JP2013253003A - Method and apparatus for producing hydrogen - Google Patents

Abstract

PROBLEM TO BE SOLVED: To improve heat resistance of a reactor which is used in an autothermal reforming process wherein a hydrocarbon is reacted with water and oxygen.SOLUTION: A reactor 2 includes: a gas introduction port 3 for introducing a gas containing a hydrocarbon and oxygen; and a peripheral wall 5 forming a reaction region 2a for the hydrocarbon and oxygen in the downstream of the gas introduction port 3. Water vapor for cooling the peripheral wall 5 which is heated by the reaction heat between the hydrocarbon and oxygen in an autothermal reforming process is introduced into the reaction region 2a from the outside of the peripheral wall 5 through a water vapor channel that penetrates through the inner and outer peripheral surfaces 5b, 5a of the peripheral wall 5. The water vapor that has cooled the peripheral wall 5 is used as at least some of the water vapor to be reacted with the hydrocarbon in the autothermal reforming process.

Description

  The present invention relates to a method for generating hydrogen by autothermal reforming in which a hydrocarbon reacts with oxygen and steam, and a hydrogen generator suitable for carrying out this method.

  Hydrogen is said to be clean energy and is expected as a fuel for hydrogen automobiles and fuel cells. Further, hydrogen has a wide range of uses such as industrially used as a reducing agent. Conventionally, a method of generating hydrogen by autothermal reforming combining a partial oxidation reaction and a steam reforming reaction is known.

  Since methanol contains oxygen, the autothermal reforming step is performed at a relatively low temperature (see Patent Document 1). However, in hydrocarbons such as methane not containing oxygen, it has been shown that the autothermal reforming process proceeds at, for example, 700 ° C. (see Patent Document 2). Further, even when a specific catalyst is used, it has been shown that the temperature at which the autothermal reforming of hydrocarbon proceeds is about 550 ° C. to 650 ° C. (see Patent Document 3).

Special table WO2008 / 149900 JP 2002-121007 A JP 2004-196646 A

  As a reactor for performing the autothermal reforming process, a gas introduction port for introducing a gas containing hydrocarbon and oxygen and a reaction region of hydrocarbon and oxygen are formed downstream of the gas introduction port. What has a surrounding wall is used. The material of such a reactor is generally carbon steel or stainless steel.

  General carbon steel is said to have a heat resistant temperature of 400 ° C. or lower, and SUS304 material, which is a general stainless steel, is said to have a heat resistant temperature of 700 ° C. or lower. Therefore, when the auto-thermal reforming process of hydrocarbons is performed using general carbon steel or stainless steel as the reactor material, it is exposed to high heat during the partial oxidation reaction, which is a reaction between hydrocarbons and oxygen. There is a problem that the life of the reactor is shortened. Further, if a material having excellent heat resistance such as SUS310S having a high chromium and nickel content is employed as the material of the reactor, there is a problem that the reactor becomes expensive.

  Therefore, it is conceivable to cool the reactor from the outside during the partial oxidation reaction. However, large thermal energy is generated in the reaction region between hydrocarbon and oxygen. Therefore, even if the reactor is cooled from the outside, the inner peripheral surface of the peripheral wall forming the reaction region is exposed to high heat, so that there is a problem that the heat resistance cannot be sufficiently improved.

  An object of the present invention is to provide a hydrogen generation method and a generation apparatus that can solve the above-described problems of the prior art.

The method for producing hydrogen according to the present invention includes an autothermal reforming process in which hydrocarbons are reacted with oxygen and steam using a catalyst in a reactor, and the reactor introduces a gas containing hydrocarbons and oxygen. And a peripheral wall that forms a reaction region of hydrocarbon and oxygen downstream of the gas inlet. In the method of the present invention, the steam for cooling the peripheral wall heated by the reaction heat of hydrocarbon and oxygen in the autothermal reforming step is passed through a steam passage that penetrates the inner and outer peripheral surfaces of the peripheral wall. Water vapor that cools the peripheral wall is used as at least part of the water vapor that is introduced into the reaction region from the outside of the peripheral wall and reacts with hydrocarbons in the autothermal reforming step.
According to the present invention, water vapor for cooling the peripheral wall heated by the reaction heat of hydrocarbon and oxygen in the autothermal reforming process is transferred to the reaction region via the water vapor passage penetrating the inner and outer peripheral surfaces of the peripheral wall. Can lead. Thereby, since the internal peripheral surface side of the surrounding wall exposed to high heat can be cooled, the heat resistance of a reactor can be improved. Furthermore, the heat of reaction in the partial oxidation reaction between hydrocarbon and oxygen can be absorbed by the steam reforming reaction between steam and hydrocarbon that have cooled the peripheral wall.

In the method of the present invention, water vapor different from the water vapor passing through the water vapor passage is reacted with hydrocarbons in the autothermal reforming step, and the reaction zone through the gas inlet with hydrocarbons and oxygen. It is preferable to introduce into
If the temperature of the gas produced by the partial oxidation reaction is too high, the catalytic activity is lowered. Therefore, by introducing water vapor different from water vapor passing through the water vapor passage to cool the peripheral wall into the reaction region together with hydrocarbons and oxygen from the gas inlet, the gas temperature generated by the partial oxidation reaction is increased. The steam can be subjected to a steam reforming reaction while preventing the steam from passing.

An apparatus for producing hydrogen according to the present invention includes a reactor for performing an autothermal reforming process in which hydrocarbons are reacted with oxygen and steam using a catalyst, and the reactor contains a gas containing hydrocarbons and oxygen. It has a gas inlet for introduction and a peripheral wall that forms a reaction region of hydrocarbon and oxygen downstream of the gas inlet. The apparatus of the present invention includes a steam passage that penetrates the inner and outer peripheral surfaces of the peripheral wall, and a supply source of steam for cooling the peripheral wall that is heated by reaction heat of hydrocarbon and oxygen in the autothermal reforming step, The steam that is connected to the steam passage and cools the peripheral wall is used as at least part of the steam that reacts with hydrocarbons in the autothermal reforming process, from the outside of the peripheral wall through the steam passage. It is introduced into the reaction zone.
According to the apparatus of the present invention, the method of the present invention can be carried out.

In the device according to the present invention, the space forming portion that covers the outer peripheral surface of the peripheral wall is provided, and in the annular region along the outer peripheral surface of the peripheral wall, a space facing the outer peripheral surface of the peripheral wall is formed by the space forming portion. And a plurality of through holes are formed in the peripheral wall at circumferential intervals, the water vapor passage is formed by the through holes, and a supply source of steam for cooling the peripheral wall is It is preferable to be connected to the water vapor passage through a space. Thereby, the water vapor | steam for cooling of a surrounding wall can be reliably guide | induced to the inner peripheral surface side of a surrounding wall. Further, the water vapor that has cooled the peripheral wall is caused to flow toward the center of the reaction region, and the temperature of the reaction region is lowered from the center toward the inner peripheral surface of the peripheral wall, thereby effectively cooling the peripheral wall.
Further, a cover extending from one end of the peripheral wall toward the gas introduction port is provided, and a recess extending inward from the inner peripheral surface of the peripheral wall is formed in an annular portion along one end of the peripheral wall in the cover. A plurality of through holes are formed in the cover at circumferential intervals between the recess and the reaction region, and a cooling water supply source for the peripheral wall is formed in the cover through the recess. It is preferable to be connected to the formed through hole. Also by this, the steam for cooling the peripheral wall can be guided to the inner peripheral surface side of the peripheral wall.
In addition, it is preferable that a flow path surrounding the space forming portion is provided, and a water vapor cooling fluid introduced into the space is introduced into the flow path. Thereby, the steam for cooling the peripheral wall can be cooled by the cooling fluid.

  According to the method and apparatus for producing hydrogen of the present invention, the heat resistance of a reactor used in an autothermal reforming process in which a hydrocarbon is reacted with water and oxygen is improved, and an expensive reactor material is used. Costs can be reduced by eliminating the necessity and extending the life of the reactor.

FIG. 4 is a longitudinal sectional view for explaining the configuration of the hydrogen generator according to the first embodiment of the present invention. II-II sectional view of FIG. FIG. 3 is a partial longitudinal sectional view for explaining the configuration of the hydrogen generator according to the first embodiment of the present invention. Structure explanatory drawing longitudinal cross-sectional view of the hydrogen generator which concerns on 2nd Embodiment of this invention Cross-sectional view taken along line VV in Fig. 4 Partial vertical sectional view for explaining the configuration of the hydrogen generator according to the second embodiment of the present invention

  The hydrogen generator 1 according to the first embodiment shown in FIGS. 1 to 3 includes a reactor 2 for executing an autothermal reforming process in which a hydrocarbon is reacted with oxygen and steam. The reactor 2 of the present embodiment has a gas inlet 3 at the upper end, a gas outlet 4 at the lower end, and a cylindrical peripheral wall 5 having a vertical axis between the gas inlet 3 and the gas outlet 4. Have.

  An upper cover 6 extending from one end of the peripheral wall 5 toward the gas inlet 3 is provided, and the gas inlet 3 is formed in the upper cover 6. The inner diameter of the upper cover 6 is increased toward the downstream of the gas flow so that the gas flow introduced from the gas inlet 3 is diffused. A lower cover 7 extending from the other end of the peripheral wall 5 toward the gas outlet 4 is provided, and the gas outlet 4 is formed in the lower cover 7. The inner diameter of the lower cover 7 is made smaller toward the downstream of the gas flow so that the gas flow flowing out from the gas outlet 4 is narrowed.

  The gas inlet 3 is used for introducing a gas containing hydrocarbon and oxygen and water vapor into the reactor 2. As the hydrocarbon, for example, natural gas mainly composed of methane, LPG, steam gasoline, naphtha, kerosene and the like are introduced into the reaction region 2a. For example, oxygen is introduced into the reaction region 2a as oxygen gas or in a state of being contained in air or oxygen-enriched gas. Hydrocarbon, oxygen, and water vapor may be supplied from an unillustrated supply source and mixed and then introduced into the gas inlet 3 or may be introduced into the gas inlet 3 without being mixed.

The peripheral wall 5 forms a reaction region 2 a of hydrocarbon and oxygen downstream of the gas inlet 3. In the reaction region 2a of the present embodiment, a reaction between a hydrocarbon and water vapor and a reaction between carbon monoxide and water vapor are also performed. That is, the autothermal reforming process is a combination of a partial oxidation reaction and a steam reforming reaction. For example, when the hydrocarbon is methane, the partial oxidation reaction represented by the following formula (1) and the formula (2) are used. Hydrogen is generated by the steam reforming reaction. Furthermore, the shift reaction represented by the formula (3) may be included in the autothermal reforming step. The temperature of the reaction region 2a is maintained above a certain level by heat generated by the partial oxidation reaction that is an exothermic reaction, and the heat is absorbed by the steam reforming reaction that is the endothermic reaction of the formula (2). Further, when hydrogen is also generated by the shift reaction, heat generated by the shift reaction is also absorbed by the steam reforming reaction.
CH ₄ +1/2 O ₂ → CO + 2H ₂ (1)
CH ₄ + H ₂ O → CO + 3H ₂ (2)
CO + H ₂ O⇔CO ₂ + H ₂ (3)

  The reaction zone 2a is filled with a catalyst that promotes the reaction in the autothermal reforming process. The type of catalyst is not particularly limited as long as it is suitable for autothermal reforming. Generally, noble metal catalysts such as platinum, palladium, nickel, rhodium can be used, and rhodium is particularly preferable. These catalysts are generally considered to be usable even at high temperatures. However, when a certain temperature level is exceeded, sintering occurs, causing a decrease in catalyst activity. For this reason, it is preferable to suppress the maximum temperature of the partial oxidation reaction to a temperature level that causes sintering. If the maximum temperature of the partial oxidation reaction is expected to be higher than the level at which sintering occurs, water vapor is introduced into the reaction region 2a from the gas inlet 3 simultaneously with the hydrocarbon and oxygen as in this embodiment. Is preferred. For example, the temperature level causing sintering is said to be about 700 ° C. for a platinum catalyst, about 600 ° C. for a palladium catalyst, and about 800 ° C. for a rhodium catalyst.

  For example, the amount of methane provided for the partial oxidation reaction is equal to the amount of methane provided for the steam reforming reaction, and methane, oxygen, and water vapor are expressed by the formula (1) with a molar ratio of 2.0: 0.5: 3.0. ) To (3) Consider the case of complete reaction. In this case, only the partial oxidation reaction of the formula (1) is generated at the end of the partial oxidation reaction, assuming that it is started at the temperature of 600 ° C. necessary to advance the steam reforming reaction of the formula (2). The temperature of the reaction gas is 820 ° C. Therefore, in order to prevent the catalytic activity from being lowered, water vapor is introduced into the reaction region 2a from the gas inlet 3 simultaneously with the hydrocarbon and oxygen as in this embodiment, and the partial oxidation reaction is performed in the presence of water vapor. It is preferable to prevent the temperature of the gas produced by the oxidation reaction from becoming too high.

  The gas containing hydrogen generated in the autothermal reforming process flows out from the gas outlet 4. In order to separate hydrogen from the gas flowing out from the gas outlet 4, a gas separation device such as a pressure swing adsorption device may be connected to the gas outlet 4.

  The outer peripheral surface 5a of the peripheral wall 5 is covered with a space by a space forming portion 11 formed of a cylindrical member. The upper and lower ends of the space forming portion 11 extend inward, and the extended ends are fixed to the upper cover 6 and the lower cover 7 by welding or the like. Thereby, in the annular region along the outer peripheral surface 5 a of the peripheral wall 5, a space 12 that faces the outer peripheral surface 5 a of the peripheral wall is formed by the space forming portion 11. A plurality of water vapor inlets 11 a for introducing cooling water vapor into the space 12 are provided in the upper portion of the space forming portion 11, while the lower portion of the space 12 is closed. A drain pipe for discharging condensed water from the space 12 may be provided.

  A plurality of through holes 13 are formed in the peripheral wall 5 between the space 12 and the reaction region 2a. The through holes 13 of the present embodiment are formed at intervals in the circumferential direction and the axial direction. The through holes 13 may be formed at least at intervals in the circumferential direction. The diameter of the through-hole 13 is made smaller than the particle size of the catalyst so that the granular catalyst filled in the reaction region 2a does not fall out of the peripheral wall 5. In addition, the diameter of the opening 13 may be equal to or larger than the particle diameter of the catalyst, and the peripheral wall 5 may be covered with a metal net that prevents the catalyst from falling off. The diameter, number, pitch, and position of the through holes 13 may be determined by experiments so that the cooling water vapor that passes through the through holes 13 can cool the peripheral wall 5. The through holes 13 of the present embodiment are formed so as to be distributed over substantially the entire area of the peripheral wall 5. However, since the partial oxidation reaction mainly proceeds upstream of the reaction region 2 a, it is distributed only in the upper region of the peripheral wall 5. You may form as follows.

  Each through hole 13 constitutes a water vapor passage that penetrates the inner and outer peripheral surfaces 5 b and 5 a of the peripheral wall 5. The cooling water vapor is introduced into the space 12 by connecting a cooling water supply source (not shown) to the water vapor inlet 11c. Thereby, the supply source of the cooling water vapor is connected to the water vapor passage constituted by the through hole 13 through the space 12. The peripheral wall 5 heated by the reaction heat of the hydrocarbon and oxygen in the autothermal reforming process is cooled by the cooling steam. That is, as shown by a broken line arrow α in FIG. 3, the cooling water vapor is guided from the outer peripheral surface 5a side of the peripheral wall 5 to the inner peripheral surface 5b side through the water vapor passage and flows toward the center of the reaction region 2a. Thereby, the inner peripheral surface 5b side of the peripheral wall 5 exposed to high heat can be cooled. The temperature of the cooling water vapor is 370 ° C. in this embodiment, but is lower than the gas produced by the partial oxidation reaction, and depends on the heat resistance temperature of carbon steel, stainless steel, etc. that are generally used as the material of the reactor 2. The peripheral wall 5 is preferably set to a temperature at which the peripheral wall 5 can be cooled to 500 ° C. or lower.

  The steam that has cooled the peripheral wall 5 is introduced into the reaction region 2a from the outside of the peripheral wall 5 through the water vapor passage formed by the through holes 13, so that it is part of the water vapor that reacts with the hydrocarbon in the autothermal reforming process. Used. Thereby, the heat of reaction in the partial oxidation reaction between the hydrocarbon and oxygen can be absorbed by the steam reforming reaction between the steam that has cooled the peripheral wall 5 and the hydrocarbon.

  In order to efficiently generate hydrogen in the autothermal reforming process, it is preferable that the exothermic amount of the exothermic reaction and the endothermic amount of the endothermic reaction are balanced in the entire system while maintaining a sufficient temperature for each reaction. . In order to achieve such a thermal balance, the amount of methane supplied to the partial oxidation reaction is made larger than the amount of methane supplied to the steam reforming reaction, for example, the molar ratio of methane, oxygen, and steam is set to 2. Complete reaction is carried out according to the formulas (1) to (3) as 00: 0.77: 2.46. In addition, it is preferable that the water vapor is slightly excessive as compared with the case of complete reaction.

  The outer peripheral surface of the space forming part 11 is covered with a flow path forming part 21 constituted by a cylindrical member. The upper and lower ends of the flow path forming portion 21 extend toward the space forming portion 11, and the extending ends are fixed to the outer peripheral surface of the space forming portion 11 by welding or the like. Thereby, in the annular region along the outer peripheral surface of the space forming part 11, the flow path 22 surrounding the space forming part 11 is formed by the flow path forming part 21. A plurality of inflow ports 21 a connected to an unillustrated supply source of the cooling fluid are formed in the upper part of the flow path forming unit 21. Thereby, the cooling fluid of the cooling water vapor introduced into the space 12 is introduced into the flow path 22. The cooling fluid introduced into the flow path 22 flows out from the plurality of outlets 21b formed in the lower part of the flow path forming portion 21. The cooling fluid flowing out from the outlet 21b may be returned to the supply source or discarded. The cooling fluid only needs to be capable of cooling the water vapor in the space 12. For example, a liquid such as water vapor, an inert gas, or water having a temperature lower than that of the water vapor in the space 12 can be used. It is preferable to do this. When air is introduced as a gas containing oxygen from the gas inlet 3 and a gas separator such as a pressure swing adsorption device is connected to the gas outlet 4, nitrogen in the air separated from hydrogen is cooled by the gas separator. It can be used as a working fluid. By using a liquid as the cooling fluid and evaporating in the flow path 22, the water vapor in the space 12 can be cooled by the heat of evaporation.

  When an autothermal reforming process in which the hydrocarbon is reacted with oxygen and water vapor in the reactor 2 using the hydrogen generating apparatus 1 having the above-described configuration, the upstream portion of the reaction region 2a, that is, the portion close to the gas inlet port 3, The oxidation reaction proceeds mainly, and the steam reforming reaction and the shift reaction proceed somewhat. At this time, water vapor for cooling the peripheral wall 5 heated by the reaction heat of the partial oxidation reaction is introduced into the reaction region 2a from the outside of the peripheral wall 5 through a water vapor passage penetrating the inner and outer peripheral surfaces 5b and 5a of the peripheral wall 5. Is done. Thereby, the water vapor | steam which cooled the surrounding wall 5 can be used as a part of water vapor | steam made to react with a hydrocarbon at an autothermal reforming process. Further, as water vapor to be reacted with hydrocarbon in the autothermal reforming process, water vapor different from water vapor passing through the water vapor passage for cooling the peripheral wall 5 is reacted with the hydrocarbon and oxygen through the gas inlet 3 through the reaction region. Introduced in 2a.

  In the reaction region 2a, the high-temperature reaction gas generated by the partial oxidation reaction and the water vapor introduced from the gas introduction port 3 flow downstream while being surrounded by the water vapor introduced from the through hole 13. As it goes downstream, the gas produced by the partial oxidation reaction is mixed with water vapor. Thereby, in the downstream part of the reaction region 2a, the steam reforming reaction and the shift reaction mainly proceed, and the partial oxidation reaction proceeds somewhat. Due to the progress of the steam reforming reaction, the temperature in the reaction zone 2a decreases as it goes downstream. In order to secure the time for the gas flow after the partial oxidation reaction in the upstream portion of the reaction region 2a to stay in the downstream portion, a baffle plate or the like is attached to the peripheral wall 5 to reduce the heat generated in the upstream portion to the steam reforming in the downstream portion. It is preferable to use it by a quality reaction. In order to mix the gas generated by the partial oxidation reaction with the water vapor introduced from the through-hole 13 as uniformly as possible, it is preferable to attach a baffle plate or the like that makes the gas flow turbulent to the peripheral wall 5.

  According to the above embodiment, the water vapor for cooling the peripheral wall 5 heated by the reaction heat of hydrocarbon and oxygen in the autothermal reforming process is supplied from the outer peripheral surface 5a of the peripheral wall 5 to the inner peripheral surface 5b side. It can be guided through a passage. Thereby, since the inner peripheral surface 5b side of the peripheral wall 5 exposed to high heat can be cooled, the heat resistance of the reactor 2 can be improved. Furthermore, the heat of reaction in the partial oxidation reaction between the hydrocarbon and oxygen can be absorbed by the steam reforming reaction between the steam that has cooled the peripheral wall 5 and the hydrocarbon. Therefore, hydrogen can be efficiently generated, and general carbon steel, stainless steel, or the like can be used as the material of the peripheral wall 5. Therefore, the matter of concern for industrially performing the autothermal reforming of hydrocarbons can be solved by controlling the temperature of the peripheral wall 5. Further, by introducing water vapor different from water vapor passing through the water vapor passage into the reaction region 2a together with hydrocarbons and oxygen from the gas introduction port 3, the gas temperature generated by the partial oxidation reaction becomes too high, and the catalytic activity is increased. The steam can be subjected to a steam reforming reaction while preventing the water from decreasing. Furthermore, the water vapor that has cooled the peripheral wall 5 flows toward the center of the reaction region 2a, and the temperature of the reaction region 2a is lowered from the center toward the inner peripheral surface 5b of the peripheral wall 5 to effectively cool the peripheral wall 5. Further, the water vapor that cools the peripheral wall 5 can be cooled by the fluid flowing through the flow path 22.

  4 to 6 show a hydrogen generator 1 'according to the second embodiment. Hereinafter, differences from the first embodiment will be described, and the same parts are denoted by the same reference numerals and description thereof will be omitted.

  In the second embodiment, a recess 30 extending inward from the inner peripheral surface 5 b of the peripheral wall 5 is formed in an annular portion along one end of the peripheral wall 5 in the upper cover 6. A plurality of through holes 31 are formed in the upper cover 6 at intervals in the circumferential direction between the recess 30 and the reaction region 2a. Since the recess 30 is continuous with the space 12, the cooling water vapor is introduced into the recess 30 through the water vapor inlet 11a. Thereby, the supply source of the cooling water vapor is connected to the through hole 31 through the recess 30. The peripheral wall 5 heated by the reaction heat of the hydrocarbon and oxygen in the autothermal reforming process is cooled by the cooling steam. That is, as shown by a broken line arrow β in FIG. 6, the cooling water vapor is guided from one end side of the peripheral wall 5 to the inner peripheral surface 5 b side through the through hole 31 and flows along the inner peripheral surface 5 b of the peripheral wall 5. . Thereby, the inner peripheral surface 5b side of the peripheral wall 5 exposed to high heat can be cooled. Others are the same as in the first embodiment.

Hydrogen was produced | generated using the production | generation apparatus 1 of 1st Embodiment. The peripheral wall 5 of the reactor 2 had an inner diameter of 10.4 mm and a length of 300 mm. 14 g of rhodium catalyst supported on alumina (0.5% Rh / Al ₂ O ₃ , manufactured by NE Chemcat) was used as a catalyst filled in the reaction zone 2a.
Methane, oxygen, and water vapor previously heated to 600 ° C. with a heater were introduced from the gas inlet 3 into the reaction region 2a at a molar ratio of 2.00: 0.77: 2.00 and a flow rate of 1.06 L / min.
As a water vapor for cooling, water at 370 ° C. was introduced into the space 12 at 88 ml / min, and the molar ratio of methane, oxygen, and water vapor introduced into the reaction region 2a was higher than 2.00: 0.77: 2.46. Was a little excessive.
The cooling fluid was not introduced into the flow path 22.
The residual water vapor was removed from the gas flowing out from the gas outlet 4 and analyzed by gas chromatography (Shimadzu Corporation GC-TCD). As a result, the composition was hydrogen, carbon monoxide and carbon dioxide, and the molar ratio was 77.8. 10.4: 11.8, and the total product gas flow rate was 2.25 L / min. When the temperature of the peripheral wall 5 in the vicinity of the entrance of the reaction region 2a was measured, it was 500 ° C. or lower.

Comparative example

Assuming that the introduction of steam for cooling into the space 12 is stopped and methane, oxygen, and steam from the gas inlet 3 are slightly more than the molar ratio of 2.00: 0.77: 2.46, the flow rate is 1. Hydrogen was produced in the same manner as in Example except that the introduction was performed at 15 L / min.
When the residual water vapor was removed from the gas flowing out from the gas outlet 4 and analyzed by gas chromatography, the composition was hydrogen, carbon monoxide, carbon dioxide, and the molar ratio was 77.7: 10.5: 11. The total product gas flow rate was 2.23 L / min. The composition and amount of the product gas were not significantly different from those in the examples. However, when the temperature of the peripheral wall 5 in the vicinity of the entrance of the reaction region 2a was measured, the maximum was 780 ° C.

The present invention is not limited to the above embodiment.
For example, in the reactor 2 of each of the above embodiments, the partial oxidation reaction, the steam reforming reaction, and the shift reaction are performed in the single reaction region 2a. However, the partial oxidation reaction is mainly performed in the reactor. A reaction region for performing, a reaction region for mainly performing the steam reforming reaction, and a reaction region for mainly performing the shift reaction may be independently formed using individual peripheral walls. In this case, the present invention may be applied to cool the peripheral wall forming the reaction region for mainly performing the partial oxidation reaction. Moreover, it is good also as a thing different in the kind of catalyst filled for every reaction area | region. For example, when the shift reaction is mainly performed in an independent reaction region filled with a noble metal catalyst such as ruthenium, palladium, or rhodium, the reaction region is heated from the outside in order to perform the reaction at 300 ° C. or higher so as not to slow down the reaction rate. You may have to do that. In contrast, a shift reaction is performed in an independent reaction region filled with a copper-based catalyst such as a Cu / Al ₂ O ₃ catalyst supporting copper on alumina or a Cu / ZnO / Al ₂ O ₃ catalyst supporting copper and zinc oxide. Is mainly carried out, the required reaction temperature is 260 to 300 ° C., which may be lower than when a noble metal catalyst is used.

  Moreover, when using a catalyst with high heat resistance, the water vapor | steam which cooled the surrounding wall 5 is made into all the water vapor | steams made to react with a hydrocarbon by an autothermal reforming process, and does not need to introduce | transduce from the gas inlet 3. In short, the steam that has cooled the peripheral wall 5 may be used as at least a part of the steam that reacts with the hydrocarbon in the autothermal reforming step.

  DESCRIPTION OF SYMBOLS 1, 1 '... Hydrogen production | generation apparatus, 2 ... Reactor, 2a ... Reaction area | region, 3 ... Gas inlet, 5 ... Perimeter wall, 5a ... Outer peripheral surface, 5b ... Inner peripheral surface, 6 ... Top cover, 11 ... Space formation Member: 12: Space, 13: Through hole, 22: Flow path, 30: Recess, 31: Through hole.

Claims (6)

Having an autothermal reforming process in which hydrocarbons are reacted with oxygen and steam using a catalyst in a reactor;
In the method for producing hydrogen, the reactor includes a gas inlet for introducing a gas containing hydrocarbon and oxygen, and a peripheral wall that forms a reaction region of hydrocarbon and oxygen downstream of the gas inlet.
Steam for cooling the peripheral wall heated by the reaction heat of hydrocarbon and oxygen in the autothermal reforming step is supplied from the outside of the peripheral wall through a steam passage that penetrates the inner and outer peripheral surfaces of the peripheral wall. Introduced into the reaction zone;
A method for producing hydrogen, comprising using, as at least a part of water vapor reacted with hydrocarbons in the autothermal reforming step, water vapor having cooled the peripheral wall.   The water vapor different from the water vapor passing through the water vapor passage is introduced into the reaction region through the gas introduction port together with hydrocarbons and oxygen as water vapor to be reacted with hydrocarbons in the autothermal reforming step. The method for producing hydrogen according to 1. A reactor for carrying out an autothermal reforming process in which hydrocarbons are reacted with oxygen and water vapor using a catalyst;
In the hydrogen generator, the reactor includes a gas inlet for introducing a gas containing hydrocarbon and oxygen, and a peripheral wall that forms a reaction region of hydrocarbon and oxygen downstream of the gas inlet.
A water vapor passage penetrating the inner and outer peripheral surfaces of the peripheral wall;
A supply source of steam for cooling the peripheral wall heated by reaction heat between hydrocarbon and oxygen in the autothermal reforming step is connected to the steam passage;
Steam that has cooled the peripheral wall is introduced into the reaction region from the outside of the peripheral wall through the steam passage so that it is used as at least part of the steam that reacts with hydrocarbons in the autothermal reforming step. A hydrogen generator characterized by the above. A space forming portion covering the outer peripheral surface of the peripheral wall;
In the annular region along the outer peripheral surface of the peripheral wall, a space facing the outer peripheral surface of the peripheral wall is formed by the space forming portion,
Between the space and the reaction region, a plurality of through holes are formed in the peripheral wall with a circumferential interval,
The water vapor passage is constituted by the through hole,
The hydrogen generating apparatus according to claim 3, wherein a supply source of water vapor for cooling the peripheral wall is connected to the water vapor passage through the space. A cover is provided extending from one end of the peripheral wall toward the gas inlet;
A concave portion extending inward from the inner peripheral surface of the peripheral wall is formed in an annular portion along one end of the peripheral wall in the cover,
Between the recess and the reaction region, a plurality of through holes are formed in the cover with a circumferential interval,
The hydrogen generating apparatus according to claim 4, wherein a supply source of water vapor for cooling the peripheral wall is connected to the through hole formed in the cover via the recess. A flow path surrounding the space forming portion is provided;
The hydrogen generating apparatus according to claim 4 or 5, wherein a fluid for cooling water vapor introduced into the space is introduced into the flow path.

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