Autothermal reforming hydrogen production facility associated with water electrolysis facility, complex hydrogen production system having the same and method for controlling oxigen supply of the same

Abstract

According to the present invention, a self-thermal reforming hydrogen production facility is provided, comprising: a self-thermal reforming reactor that performs a self-thermal reforming reaction on a methane feedstock gas containing methane to produce a reformed gas containing hydrogen; and an oxygen supply unit that supplies oxygen required for the self-thermal reforming reaction to the self-thermal reforming reactor, wherein the oxygen supply unit is equipped with a byproduct supply facility that supplies byproducts generated in a water electrolyzer that electrolyzes water into hydrogen and oxygen to the self-thermal reforming reactor.

Description

Technology Field

[0001] The present invention relates to hydrogen production technology, and more specifically, to a technology for producing hydrogen using a self-thermal reforming method. Background Technology

[0002] Hydrogen production primarily utilizes water electrolysis, the reforming method that reforms methane contained in fossil fuels, and the byproduct purification method that refines hydrogen-containing byproducts generated during processes such as steel production.

[0003] Reforming methods include Steam Methane Reforming (SMR) and Autothermal Reforming (ATR). The SMR method produces hydrogen by reacting methane with steam at high temperature and pressure, while the ATR method utilizes both the endothermic reaction of SMR and the exothermic reaction of Partial Oxidation (POX), employing the heat generated by the exothermic reaction of partial oxidation into the SMR. In the ATR method, oxygen is supplied for partial oxidation.

[0004] Published Patent No. 10-2022-0053089, a patent document related to the technical field of the present invention regarding hydrogen production using the ATR method, describes the configuration of an ATR device that produces a reformed gas containing hydrogen by performing an autothermal reforming reaction, and an Air Separation Unit (ASU) that separates oxygen from air for partial oxidation and supplies it to the ATR device. Since such conventional ATR-based hydrogen production facilities require a large-capacity Air Separation Unit (ASU), improvements are required in terms of Capital Expenditures (CAPEX) and Operating Expenditures (OPEX). Prior art literature

[0005] Republic of Korea Published Patent Application No. 10-2022-0053089 (April 29, 2022) The problem to be solved

[0006] The objective of the present invention is to provide a self-thermal reforming hydrogen production facility and a combined hydrogen production system equipped with the same, which can reduce capital expenditures (CAPEX) and operating expenditures (OPEX) by enabling the use of a small-scale air separation unit. means of solving the problem

[0007] To achieve the above-described objective of the present invention, according to one aspect of the present invention, a self-thermal reforming hydrogen production facility is provided, comprising: a self-thermal reforming reactor that performs a self-thermal reforming reaction on a methane feedstock gas containing methane to produce a reformed gas containing hydrogen; and an oxygen supply unit that supplies oxygen required for the self-thermal reforming reaction to the self-thermal reforming reactor, wherein the oxygen supply unit is equipped with a byproduct supply facility that supplies byproducts generated in a water electrolyzer that electrolyzes water into hydrogen and oxygen to the self-thermal reforming reactor.

[0008] To achieve the above-described objective of the present invention, according to another aspect of the present invention, a combined hydrogen production system is provided, comprising: a self-thermal reforming hydrogen production facility having a self-thermal reforming reactor that performs a self-thermal reforming reaction on a methane feedstock gas containing methane to produce a reformed gas containing hydrogen; an oxygen supply unit that supplies oxygen required for the self-thermal reforming reaction to the self-thermal reforming reactor; and a water electrolysis hydrogen production facility having a water electrolyzer that produces hydrogen by electrolyzing water into hydrogen and oxygen, wherein the oxygen supply unit has a by-production supply facility that supplies oxygen generated by the water electrolyzer to the self-thermal reforming reactor.

[0009] To achieve the above-described objective of the present invention, according to another aspect of the present invention, a method for controlling the flow rate of oxygen supplied to a self-thermal reforming reactor in a self-thermal reforming hydrogen production facility comprises: a self-thermal reforming reactor that performs a self-thermal reforming reaction on a methane feedstock gas containing methane to produce a reformed gas containing hydrogen; an oxygen supply unit that supplies oxygen required for the self-thermal reforming reaction to the self-thermal reforming reactor; wherein the oxygen supply unit comprises a byproduct supply facility that supplies byproducts generated in a water electrolyzer that electrolyzes water into hydrogen and oxygen to the self-thermal reforming reactor; an air separation unit that separates oxygen from air and supplies additional oxygen to the self-thermal reforming reactor; and a controller that controls the operation of the byproduct supply facility and the air separation unit to control the flow rate of oxygen supplied to the self-thermal reforming reactor, the method comprising: a basic information verification step in which reaction basic information including the flow rate of the methane feedstock gas and the flow rate of water vapor flowing into the self-thermal reforming reactor is verified by the controller; An oxygen flow rate calculation step in which the optimal oxygen supply flow rate required for the autothermal reforming reaction in the autothermal reforming reactor is calculated by the controller based on the reaction basic information; a flow rate comparison step in which the byproduct supply flow rate, which is the flow rate of the byproduct supplied to the autothermal reforming reactor, is compared with the optimal oxygen supply flow rate by the controller; a maintenance step in which the byproduct supply flow rate is maintained without change by the controller when the difference between the byproduct supply flow rate compared in the flow rate comparison step and the optimal oxygen supply flow rate is within a set range; and a reduction step in which the byproduct supply flow rate is reduced by the controller when the difference between the optimal oxygen supply flow rate compared in the flow rate comparison step and the byproduct supply flow rate is outside the set range and the byproduct supply flow rate is greater than the optimal oxygen supply flow rate.A method for controlling oxygen supply in a self-thermal reforming hydrogen production facility linked to a water electrolysis facility is provided, comprising the step of increasing the flow rate of oxygen supplied to the self-thermal reforming reactor by the controller when the difference between the optimal oxygen supply flow rate and the by-product supply flow rate compared in the flow rate comparison step is outside the set range and the by-product supply flow rate is smaller than the optimal oxygen supply flow rate. Effects of the invention

[0010] According to the present invention, all the objectives of the invention described above can be achieved. Specifically, since by-products generated from a water electrolysis hydrogen production facility are supplied to the autothermal reforming reactor as oxygen required for the autothermal reforming reaction, the air separation unit supplying oxygen to the autothermal reforming reactor may be used on a small scale or may not be used at all. Accordingly, the total capital expenditure (CAPEX) and operating expenditure (OPEX) can be significantly reduced. Brief explanation of the drawing

[0011] FIG. 1 is a block diagram illustrating the schematic configuration of a self-thermal reforming hydrogen production facility linked to a water electrolysis facility and a composite hydrogen production system equipped with the same, according to one embodiment of the present invention. FIG. 2 is a flowchart schematically illustrating a method for controlling oxygen supply in a self-thermal reforming hydrogen production facility linked to a water electrolysis facility according to one embodiment of the present invention. Specific details for implementing the invention

[0012] Hereinafter, the configuration and operation of an embodiment of the present invention will be described in detail with reference to the drawings.

[0013] FIG. 1 illustrates, as a block diagram, the schematic configuration of a self-thermal reforming hydrogen production facility linked to a water electrolysis facility and a composite hydrogen production system equipped therewith according to an embodiment of the present invention. Referring to FIG. 1, a composite hydrogen production system (100) according to an embodiment of the present invention includes a self-thermal reforming reactor (110) that performs a self-thermal reforming reaction to produce a reformed gas containing hydrogen, an oxygen supply unit (120) that supplies oxygen required for the self-thermal reforming reaction to the self-thermal reforming reactor (110), a carbon dioxide capturer (150) that captures and removes carbon dioxide from the reformed gas produced in the self-thermal reforming reactor (110), and a water electrolysis hydrogen production facility (160) that produces hydrogen by a water electrolysis method and supplies oxygen produced together with hydrogen to the self-thermal reforming reactor (110) by the oxygen supply unit (120). The self-thermal reforming reactor (110), oxygen supply unit (120), and carbon dioxide capture unit (150) constitute a self-thermal reforming hydrogen production facility (105) connected to a water electrolysis facility according to one embodiment of the present invention.

[0014] The autothermal reforming reactor (110) performs a conventional autothermal reforming reaction on a methane feedstock gas containing methane to produce a reformed gas containing hydrogen. Methane feedstock gas (G1), steam (V), and oxygen are introduced into the autothermal reforming reactor (110) for the autothermal reforming reaction. Although not illustrated, the flow rates of the methane feedstock gas (G1) and steam (V) introduced into the autothermal reforming reactor (110) are each measured by a flow sensor to control the flow rate of oxygen supplied to the autothermal reforming reactor (110). Since the autothermal reforming reactor (110) includes the configuration of a conventional autothermal reforming reactor, a detailed description thereof is omitted here. The autothermal reforming reactor (110) receives oxygen gas required for the autothermal reforming reaction from an oxygen supply unit (120). The reformed gas (G2) discharged from the self-heating reforming reactor (110) is supplied to the carbon dioxide capturer (150).

[0015] The oxygen supply unit (120) supplies oxygen gas required for the self-thermal reforming reaction to the self-thermal reforming reactor (110). The oxygen supply unit (120) is equipped with a byproduct supply facility (130) that supplies byproducts generated from a water electrolysis hydrogen production facility (160) to the self-thermal reforming reactor (110), an air separation unit (ASU) (140) that separates oxygen from air and supplies it to the self-thermal reforming reactor (110), and a controller (145) that controls the flow rate of the oxygen gas supplied to the self-thermal reforming reactor (110).

[0016] The byproduct supply facility (130) supplies byproduct generated from the water electrolysis hydrogen production facility (160) to the natural heat reforming reactor (110). The byproduct supply facility (130) is equipped with a byproduct supply line (132) through which byproduct discharged from the water electrolysis hydrogen production facility (160) flows and is supplied to the natural heat reforming reactor (110), a buffer tank (134) installed on the byproduct supply line (132) for storing byproduct, a compressor (136) installed on the byproduct supply line (132) for flowing byproduct, and a flow control valve (138) installed on the byproduct supply line (132).

[0017] The byproduct supply line (132) connects the electrolytic hydrogen production facility (160) and the autothermal reforming reactor (110). Through the byproduct supply line (132), the byproduct generated and discharged from the electrolytic hydrogen production facility (160) flows and is supplied to the autothermal reforming reactor (110). A buffer tank (134), a compressor (136), and a flow control valve (138) are installed on the byproduct supply line (132).

[0018] A buffer tank (134) is installed on the auxiliary production supply line (132). The auxiliary production flowing along the auxiliary production supply line (132) is temporarily stored in the buffer tank (134). The auxiliary production is stably supplied to the self-thermal reforming reactor (110) by the buffer tank (134).

[0019] The compressor (136) is installed on the auxiliary production supply line (132) to flow the auxiliary production. The compressor (136) is located upstream of the buffer tank (134) on the auxiliary production supply line (132).

[0020] A flow control valve (138) is installed in the auxiliary production supply line (132) to control the flow rate of the auxiliary production supplied to the self-thermal reforming reactor (110) through the auxiliary production supply line (132). The flow control valve (138) is located downstream of the buffer tank (134), and it is preferable to be located as close as possible to the self-thermal reforming reactor (110). The operation of the flow control valve (138) is controlled by a controller (145). Although not illustrated, an auxiliary production flow sensor may be installed in the auxiliary production supply line (132) to measure the flow rate of the auxiliary production supplied to the self-thermal reforming reactor (110) through the auxiliary production supply line (132), located downstream of the flow control valve (138). The flow rate data of the auxiliary production measured by the auxiliary production flow sensor is transmitted to the controller (145) in real time.

[0021] The air separation unit (ASU) (140) separates oxygen from air and supplies it to the self-thermal reforming reactor (110). Since the air separation unit (ASU) (140) includes the configuration of a conventional air separation unit (ASU), a detailed description thereof is omitted here. The operation of the air separation unit (ASU) is controlled by a controller (145) so that the flow rate of oxygen supplied by the air separation unit (ASU) to the self-thermal reforming reactor (110) can be regulated.

[0022] The controller (145) controls the operation of the flow control valve (138) and the air separation unit (140) to control the flow rate of oxygen gas supplied to the self-thermal reforming reactor (110). The control of the flow rate of oxygen gas supplied to the self-thermal reforming reactor (110) by the controller (145) will be described in detail later with reference to FIG. 2.

[0023] The carbon dioxide capturer (150) captures and removes carbon dioxide from the reformed gas produced in the self-heating reforming reactor (110).

[0024] The water electrolysis hydrogen production facility (160) produces hydrogen by water electrolysis, and the oxygen produced along with the hydrogen is supplied to the self-thermal reforming reactor (110) by the oxygen supply unit (120). The water electrolysis hydrogen production facility (160) is equipped with a water electrolyzer (170) that produces hydrogen by electrolyzing water (W) into hydrogen and oxygen. Since the water electrolyzer (170) includes the configuration of a conventional water electrolyzer, a detailed description thereof is omitted here. The oxygen generated by the water electrolyzer (170) is discharged from the water electrolyzer (170) as a byproduct. The byproduct discharged from the water electrolyzer (170) is supplied to the self-thermal reforming reactor (110) by the byproduct supply facility (130) and used in the self-thermal reforming reaction. In this embodiment, the electrical energy (E) supplied for the electrolysis performed by the water electrolyzer (170) is described as being generated by renewable energy. Although not shown, the same power source as the electric energy (E) supplied to the electrolytic generator (170) can supply power to the compressor (136) of the auxiliary production supply facility (130), and the power line supplying power to the compressor (136) can be installed to extend along the auxiliary production supply line (132).

[0025] FIG. 2 is a flowchart schematically illustrating a method for controlling oxygen supply in a self-thermal reforming hydrogen production facility linked to a water electrolysis facility according to one embodiment of the present invention. A flowchart schematically describing the oxygen supply control method of a self-thermal reforming hydrogen production facility linked to a water electrolysis facility illustrated in FIG. 2 is an oxygen supply control method of a self-thermal reforming hydrogen production facility (105) linked to a water electrolysis facility illustrated in FIG. 1, comprising: a basic information verification step (S110) in which reaction basic information including flow rate information of methane raw gas (G1) flowing into a self-thermal reforming reactor (110) and flow rate information of water vapor (V) is verified; an oxygen flow rate calculation step (S120) in which an optimal oxygen supply flow rate required for the self-thermal reforming reaction in the self-thermal reforming reactor (110) is calculated based on the reaction basic information verified in the basic information verification step (S110); a flow rate comparison step (S130) in which the optimal oxygen supply flow rate calculated in the oxygen flow rate calculation step (S120) is compared with the byproduct oxygen supply flow rate, which is the flow rate of a byproduct supplied to the self-thermal reforming reactor (110) through a byproduct supply line (132); and a flow rate comparison The method includes a maintenance step (S140) in which the supply flow rate of a secondary production facility is maintained according to the result of comparing the optimal oxygen supply flow rate and the supply flow rate of a secondary production facility in step (S130); a reduction step (S150) in which the supply flow rate of a secondary production facility is reduced according to the result of comparing the optimal oxygen supply flow rate and the supply flow rate of a secondary production facility in the flow rate comparison step (S130); an additional comparison step (S160) in which the optimal oxygen supply flow rate and the maximum supply flow rate of a secondary production facility of a secondary production facility supply facility (130) are compared according to the result of comparing the optimal oxygen supply flow rate and the supply flow rate of a secondary production facility in the flow rate comparison step (S130); an increase step (S170) in which the supply flow rate of a secondary production facility is increased according to the result of the additional comparison step (S160); and an additional supply step (S180) in which an air separation unit (ASU) (140) is operated according to the result of the additional comparison step (S160) to additionally supply oxygen to the self-thermal reforming reactor (110).

[0026] In the basic information verification step (S110), reaction basic information including flow rate information of methane raw gas (G1) flowing into the autothermal reforming reactor (110) and flow rate information of water vapor (V) is verified. The basic information verification step (S110) is performed by receiving raw gas flow rate data and water vapor flow rate data from the controller (145) from flow sensors that measure the flow rates of methane raw gas (G1) and water vapor (V) flowing into the autothermal reforming reactor (110), respectively. Based on the reaction basic information verified through the basic information verification step (S110), the oxygen flow rate calculation step (S120) is performed.

[0027] In the oxygen flow rate calculation step (S120), the optimal oxygen supply flow rate required for the autothermal reforming reaction in the autothermal reforming reactor (110) is calculated based on the reaction basic information confirmed in the basic information verification step (S110). The oxygen flow rate calculation step (S120) is performed by the controller (145) calculating the optimal oxygen supply flow rate required for the autothermal reforming reaction based on the flow rate of methane feedstock gas (G1) and the flow rate of water vapor (V) flowing into the autothermal reforming reactor (110) confirmed in the basic information verification step (S110). After the optimal oxygen supply flow rate is calculated through the oxygen flow rate calculation step (S120), the flow rate comparison step (S130) is performed.

[0028] In the flow rate comparison step (S130), the byproduct supply flow rate, which is the flow rate of the byproduct supplied to the self-thermal reforming reactor (110) through the byproduct supply line (132), is compared with the optimal oxygen supply flow rate calculated in the oxygen flow rate calculation step (S120). The flow rate comparison step (S130) is performed by the controller (145) comparing the byproduct supply flow rate transmitted from the byproduct flow sensor installed in the byproduct supply line (132) with the optimal oxygen supply flow rate calculated in the oxygen flow rate calculation step (S120). Depending on the comparison result through the flow rate comparison step (S130), one of the following steps is performed: the maintenance step (S140), the reduction step (S150), and the additional comparison step (S160).

[0029] In the maintenance step (S140), the supply flow rate of the auxiliary production facility is maintained without change. The maintenance step (S140) is performed when the difference between the supply flow rate of the auxiliary production facility compared in the flow rate comparison step (S130) and the optimal oxygen supply flow rate is within a set range, by the controller (145) controlling the flow control valve (138) so that the supply flow rate of the auxiliary production facility is maintained without change.

[0030] In the reduction step (S150), the supply flow rate of the auxiliary production facility is reduced. The reduction step (S150) is performed when the difference between the optimal oxygen supply flow rate and the supply flow rate of the auxiliary production facility compared in the flow rate comparison step (S130) is outside the set range and the supply flow rate of the auxiliary production facility is greater than the optimal oxygen supply flow rate, by the controller (145) controlling the flow control valve (138) so that the supply flow rate of the auxiliary production facility is reduced and the difference from the optimal oxygen supply flow rate is within the set range.

[0031] In the additional comparison step (S160), the optimal oxygen supply flow rate and the maximum supply flow rate of the auxiliary production facility (130) are compared. The additional comparison step (S160) is performed when the difference between the optimal output supply flow rate and the auxiliary production facility supply flow rate compared in the flow rate comparison step (S130) is outside the set range and the auxiliary production facility supply flow rate is smaller than the optimal oxygen supply flow rate, by the controller (145) comparing the maximum supply flow rate of the auxiliary production facility (130) with the optimal oxygen supply flow rate. Depending on the comparison result through the additional comparison step (S160), either the increase step (S170) or the additional supply step (S180) is performed.

[0032] In the increase step (S170), the supply flow rate of the auxiliary production facility is increased. The increase step (S170) is performed when, as a result of the comparison in the additional comparison step (S160), the maximum supply flow rate of the auxiliary production facility is greater than or equal to the optimal oxygen supply flow rate, and the controller (145) controls the flow control valve (138) so that the supply flow rate of the auxiliary production facility is increased and the difference from the optimal supply flow rate is within a set range. In the increase step (S170), the air separation unit (ASU) does not operate.

[0033] In the additional supply step (S180), the air separation unit (ASU) (140) is operated to supply additional oxygen to the self-thermal reforming reactor (110). The additional supply step (S180) is performed when, as a result of the comparison in the additional comparison step (S160), the maximum supply flow rate of the auxiliary production facility is smaller than the optimal oxygen supply flow rate, the controller (145) operates the air separation unit (ASU) (140) to supply additional air to the self-thermal reforming reactor (110) by the air separation unit (ASU) (140), thereby controlling the operation of the air separation unit (ASU) (140) so that the total oxygen flow rate supplied to the self-thermal reforming reactor (110) is within a set range compared to the optimal supply flow rate, and controls the flow control valve (138) so that the supply flow rate of the auxiliary production facility becomes the maximum supply flow rate.

[0034] As presented in the present invention, the total oxygen flow rate can be controlled to the optimal conditions through a flow rate comparison (S130) and additional comparison (S160) between the supply flow rate of the auxiliary production facility and the optimal supply flow rate. However, depending on the variable operating environment of the water electrolyzer (170), the supply from the auxiliary production facility may also be unstable, and accordingly, among the control methods, the additional supply step (S180) through the air separation unit (ASU) (140) may be excessively and repeatedly turned on and off. This may reduce the energy efficiency and equipment durability of the entire system. To prevent this, during periods when the supply from the auxiliary production facility is unstable, the air separation unit (ASU) (140) may be utilized as the main supply means rather than an additional supply means.

[0035] Although the present invention has been described through the above embodiments, the present invention is not limited thereto. The above embodiments may be modified or changed without departing from the spirit and scope of the present invention, and those skilled in the art will understand that such modifications and changes are also within the scope of the present invention. Explanation of the symbols

[0036] 100: Complex hydrogen production system 105: Electrolysis-linked Autothermal Reforming Hydrogen Production Facility 110: Autothermal reforming reactor 120: Oxygen supply unit 130: Subsidiary Production Plant Supply Facility 132: Sub-production plant supply line 134: Buffer Tank 136: Compressor 138: Flow control valve 140: Air separation unit 145: Controller 150: Carbon dioxide capture device 160: Water electrolysis hydrogen production facility 170: Electrolyzer

Claims

Claim 1 delete Claim 2 delete Claim 3 delete Claim 4 delete Claim 5 delete Claim 6 A self-thermal reforming hydrogen production facility equipped with a self-thermal reforming reactor that performs a self-thermal reforming reaction on a methane feedstock gas containing methane to produce a reformed gas containing hydrogen; an oxygen supply unit that supplies oxygen required for the self-thermal reforming reaction to the self-thermal reforming reactor; The water electrolysis hydrogen production facility includes a water electrolyzer that produces hydrogen by electrolyzing water into hydrogen and oxygen, and the oxygen supply unit comprises a byproduct supply facility that supplies oxygen generated by the water electrolyzer to the autothermal reforming reactor, an air separation unit (ASU) that separates oxygen from air and supplies it to the autothermal reforming reactor, and a controller that controls the flow rate of oxygen supplied to the autothermal reforming reactor. The controller calculates the optimal oxygen supply flow rate required for the autothermal reforming reaction based on the flow rate of the methane feedstock gas and the flow rate of water vapor introduced into the autothermal reforming reactor, and controls the operation of the byproduct supply facility and the air separation unit using the flow rate difference, which is the difference between the byproduct supply flow rate supplied to the autothermal reforming reactor and the optimal oxygen supply flow rate. The controller includes a first control condition in which the flow rate difference is within a set range, a second control condition in which the byproduct supply flow rate is greater than the optimal oxygen supply flow rate outside the set range, and a second control condition in which the flow rate difference is outside the set range The operation of the auxiliary production facility supply facility and the air separation unit is controlled by classifying into a third control condition in which the auxiliary production facility supply flow rate is smaller than the optimal oxygen supply flow rate, wherein in the first control condition, the controller maintains the auxiliary production facility supply flow rate without change, in the second control condition, the controller reduces the auxiliary production facility supply flow rate, and in the third control condition, the controller classifies into a third A control condition in which the maximum auxiliary production facility supply flow rate is greater than or equal to the optimal oxygen supply flow rate according to the maximum auxiliary production facility supply flow rate of the auxiliary production facility, andA combined hydrogen production system comprising: a third control condition (3B) in which the maximum byproduct supply flow rate is smaller than the optimal oxygen supply flow rate, thereby controlling the operation of the byproduct supply facility and the air separation unit; in the third control condition (3A), the controller increases the byproduct supply flow rate without operating the air separation unit; in the third control condition (3B), the controller operates the air separation unit to supply additional oxygen while maintaining the byproduct supply flow rate at the maximum byproduct supply flow rate; and the byproduct supply facility comprises a byproduct supply line through which the byproduct flows and is supplied to the autothermal reforming reactor, a buffer tank installed in the byproduct supply line, and a compressor installed upstream of the buffer tank in the byproduct supply line to flow the byproduct. Claim 7 A combined hydrogen production system according to claim 6, wherein the byproduct supply facility further comprises a flow control valve installed in the byproduct supply line to regulate the flow rate of the byproduct supplied to the autothermal reforming reactor and whose operation is controlled by the controller. Claim 8 delete Claim 9 delete Claim 10 delete Claim 11 delete Claim 12 delete Claim 13 delete Claim 14 delete

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