KR102471954B1 - Hydrocarbon pyrolysis apparatus and operation method thereof - Google Patents

Abstract

The present invention relates to a hydrocarbon pyrolysis hydrogen production device and a hydrogen production method that solve the deterioration of catalyst activity, and more particularly, to a hydrocarbon gas supplied to the ejector through a gas injection nozzle by providing an ejector in the center of the reactor and to a pressure difference After mixing and preheating the unreacted hydrocarbon and hydrogen at the bottom of the reactor introduced into the ejector by the ejector, the reaction is performed at the catalyst provided at the edge of the reactor where the temperature is relatively high and uniform. The present invention relates to a technology capable of improving hydrogen productivity by preventing deterioration of catalyst activity by allowing thermal decomposition to occur in a catalyst in a state in which hydrogen is mixed.

Description

Hydrocarbon pyrolysis hydrogen production device and hydrogen production method solving catalyst activity degradation {HYDROCARBON PYROLYSIS APPARATUS AND OPERATION METHOD THEREOF}

The present invention relates to a hydrocarbon pyrolysis hydrogen production device and a hydrogen production method that solve the deterioration of catalyst activity, and more particularly, an ejector is provided in the center of the reactor so that high concentration hydrogen together with hydrocarbon gas is introduced into the ejector at the bottom of the reactor. The present invention relates to a technology capable of improving hydrogen productivity by preventing the deterioration of catalyst activity by hydrogen supplied to the catalyst as well as improving the pyrolysis reactivity of hydrocarbons by performing the reaction.

Hydrogen is widely used as a raw material for chemical products and a process gas for chemical plants, and recently, its demand as a raw material for fuel cells, which is a future energy technology, is increasing. In addition, it is evaluated as the most powerful and only alternative to solve the problems of environmental problems and fossil fuel price increase or depletion that mankind is currently facing. At this level, research on the production, storage and use of hydrogen is being actively conducted all over the world.

Hydrogen is ultimately evaluated as being preferable to be produced from renewable energy sources without generating carbon dioxide, but at present, hydrogen produced from coal or natural gas is the most economical and can significantly reduce carbon dioxide emissions.

As methods for producing hydrogen in large quantities from hydrocarbons, steam reforming of natural gas, partial oxidation of hydrocarbons, etc. are known, but existing methods cause environmental problems such as global warming because a large amount of carbon dioxide is simultaneously produced. There is a problem.

As another method, there is a plasma decomposition method that has been extensively researched and is in the commercialization stage in some countries including Norway. However, since the plasma decomposition method consumes a lot of power, it is not economically viable, and since carbon dioxide is unavoidably emitted in power generation, environmental problems may be raised.

As another method, a process of producing carbon black and hydrogen by thermally decomposing natural gas, heavy oil, coal tar, and the like at a high temperature may be mentioned. However, this method requires a very high reaction temperature of 1400° C. or more, and is a cumbersome semi-continuous process in which two reactors are periodically used due to the deposition of the produced carbon.

Another method is a catalytic decomposition method using a metal catalyst as a method for lowering the high reaction temperature required for direct decomposition of hydrocarbons. However, there is a problem in that carbon generated in the course of the catalyst decomposition reaction is deposited on the catalyst and the activity of the catalyst is lowered, so a process of regenerating the catalyst using air or steam at a high temperature to regenerate the catalyst with reduced activity is required. It is additionally required, and there is a problem in that carbon dioxide, which is a greenhouse gas, is generated in this regeneration process.

In addition, the catalytic decomposition method as described above has a problem in that the temperature inside the reactor is not uniform, so that the thermal decomposition reactivity of hydrocarbons is lowered. That is, the temperature of the edge of the reactor is relatively high and uniform, while the center of the reactor is relatively difficult to transfer heat through radiation and conduction, so the temperature is relatively low compared to the edge of the reactor. There is a problem that the activity of the thermal decomposition reaction is lowered.

On the other hand, there is a Korean Patent Registration No. 10-0886148 as a prior art related to a hydrocarbon pyrolysis device.

The present invention is to solve the above-mentioned problems, by providing an ejector in the center of the reactor to introduce hydrogen together with hydrocarbon gas to perform a pyrolysis reaction, thereby preventing the catalyst from deteriorating and improving the productivity of hydrogen. An object of the present invention is to provide a hydrocarbon pyrolysis hydrogen production device and a hydrogen production method that solve the possible catalyst activity decrease.

The problem to be solved by the present invention is not limited to the above problem, and other technical problems not mentioned will be clearly understood by those skilled in the art from the description below.

Hydrocarbon pyrolysis hydrogen production apparatus according to the present invention for achieving the above object includes a reactor for decomposing hydrocarbon gas into hydrogen and carbon; and an ejector provided inside the reactor.

At this time, the ejector is located at the inner center of the reactor, and the catalyst is characterized in that it is located between the ejector and the inner wall of the reactor.

In addition, the hydrogen production device further includes a circulation pipe provided to recover hydrogen decomposed in the reactor and resupply unreacted hydrocarbons to the reactor, wherein the circulation pipe is connected to the upper end of the reactor. to be characterized

In addition, the inlet of the ejector is located below the catalyst, and the outlet of the ejector is located above the catalyst.

On the other hand, the hydrogen production method of the hydrocarbon pyrolysis hydrogen production apparatus according to the present invention for achieving the above object comprises the steps of injecting high-pressure hydrocarbon gas into the chamber of the ejector; Step of introducing high-concentration hydrogen into the lower end of the ejector and mixing with the hydrocarbon gas; and dissolving the mixed gas in the presence of a catalyst while descending after the mixed gas is injected into the upper end of the reactor through the diffusion part of the ejector.

At this time, the gas passing through the ejector is preheated while rising in the ejector.

Hydrocarbon pyrolysis hydrogen production apparatus and hydrogen production method that solves the deterioration of catalyst activity according to the present invention have an ejector in the center of the reactor to supply hydrocarbon gas and hydrogen generated through the reaction process together, so that the activity of the catalyst is reduced. can delay

In addition, since the catalyst is disposed in the space around the outer circumference of the ejector of the reactor, the thermal decomposition reaction is performed in the edge region of the reactor where the temperature is relatively high and uniform, so that the reaction temperature can be uniform.

In addition, since unreacted hydrocarbons that have not been decomposed through the catalyst are introduced through an ejector and recycled back to the top of the reactor, unreacted hydrocarbons are not discarded and thus are economical.

In addition, the inlet through which unreacted hydrocarbons are re-introduced into the reactor through the circulation pipe and the diffuser of the ejector are formed to face each other at a predetermined interval, so that the unreacted hydrocarbon gas flowing into the reactor through the circulation pipe passes through the diffuser of the ejector. Mixability and fluidity of the gas inside the reactor can be improved by allowing the gas to flow into the catalyst after being mixed with the injected mixed gas.

In addition, the hydrocarbon gas supplied to the reactor through the hydrocarbon gas supply pipe and the combustion exhaust gas discharged from the combustion chamber are heat-exchanged through a heat exchanger to preheat the hydrocarbon gas, thereby increasing the hydrocarbon gas injection speed of the gas injection nozzle to the chamber and mixing part of the ejector. By further lowering the pressure, the pressure difference with the surroundings of the ejector can be increased to increase the recirculation flow rate of unreacted hydrocarbons and high-concentration hydrogen at the bottom of the reactor. Accordingly, the effect of preventing the catalyst from being lowered is improved, and more unreacted hydrocarbons are directly recycled in the reactor and re-reacted through the catalyst, thereby improving hydrogen productivity.

The effects of the present invention are not limited to the effects mentioned above, and other effects not mentioned will be clearly understood by those skilled in the art from the description of the claims.

1 is a diagram showing the internal structure of a reactor in a hydrocarbon pyrolysis hydrogen production apparatus according to a preferred embodiment of the present invention.
Figure 2 is a view showing the external structure of the reactor in the hydrocarbon pyrolysis hydrogen production apparatus according to a preferred embodiment of the present invention.
Figure 3 is a schematic diagram showing the overall configuration of a hydrocarbon pyrolysis hydrogen production apparatus according to a preferred embodiment of the present invention.

A preferred embodiment of the present invention will be described in more detail with reference to the accompanying drawings, but the already well-known technical parts will be omitted or compressed for conciseness of description.

Hereinafter, a hydrocarbon pyrolysis hydrogen production apparatus according to a preferred embodiment of the present invention will be described in detail with reference to the accompanying drawings.

1 is a view showing the internal structure of a reactor in a hydrocarbon pyrolysis hydrogen production apparatus according to a preferred embodiment of the present invention, Figure 2 shows the external structure of a reactor in a hydrocarbon pyrolysis hydrogen production apparatus according to a preferred embodiment of the present invention Figure 3 is a schematic diagram showing the overall configuration of a hydrocarbon pyrolysis hydrogen production apparatus according to a preferred embodiment of the present invention.

1 to 3, the hydrocarbon pyrolysis hydrogen production device according to a preferred embodiment of the present invention includes a hydrocarbon gas supply control valve 100, a desulfurization device 120, a compressor 130, and a heat exchanger 140 , Reactor 200, ejector 240, carbon recovery device 300, hydrogen separator 400, purge valve 800, buffer tank 500 and recirculation blower 600, and is formed including, as shown in the drawing Although not shown, a controller (not shown) for controlling the entire configuration of the hydrocarbon pyrolysis hydrogen production device is provided separately.

The hydrocarbon gas supply control valve 100 controls the supply and blocking of hydrocarbon gas supplied through the hydrocarbon gas supply pipe 110 .

The desulfurization device 120 is provided to remove sulfur contained in the supplied hydrocarbon gas.

Compressor 130 is provided to compress hydrocarbon gas to high pressure.

The heat exchanger 140 exchanges heat between the hydrocarbon gas introduced through the hydrocarbon gas supply pipe 110 and the combustion exhaust gas introduced into the heat exchanger 140 from the combustion chamber 210 through the combustion exhaust gas inlet pipe 141. It serves to preheat the hydrocarbon gas, and the combustion exhaust gas after heat exchange is discharged through the combustion exhaust gas discharge pipe 142.

As described above, the gas injection speed of the gas injection nozzle 150 may be increased by preheating the hydrocarbon gas through the heat exchanger 140 to increase the temperature of the gas and then supplying the gas to the gas injection nozzle 150 .

RT,

: 비열비, R : 가스 상수, T : 절대 온도, 즉 노즐의 음속 a는 노즐 내부의 절대 온도 T에 비례하여 상승함하게 되며, 가스 분사 노즐(150)의 끝단에서의 가스 분사 속도는 음속과 동일한 속도가 되기 때문에 열교환기(140)를 통해 탄화수소 가스를 예열함으로써 가스 분사 노즐(150)의 분사 속도를 최대로 높일 수 있는 것(노즐의 유체 분사 속도는 음속을 넘어설 수 없음)이다.That is, as described above, in the present invention, the hydrocarbon gas is compressed and preheated through the compressor 130 and the heat exchanger 140, and the high-temperature and high-pressure hydrocarbon gas is supplied to the gas injection nozzle 150 so that the gas of the gas injection nozzle 150 is supplied. The injection speed can be increased, and as the temperature of the hydrocarbon gas increases through the heat exchanger 140, the temperature inside the gas injection nozzle 150 rises, and accordingly, the sound speed of the nozzle increases (the sound speed of the nozzle a =

RT,

: specific heat ratio, R: gas constant, T: absolute temperature, that is, the sound speed a of the nozzle rises in proportion to the absolute temperature T inside the nozzle, and the gas ejection speed at the end of the gas injection nozzle 150 is Since the speed is the same, the injection speed of the gas injection nozzle 150 can be increased to the maximum by preheating the hydrocarbon gas through the heat exchanger 140 (the fluid injection speed of the nozzle cannot exceed the speed of sound).

The reactor 200 is provided to decompose hydrocarbon gas into gaseous hydrogen and solid carbon, and a combustion chamber 210 and an electric heater 220 for increasing the internal temperature of the reactor 200 to the reaction temperature are provided in the reactor ( 200), and the catalyst 250 supported on the carrier is provided at the inner edge of the reactor 200. Accordingly, the hydrocarbon gas supplied to the reactor 200 is decomposed into gaseous hydrogen and solid carbon through an endothermic reaction in the presence of the catalyst 250 . At this time, in the present invention, it is also possible to selectively install the combustion chamber 210 or the electric heater 220 in the reactor 200 as needed.

The support has high porosity so as to support a plurality of catalysts 250 and is designed so that solid-state carbon deposited on the catalyst 250 can fall downward by gravity and flow depending on conditions, and the catalyst 250 uses a heterogeneous catalyst such as nickel, iron, carbon or platinum group metal (PGM).

In addition, the hydrocarbon gas may be used alone or in combination with methane, propane, butane, liquefied petroleum gas (LPG), liquefied natural gas (LNG), methanol, ethanol, and the like.

In addition, air necessary for combustion is supplied to the combustion chamber 210 through an air injection pipe 211, and an orifice 212 is provided in the air injection pipe 211 to adjust the flow rate of air supplied to the combustion chamber 210, The combustion exhaust gas generated in the combustion chamber 210 flows into the heat exchanger 140 through the combustion exhaust gas inlet pipe 141, preheats the hydrocarbon gas, and then is discharged through the combustion exhaust gas outlet pipe 142.

Meanwhile, an ejector 240 is provided at the inner center of the reactor 200 . The ejector 240 is composed of a chamber 241 into which the hydrocarbon gas injected through the gas injection nozzle 150 is introduced, a mixing section 242 whose inner diameter rapidly decreases, and a diffusion section 243 whose inner diameter rapidly increases. .

The hydrocarbon gas ejected at high speed from the gas injection nozzle 150 by the ejector 240 configured as described above passes through the chamber 241 of the ejector 240 and moves to the mixing section 242 where the inner diameter rapidly decreases, increasing the speed. As the pressure increases rapidly, the pressure rapidly decreases and the pressure in the chamber 241 and the mixing unit 242 of the ejector 240 is rapidly reduced. As a result, a large pressure difference is generated between the chamber 241 and mixing unit 242 of the ejector 240 and the surroundings of the chamber 241 (the lower end of the reactor 200), resulting in unreacted Hydrocarbon and hydrogen generated through the reaction process are introduced into the chamber 241 of the ejector 240 and mixed with the supplied hydrocarbon gas to form a mixed gas. Thereafter, the mixed gas rises to the top of the reactor 200 through the diffusion part 243 of the ejector 240 and then descends again along the outer circumferential space of the ejector 240, whereby a thermal decomposition reaction takes place in the presence of the catalyst 250. After that, it moves to the bottom of the reactor 200.

Accordingly, "the hydrocarbon gas supplied to the ejector 240 and the unreacted hydrocarbon and hydrogen at the bottom of the reactor 200 flowing into the ejector 240 by the pressure difference" are mixed with each other and then moved inside the ejector 240. While being preheated to increase the temperature, the reaction temperature can be uniformed by performing a thermal decomposition reaction in the catalyst 250 disposed in the outer circumferential space of the ejector 240 located in the center of the reactor 200, thereby reducing the thermal decomposition reactivity of hydrocarbons. It can improve the productivity of hydrogen.

In addition, unreacted hydrocarbons that have not been decomposed while passing through the catalyst 250 are introduced into the ejector 240 and then recycled to the catalyst of the reactor 200 so that the unreacted hydrocarbons can participate in the reaction again and be thermally decomposed.

In addition, the high concentration hydrogen generated through the reaction process at the bottom of the reactor 200 is re-introduced through the ejector 240 and supplied to the catalyst 250 in a mixed state with hydrocarbon gas, thereby reducing the activity of the catalyst 250 can be prevented or delayed. When hydrogen is added to the hydrocarbon gas supplied to the catalyst 250 of the reactor 200, it is a known fact confirmed in the paper below that hydrogen improves the stability of the catalyst 250 and delays the deterioration of the catalyst 250. to be. (See the paper: Jiaofei Wang, Lijun Jin, Yang Li, Mingyi Wang, Haoquan Hu, "Effect of hydrogen additive on methane decomposition to hydrogen and carbon over activated carbon catalyst", International Journal of Hydrogen Energy, Volume 43, Issue 37, 13 September 2018, Pages 17611-17619)

Meanwhile, although the gas injection nozzle 150 is described as being formed separately from the ejector 240 in this embodiment, it is also possible to integrally form the gas injection nozzle 150 with the ejector 240.

In the present invention, as described above, the high-pressure hydrocarbon gas preheated through the compressor 130 and the heat exchanger 140 is supplied to the gas injection nozzle 150 to increase the gas injection speed to the maximum, so that the injected hydrocarbon gas As the speed in the mixing section 242 of the ejector 240 rises more rapidly, the pressure in the chamber 241 and the mixing section 242 drops more significantly, thereby causing the chamber 241 and the mixing section of the ejector 240 to The pressure difference between the part 242 and the surroundings of the chamber 241 (the lower part of the reactor 200) becomes larger, so that more unreacted hydrocarbons at the lower part of the reactor 200 flow into the chamber 241 of the ejector 240 and are recycled. flow is increased. Accordingly, more unreacted hydrocarbons are immediately recycled in the reactor 200 and re-reacted through the catalyst 250, thereby improving hydrogen productivity.

The carbon recovery device 300 is provided to recover carbon deposited on the catalyst 250 in a solid state when it falls and discharge it to the outside, and a carbon filter (not shown) is provided inside.

The hydrogen separator 400 serves to separate hydrogen from a mixed gas of hydrogen and unreacted hydrocarbons and discharge it to the outside through a hydrogen discharge pipe 410.

The purge valve 800 is opened at regular intervals and hydrogen is separated through the hydrogen separator 400 and serves to introduce remaining unreacted hydrocarbons into the combustion chamber 210 through the combustion gas inlet pipe 810, thereby purging A heat source is periodically supplied to the combustion chamber 210 by the valve 800 .

The buffer tank 500 serves to maintain a constant pressure of unreacted hydrocarbons recycled to the reactor 200 through the circulation pipe 610.

The recirculation blower 600 serves to recirculate unreacted hydrocarbons to the reactor 200 through the circulation pipe 610. At this time, in the present invention, the inlet 611 through which the unreacted hydrocarbon flows into the reactor 200 through the circulation pipe 610 and the diffusion part 243 of the ejector 240 are formed to face each other at a predetermined interval, After the unreacted hydrocarbon flowing into the reactor 200 through the circulation pipe 610 is mixed with the mixed gas injected through the diffusion part 243 of the ejector 240, it can flow to the catalyst 250 so that the inside of the reactor Mixability and fluidity of gas can be improved.

Meanwhile, in the present invention, it is also possible to selectively install the nitrogen gas supply unit 700, the flow controller 720, and the nitrogen gas supply pipe 710 for nitrogen purge as needed.

Hereinafter, a hydrogen production method of the hydrocarbon pyrolysis hydrogen production apparatus according to the present invention having the above configuration will be described in detail.

The hydrocarbon gas supplied to the hydrocarbon gas supply pipe 110 by the hydrocarbon gas supply control valve 100 passes through the desulfurization device 120 to remove sulfur, and is compressed and preheated through the compressor 130 and the heat exchanger 140. and is injected into the chamber 241 of the ejector 240 through the gas injection nozzle 150 in a high-temperature and high-pressure state.

The hydrocarbon gas injected into the chamber 241 of the ejector 240 moves to the mixing section 242 where the inner diameter rapidly decreases, and as the speed increases rapidly, the pressure rapidly decreases and the chamber 241 and The pressure of the mixing unit 242 is rapidly reduced. As a result, a large pressure difference is generated between the chamber 241 and mixing unit 242 of the ejector 240 and the surroundings of the chamber 241 (the lower end of the reactor 200), resulting in unreacted Hydrogen generated during the hydrocarbon and thermal reaction flows into the chamber 241 of the ejector 240 by a pressure difference and is mixed with the hydrocarbon gas.

Thereafter, as the mixed gas flows into the diffusion unit 243, the speed rapidly decreases and the pressure rapidly increases, and is injected to the upper end of the reactor 200, and then decomposed through an endothermic reaction in the presence of the catalyst 250 while descending to the reactor ( 200) to the bottom.

As described above, in the present invention, the hydrocarbon gas supplied to the ejector 240 and the unreacted hydrocarbon at the bottom of the reactor 200 flowing into the ejector 240 by the pressure difference and high concentration hydrogen are mixed with each other, and then preheated while rising. By performing a thermal decomposition reaction in the catalyst 250 provided at the edge of the reactor 200 where the temperature is relatively high and uniform in the state, the productivity of hydrogen can be increased by improving the thermal decomposition reactivity of hydrocarbons. That is, in the present invention, while the hydrocarbon gas is supplied to the reactor 200, it does not immediately react with the catalyst 250, but moves to the top of the reactor 200 through the ejector 240 and reacts with the catalyst 250 while descending again. Therefore, before reacting with the catalyst 250, it is preheated while ascending inside the ejector 240, and then reacts with the catalyst 250.

In addition, unreacted hydrocarbons that have not been decomposed while passing through the catalyst 250 are introduced through the ejector 240 and recycled back to the top inside the reactor 200, so that the unreacted hydrocarbons are directly recycled in the reactor 200 and the catalyst 250 ) can be decomposed.

In addition, hydrogen generated through the reaction process is introduced from the bottom of the reactor 200 through the ejector 240 and supplied to the catalyst 250 in a mixed state with hydrocarbon gas, delaying the deterioration of the activity of the catalyst 250. can make it

At this time, in the present invention, as described above, the high-temperature and high-pressure hydrocarbon gas is supplied to the gas injection nozzle 150 through the compressor 130 and the heat exchanger 140 to increase the injection speed of the gas injection nozzle 150 to the maximum value. As the velocity of the injected hydrocarbon gas increases more rapidly in the mixing section 242 of the ejector 240, the pressure in the chamber 241 and the mixing section 242 drops more significantly, thereby causing the ejector 240 The pressure difference between the chamber 241 and the mixing unit 242 and the surroundings of the chamber 241 (the lower end of the reactor 200) becomes larger, so that unreacted hydrocarbons and high-concentration hydrogen at the bottom of the reactor 200 are removed from the ejector 240. More of the flow is introduced into the chamber 241 of the recirculation flow rate is increased. Accordingly, as the recirculation flow rate increases, the effect of preventing the catalyst 250 from decreasing in activity is improved, and more unreacted hydrocarbons are directly recycled in the reactor 200 and re-reacted through the catalyst 250. By doing so, the productivity of hydrogen can be improved.

On the other hand, some of the unreacted hydrocarbons and hydrogen decomposed by the catalyst 250 and moved to the bottom of the reactor 200 are introduced into the ejector 240 and recycled inside the reactor 200, and the rest is solid carbon and hydrogen. The carbon in the solid state flows through the circulation pipe 610 together and is recovered to the carbon recovery device 300, and the mixed gas of hydrogen and unreacted hydrocarbons passes through the carbon recovery device 300 to the hydrogen separator 400. is introduced

Hydrogen is separated in the hydrogen separator 400 and discharged through the hydrogen discharge pipe 410, and unreacted hydrocarbons are returned to the reactor 200 through the circulation pipe 610 by the buffer tank 500 and the recirculation blower 600 are supplied

Unreacted hydrocarbons introduced through the inlet 611 at the top of the reactor 200 are mixed with the mixed gas discharged through the diffusion part 243 of the ejector 240, and then pass through the catalyst 250 to the bottom of the reactor 200. flow with

Hydrocarbon pyrolysis hydrogen production apparatus and hydrogen production method, which solves the catalyst activity decrease according to the present invention as described above, have an ejector in the center of the reactor, mix unreacted hydrocarbon and hydrogen at the bottom of the reactor flowing into the ejector, and preheat Hydrogen productivity can be increased by improving the pyrolysis reactivity of hydrocarbons by performing a pyrolysis reaction in a catalyst provided at the edge of a reactor having a relatively high and uniform post-temperature.

In addition, unreacted hydrocarbons that have not been decomposed while passing through the catalyst are introduced through an ejector and recycled back to the top inside the reactor, whereby the unreacted hydrocarbons can be directly recycled in the reactor and decomposed through the catalyst.

In addition, a high concentration of hydrogen already present at the bottom of the reactor is introduced through an ejector and supplied to the reaction unit, thereby preventing or delaying the deterioration of catalyst activity.

In addition, the inlet through which unreacted hydrocarbons are re-introduced into the reactor through the circulation pipe and the diffuser of the ejector are formed to face each other at a predetermined interval, so that the unreacted hydrocarbon gas flowing into the reactor through the circulation pipe passes through the diffuser of the ejector. Mixability and fluidity of the gas inside the reactor can be improved by allowing the gas to flow into the catalyst after being mixed with the injected mixed gas.

In addition, the hydrocarbon gas supplied to the reactor through the hydrocarbon gas supply pipe and the combustion exhaust gas discharged from the combustion chamber are heat exchanged through a heat exchanger to preheat the hydrocarbon gas, thereby improving hydrogen production efficiency and recirculating hydrogen at the bottom of the reactor through an ejector. By supplying it to the catalyst, it has the effect of preventing or delaying the deterioration of the catalyst's activity, and the productivity of hydrogen can be improved by re-reacting through the catalyst by directly recycling unreacted hydrocarbons in the reactor.

As described above, the detailed description of the present invention has been made by the embodiments with reference to the accompanying drawings, but since the above-described embodiments have only been described as preferred examples of the present invention, the present invention is limited to the above embodiments. It should not be understood that it is, and the scope of the present invention should be understood as the following claims and their equivalent concepts.

100: hydrocarbon gas supply control valve
110: hydrocarbon gas supply pipe
120: desulfurization device
130: compressor
140: heat exchanger
141: Combustion exhaust gas inlet pipe
142: combustion exhaust gas discharge piping
150: gas injection nozzle
200: reactor
210: combustion chamber
211: air injection pipe
212: Orifice
220: electric heater
240: ejector
241: chamber
242: mixing section
243: diffusion unit
250: Catalyst
300: carbon recovery device
400: hydrogen separator
410: hydrogen discharge pipe
500: buffer tank
600: recirculation blower
610: circulation piping
611: inlet
700: nitrogen gas supply unit
710: nitrogen gas supply pipe
720: flow controller
800: purge valve
810: Combustion gas inflow pipe

Claims (6)

a reactor that decomposes hydrocarbon gas into hydrogen and carbon;
an ejector provided at the inner center of the reactor;
a catalyst provided between the ejector and the inner wall of the reactor; and
A circulation pipe provided to recover hydrogen decomposed in the reactor and resupply unreacted hydrocarbons to the reactor and connected to the upper end of the reactor; includes,
The ejector,
a chamber into which the hydrocarbon gas injected through the gas injection nozzle is introduced;
a mixing unit located at an upper end of the chamber and having a rapidly reduced inner diameter;
It is located at the upper end of the mixing section and has a rapidly increasing inner diameter; and a diffusion section.
The inlet of the ejector is located below the catalyst, and the outlet of the ejector is located above the catalyst,
While the hydrocarbon gas injected through the gas injection nozzle and introduced into the chamber moves to the mixing section where the inner diameter rapidly decreases, a pressure difference is generated between the chamber of the ejector, the mixing section, and the lower end of the reactor, thereby generating the reactor. Unreacted hydrocarbons present at the bottom and hydrogen generated through the reaction process are introduced into the chamber of the ejector and mixed with hydrocarbon gas supplied through the gas injection nozzle to form a first mixed gas,
The first mixed gas rises to the upper end of the reactor through the diffusion part of the ejector and is mixed again with unreacted hydrocarbons flowing into the upper end of the reactor through the circulation pipe to form a second mixed gas;
As the second mixed gas descends to the bottom of the reactor again along the catalyst formed in the outer circumferential space of the ejector, the unreacted hydrocarbons included in the second mixed gas are re-reacted with the catalyst, and at the same time, the second mixed gas Hydrocarbon pyrolysis hydrogen production apparatus, characterized in that the hydrogen contained in is supplied to the catalyst to prevent the activity of the catalyst from deteriorating.
delete delete delete injecting high-pressure hydrocarbon gas through a gas injection nozzle into an ejector chamber provided at the center of the reactor;
While the hydrocarbon gas introduced into the chamber of the ejector moves to the mixing section of the ejector whose inner diameter rapidly decreases, a large pressure difference is generated between the chamber and the mixing section of the ejector and the lower end of the reactor so that the lower end of the reactor forming a first mixed gas by mixing existing unreacted hydrocarbons and hydrogen generated through the reaction process into the chamber of the ejector and mixing with the hydrocarbon gas injected through the gas injection nozzle;
forming a second mixed gas by injecting the first mixed gas into an upper end of the reactor through a diffusion part of the ejector and mixing again with unreacted hydrocarbons flowing into the upper end of the reactor through a circulation pipe; and
As the second mixed gas descends to the lower end of the reactor again along the catalyst formed in the outer circumferential space of the ejector, the unreacted hydrocarbons included in the second mixed gas are re-reacted with the catalyst and simultaneously added to the second mixed gas. Hydrogen production method of a hydrocarbon pyrolysis hydrogen production apparatus comprising the; step of preventing the contained hydrogen is supplied to the catalyst to reduce the activity of the catalyst.
According to claim 5,
Hydrogen production method of hydrocarbon pyrolysis hydrogen production apparatus, characterized in that the gas passing through the ejector is preheated while rising in the ejector.

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