JP2011057480A - Apparatus for producing hydrogen - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To shorten starting time by heating to a temperature which the whole conversion catalyst is rapidly activated in the starting time of an apparatus for producing hydrogen. <P>SOLUTION: The apparatus 1 for producing hydrogen includes a heating cylinder 2 in the inside of which a heating part for combusting fuel for combustion is arranged, an inner cylinder 4 and an outer cylinder 3 arranged with a certain interval concentrically with the heating cylinder 2 and having successively increased diameter, a reforming part 7 held in a space formed between the heating cylinder 2 and the inner cylinder 4 and having a reforming catalyst to produce a hydrogen-containing gas obtained by the reforming reaction of a raw material gas with steam and a conversion part 8 held in a space formed between the inner cylinder 4 and the outer cylinder 3 and having a conversion catalyst 9 to reduce carbon monoxide in the hydrogen-containing gas produced in the reforming part 7 and is constituted of a heater 11 arranged at a position of the conversion part 8 to correspond to the conversion catalyst 9 in the outer surface side of the outer cylinder 3 and heating the conversion catalyst 9 and a soaking plate 12 arranged between the heater 11 and the outer cylinder 3 and thereby, the whole of the conversion part 8 is efficiently heated and the whole conversion catalyst 9 is uniformly heated. <P>COPYRIGHT: (C)2011,JPO&INPIT

Description

  The present invention relates to a hydrogen generator including a carbon monoxide reduction unit that generates a hydrogen-containing gas by a reforming reaction between a raw material such as a hydrocarbon and water and reduces carbon monoxide in the hydrogen-containing gas.

  Fuel cells that enable highly efficient power generation even with small devices are being developed as power generation systems for distributed energy sources. Hydrogen gas or hydrogen-containing gas used as fuel during power generation has not been developed as a general infrastructure. For this reason, for example, a hydrogen generator that uses raw materials supplied from existing fossil raw material infrastructures such as city gas and propane gas and generates a hydrogen-containing gas by a reforming reaction between these raw materials and water is provided.

  The hydrogen generator includes a reforming unit that causes a reforming reaction between a raw material and water to generate a hydrogen-containing gas. Moreover, the structure which provides the conversion part which makes the carbon monoxide reduction part which reduces carbon monoxide in hydrogen-containing gas and water-gas shift reaction of carbon monoxide and water vapor | steam is often taken. In these reaction parts, a catalyst suitable for each reaction, for example, a Ru catalyst or Ni catalyst is used in the reforming part, and a Cu-Zn catalyst is used in the modification part. Each reaction section has a suitable temperature, and the reforming section is often used at about 650 ° C. and the transformation section is used at about 200 ° C.

  When a fuel cell power generation system is used for home use, it is desirable to correspond to the power load of the home, and to support start / stop operation that stops the system at night when the load is small, and a desirable operation method for obtaining high energy efficiency Become.

  The hydrogen generation apparatus also needs to correspond to the operation method thereof, and in order to supply the hydrogen-containing gas promptly at the time of startup, it is necessary to heat the reforming catalyst and the shift catalyst to temperatures that can be activated at the time of startup. .

  Then, the structure heated to the temperature which can activate a shift catalyst by providing the heater which heats a shift catalyst in the part upstream from the shift part which is a carbon monoxide reduction part is examined (for example, refer patent document 1). ).

JP 2001-354404 A

  However, Patent Document 1 only discloses that a shift heater for heating the gas from the reforming section and the shift catalyst is provided, and a specific configuration of the shift heater is not disclosed. In such a configuration, since heat from the heater is taken away upstream of the shift catalyst, it takes time to reach the activation temperature in the middle and downstream portions compared to the upstream portion. Therefore, the predetermined carbon monoxide reduction effect cannot be obtained until the entire shift catalyst is heated to the activation temperature, and further reduction of the start-up time is desired.

  This invention solves the said conventional subject, and it aims at providing the hydrogen production | generation apparatus which heats a metamorphic part to active temperature rapidly.

  In order to solve the above-described problems, the hydrogen generator of the present invention includes a heating cylinder in which a heating unit for burning combustion fuel is disposed, a concentric spacing with the heating cylinder, and an inner diameter that is sequentially increased. A reforming section having a reforming catalyst which is held in a space formed between the cylinder and the outer cylinder, the heating cylinder and the inner cylinder, and which generates a hydrogen-containing gas by reforming the raw material gas and water vapor; A hydrogen generation apparatus comprising a shift section having a shift catalyst that is held in a space formed between a cylinder and an outer cylinder and reduces carbon monoxide in a hydrogen-containing gas generated in a reforming section. The heater is disposed at a position corresponding to the shift catalyst on the outer surface side of the outer cylinder of the shift section, and includes a heater for heating the shift catalyst and a heat equalizing plate disposed between the heater and the outer cylinder.

  With the above configuration, the hydrogen generator of the present invention is provided with a soaking plate between the heater and the outer cylinder, so that the shift catalyst for reducing carbon monoxide in the hydrogen-containing gas generated in the reforming section can be quickly provided. Heating to the activation temperature can be performed uniformly, and the startup time can be shortened.

  In the hydrogen generator of the present invention, a soaking plate is provided between the heater and the outer cylinder, so that the shift catalyst for reducing carbon monoxide in the hydrogen-containing gas generated in the reforming section can be rapidly and uniformly activated. The start-up time can be shortened.

Schematic configuration diagram of a hydrogen generator in Embodiment 1 of the present invention The front view which shows the principal part schematic structure of the hydrogen generator in Embodiment 1 of this invention. The top view which shows the principal part schematic structure of the hydrogen generator in Embodiment 1 of this invention The side view which shows the principal part schematic structure of the hydrogen generator in Embodiment 1 of this invention

  The first invention is a heating cylinder in which a heating unit for burning combustion fuel is disposed, an inner cylinder and an outer cylinder, which are arranged concentrically with the heating cylinder and are arranged in a large diameter, and a heating cylinder and an inner cylinder. Formed between the inner cylinder and the outer cylinder, and a reforming section that has a reforming catalyst that is held in a space formed between the cylinder and reforms the raw material gas and water vapor to generate a hydrogen-containing gas. And a shift section having a shift catalyst for reducing carbon monoxide in the hydrogen-containing gas generated in the reforming section, the outer surface side of the outer cylinder of the shift section It is arranged at a position corresponding to the shift catalyst and is composed of a heater for heating the shift catalyst and a heat equalizing plate disposed between the heater and the outer cylinder, so that the entire shift section can be heated uniformly. it can.

  In the second invention, since the heater is fixed to the fixing portion formed on the soaking plate, it is not necessary to use another fixing bracket for fixing the heater and the soaking plate, and the number of parts can be reduced.

  In 3rd invention, since the said heater is divided and arranged centering on the axial direction of the said outer cylinder, since it can attach to an outer cylinder from right and left, attachment of a heater becomes easy.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. Note that the present invention is not limited to the embodiment.

(Embodiment 1)
FIG. 1 is a diagram showing a cross-section of the main part of a hydrogen generator 1 according to an embodiment of the present invention. The hydrogen generator 1 has a substantially cylindrical multi-cylinder configuration, and an inner cylinder 4 is arranged outside the heating cylinder 2 and an outer cylinder 3 is arranged outside. The inner cylinder 4 forms a gas flow path that folds back in the opposite direction (in FIG. 1, from the lower side to the upper side) using the space between the heating cylinder 2 and the outer cylinder 3. Moreover, the raw material supply part 5 which supplies raw material gas and the water supply part 6 which supplies water are provided on the opposite side (upper side in FIG. 1) of the gas return part (lower side in FIG. 1) of the inner cylinder 4. In addition, the reforming unit 7 that generates a hydrogen product gas by reforming the raw material gas and water vapor using the reforming catalyst and the monoxide in the hydrogen-containing gas generated in the reforming unit 7 using the shift catalyst 9 A metamorphic portion 8 for reducing carbon is provided. The reforming part 7 is located between the heating cylinder 2 and the inner cylinder 4, and the transformation part 8 is located so as not to overlap the outer cylinder direction between the inner cylinder 4 and the outer cylinder 3. In addition, a heat insulating wall 13 is provided outside the outer cylinder 3.

  The reforming section 7 is provided with a Ru-based reforming catalyst, and the shift section 8 is provided with a Cu—Zn-based shift catalyst 9. In addition, the temperature of the reforming temperature detector 15 for detecting the temperature (reaction temperature) of the reforming catalyst (or hydrogen-containing gas) in the reforming unit 7, and the temperature of the shift catalyst 9 (or a mixed gas of raw material and steam) in the shift unit 8. Is provided with a shift catalyst temperature detection unit 14 for detecting.

  In addition, the hydrogen generator 1 includes a combustion unit 10 serving as a heating unit for supplying reaction heat necessary for the reforming reaction in the reforming unit 7 to the inside of the heating cylinder 2. The combustion unit 10 is a burner that burns combustion gas that serves as a heating source, a combustion detection unit 16 that is a flame rod that detects the combustion state of the combustion unit 10, and combustion air that supplies fuel air to the combustion unit 10 A combustion fan 17 serving as a supply unit is provided. Combustion gas burned in the combustion unit 10 is supplied to the combustion unit 10 via a combustion gas supply path (not shown).

  2 to 4 are a front view, a top view, and a side view showing a schematic configuration of a main part of the hydrogen generator according to Embodiment 1 of the present invention.

  In the figure, the heater 11 for heating the shift catalyst 9 is disposed at a position corresponding to the shift catalyst 9 on the outer surface side of the outer cylinder 3 of the shift section 8, and the leveler disposed between the heater 11 and the outer cylinder 3. And a hot plate 12. The soaking plate 12 is provided with a fixing portion 12 a formed by cutting and raising the soaking plate 12, and the heater 11 is fixed by the fixing portion 12 a so as to be in close contact with the soaking plate 12.

  The heater 11 is divided into two parts around the axial direction, and is attached to the outer cylinder 3 from the left and right. The heater 11 is formed by bending a rod-like shape into a U-shape so as to be in close contact with the outer shape of the soaking plate 12, and is provided with a power supply connection portion (not shown) at one end. The heat equalizing plate 12 is a flat plate formed in a shape that is in close contact with the outer shape of the outer cylinder 3, and for example, a material having high thermal conductivity such as brass is selected. The heater 11 and the soaking plate 12 are fixed at positions corresponding to the shift catalyst 9.

  Next, the start-up operation, the normal operation operation, and the stop operation of the hydrogen generator 1 will be described focusing on the operation of the hydrogen generator 1.

  When the hydrocarbon fuel is subjected to steam reforming, the gas exiting the reforming section 7 contains a little steam. When water is condensed, since the temperature does not reach the boiling point or higher, particularly the shift section 8 has a shift catalyst 9 having a large heat capacity, so that much water is condensed. As a result, the time for heating the shift catalyst 9 to the optimum reaction temperature becomes longer and the startup time becomes longer. Moreover, the catalytic activity of the shift catalyst 9 is reduced by the condensed water, the carbon monoxide concentration in the gas after the shift is increased, and the power generation characteristics are greatly reduced.

  Therefore, when the hydrogen generator 1 is started from the stopped state, the heater 11 is energized in accordance with a command from an operation control unit (not shown), and based on the temperature detected by the shift temperature detection unit 14, the shift unit Heating 8 is performed. If the transformation temperature detection unit 14 is heated to a predetermined temperature, the raw material is then supplied to the combustion unit 10, and the combustion unit 10 ignites the raw material to start heating the hydrogen generator 1.

After starting the heating in the combustion unit 10, the raw material is supplied to the hydrogen generator 1 through the raw material supply unit 5, and water is supplied from the water supply unit 6 to the hydrogen generator 1 to start the reforming reaction between water and the raw material. Let In the present embodiment, city gas (13A) containing methane as a main component is used as a raw material. The amount of water supplied from the water supply unit 3 is controlled so that water vapor is about 3 moles per 1 mole of carbon atoms in the average molecular formula of the city gas (steam carbon ratio (S / C) is 3). degree).

  In the hydrogen generator 1, the steam reforming reaction is advanced in the reforming unit 7, and the shift reaction is advanced in the shift unit 8. The generated hydrogen-containing gas passes through a sealing portion (not shown) until the carbon monoxide concentration can be reduced to a predetermined concentration (in this embodiment, 20 ppm or less on a dry gas basis). (Not shown) is supplied to the combustion section 10. At this time, based on the temperature detected by the reforming temperature detector 15, the combustion of the combustor 10 is controlled so that the reformer 7 and the shifter 8 have temperatures suitable for each reaction.

  After the metamorphic unit 8 reaches an appropriate temperature for the reaction and the carbon monoxide concentration is reduced to a predetermined concentration, the sealing unit (not shown) is operated, and the hydrogen-containing gas is supplied through the hydrogen gas supply path (not shown). For example, supply to a fuel cell or the like is started.

When the apparatus is stopped, the supply of raw materials and water is stopped, and the temperatures of the catalyst layers of the reforming unit 7 and the shift unit 8 in the hydrogen generator 1 are lowered. At this time, the basic operation of the combustion unit 10 is stopped. After lowering the temperature of each catalyst layer to a set temperature, the raw material is circulated through the hydrogen generator 1 and the operation of replacing the hydrogen-containing gas staying in the gas path of the hydrogen generator 1 with the raw material is performed as appropriate. The operation | movement which seals 1 is performed. The hydrogen-containing gas generated by the hydrogen generator 1 is supplied to a fuel cell or the like installed outside via a hydrogen gas supply path 18. Moreover, the combustion exhaust gas generated in the combustion unit 10 is exhausted to the outside of the hydrogen generator 1 from the discharge port on the upper right side of the drawing.
A water supply path (not shown) is connected to the water supply unit 6. A raw material supply path (not shown) is connected to the raw material supply unit 5. The raw material supplied from the raw material supply unit 5 may be a raw material containing an organic compound composed of at least carbon and hydrogen elements such as hydrocarbons, for example, city gas mainly composed of methane, natural gas, LPG, etc. is there. Here, a gas infrastructure line (not shown) of city gas is used as a raw material supply source, and a desulfurization unit (not shown) for removing sulfur compounds, which are odorous components in the raw material, in the gas infrastructure line (not shown). (Not shown) is connected.

<Characteristics of configuration of hydrogen generator 1>
(1) In the hydrogen generator 1 of the first embodiment, the entire shift unit 8 is heated quickly especially at the time of start-up, and the shift catalyst 9 that reduces the carbon monoxide contained in the shift unit 8 is heated evenly and quickly. The start time is shortened.

  For example, if the heater 11 is composed of a sheathed heater, it is inexpensive, but there is a problem in processing (flexibility), and there is a problem that the pitch bent into a U-shape increases. When the pitch is increased, the shift catalyst 9 in the vicinity of the outer cylinder 3 to which the sheathed heater is closely attached is easily heated, but the temperature of the shift catalyst 9 in the vicinity of the outer cylinder 3 that is not in close contact is increased. By arranging the soaking plate 12 between the heater 11 and the outer cylinder 3 as described above, the heat of the heater 11 is conducted to the entire soaking plate 12, and the heat of the heated soaking plate 12 is transferred to the outer cylinder 3. It can be made to conduct to the whole of the shift catalyst 9 through.

  That is, the entire shift section 8 can be heated, and the shift catalyst 9 accommodated in the shift section 8 can be heated uniformly and promptly.

  (2) Further, the heater 11 is fixed to a fixing portion 12a formed by cutting and raising the soaking plate 12. In fixing the heater 11 and the heat equalizing plate 12, it is not necessary to use another fixing bracket, and the number of parts can be reduced.

(3) Further, the heater 11 is divided into two parts around the axial direction of the outer cylinder 3.
Since the attachment without interfering with the projections such as the shift catalyst detection unit 14 can be performed, the heater 11 can be easily attached.

  The present invention is useful for a hydrogen generator having a shift unit that reduces carbon monoxide in a hydrogen-containing gas.

DESCRIPTION OF SYMBOLS 1 Hydrogen generator 2 Heating cylinder 3 Outer cylinder 4 Partition cylinder 5 Raw material supply part 6 Water supply passage part 7 Reformation part 8 Transformation part 9 Combustion part 10 Transformation heater 11 Heater 12 Heat equalizing plate 13 Insulation wall 14 Transformation catalyst detection part 15 Reforming temperature detector 16 Combustion detector 17 Fan 18 Hydrogen gas supply path

Claims (3)

A heating cylinder in which a heating unit for burning combustion fuel is disposed; an inner cylinder and an outer cylinder, which are arranged concentrically with the heating cylinder and are sequentially increased in diameter; and the heating cylinder and the inner cylinder Formed between the inner cylinder and the outer cylinder, and a reforming section having a reforming catalyst that is held in a space formed between them and reforms the raw material gas and water vapor to generate a hydrogen-containing gas. A hydrogen generation device comprising a shift section having a shift catalyst for reducing carbon monoxide in the hydrogen-containing gas generated in the reforming section, which is held in a space, and is provided outside the outer cylinder of the shift section. Hydrogen generation, comprising a heater for heating the shift catalyst, and a heat equalizing plate disposed between the heater and the outer cylinder, the heater being arranged at a position corresponding to the shift catalyst on the surface side apparatus. The hydrogen generator according to claim 1, wherein the heater is fixed to a fixing portion formed on the soaking plate. The hydrogen generator according to claim 1, wherein the heater and the heat equalizing plate are divided and arranged around the axial direction of the outer cylinder.