gas tank is supplied to the reformer by the compressor while the supply of the steam is stopped and the heating of the reformer by the heating burner is continued, and the product gas from the reforming section is supplied to the plurality of adsorption columns that perform the pressure swing adsorption operation.

6. The hydrogen production apparatus according to claim 4 or 5,

the pressure swing adsorption operation is repeated for each of the plurality of adsorption towers in an operation cycle including an adsorption step of supplying the reformed gas to the adsorption tower to generate the product gas, a pressure reduction step of discharging the gas inside the adsorption tower, a regeneration step of regenerating the adsorbent in the adsorption tower, and a pressure increase step of supplying the product gas to the inside of the adsorption tower, with the operation phases of the plurality of adsorption towers being different from each other,

in the initial operation process, the time for performing the operation cycle with respect to the supply amount of the raw material gas supplied by the compressor is set to be shorter than the time for performing the product gas production operation.

Technical Field

The present invention relates to a method for operating a hydrogen production apparatus and a hydrogen production apparatus provided with an operation control unit for executing the product gas production operation, wherein the hydrogen production apparatus is provided with a reforming processing unit including a compressor for supplying a raw material gas containing a hydrogen component and a reformer for performing a steam reforming process on the raw material gas while being heated to a reforming temperature by a heating burner to generate a reformed gas containing a large amount of hydrogen component, a pressure swing adsorption unit including a plurality of adsorption towers for performing a pressure swing adsorption operation for adsorbing adsorption target components other than the hydrogen component from the reformed gas to an adsorbent, a product gas is generated and the component to be adsorbed is discharged as an exhaust gas, the product gas is collected in the product gas tank, the exhaust gas supply passage supplies the exhaust gas as a fuel for combustion to the heating burner, and the hydrogen production apparatus is configured to execute a product gas production operation of supplying the raw material gas and water vapor to the reformer to generate the reformed gas and supplying the reformed gas from the reforming processing unit to the adsorption tower to produce the product gas.

Background

In this hydrogen production apparatus, a raw gas, which is a hydrocarbon-based gas such as natural gas or naphtha, is reformed into a reformed gas having a large hydrogen content by a steam reforming treatment in a reforming section, and an adsorption object component is adsorbed on an adsorbent from the reformed gas containing the hydrogen component and the adsorption object component other than the hydrogen component in a pressure fluctuation adsorption section, thereby producing a product gas having a high hydrogen concentration.

Since the exhaust gas discharged from the pressure fluctuation adsorption unit contains combustible components, the exhaust gas discharged from the pressure fluctuation adsorption unit is supplied to a heating burner for heating the reformer and is burned as a fuel gas.

As a conventional method for operating the hydrogen production apparatus, there is, for example, the following method: when the product gas production operation is stopped, the adsorbent of the adsorption tower is maintained in a state in which the gas supply line from the reforming treatment unit to the pressure swing adsorption unit is cut, the adsorbent of the adsorption tower is in a state in which the component to be adsorbed is desorbed from the pressure swing adsorption unit, and the product gas production operation is restarted by performing a standby operation in which the product gas charged into the reforming treatment unit is circulated through the return line to the compressor when the product gas is discharged from the reforming treatment unit while the supply of water vapor is stopped and the heating of the reformer by the heating burner is continued. (see, for example, patent document 1.).

Incidentally, patent document 1 also describes the following steps: when the product gas production operation is stopped, the gas supply line from the reforming treatment unit to the pressure swing adsorption unit is cut off before the standby operation, performing a rinsing operation in which a steam rinsing treatment and a product gas rinsing treatment are sequentially performed, and then performing a standby operation, in a state where the reformer is heated by the heating burner and the steam continues to be supplied to the reformer, the product gas from the product gas tank is supplied to the reformer by a compressor instead of the raw gas, and the reformed gas from the reforming section is discarded to the outside, and the product gas is purged, the product gas from the product gas tank is supplied to the reformer by the compressor while the supply of the water vapor is stopped and the heating of the reformer by the heating burner is continued, and the product gas from the reforming treatment unit is discarded to the outside.

In patent document 1, although detailed description is omitted, when the standby operation is stopped and the product gas production operation is started, as has been generally performed conventionally, a pressure raising process is performed in which a product gas from a product gas tank is supplied by a compressor to raise the pressure, and when the pressure raising process is completed, in the case where a raw material introducing process is performed in which a raw material gas is supplied by a compressor instead of a product gas, and a reformed gas is appropriately generated by the raw material introducing process, starting the supply of the reformed gas to the pressure swing adsorption part, producing a product gas by the pressure swing adsorption operation, when the concentration of the hydrogen component in the produced product gas is less than a set value, a purification process of discarding the product gas is performed, and thereafter, when the concentration of the hydrogen component in the produced product gas is equal to or higher than a set value, a product gas production operation is performed in which the product gas is recovered in a product gas tank.

Patent document 1, Japanese patent laid-open No. 2016 and 675.

In the conventional operation method of the hydrogen production apparatus, when the standby operation is stopped and the product gas production operation is started, the pressure increasing process, the raw material introducing process, and the purifying process are sequentially executed, so that there are problems that the product gas is consumed until the product gas production operation is started, the raw material gas is uselessly consumed, and the time until the product gas production operation is started is long, and improvement is desired.

That is, the product gas is consumed due to the pressure-raising process.

Incidentally, in patent document 1, since the product gas from the product gas tank is supplied to the compressor during the standby operation to increase the pressure of the product gas circulating in the reforming treatment unit, the consumption amount of the product gas consumed in the pressure increasing step is reduced, but the product gas is consumed during the standby operation, and as a result, the consumption amount of the product gas is increased.

In the raw material introduction process, although the reformed gas including the hydrogen component is sequentially generated, the reformed gas generated in the raw material introduction process is not used for production of the product gas, for example, by supplying the reformed gas to a heating burner for heating the reformer and burning the reformed gas.

Further, when the standby operation is stopped and the product gas production operation is started, the pressure raising process, the raw material introduction process, and the purification process are sequentially performed, so that the time until the product gas production operation is started becomes long.

Disclosure of Invention

The present invention has been made in view of the above circumstances, and an object thereof is to provide an operation method of a hydrogen production apparatus capable of starting a product gas production operation while suppressing consumption of a product gas and wasteful consumption of a raw material gas, and capable of shortening a time required to start the product gas production operation, and a hydrogen production apparatus for executing the operation method.

The operation method of a hydrogen production apparatus of the present invention is a method for operating a hydrogen production apparatus, the hydrogen production apparatus being provided with a reforming processing unit including a compressor for supplying a raw material gas including a hydrogen component, and a reformer for performing a water vapor reforming process on the raw material gas in a state heated to a reforming temperature by a heating burner to generate a reformed gas having a large hydrogen component, a pressure swing adsorption unit including a plurality of adsorption towers performing a pressure swing adsorption operation for adsorbing adsorption target components other than the hydrogen component from the reformed gas to an adsorbent to generate a product gas and discharging the adsorption target components as an exhaust gas, a product gas tank for recovering the product gas, and an exhaust gas supply path for supplying the exhaust gas as a combustion fuel to the heating burner, the hydrogen production apparatus is configured to perform a product gas production operation in which the raw gas and steam are supplied to the reformer to produce the reformed gas, and the reformed gas from the reforming treatment unit is supplied to the adsorption tower to produce the product gas, and the operation method of the hydrogen production apparatus is characterized in that the standby operation is performed in which the adsorbent in the adsorption tower is maintained in a state in which the gas supply line from the reforming treatment unit to the pressure swing adsorption unit is cut off, the adsorbent in the adsorption tower is maintained in a state in which the component to be adsorbed is desorbed from the pressure swing adsorption unit, and the product gas filled in the reforming treatment unit is returned to the compressor through the return line to the compressor in the reforming treatment unit in a state in which the supply of steam is stopped and the heating of the reformer by the heating burner is continued And a cycle of stopping the standby operation and starting the product gas production operation, wherein an initial operation process is executed immediately after the start, the initial operation process is performed in which the raw material gas and the steam are supplied to the reformer to generate the reformed gas, the reformed gas from the reforming unit is supplied to the adsorption tower to produce the product gas, the product gas is discarded when the concentration of the hydrogen component of the produced product gas is less than a predetermined value, and then the product gas production operation is performed in which the product gas is recovered to the product gas tank when the concentration of the hydrogen component of the produced product gas is greater than or equal to the predetermined value.

That is, as a standby operation to be waited for the start of the product gas production operation, the following standby operation is performed: in the state where the gas supply line from the reforming treatment unit to the pressure swing adsorption unit is cut off, the adsorbent of the adsorption tower is maintained in a state where the adsorbent desorbs the component to be adsorbed in the pressure swing adsorption unit, and in the state where the supply of steam is stopped and the heating of the reformer by the heating burner is continued in the reforming treatment unit, the product gas filled in the reforming treatment unit is circulated so as to flow through the reforming treatment unit and return to the compressor through the return line when discharged from the reforming treatment unit.

And stopping the standby operation, starting a product gas production operation, and executing an initial operation process immediately after the start, wherein the initial operation process comprises supplying the raw material gas and the steam to the reformer to generate a reformed gas, supplying the reformed gas from the reforming unit to the adsorption tower to produce the product gas, and when the concentration of the hydrogen component in the produced product gas is less than a set value, the product gas is discarded, and then, when the concentration of the hydrogen component in the produced product gas is greater than or equal to the set value, the product gas production operation is performed in which the product gas is recovered to the product gas tank.

That is, by performing the standby operation, the heating of the reformer by the heating burner is continued in the reforming treatment section, and therefore, the steam reforming treatment can be immediately started, and the pressure swing adsorption section is in a state in which the adsorbent of the adsorption tower is maintained in a state in which the adsorption target component is desorbed, and therefore, the pressure swing adsorption operation can be immediately started.

Therefore, when the product gas production operation is started by stopping the standby operation in view of the standby operation, an initial operation process is performed immediately after the start, in which the raw material gas and the steam are supplied to the reformer to generate the reformed gas, the reformed gas from the reforming unit is supplied to the adsorption tower to produce the product gas, and the product gas is discarded when the concentration of the hydrogen component in the produced product gas is less than a predetermined value.

Then, by performing the initial operation processing, when the concentration of the hydrogen component in the produced product gas is equal to or higher than a set value, the product gas production operation of recovering the product gas to the product gas tank is performed.

In this way, when the standby operation is stopped and the product gas production operation is started, the raw material gas and the steam are supplied to the reformer to generate the reformed gas immediately after the start of the product gas production operation, and the reformed gas from the reforming treatment unit is supplied to the adsorption tower to produce the product gas.

In addition, the time until the product gas production operation is started can be shortened.

In summary, according to the method for operating a hydrogen production apparatus of the present invention, it is possible to start the product gas production operation while suppressing unnecessary consumption of the raw material gas while suppressing consumption of the product gas, and it is possible to shorten the time until the start of the product gas production operation.

A further aspect of the method for operating a hydrogen production apparatus of the present invention is that, when the product gas production operation is stopped, a purge operation is performed in which a steam purge process and a product gas purge process are sequentially performed, the steam purge process being performed in which the product gas from the product gas tank is supplied to the reformer by the compressor and the reformed gas from the reforming unit is supplied to the plurality of adsorption towers that perform the pressure fluctuation adsorption operation, instead of the raw material gas, in a state in which the reformer is heated by the heating burner and the steam supply to the reformer is continued, the product gas purge process being performed in a state in which the supply of the steam is stopped and the heating of the reformer by the heating burner is continued, the product gas from the product gas tank is supplied to the reformer by the compressor, and the product gas from the reforming section is supplied to the plurality of adsorption columns that perform the pressure swing adsorption operation.

That is, when the product gas production operation is stopped, the steam purge treatment and the product gas purge treatment are sequentially performed as the purge operation.

Therefore, the flushing operation can be transitioned to the standby operation.

That is, in the steam flush treatment, in a state where the reformer is heated by the heating burner and the state where the steam supply to the reformer is continued, the product gas from the product gas tank is supplied to the reformer by the compressor instead of the raw material gas, and the reformed gas from the reforming treatment section is supplied to the plurality of adsorption towers that perform the pressure fluctuation adsorption operation, so that the raw material gas remaining in the reformer or the like is subjected to the steam reforming treatment to generate the reformed gas, and the reformed gas that has been generated is supplied to the plurality of adsorption towers that perform the pressure fluctuation adsorption operation, whereby the gas having a high hydrogen component concentration contained in the reformed gas from the reforming treatment section is recovered as the product gas, and the gas having a low hydrogen component concentration contained in the reformed gas from the reforming treatment section (the gas having a high concentration of the adsorption object component) is supplied as the exhaust gas to the heating burner of the heating reformer as the fuel for combustion, therefore, the hydrogen component can be prevented from being discarded to the outside in the steam flush treatment.

In the product gas purging process, the product gas from the product gas tank is supplied to the reformer by the compressor while the supply of the water vapor is stopped and the heating of the reformer by the heating burner is continued, and the product gas from the reforming processing unit is supplied to the plurality of adsorption towers that perform the pressure swing adsorption operation, so that the gas having a high concentration of the hydrogen component contained in the product gas from the reforming processing unit is recovered as the product gas, and the gas having a low concentration of the hydrogen component contained in the product gas from the reforming processing unit (the gas having a high concentration of the component to be adsorbed) is supplied as the exhaust gas to the heating burner as the combustion fuel, so that the hydrogen component can be suppressed from being discarded to the outside in the product gas purging process.

In the product gas purging process, the product gas from the product gas tank is filled into the interior of the reformer or the like of the reforming unit, and the product gas from the reforming unit is flowed into the adsorption tower, whereby the adsorbent of the adsorption tower can be brought into a state in which the component to be adsorbed is desorbed, and thereafter, the operation can be appropriately shifted to the standby operation.

In summary, according to a further aspect of the method for operating a hydrogen generator of the present invention, it is possible to appropriately transition to the standby operation while suppressing the discharge of a large amount of hydrogen components to the outside during the flushing operation.

In a further aspect of the method for operating a hydrogen production apparatus of the present invention, the pressure swing adsorption operation is performed in such a manner that the operation cycle including the adsorption step, the pressure reduction step, the regeneration step, and the pressure increase step is changed in such a manner that the operation phases of the plurality of adsorption towers are different from each other, the operation cycle is repeated for each of the plurality of adsorption towers, the modified gas is supplied to the adsorption tower in the adsorption step to generate the product gas, the internal gas of the adsorption tower is discharged in the pressure reduction step, the adsorbent in the adsorption tower is regenerated in the regeneration step, the product gas is supplied to the inside of the adsorption tower in the pressure increase step, and the time for performing the operation cycle with respect to the supply amount of the raw material gas supplied via the compressor in the initial operation process is set to be shorter than the time for performing the product gas production operation.

That is, as the pressure swing adsorption operation, an operation cycle including an adsorption step, a regeneration step, and a pressure raising step is repeated at each of the plurality of adsorption towers in a state where operation phases of the plurality of adsorption towers are different from each other.

The time for performing the operation cycle is set to be shorter as the supply amount of the raw material gas supplied by the compressor is larger, and is determined in accordance with the time for the adsorbent to adsorb the adsorption target component to the allowable limit in the adsorption step in the product gas production operation.

In contrast, in the initial operation process, the time of the operation cycle for the supply amount of the raw material gas by the compressor is set to be shorter than the time of the product gas production operation, and therefore, for example, the concentration of the hydrogen component in the reformed gas initially generated in the initial operation process is low, and therefore, even if the adsorbent in the adsorption tower adsorbs the target component beyond the allowable limit, the frequency of the regeneration step is increased by repeating the operation cycle in a short time, the adsorbent in the adsorption tower is quickly returned to the appropriate state for desorbing the target component, and the transition to the product gas production operation can be quickly made.

In short, according to the further aspect of the method for operating a hydrogen generator of the present invention, it is possible to quickly transition to a state in which the product gas is appropriately produced by the product gas production operation.

A hydrogen production apparatus of the present invention is provided with a reforming processing unit including a compressor for supplying a raw material gas including a hydrogen component, and a reformer for generating a reformed gas containing a large amount of hydrogen component by subjecting the raw material gas to a steam reforming process in a state heated to a reforming temperature by a heating burner, a pressure swing adsorption unit including a plurality of adsorption towers performing a pressure swing adsorption operation for adsorbing adsorption target components other than the hydrogen component from the reformed gas to an adsorbent to generate a product gas and discharging the adsorption target components as an exhaust gas, a product gas tank for recovering the product gas, an exhaust gas supply path for supplying the exhaust gas as a combustion fuel to the heating burner, and an operation control unit, in the hydrogen production apparatus, the operation control unit performs a product gas production operation for supplying the raw material gas and steam to the reformer to produce the reformed gas, and supplying the reformed gas from the reforming unit to the adsorption tower to produce the product gas, wherein the operation control unit performs a standby operation for maintaining the adsorbent in the adsorption tower in a state in which the adsorbent is desorbed from the adsorption target component in the pressure swing adsorption unit while the gas supply line from the reforming unit to the pressure swing adsorption unit is cut off, and for stopping the supply of the steam in the reforming unit and continuing the heating of the reformer by the heating burner, and a step of circulating the product gas filled in the reforming unit through a return line to the compressor, and when the standby operation is stopped and the product gas production operation is started, executing an initial operation process immediately after the start of the standby operation, the initial operation process being a process of supplying the raw material gas and water vapor to the reformer to generate the reformed gas, supplying the reformed gas from the reforming unit to the adsorption tower to produce the product gas, and when the concentration of the hydrogen component in the produced product gas is less than a set value, discarding the product gas, and then, when the concentration of the hydrogen component in the produced product gas is equal to or greater than the set value, performing the product gas production operation of recovering the product gas to the product gas tank.

The hydrogen production apparatus of the present invention has the same technical means as the technical means of the method for operating a hydrogen production apparatus described above, and therefore, the same operational effects as the technical means of the method for operating a hydrogen production apparatus described above can be achieved.

That is, the operation control unit performs a standby operation that stands by in response to the start of the product gas production operation, stops the standby operation, and upon starting the product gas production operation, executes an initial operation process immediately after the start, the initial operation process being a process of supplying the raw material gas and the steam to the reformer to generate the reformed gas, supplying the reformed gas from the reforming unit to the adsorption tower to produce the product gas, and when the concentration of the hydrogen component of the produced product gas is less than a set value, the product gas is discarded, and thereafter, when the concentration of the hydrogen component of the produced product gas is equal to or more than the set value, the product gas production operation of recovering the product gas to the product gas tank is performed.

That is, by performing the standby operation, the heating of the reformer by the heating burner is continued in the reforming treatment section, and therefore, the steam reforming treatment can be immediately started, and the pressure swing adsorption section is in a state in which the adsorbent of the adsorption tower is maintained in a state in which the adsorption target component is desorbed, and therefore, the pressure swing adsorption operation can be immediately started.

Therefore, when the product gas production operation is started by stopping the standby operation in view of the standby operation, the raw material gas and the steam are supplied to the reformer to generate the reformed gas immediately after the start of the product gas production operation, and the reformed gas from the reforming unit is supplied to the adsorption tower to produce the product gas, and when the concentration of the hydrogen component in the produced product gas is less than the set value, the initial operation process of discarding the product gas is performed.

Then, by performing the initial operation processing, when the concentration of the hydrogen component in the produced product gas is equal to or higher than a set value, the product gas production operation of recovering the product gas to the product gas tank is performed.

In this way, when the standby operation is stopped and the product gas production operation is started, the raw material gas and the steam are supplied to the reformer to generate the reformed gas immediately after the start of the product gas production operation, and the reformed gas from the reforming treatment unit is supplied to the adsorption tower to produce the product gas.

In addition, the time until the product gas production operation is started can be shortened.

In summary, according to the method for operating a hydrogen production apparatus of the present invention, it is possible to suppress the consumption of the product gas until the start of the product gas production operation, and to restart the product gas production operation while suppressing the wasteful consumption of the raw material gas.

In a further aspect of the hydrogen production apparatus of the present invention, when the operation control unit stops the product gas production operation, a purge operation is performed in which a steam purge process and a product gas purge process are sequentially performed, the steam purge process is performed in which the product gas from the product gas tank is supplied to the reformer by the compressor and the reformed gas from the reforming processing unit is supplied to the plurality of adsorption towers performing the pressure fluctuation adsorption operation, instead of the raw material gas, in a state where the reformer is heated by the heating burner and the steam is supplied to the reformer is continued, and the product gas purge process is performed in a state where the supply of the steam is stopped and the heating of the reformer by the heating burner is continued, the product gas from the product gas tank is supplied to the reformer through the compressor, and the product gas from the reforming unit is supplied to the plurality of adsorption towers that perform the pressure swing adsorption operation.

Further, since the hydrogen production apparatus according to the present invention has the same technical means as the above-described further technical means of the method for operating a hydrogen production apparatus, the same operational effects as the above-described further technical means of the method for operating a hydrogen production apparatus can be achieved.

That is, the operation control unit performs the steam flushing process and the product gas flushing process in sequence as the flushing operation when the product gas production operation is stopped.

Therefore, the flushing operation can be transitioned to the standby operation.

That is, in the steam purging, the raw material gas remaining in the reformer or the like is subjected to steam reforming to generate a reformed gas, and the reformed gas thus generated is supplied to the plurality of adsorption towers that are subjected to the pressure swing adsorption operation, whereby the gas having a high concentration of the hydrogen component contained in the reformed gas from the reforming unit is recovered as the product gas, and the gas having a low concentration of the hydrogen component contained in the reformed gas from the reforming unit (the gas having a high concentration of the component to be adsorbed) is supplied as the exhaust gas to the heating burner that heats the reformer as the combustion fuel, so that the hydrogen component can be suppressed from being discarded to the outside in the steam purging.

In the product gas purging process, the gas having a high concentration of the hydrogen component contained in the product gas from the reforming unit is recovered as the product gas, and the gas having a low concentration of the hydrogen component contained in the product gas from the reforming unit (the gas having a high concentration of the component to be adsorbed) is supplied as the exhaust gas to the heating burner for heating the reformer as the combustion fuel, so that the hydrogen component can be suppressed from being discarded to the outside in the product gas purging process.

In the product gas purging process, the product gas from the product gas tank is filled into the reformer or the like of the reforming unit, and the product gas from the reforming unit is flowed into the adsorption tower, whereby the adsorbent of the adsorption tower can be made into a state in which the component to be adsorbed is desorbed, and therefore, the operation can be appropriately shifted to the standby operation thereafter.

In short, according to the further aspect of the hydrogen production apparatus of the present invention, it is possible to appropriately transition to the standby operation while suppressing the discharge of a large amount of hydrogen components to the outside during the flushing operation.

In a further aspect of the hydrogen production apparatus of the present invention, the pressure swing adsorption operation is performed in such a manner that the operation cycle including the adsorption step, the pressure reduction step, the regeneration step, and the pressure increase step is changed in such a manner that the operation phases of the plurality of adsorption towers are different from each other, the operation cycle is repeated for each of the plurality of adsorption towers, the modified gas is supplied to the adsorption tower in the adsorption step to generate the product gas, the internal gas of the adsorption tower is discharged in the pressure reduction step, the adsorbent in the adsorption tower is regenerated in the regeneration step, the product gas is supplied to the inside of the adsorption tower in the pressure increase step, and the time for performing the operation cycle with respect to the supply amount of the raw material gas supplied via the compressor in the initial operation process is set to be shorter than the time for performing the product gas production operation.

Further, since the hydrogen production apparatus according to the present invention has the same technical means as the above-described further technical means of the method for operating a hydrogen production apparatus, the same operational effects as the above-described further technical means of the method for operating a hydrogen production apparatus can be achieved.

That is, as the pressure swing adsorption operation, an operation cycle including an adsorption step, a regeneration step, and a pressure raising step is repeated at each of the plurality of adsorption towers in a state where operation phases of the plurality of adsorption towers are different from each other.

The time for performing the operation cycle is set to be shorter as the supply amount of the raw material gas supplied by the compressor is larger, and is determined in accordance with the time for the adsorbent to adsorb the adsorption target component to the allowable limit in the adsorption step in the product gas production operation.

In contrast, in the initial operation process, the time of the operation cycle for the supply amount of the raw material gas by the compressor is set to be shorter than the time of the product gas production operation, and therefore, for example, the concentration of the hydrogen component in the reformed gas initially generated in the initial operation process is low, and therefore, even if the adsorbent in the adsorption tower adsorbs the target component beyond the allowable limit, the frequency of the regeneration step is increased by repeating the operation cycle in a short time, the adsorbent in the adsorption tower is quickly returned to the appropriate state for desorbing the target component, and the transition to the product gas production operation can be quickly made.

In short, according to the further aspect of the hydrogen production apparatus of the present invention, it is possible to quickly transition to a state in which the product gas is appropriately produced by the product gas production operation.

Drawings

Fig. 1 is an overall view showing a hydrogen production apparatus.

Fig. 2 is a schematic view showing the pressure fluctuation adsorption unit.

Fig. 3 is a diagram showing an operation cycle of the pressure fluctuation adsorption unit.

Fig. 4 is an explanatory diagram illustrating an operation state of the pressure fluctuation adsorption unit.

Fig. 5 is an explanatory diagram illustrating an operation state of the pressure fluctuation adsorption unit.

Fig. 6 is an explanatory diagram illustrating an operation state of the pressure fluctuation adsorption unit.

Fig. 7 is a view showing a steam flushing process.

Fig. 8 is a diagram showing a product gas purging process.

Fig. 9 is a diagram showing a standby operation.

Fig. 10 is a diagram showing the boosting process in the initial operation process.

Fig. 11 is a diagram showing a purification process in the initial operation process.

Detailed Description

[ embodiment ]

Embodiments of the present invention will be described below with reference to the drawings.

(integral construction of Hydrogen production apparatus)

As shown in fig. 1, the hydrogen production apparatus is provided with a reforming treatment section AK for reforming a raw material gas G, which is a hydrocarbon-based gas such as natural gas, naphtha, etc., into a reformed gas K having a large hydrogen component, a pressure swing adsorption section BS including an adsorption tower 1 for adsorbing adsorption target components other than the hydrogen component from the reformed gas K from the reforming treatment section AK to an adsorbent to produce a product gas H, a product gas tank U for collecting the product gas H produced by the pressure swing adsorption section BS, an exhaust gas tank T for collecting an exhaust gas discharged from the pressure swing adsorption section BS, and an operation control section M for controlling the operation of the reforming treatment section AK and the pressure swing adsorption section BS.

The raw material gas G includes methane, carbon dioxide, carbon monoxide and nitrogen in addition to the hydrogen component, and methane, carbon dioxide, carbon monoxide and nitrogen as adsorption target components other than hydrogen are adsorbed by the adsorbent of the adsorption column 1.

(details of the modification section)

The reforming treatment section AK comprises a steam mixing section J for mixing steam with the raw material gas G, a reforming reaction tube 2 as a reformer for reforming the raw material gas G into a reformed gas K having a large hydrogen content by the steam reforming treatment, and a heating burner N for heating the reforming reaction tube 2 to a reforming reaction temperature (e.g., 700 ℃).

An exhaust gas supply path 4 for supplying the exhaust gas accumulated in the exhaust gas tank T to the heating burner N is provided, and an air supply path 5a for supplying combustion air from an air supply unit 5 such as a blower to the heating burner N is provided.

Further, an auxiliary fuel gas passage 3 for supplying the raw material gas G as a fuel gas to the heating burner N is provided.

Further, the off-gas supply passage 4 is provided with an off-gas on-off valve 4A for opening and closing the off-gas supply passage 4, and the auxiliary fuel gas passage 3 is provided with a fuel gas valve 3A for opening and closing the auxiliary fuel gas passage 3.

A compressor 7 is provided, the compressor 7 sends the raw material gas G introduced through the gas introduction line 7A to the desulfurizer 6 through a sending line 7D, and a mixing section transfer line 9 is provided, and the mixing section transfer line 9 transfers the raw material gas G desulfurized by the desulfurizer 6 to the water mixing section 8.

The water mixing unit 8 is configured to mix the raw material gas G after the desulfurization treatment with water (pure water) supplied from the water supply unit 10.

Further, a raw material gas supply valve Ga is provided to interrupt the supply of the raw material gas G to the gas introduction line 7A.

An evaporation carrier line 12 is provided, and the evaporation carrier line 12 carries the raw material gas G mixed with water by the water mixing unit 8 to the evaporation heat exchange unit 11, and the water mixed with the raw material gas G is heated by the evaporation heat exchange unit 11 to become steam.

Incidentally, in the present embodiment, the water vapor mixing portion J is mainly constituted by the water mixing portion 8 and the evaporation heat exchange portion 11.

The raw material gas G heated in the state of vapor (in the state of being mixed with vapor) by the evaporation heat exchange unit 11 is transported to the reforming reaction tubes 2 by the reaction tube transport lines 13, and reformed into a reformed gas K having a large hydrogen content by the vapor reforming treatment.

That is, the interior of the reforming reaction tube 2 is filled with a reforming catalyst, and the reforming reaction tube is heated to a reforming reaction temperature (for example, 700 ℃) by the heating burner N as described above, thereby being reformed into the reformed gas K having a large hydrogen component by the steam reforming treatment.

In the present embodiment, the combustion gas from the heating burner N is configured to heat the reforming reaction tube 2, flow through the evaporation heat exchange portion 11, heat the evaporation heat exchange portion 11, and then be discharged through the exhaust gas passage 14.

An modifier transport line 16 for transporting the reformed gas K from the reforming reaction tube 2 to the CO modifier 15 is provided, and carbon monoxide contained in the reformed gas K is modified by the CO modifier 15 into carbon dioxide.

The reformed gas K reformed by the CO reformer 15 is supplied to the pressure swing adsorption unit BS through the reformed gas supply line 17.

A water separator 18 for removing excess water from the reformed gas K is provided in the reformed gas supply line 17, and a supply interruption valve 17A is provided in a downstream side portion of the water separator 18 in the reformed gas supply line 17.

Further, in order to supply the reformed gas K from which water has been removed by the water separator 18 as hydrogen gas for the desulfurization treatment in the desulfurizer 6, a recycle gas line 19 is provided which guides the reformed gas K flowing through the reformed gas supply line 17 to a portion on the upstream side of the compressor 7, i.e., the gas introduction line 7A. A line opening/closing valve 19A is provided in the recycle gas line 19.

Further, a communication line L connecting the product gas tank U and the intermediate portion of the recycle gas line 19 is provided, a communication opening/closing valve La opening and closing the communication line L, and a communication resistance adjustment valve Lb adjusting a flow path resistance (opening degree) of the communication line L are provided.

The communication resistance adjustment valve Lb is formed of, for example, a needle valve.

(details of the pressure fluctuation adsorption part)

The pressure swing adsorption unit BS of the present embodiment includes the 1 st adsorption column a, the 2 nd adsorption column B, and the 3 rd adsorption column C as the adsorption column 1.

As shown in fig. 2, the lower portion of each of the three adsorption columns 1 is connected to the reformed gas supply line 17 via a 1 st supply branch 21a having a 1 st supply valve 20a, a 2 nd supply branch 21b having a 2 nd supply valve 20b, and a 3 rd supply branch 21c having a 3 rd supply valve 20 c.

In each adsorption column 1, an adsorbent for adsorbing the adsorption target components other than the hydrogen component from the reformed gas K is filled.

The adsorption target components other than the hydrogen component include carbon dioxide, carbon monoxide, methane, nitrogen, and the like, and carbon monoxide and methane are combustible components.

Further, the upper portions of the three adsorption columns 1 are connected to a product gas discharge line 22 connected to the product tank U via a 1 st discharge branch 22a having a 1 st discharge valve 23a, a 2 nd discharge branch 22b having a 2 nd discharge valve 23b, and a 3 rd discharge branch 22c having a 3 rd discharge valve 23 c.

As shown in fig. 1, the product gas discharge line 22 is provided with a product gas discharge valve Qa for opening and closing the product gas discharge line Q, the product gas discharge line Q being branched, and a product gas valve 22A for opening and closing the product gas discharge line 22, the product gas discharge line being provided on a downstream side of the product gas discharge line 22 from the branching portion of the product gas discharge line Q.

In fig. 2, the product gas release line Q, the product gas release valve Qa, and the product gas valve 22A are not shown.

As shown in fig. 2, the upper portions of the three adsorption columns 1 are connected to the pressure equalizing line 24 via a 1 st pressure equalizing branch 24a having a 1 st pressure equalizing valve 25a, a 2 nd pressure equalizing branch 24b having a 2 nd pressure equalizing valve 25b, and a 3 rd pressure equalizing branch 24c having a 3 rd pressure equalizing valve 25 c.

Furthermore, a purge line 26 is provided for flowing the product gas H flowing through the product gas discharge line 22 to the pressure equalizing line 24, and a purge valve 27 is disposed in the purge line 26.

Further, as shown in fig. 2, the lower portions of the three adsorption towers 1 are connected to an exhaust gas discharge line 28 via a 1 st exhaust gas branch 28a having a 1 st exhaust gas valve 29a, a 2 nd exhaust gas branch 28b having a 2 nd exhaust gas valve 29b, and a 3 rd exhaust gas branch 28c having a 3 rd exhaust gas valve 29c, and the exhaust gas discharge line 28 is connected to an exhaust gas tank T.

The pressure swing adsorption unit BS is configured to generate a product gas H containing a hydrogen component at high purity from the reformed gas K by repeating an operation cycle composed of an adsorption step, a pressure equalizing and discharging step, a pressure reducing step, a washing step as a regeneration step, a pressure equalizing and receiving step, and a pressure increasing step at each of the three adsorption towers 1 in a state where the operation phases are different as shown in fig. 3 by controlling the operation by the operation control unit M.

That is, the operation cycle is configured to repeat the 1 st unit cycle in which the adsorption step is performed by the 1 st adsorption column a, the 2 nd unit cycle in which the adsorption step is performed by the 2 nd adsorption column B, and the 3 rd unit cycle in which the adsorption step is performed by the 3 rd adsorption column C.

The adsorption step is a step of supplying the reformed gas K to the adsorption tower 1 to generate the product gas H.

The pressure equalizing discharge step is a step of discharging the internal gas of the adsorption column 1 after the completion of the adsorption step as a pressure equalizing gas.

The pressure reducing step is a step of discharging the internal gas of the adsorption tower 1 after the completion of the pressure equalizing discharge step to the off-gas discharge line 28.

The washing step is a step of flowing the product gas H into the adsorption tower 1 after the pressure reduction step is completed to regenerate the adsorbent into a state in which the component to be adsorbed is desorbed, and the product gas H flowing through the adsorption tower 1 is discharged as a washing gas to the off-gas discharge line 28.

The pressure equalization receiving step is a step of receiving the pressure equalization gas discharged from the adsorption column 1 after the completion of the washing step in the pressure equalization discharge step.

The pressure increasing step is a step of supplying the product gas H to the inside of the adsorption column 1 after the pressure equalizing receiving step is completed to increase the pressure.

The 1 st unit cycle, the 2 nd unit cycle, and the 3 rd unit cycle are the same, and therefore the description will be given based on fig. 4 to 6, with the 1 st unit cycle as a representative example.

In fig. 4 to 6, the flow path portions through which the gas actually flows in the various flow path portions are indicated by thick lines, and the flow path portions through which the gas does not flow are indicated by thin lines.

Therefore, it is obvious that the valves corresponding to the flow path portions described in bold lines are in an open state and the valves corresponding to the flow path portions described in thin lines are in a closed state, and therefore, in the following description, the description of the open/closed state of the valves provided in each flow path portion will be described only with respect to the opening/closing of a representative valve.

As shown in fig. 4 to 6, in the 1 st unit cycle of the adsorption step performed in the 1 st adsorption column a, the 1 st supply valve 20a and the 1 st discharge valve 23a are opened, the adsorption step of adsorbing the adsorption target components contained in the reformed gas K is performed, and the product gas H is discharged from the 1 st adsorption column a to the product gas discharge line 22.

As shown in fig. 4, at the beginning of the 1 st unit cycle, the 2 nd pressure equalizing valve 25B of the 2 nd adsorption column B and the 3 rd pressure equalizing valve 25C of the 3 rd adsorption column C are opened, and pressure equalization processing is performed to supply the internal gas of the 3 rd adsorption column C to the 2 nd adsorption column B as an equalized gas.

The pressure equalizing treatment corresponds to a pressure equalizing discharge step in the 3 rd adsorption column C and a pressure equalizing reception step in the 2 nd adsorption column B.

As shown in fig. 5, in the middle stage of the 1 st unit cycle, the 2 nd adsorption column B is subjected to a pressure raising step of introducing the product gas H discharged from the 1 st adsorption column a by closing the 2 nd equalizing valve 25B and opening the 2 nd discharge valve 23B, and this pressure raising step is also performed in the later stage of the 1 st unit cycle (see fig. 6).

As shown in fig. 5, in the middle stage of the 1 st unit cycle, the 3 rd adsorption tower C is subjected to a depressurization step of closing the 3 rd pressure equalizing valve 25C and opening the 3 rd off-gas valve 29C to discharge the internal gas of the 3 rd adsorption tower C to the off-gas discharge line 28.

Thereafter, as shown in fig. 6, in the latter stage of the 1 st unit cycle, the 3 rd pressure equalizing valve 25c and the purge valve 27 are opened with the 3 rd waste gas valve 29c opened, and a purge step of flowing the product gas H through the purge line 26 is performed.

The exhaust gas discharged to the exhaust gas discharge line 28 in the pressure reduction step and the washing step is collected in the exhaust gas tank T, and then passed through the exhaust gas supply passage 4 to be supplied to the heating burner N of the reforming section AK.

In addition, the exhaust gas contains carbon monoxide, methane and hydrogen as combustible components.

As described above, the pressure swing adsorption unit BS performs the pressure swing adsorption operation of adsorbing the adsorption target components other than the hydrogen component from the reformed gas K to the adsorbent to generate the product gas H and discharging the adsorption target components as the off gas by the plurality of (3) adsorption towers 1.

Further, the following operation is performed as the pressure fluctuation adsorption operation: the operation cycle including an adsorption step of supplying the reformed gas K to the adsorption tower 1 to generate the product gas H, a pressure reduction step of discharging the internal gas of the adsorption tower 1, a washing step as a regeneration step of regenerating the adsorbent of the adsorption tower 1, and a pressure increase step of supplying the product gas H to the interior of the adsorption tower 1 is repeated for each of the plurality of adsorption towers in a state where the operation phases of the plurality of adsorption towers 1 are different from each other.

(outline of operation control)

The operation control unit M performs a product gas production operation of supplying the raw material gas G and the steam to the reforming reaction tube 2 to generate the reformed gas K, and supplying the reformed gas K from the reforming treatment unit AK to the adsorption tower 1 to produce the product gas.

In this product gas production operation, the reforming reaction tube 2 is heated by the heating burner N, and the pressure swing adsorption section BS performs the pressure swing adsorption operation.

When the operation control unit M stops the product gas production operation, the flushing operation is performed in which the steam flushing process and the product gas flushing process are sequentially performed, and then the standby operation is performed.

The operation control unit M is configured to execute an initial operation process when the standby operation is stopped and the product gas production operation is started, and thereafter, to start the product gas production operation.

Next, the steam flushing treatment, the product gas flushing treatment, the standby operation, and the initial operation treatment will be described with reference to fig. 7 to 11, but in fig. 7 to 11, the flow path through which the gas flows is indicated by a thick line, and the flow path through which the gas does not flow is indicated by a thin line. Therefore, it is obvious that the valves of the flow path through which the gas flows are in an open state, and the valves of the flow path through which the gas does not flow are in a closed state, and therefore, the description of the opening and closing control of the valves will be described only with respect to necessary portions.

(details of the steam flushing treatment)

The water vapor rinsing treatment is, as shown in fig. 7, the following treatment: in a state where the reforming reaction tube 2 is heated by the heating burner N and the state where the steam supply to the reforming reaction tube 2 is continued, the product gas H from the product gas tank U is supplied to the reforming reaction tube 2 by the compressor 7 instead of the raw material gas G, and the reformed gas K from the reforming treatment section AK is supplied to the plurality of adsorption towers 1 performing the pressure swing adsorption operation.

The steam flushing process is continued to such an extent that the pressure swing adsorption section BS performs an operation cycle including the 1 st unit cycle, the 2 nd unit cycle, and the 3 rd unit cycle at least once.

When the product gas production operation is stopped and the steam flush treatment is performed, the combustion by the heating burner N is continued, the supply of water (pure water) from the water supply unit 10 is continued, the supply of steam from the steam mixing unit J is continued, and the pressure swing adsorption operation by the pressure swing adsorption unit BS is continued.

Incidentally, the off-gas is supplied as the fuel gas to the heating burner N, but when the amount of the off-gas is insufficient, the fuel gas valve 3A is opened to supply the raw material gas G as the fuel gas.

Then, in a state where the raw material gas supply valve Ga is closed and the supply of the raw material gas G is stopped, the communication opening/closing valve La is opened, and the product gas from the product gas tank U is caused to flow into the gas introduction line 7A through the communication line L and a part of the recycle gas line 19.

Incidentally, due to the resistance of the communication resistance adjustment valve Lb, the pressure of the product gas H flowing through the communication line L drops, the pressure on the inlet side of the compressor 7 is, for example, about 0.25MPaG, and the pressure on the outlet side of the compressor 7 is, for example, about 0.75 MPaG.

Therefore, in the steam purge process, the raw material gas G remaining in the desulfurizer 6, the reforming reaction tube 2, and the like is subjected to a steam reforming process to generate a reformed gas K, and the product gas H containing the reformed gas K thus generated is supplied to the pressure swing adsorption unit BS in the same manner as in the product gas production operation, and the process of generating the product gas H is performed while performing the pressure swing adsorption operation by the plurality of adsorption towers 1.

Fig. 7 shows a state in which the 1 st adsorption column a performs the adsorption step and the 3 rd adsorption column C performs the pressure reduction step.

(details of product gas flushing treatment)

The product gas flushing process is as follows as shown in fig. 8: while the supply of the water vapor is stopped and the heating of the reforming reaction tube 2 by the heating burner N is continued, the product gas H from the product gas tank U is supplied to the reforming reaction tube 2 by the compressor 7, and the product gas H from the reforming treatment section AK is supplied to the adsorption tower 1.

The product gas purging process is continued to such an extent that the pressure swing adsorption section BS performs at least one operation cycle including the 1 st unit cycle, the 2 nd unit cycle, and the 3 rd unit cycle.

When the product gas purging process is performed after the steam purging process is stopped, the combustion by the heating burner N is continued, the supply of water (pure water) from the water supply unit 10 is stopped, the supply of steam from the steam mixing unit J is stopped, and the pressure swing adsorption operation by the pressure swing adsorption unit BS is continued.

Incidentally, in the heating burner N, the fuel gas valve 3A is opened, the raw material gas supply valve Ga is opened, and the raw material gas G is supplied as the fuel gas.

Then, following the steam purge process, the raw material gas supply valve Ga is closed, the supply of the raw material gas G is stopped, and the communication on-off valve La is opened, so that the product gas from the product gas tank U flows into the gas introduction line 7A through the communication line L and a part of the recycle gas line 19.

Incidentally, due to the resistance of the communication resistance adjustment valve Lb, the pressure of the product gas H flowing through the communication line L drops, the pressure on the inlet side of the compressor 7 is, for example, about 0.25MPaG, and the pressure on the outlet side of the compressor 7 is, for example, about 0.75 MPaG.

Therefore, in the product gas purging process, the product gas H is passed through the desulfurizer 6, the reforming reaction tube 2, the CO modification device 15, and the like, the product gas H from the reforming processing section AK is supplied to the pressure swing adsorption section BS in the same manner as in the product gas production operation, and the process of producing the product gas H is performed while performing the pressure swing adsorption operation by the plurality of adsorption towers 1.

Fig. 8 shows a state in which the 1 st adsorption column a performs the adsorption step and the 3 rd adsorption column C performs the pressure reduction step.

Then, by performing the product gas purging process, the product gas H is charged into the reforming section AK and maintained in a high temperature state equal to the state in which the reforming section AK performs the steam reforming process, and the adsorbent in the plurality of adsorption towers 1 of the pressure swing adsorption section BS is subjected to the pressure swing adsorption operation with respect to the product gas H, whereby the adsorbent is regenerated into a desorption state in which the component to be adsorbed is not adsorbed.

(details of the standby operation)

The standby operation is as follows as shown in fig. 9: in the state where the modified gas supply line 17 as a gas supply line from the modified process section AK to the pressure swing adsorption section BS is cut off, the adsorbent of the adsorption column 1 is maintained in a state where the component to be adsorbed is desorbed in the pressure swing adsorption section BS, and in the state where the supply of water vapor is stopped and the heating of the modification reaction tube 2 by the heating burner N is continued in the modified process section AK, when the product gas H filled in the modified process section AK is discharged from the modified process section AK, the product gas H circulates so as to pass through the recycle gas line 19 as a return line and return to the compressor 7.

When the product gas flushing process is stopped and the standby operation is performed, the combustion of the heating burner N is continued, the supply of water (pure water) from the water supply unit 10 is stopped, the supply of steam from the steam mixing unit J is stopped, the supply shutoff valve 17A of the reformed gas supply line 17 is closed, and the communication between the reformed gas supply line 17 and the three adsorption towers 1 is shut off.

Incidentally, in the heating burner N, the fuel gas valve 3A is opened, the raw material gas supply valve Ga is opened, and the raw material gas G is supplied as the fuel gas.

Then, the communication between the reformed gas supply line 17 and the three adsorption towers 1 is cut off, and the product gas H filled in the reforming section AK is circulated so as to pass through the recycle gas line 19 and return to the compressor 7.

In this circulation state, the product gas H filled in the reforming section AK circulates in a state where the flow path resistance is lower than that in the steam purge process and the product gas purge process, and therefore the pressure on the outlet side of the compressor 7 is lower than 0.75 MPaG.

Further, the 1 st supply valve 20a, the 2 nd supply valve 20b, and the 3 rd supply valve 20c of the pressure swing adsorption unit BS are each closed, and the pressure swing adsorption operation of the pressure swing adsorption unit BS is stopped.

In addition, in a state where the other valves of the pressure fluctuation adsorbing section BS, that is, the 1 st discharge valve 23a, the 2 nd discharge valve 23b, the 3 rd discharge valve 23c, the 1 st pressure equalizing valve 25a, the 2 nd pressure equalizing valve 25b, the 3 rd pressure equalizing valve 25c, the 1 st exhaust valve 29a, the 2 nd exhaust valve 29b, and the 3 rd exhaust valve 29c are all closed, the adsorbent of the adsorption tower 1 is maintained in a state where the component to be adsorbed is desorbed in the pressure fluctuation adsorbing section BS.

Therefore, in the standby operation, the product gas H filled in the reforming section AK is circulated through the desulfurizer 6, the reforming reaction tube 2, the CO reformer 15, and the like, and is maintained in a high-temperature state similar to the state in which the steam reforming treatment is performed in the reforming section AK.

In the pressure swing adsorption section BS, the adsorbent in the adsorption column 1 is maintained in a state in which the component to be adsorbed is desorbed.

(details of initial operation treatment)

The initial operation process is a process for stopping the standby operation and starting the product gas production operation, and includes the following processes: the raw material gas G and the steam are supplied to the reforming reaction tube 2 immediately after the start to produce the reformed gas K, the reformed gas K from the reforming treatment section AK is supplied to the adsorption tower 1 to produce the product gas H, and when the concentration of the hydrogen component in the produced product gas H is less than a predetermined value, the product gas H is discarded.

After the initial operation processing, when the hydrogen component concentration of the produced product gas H is equal to or higher than the set value, the process proceeds to a product gas production operation for recovering the product gas H to the product gas tank U.

In the present embodiment, as the initial operation process, the pressure raising process of raising the pressure of the adsorption tower 1 in which the reformed gas K is first supplied in the reforming section AK and the pressure swing adsorption section BS is first performed, and then the product gas H is produced while the pressure swing adsorption section BS is performing the pressure swing operation, and when the concentration of the hydrogen component in the produced product gas H is less than a set value, the purification process of discarding the product gas H is performed.

When the standby operation is stopped and the pressure raising process is performed, as shown in fig. 10, the combustion by the heating burner N is continued, the supply of water (deionized water) from the water supply unit 10 is started, and the supply of steam from the steam mixing unit J is started.

Further, the supply interruption valve 17 of the reformed gas supply line 17 is opened.

Incidentally, with respect to the heating burner N, the fuel gas valve 3A is opened, and the raw material gas G is supplied as the fuel gas.

Then, the pressure swing adsorption operation of the pressure swing adsorption unit BS is stopped, but the 1 st supply valve 20a of the adsorption column 1, for example, the 1 st adsorption column a, of the pressure swing adsorption unit BS, which is first supplied with the reformed gas K, is opened and the 1 st discharge valve 23a is closed.

Further, the recycle gas line 19 is closed by a line open-close valve 19A. Incidentally, instead of closing the recycle gas line 19, for example, the flow path resistance of the recycle gas line 19 may be increased by setting the on-off valve 19A to a half-open state or the like.

Therefore, the reformed gas K is generated in the reforming section AK, and the reformed gas K is supplied to the adsorption column 1, for example, the 1 st adsorption column a of the pressure swing adsorption section BS, which first supplies the reformed gas K, and the 1 st discharge valve 23a of the 1 st adsorption column a is closed, so that the internal pressure of the reforming section AK and the internal pressure of the 1 st adsorption column a, which first supplies the reformed gas K, are increased to the set pressure (for example, 0.75 MPaG).

When the internal pressure of the reforming section AK and the internal pressure of the 1 st adsorption column a to which the reformed gas K is first supplied are increased to the set pressure, the purification process is performed as shown in fig. 11.

When the purification process is performed, the pressure swing adsorption operation of the pressure swing adsorption section BS is started with the product gas valve 22A closed and the product gas release valve Qa opened.

Further, the line open/close valve 19A is opened, and the recycle gas line 19 is opened.

Therefore, when the reformed gas K is supplied from the reforming section AK to the pressure swing adsorption section BS, the product gas H is produced by the pressure swing adsorption operation, and when the concentration of the hydrogen component in the produced product gas H is less than the set value, the product gas H passes through the product gas release line Q and is discarded.

When the hydrogen component concentration of the produced product gas H is equal to or higher than the set value, the product gas release valve Qa is closed and the product gas valve 22A is opened, thereby shifting to the product gas production operation for recovering the product gas to the product gas tank U.

In the present embodiment, the supply amount of the raw gas G supplied via the compressor 7 in the initial operation processing is set to 40% of the maximum supply amount in the product gas production operation, and the time for performing the operation cycle with respect to the supply amount of the raw gas G supplied via the compressor 7 is set to be, for example, about 20% less than the time for performing the product gas production operation.

Incidentally, although not shown, a pressure sensor for detecting the internal pressure of the adsorption column 1 is provided, and the pressure sensor is configured to detect a state in which the internal pressure of the adsorption column 1 is increased to a set pressure (for example, 0.75MPaG) during the pressure increasing process.

Further, a concentration sensor for detecting the concentration of the hydrogen component in the product gas H is provided at an upstream portion of the product gas discharge line 22 from the branching portion of the product gas discharge line Q, and it is configured to detect whether or not the concentration of the hydrogen component in the product gas H is equal to or higher than a set value in the purification process.

Further, a temperature sensor for detecting the temperature of the reforming catalyst is provided inside the reforming reaction tube 2, and the combustion amount of the heating burner N is controlled so that the detected temperature becomes the reforming reaction temperature (e.g., 700 ℃).

That is, the amount of the off gas as the fuel gas supplied through the off gas supply passage 4 and the amount of the raw material gas G as the fuel gas supplied through the auxiliary fuel gas passage 3 are controlled, and the amount of the air supplied through the air supply passage 5a is adjusted in accordance with the amount of the fuel gas supplied by controlling the combustion amount of the heating burner N.

(comparison of the present invention construction with conventional constructions)

When the configuration of the present invention described in the above embodiment is compared with the conventional configuration described below, the configuration of the present invention can reduce the consumption of the raw gas G and the consumption of the product gas H consumed during the shutdown operation and the startup operation.

That is, the conventional structure is as follows.

When stopping the operation of producing the product gas, first, in a state where the modified gas supply line 17 from the modifying section AK to the pressure swing adsorption section BS is cut off, a purging operation is performed in which a steam purging process of supplying the product gas H from the product gas tank U to the modifying reaction tube 2 through the desulfurizer 6 and discharging the modified gas K from the modifying section AK to the outside in place of the raw material gas G in a state where the modifying reaction tube 2 is heated by the heating burner N and the steam is supplied to the modifying reaction tube 2 is continued, and a product gas purging process of supplying the product gas H from the product gas tank U to the modifying reaction tube 2 through the desulfurizer 6 and discharging the modified gas K from the modifying section AK through the compressor 7 in a state where the supply of the steam is stopped and the heating of the modifying reaction tube 2 by the heating burner N is continued, and the product gas from the reforming section AK is discarded to the outside.

Then, the following standby operation is performed: in the state where the modified gas supply line 17 from the modified processing section AK to the pressure swing adsorption section BS is cut off, the adsorbent in the adsorption column 1 is maintained in a state where the adsorption target component is desorbed in the pressure swing adsorption section BS, and in the modified processing section AK, the product gas H filled in the modified processing section AK is circulated so as to pass through the recycle gas line 19 and return to the compressor 7 in a state where the supply of water vapor is stopped and the heating of the reforming reactor 2 by the heating burner N is continued.

In the start-up operation for stopping the standby operation and starting the product gas production operation, a pressure raising process is performed in which the product gas H from the product gas tank U is supplied by the compressor 7 to raise the pressure, when the pressure raising process is completed, a raw material introduction process is performed in which the raw material gas G is supplied by the compressor 7 in place of the product gas H, when the reformed gas K is appropriately generated by the raw material introduction process, the supply of the reformed gas to the pressure fluctuation adsorption unit BS is started, and when the product gas is produced by the pressure fluctuation adsorption operation, and the concentration of the hydrogen component of the produced product gas is less than a set value, a purification process for discarding the product gas is performed, and then, when the concentration of the hydrogen component of the produced product gas is equal to or more than the set value, the product gas production operation for recovering the product gas H to the product gas tank U is performed.

In the conventional configuration, for example, 7Nm of raw material gas G is consumed during shutdown³E.g. consumption of 21Nm of product gas H³In contrast, in the structure of the present invention, the consumption of the raw gas G is zero, for example, 3Nm for the product gas H³The consumption of the raw gas G and the consumption of the product gas H can be reduced.

In the conventional configuration, for example, 18Nm of raw material gas G is consumed at the time of start-up operation³E.g. consumption of 19Nm of product gas H³In contrast, in the structure of the present invention, for example, 13Nm is consumed for the raw material gas G³The consumption of the product gas H is zero, and the consumption of the source gas G and the consumption of the product gas H can be reduced.

[ other embodiments ]

Next, other embodiments are described.

(1) In the above embodiment, the example in which three adsorption towers 1 are provided as the pressure swing adsorption unit BS has been described, but the present invention can also be applied to a case in which the pressure swing adsorption unit BS is configured to include two or more adsorption towers 1.

(2) In the above embodiment, the pressure swing adsorption unit BS is exemplified as a system configured to perform the washing step as the regeneration step, but the present invention can also be applied to a case where the pressure swing adsorption unit BS performs, as the regeneration step, a suction step of sucking the inside of the adsorption tower 1 by a vacuum pump instead of the washing step.

(3) In the above embodiment, the case where the water-vapor mixing section J mixes water with the raw material gas G and then the mixed water is evaporated by the evaporation heat exchange section 11 has been exemplified, but the water-vapor mixing section J may be implemented so that water vapor generated in advance is mixed with the raw material gas G.

(4) In the above embodiment, the case where the pressure is increased only by the reformed gas K from the reforming section AK in the pressure increasing process in the initial operation process has been described, but the specific configuration of the initial operation process may be changed to various configurations such as supplying the product gas H to the adsorption tower 1 to which the reformed gas K is first supplied and increasing the pressure thereof.

(5) In the above embodiment, the supply interruption valve 17A is provided in the reformed gas supply line 17, but the communication between the reformed gas supply line 17 and the adsorption tower 1 may be interrupted by closing each of the 1 st supply valve 20a, the 2 nd supply valve 20b, and the 3 rd supply valve 20c of the pressure fluctuation adsorption unit BS, and the supply interruption valve 17A may be omitted.

Note that the configurations disclosed in the above embodiments (including other embodiments, the same below) can be combined with the configurations disclosed in the other embodiments without contradiction, and the embodiments disclosed in the present specification are exemplary, and the embodiments of the present invention are not limited thereto, and can be appropriately changed within a range not departing from the object of the present invention.

Description of the reference numerals

1 adsorption column

2 quality modifier

4 exhaust gas supply path

7 compressor

17 gas supply line

19 return line

A modification processing part

B pressure fluctuation adsorption part

G raw material gas

H product gas

K modified gas

M operation control unit

N heating burner

And U product gas tank.