JP2010222429A - Hydrogen production method and device - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method and a device for hydrogen production, capable of further improving reaction efficiency between a carbon material and steam and therefore hydrogen production efficiency. <P>SOLUTION: The hydrogen production method comprises: applying a microwave to the carbon material 2 and the steam 1 fed to a reactor 10; and heating the carbon material with the microwave and inducing its reaction with the steam so as to produce hydrogen and carbon monoxide. In the hydrogen production process, a rotational flow 18 of the steam is formed in the reactor 10 so as to secure an air retention time of the carbon material in the steam. The microwave is applied to the carbon material and the steam in an air retention space so as to produce hydrogen and carbon monoxide. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydrogen production method and apparatus for producing hydrogen by heating and reacting carbon and water vapor.

  FIG. 2 shows a hydrogen production apparatus previously proposed by the present inventors. This prior art is disclosed in Japanese Patent Laid-Open No. 2006-89322. According to this hydrogen production apparatus, the upper part of the reactor 20 is provided with the steam pipe 21 and the carbon supply port 23. Carbon 2 supplied through the carbon supply port 23 and water vapor 1 supplied through the steam pipe 21 are held on a porous plate 24 installed in the reactor 20. The microwave 27 is irradiated into the reactor 20 through the waveguide 26. By the microwave irradiation, the carbon material is self-heated and heated up to about 1000 ° C. Under the condition of 1000 ° C., carbon and water vapor react as follows to generate hydrogen and carbon monoxide. The hydrogen and carbon monoxide are discharged to the outside through a discharge port 22 provided at the lower portion of the reactor 20 as indicated by reference numeral 28. Reference numeral 25 denotes a metal shielding plate.

C + H ₂ O → CO + H ₂

JP 2006-89322 A

  The conventional system described above is a form in which water vapor is circulated in a state where a carbon material is deposited on a perforated plate, and it is possible to generate hydrogen with high efficiency by reducing the size of the reactor. However, it is conceivable that the vapor does not come into contact at the place where the carbon materials are in contact with each other, and the reaction area may be sacrificed accordingly.

  Moreover, in the location which contact | connects the reactor inner wall among the carbon materials heated by the microwave, it is also considered that temperature falls by the heat absorption by a wall material and the reaction in that part is suppressed.

  The present invention is to solve the above problems and provide a hydrogen production method and apparatus capable of further improving the reaction efficiency between the carbon material and water vapor, and thus the hydrogen generation efficiency.

The present invention generates hydrogen and carbon monoxide by irradiating the carbon material and water vapor supplied into the reactor with microwaves and heating the carbon material by the microwaves to react with the water vapor. In the hydrogen production method,
Forming a swirl flow of the water vapor in the reactor, ensuring the air residence time in the water vapor of the carbon material by the water vapor swirl flow, and irradiating the carbon material and water vapor in the air stay region To generate hydrogen and carbon monoxide.

  An apparatus for carrying out the hydrogen production method is configured as follows.

  A reactor for producing hydrogen to which a carbon material and water vapor are supplied, and a microwave irradiation device for irradiating the carbon material and water vapor supplied into the reactor with microwaves. In addition, it has a cyclone section that forms a swirling flow of water vapor in the reactor and secures the air residence time necessary for microwave irradiation to the carbon material in the reaction vessel by this water vapor swirling flow. Further, the microwave irradiation device is provided so as to irradiate microwaves to a region where the carbon material in the reactor stays in the air.

  According to the present invention, the carbon material in the form of powder or granules can be made to stay in the reactor (floating in the air) by the steam swirl flow, and the time required for the air residence, that is, hydrogen generation Therefore, it is possible to ensure the residence time in the air necessary for the heating reaction (microwave irradiation) of water vapor and carbon material.

  According to the present invention, since the powder or granular carbon material is in the air at the time of microwave irradiation, the contact between the carbon materials and the contact between the carbon material and the reactor wall surface are minimized and contacted. In this case, the carbon material powders and granules can react with water vapor almost with respect to the entire surface area, improving the reaction efficiency and enabling highly efficient hydrogen production.

1 is a schematic cross-sectional configuration diagram of a hydrogen production apparatus according to a first embodiment of the present invention. The schematic cross-section block diagram which showed an example of the conventional hydrogen production apparatus. The figure which shows the experimental result which irradiated the microwave to the carbon material, and performed the heating test. The figure which shows the production | generation test result of hydrogen and carbon monoxide by the said Example. The figure which compares and shows the dielectric constant of various substances. The schematic cross section block diagram of the hydrogen production apparatus which concerns on 2nd Example of this invention. The schematic cross section block diagram of the hydrogen production apparatus which concerns on 3rd Example of this invention.

An embodiment of the present invention will be described with reference to FIG. 1 and FIGS.
[Example 1]
FIG. 1 is a configuration diagram of a hydrogen production apparatus according to a first embodiment of the present invention.

  The cyclone reactor 10 of this example has a vertical cylindrical shape, and a vertical hole-shaped cylindrical duct 11 having a smaller diameter than the inner diameter of the upper portion of the housing 10A of the reactor 10 is provided in the upper part of the inside. A space 10B for forming a steam swirl flow 18 in the cyclone portion is formed by the annular space 10B between the outer periphery of the cylindrical duct 11 and the inner periphery of the upper portion of the housing of the reactor 10.

  A raw material supply port 19 for injecting water vapor 1 and powder or granular carbon material 2 into the reactor 10 is provided on the upper peripheral wall or upper portion of the reactor 10. The carbon material 2 is pulverized coal or the like, and can be manufactured from biomass or the like.

  A supply port 15 of a carbon material transfer pipe 14 is connected to the water supply pipe 13, and a pipe system is formed to join the carbon material 2 with water vapor in the transfer process before being supplied into the reactor 10. Has been. The merged water vapor 1 and carbon material 2 are injected together through a raw material supply port 19 into a water vapor swirl flow forming space 10B in the reactor 10.

  An irradiation region 10 </ b> C of the microwave 17 is provided between the swirling flow forming space 10 </ b> B and the cylindrical duct 11 in the reactor 10 and the inner bottom of the reactor 10.

  The microwave 17 is irradiated to the reactor 10 surrounded by the metal shielding plate 4 through the waveguide 16 of the microwave irradiation device 30. The metal shielding plate 4 plays a role of reflecting the microwave to be leaked around the reactor to the reactor 10 and absorbing the reflected microwave by the carbon material. The metal shielding plate 4 can use various existing members.

  A structure in which the carbon material 2 is heated by irradiation of the microwave 17 and a gas 28 (hydrogen and carbon monoxide) generated by reacting the carbon material with the water vapor 1 is led out of the reactor through the cylindrical duct 11. have.

  Here, an example of the material and specifications of the reactor 10 will be described.

  In general, when a dielectric is placed in a microwave electromagnetic field, the dipole constituting the dielectric vibrates violently due to a change in the polarity of the electric field. At this time, if the dipole vibration becomes unable to follow the external electric field, heat is generated and the temperature of the dielectric is increased. The calorific value Q of the dielectric per unit volume is expressed by the following equation.

Q = 2π × ε ₀ × f × E ² × ε _r × tan δ
Here, ε ₀ is the dielectric constant of vacuum, f is the microwave frequency, E is the electric field strength, ε _r is the relative dielectric constant, and tan δ is the dielectric loss tangent. In particular, ε _r × tan δ is called dielectric loss. FIG. 5 shows a comparison of relative dielectric constants of various substances. If the relative dielectric constant close to carbon is selected as the material of the reactor 10, it is not preferable because the microwave is absorbed and the reactor itself is heated like carbon. Therefore, in this embodiment, since the microwave selects a frequency for efficiently heating the carbon material, the material of the reactor 10 is carbon and a relative dielectric constant ε _r × tan δ, such as alumina or ceramics. In other words, it is preferable to use a high melting point material having a remarkably small dielectric loss. If alumina or ceramics is used, the microwave can be selectively absorbed and heated only by the carbon material.

  For example, the microwave irradiation apparatus is about 50 to 100 W and the frequency is 2,500 MHz.

The specifications of the cyclone section are various. For example, the vertical length of the reactor 10 is 1500 mm, the inner diameter is 530 mm, the outer diameter of the duct 11 is 210 mm, and the duct length is about 350 mm. In order to form the swirl flow 18 of the steam, the raw material supply port 19 is arranged so that the injection direction forms an oblique angle with respect to the radial direction of the reactor, for example, the steam is flowed at a flow rate of 1.5 m ³ / s. Eject.

  The capacity of the irradiation region 10C of the microwave 17 is set so that the carbon material 2 can be heated to about 1000 ° C. and can react with the water vapor 1 to generate an air residence time during which hydrogen gas and carbon monoxide can be generated. For example, it may be set to a capacity capable of securing a dwell time of 10 seconds or more under microwave irradiation conditions of about 50 to 100 W. FIG. 3 shows the time change of the temperature of carbon when the present inventors irradiate and heat pulverized coal with the above microwaves in an experiment.

  Although it depends on the power of the microwave, it can be seen from the results of this experiment that the carbon temperature exceeds 100 ° C. in 10 seconds or less. Such a rapid temperature raising process is difficult with a heating method that relies on normal heat transfer, and it can be seen that carbon is efficiently heated by this embodiment.

  Furthermore, FIG. 4 shows the production test results of hydrogen and carbon monoxide from the thermal reaction between a carbon material and water vapor by the present inventor. After 10 (dimensionless time) established by the experimental conditions, gas generation is stable, and it has been confirmed that hydrogen and carbon monoxide are generated at a constant flow rate ratio with respect to time.

  A method for producing hydrogen using the above configuration will be described below.

  In the process of transporting the steam 1 to the reactor 10 via the steam pipe 13, the carbon material 2 is introduced into the steam pipe 13 from the carbon supply port 15, and the steam 1 containing the carbon material 2 passes through the raw material supply port 19. An annular space (swirl flow forming space) 10B in the reactor 10 is supplied.

  A swirl flow 18 of water vapor containing the carbon material 2 is formed in the annular space in the reactor 10. The water vapor swirling flow 18 and the carbon material 2 descend along the outer periphery of the cylindrical duct 11 and reach the microwave irradiation space 10C. In the microwave irradiation space 10C, the carbon material 2 has an air residence time (for example, around 10 seconds or more) in the water vapor by the force of the water vapor swirling flow. By irradiating the carbon material and water vapor with microwaves in this air residence state (floating state in the air), the carbon material is heated to about 1000 ° C., and the carbon material is heated and reacted with the water vapor. To generate hydrogen and carbon monoxide.

  The generated hydrogen and carbon monoxide are transferred as gas 28 together with surplus water vapor from the upper part of the cyclone reactor 10 through the duct 11 to the gas conveyance pipe outside the reactor (downstream of the reactor).

According to the present embodiment, the following effects can be obtained.
(1) During microwave irradiation, contact between pulverized coals and contact between the pulverized coal and the reactor wall surface is minimized, and even if contacted, the pulverized coal can be heated uniformly. Maximizing the heating reaction area of charcoal to water vapor improves the reaction efficiency and enables highly efficient hydrogen production.
(2) By forming an air retention space where pulverized coal is held for a certain period of time by swirling steam with a material that does not absorb microwaves, all the microwaves are absorbed by the carbon material (pulverized coal) and the carbon material is heated. Efficiency can be increased.
(3) For water vapor and carbon material administered to the reactor, the transport amount per unit time can be determined from the fluid velocity, and the carbon material can be quantitatively managed.
[Example 2]
FIG. 6 shows a schematic cross-sectional configuration diagram of a hydrogen production apparatus according to the second embodiment of the present invention.

  In FIG. 6, the same components as those in the first embodiment are denoted by the same reference numerals. Since the structure of the reactor 10, the structure of the raw material supply system, and the plasma irradiation system are the same as those in the first embodiment, description thereof is omitted.

  The present embodiment is different from the first embodiment in that a heat exchanger 30, a water condenser 31, and a filter 33 are provided in the gas discharge system of the reactor 10.

  In the condenser 31, the gas discharge system is branched into a hydrogen gas transfer pipe 35 and a water discharge system pipe 36.

  The gas 28 (hydrogen gas and carbon monoxide) transferred to the outside of the reactor 10 is cooled to 100 ° C. or less by exchanging heat with the heat exchanger 30 in the transfer process. The heat exchanged at that time can be used as a heat source for generating water vapor 1. Residual water vapor in the gas 28 is cooled by a condenser 31 to become condensed water 32 containing residual carbon. Residual carbon is removed from the condensed water 32 through the filter 33, and the filtered water 34 is reused to produce the reaction water vapor 1.

  According to the present embodiment, the recovered water after hydrogen gas generation can be reused as water for reaction steam generation, and the heat recovered by the heat exchanger 30 can also be used as heat for steam generation. Can be achieved.

In addition, although the vertical reactor was illustrated in the present Example, the hydrogen production may be a horizontal reactor. That is, the present invention can be carried out by forming a steam swirl flow that proceeds in the horizontal direction in a horizontal reactor.
[Example 3]
FIG. 7 shows a schematic cross-sectional configuration diagram of a hydrogen production apparatus according to the third embodiment of the present invention.

  In FIG. 7, the same components as those in the first embodiment are denoted by the same reference numerals. Since the structure of the reactor 10 and the structure of the raw material supply system are the same as those in the first embodiment, description thereof is omitted.

  In this embodiment, the difference from the first embodiment is that a filter for collecting the carbon material is provided on the outer peripheral side of the cylindrical duct 11A, and the waveguide and the metal shielding plate of the microwave irradiation device 30 are provided. The metal shielding part 4a having an integral structure is provided, and the microwave irradiation space 10C is enlarged in the vertical direction of the reactor 10.

  A filter in which pores smaller than the particle diameter of the carbon material are distributed is provided on the outer surface of the cylindrical duct 11A. Since this filter collects the carbon material inside the reactor, the carbon material can be prevented from flowing out to the downstream side of the reactor. In addition, since the carbon material does not flow out to the downstream side of the reactor, a shift reaction system that changes hydrogen and carbon monoxide discharged from the reactor into carbon dioxide and water can be provided on the downstream side of the reactor. is there. At the same time, it is possible to use the energy flowing out downstream of the reactor in the shift reaction system. The filter can be attached not only to the outer peripheral surface of the cylindrical duct 11A but also to the bottom surface, so that almost all of the carbon material inside the reactor can be collected.

  And the waveguide 16 and the metal shielding plate 4 of the microwave irradiation apparatus 30 shown in FIG. 6 are made into the integral structure 4a as shown in FIG. A microwave is irradiated to the cylindrical duct 11A. Since the cylindrical duct 11A is provided with a filter, all of the carbon material collected by the filter can be gasified.

  In addition, instead of providing a filter in the cylindrical duct 11A, the same effect as that of the filter can be obtained even if the hole provided in the side surface of the cylindrical duct has a smaller diameter than the carbon material.

  In the present invention, a carbon material that can also be produced from biomass can be used as a raw material for hydrogen generation.

DESCRIPTION OF SYMBOLS 1 ... Steam, 2 ... Carbon material, 10 ... Reactor, 10A ... Reactor housing, 10B ... Space for forming swirl flow, 10C ... Microwave irradiation space, 11 ... Cylindrical duct, 19 ... Raw material inlet, 17 ... Micro Wave, 30 ... micro irradiation device, 30 ... heat exchanger, 31 ... condenser, 33 ... filter.

Claims (8)

In a hydrogen production method for generating hydrogen and carbon monoxide by irradiating a carbon material and water vapor supplied into a reactor with microwaves, heating the carbon material by the microwaves and reacting with the water vapor. ,
Forming a swirl flow of the water vapor in the reactor, ensuring the air residence time in the water vapor of the carbon material by the water vapor swirl flow, and irradiating the carbon material and water vapor in the air stay region To generate hydrogen and carbon monoxide. The carbon material is a powder or granule made of at least one of carbon and a carbon-containing substance,
The carbon material is combined with the water vapor in a conveying process before being supplied into the reactor, and the combined water vapor and the carbon material are injected together into a water vapor swirl flow formation space in the reactor. The method for producing hydrogen according to claim 1. In a hydrogen production apparatus comprising a hydrogen production reactor to which a carbon material and water vapor are supplied, and a microwave irradiation apparatus for irradiating the carbon material and water vapor to be supplied into the reactor with microwaves,
Forming a swirl flow of the water vapor in the reactor, and having a cyclone section for ensuring a residence time in air necessary for the microwave irradiation to the carbon material in the reactor by the water vapor swirl flow;
The said microwave irradiation apparatus is provided so that the said microwave may be irradiated to the air residence area | region of the said carbon material in the said reactor, The hydrogen production apparatus characterized by the above-mentioned. In the upper part of the reactor, a cylindrical duct having a vertical hole shape smaller than the inner diameter of the upper part of the housing of the reactor is provided, and an annular shape between the outer periphery of the cylindrical duct and the inner upper part of the housing of the reactor is provided. By the space, a space for forming a steam swirl flow in the cyclone portion is formed,
A raw material supply port for injecting the water vapor and the carbon material into the reactor is provided at the top of the reactor,
A microwave irradiation space for irradiating the carbon material with the microwave while ensuring the air residence time of the carbon material is provided between the space for forming the water vapor swirl flow in the reactor and the bottom of the reactor. And
The hydrogen and carbon monoxide produced | generated by heating the said carbon material by the said microwave irradiation and making it react with water vapor | steam has the structure guide | induced outside a reactor through the said cylindrical duct. Hydrogen production equipment.   The carbon material is provided with a raw material supply pipe for joining the water vapor before being supplied to the reactor, and the joined carbon material and the water vapor are connected to the upper part of the reactor through the raw material supply port. The hydrogen production apparatus according to claim 3 or 4, wherein the hydrogen production apparatus is injected into a space for forming a swirl flow.   The hydrogen production apparatus according to claim 5, wherein the space irradiated with the microwave in the reaction vessel is formed by a wall material that does not absorb the microwave. In a hydrogen production apparatus comprising a hydrogen production reactor to which a carbon material and water vapor are supplied, and a microwave irradiation apparatus for irradiating the carbon material and water vapor to be supplied into the reactor with microwaves,
Forming a swirl flow of the water vapor in the reactor, and having a cyclone section for ensuring an air residence time necessary for the microwave irradiation to the carbon material in the reactor by the water vapor swirl flow;
The upper part in the reactor has a vertical hole shape smaller than the inner diameter of the upper part of the housing of the reactor,
A cylindrical duct having a filter for collecting the carbon material is provided, and an annular space between the outer periphery of the cylindrical duct and the inner periphery of the upper part of the housing of the reactor is used to form a steam swirl flow in the cyclone section. A space is formed,
A raw material supply port for injecting the water vapor and the carbon material into the reactor is provided at the top of the reactor,
An air residence time of the carbon material is secured in the space for forming the steam swirl flow in the reactor and in the space between the space for forming the steam swirl flow and the bottom of the reactor in the reactor. A microwave irradiation space for irradiating the carbon material with the microwave is provided,
A hydrogen production apparatus having a structure in which hydrogen and carbon monoxide generated by heating the carbon material by the microwave irradiation and reacting with water vapor are guided to the outside of the reactor through the cylindrical duct. In a hydrogen production apparatus comprising a hydrogen production reactor to which a carbon material and water vapor are supplied, and a microwave irradiation apparatus for irradiating the carbon material and water vapor to be supplied into the reactor with microwaves,
Forming a swirl flow of the water vapor in the reactor, and having a cyclone section for ensuring an air residence time necessary for the microwave irradiation to the carbon material in the reactor by the water vapor swirl flow;
The upper part in the reactor has a vertical hole shape smaller than the inner diameter of the upper part of the housing of the reactor,
A cylindrical duct provided with a hole having a smaller diameter than the carbon material is provided, and a steam swirl flow formation in the cyclone section is formed by an annular space between the outer periphery of the cylindrical duct and the inner periphery of the upper part of the housing of the reactor. A space for is formed,
A raw material supply port for injecting the water vapor and the carbon material into the reactor is provided at the top of the reactor,
An air residence time of the carbon material is ensured in the space for forming the steam swirl flow in the reactor and in the space between the space for forming the steam swirl flow and the bottom of the reactor in the reactor. A microwave irradiation space for irradiating the carbon material with the microwave is provided,
A hydrogen production apparatus having a structure in which hydrogen and carbon monoxide generated by heating the carbon material by the microwave irradiation and reacting with water vapor are guided to the outside of the reactor through the cylindrical duct.

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