JP2006151700A - Method of producing hydrogen-generating substance and apparatus therefor - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a method of producing a hydrogen-generating substance which, when converting a substance to which hydrogen atom is applied to the hydrogen-generating substance with a reducing substance, can raise only the concentration of the hydrogen-generating substance to a given value because the reducing substance does not remain in the liquid phase. <P>SOLUTION: The method of producing a hydrogen-generating substance has a substance-supplying step for supplying a substance 21 to which hydrogen atom is applied to a reaction vessel 2, a reducing substance-supplying step for supplying a reducing substance 22 that decomposes upon chemical reaction to the reaction vessel 2, and a chemical reaction step for chemically reacting the substance 21 to which a hydrogen atom is applied with the reducing substance 22 to produce the hydrogen-generating substance 23. <P>COPYRIGHT: (C)2006,JPO&NCIPI

Description

  The present invention relates to a method and apparatus for producing a hydrogen generating material that generates a hydrogen generating material.

  Hydrogen is attracting attention as a representative clean fuel that can replace fossil fuels such as oil.

  In relation to the method for producing the raw material for generating hydrogen, an IS method (Iodine-Sulfur Method) for decomposing water with iodine and sulfur dioxide has been proposed by GA (General Atomic) in the United States (for example, patent literature). 1-7).

  This method uses thermal energy generated in a HTGR and decomposes water into hydrogen and oxygen using iodine and sulfur dioxide.

  The main reaction of the IS method consists of three steps. Water, iodine and sulfur dioxide are reacted at 70 to 100 ° C. to generate hydrogen iodide which is a raw material of hydrogen. At this time, sulfuric acid is also produced, but hydrogen iodide and sulfuric acid are separated. As a second step, hydrogen iodide is thermally decomposed at 400 ° C. to obtain the target hydrogen. In the third step, sulfuric acid is pyrolyzed back to sulfur dioxide at a high temperature of 900 ° C. Since iodine is obtained by thermal decomposition of hydrogen iodide, it is reused together with sulfur dioxide. As described above, the IS method is also referred to as a thermochemical decomposition method because water is decomposed into hydrogen and oxygen using sulfur dioxide, iodine and thermal energy.

  Regarding the reaction for decomposing hydrogen iodide into hydrogen and iodine, in 1897 the German M.I. A detailed study by Bodenstein. The hydrogen iodide decomposition reaction (Bodenstein reaction) is a homogeneous gas phase reaction, dissociated into hydrogen and iodine in the vicinity of 400 ° C., and present as a mixed equilibrium gas of hydrogen iodide, hydrogen and iodine. This pressure equilibrium constant is required to be about 50, and the degree of dissociation is 22%.

  On the other hand, hydrogen iodide can be easily obtained by causing a redox reaction by causing sulfur dioxide or sulfite water to act on iodine.

  In addition, basic research on this IS method has been conducted at the Japan Atomic Energy Research Institute since the 1980s. Studies have been made on the reaction of extracting hydrogen as a fuel by reacting iodine and sulfur dioxide to form hydrogen iodide and then decomposing the hydrogen iodide into hydrogen and iodine.

In addition, iodine and sulfur dioxide can be taken out again by decomposing the reaction product. In practice, the IS method can be regarded as a water decomposition reaction using iodine and sulfur dioxide as catalysts.
Japanese Patent Publication No. 60-52081 Japanese Examined Patent Publication No. 60-48442 Japanese Patent Publication No. 04-37001 Japanese Examined Patent Publication No. 04-37002 U.S. Pat. No. 4,089,939 U.S. Pat. No. 4,089,940 U.S. Pat. No. 4,127,644

  However, in the conventional IS method described above, in order to produce hydrogen iodide as a target product by reacting iodine, sulfur dioxide and water, the product sulfuric acid must be separated. For this purpose, a large amount of iodine is required, and there is a problem that two-phase separation is required between an aqueous sulfuric acid solution and an aqueous solution containing iodine / hydrogen iodide.

  Moreover, in order to thermally decompose the separated sulfuric acid and use it again as sulfur dioxide, there is a problem that it is necessary to carry out at a high temperature of 900 ° C. or higher.

  Furthermore, in order to obtain hydrogen iodide without separating and extracting, there is a problem that it is necessary to take out as an aqueous solution system in which compounds other than hydrogen iodide are not mixed.

  The present invention has been made to solve the above-described problem, and a method for producing a hydrogen generating material that generates a hydrogen generating material by chemically reacting a reducing material that decomposes when chemically reacting with a material to which a hydrogen atom is attached, and An object is to provide such a device.

  In order to achieve the above object, in the method for producing a hydrogen generating substance of the present invention, a substance supplying step for supplying a substance for imparting hydrogen atoms to a reaction tank, and a reducing substance that decomposes during a chemical reaction are added to the reaction tank. A reducing substance supplying step for supplying, and a chemical reaction step for generating a hydrogen generating substance by chemically reacting the reducing substance with the substance to which the hydrogen atom is added.

  In order to achieve the above object, the present invention provides a method for producing a hydrogen generating substance that generates hydrogen iodide by chemically reacting iodine, sulfur dioxide, and water, and acts on hydrazine as a reducing substance on the unreacted iodine. It is made to reduce or prevent the production | generation of sulfur, It is characterized by the above-mentioned.

  In order to achieve the above object, in the apparatus for producing a hydrogen generating material according to the present invention, a reaction vessel that generates a hydrogen generating material by chemically reacting a reducing material with a material to which a hydrogen atom is attached, and the reducing material. An exhaust pipe provided at an upper part of the reaction tank for exhausting the changed gas, and a storage container for storing an aqueous solution containing a hydrogen-generating substance changed from the substance to which the hydrogen atom is imparted. It is.

  According to the present invention, when a reducing substance is chemically reacted with a substance to which a hydrogen atom is imparted to change to a hydrogen generating substance, the reducing substance moves to the gas phase, so that only an aqueous solution containing the hydrogen generating substance is predetermined. The concentration can be increased to. For this reason, since the liquid phase of the aqueous solution containing the hydrogen generating substance is one phase, there is no fear that the substance changed from the reducing substance due to the side reaction will be changed to another substance.

  When hydrogen iodide is produced from sulfur dioxide, iodine and water, it is transferred to a container as a two-phase liquid. At this time, by making hydrazine act on unreacted iodine, the concentration of hydrogen iodide in the lower phase liquid can be increased, and at the same time, sulfur alone produced in the side reaction can be dissolved. For this reason, it can suppress that piping of a liquid transfer is obstruct | occluded with sulfur simple substance.

  Embodiments of a method for producing a hydrogen-producing raw material and an apparatus therefor according to the present invention will be described below with reference to FIGS. Here, the same or similar parts are denoted by common reference numerals, and redundant description is omitted.

  FIG. 1 is a configuration diagram showing the configuration of the hydrogen generating raw material manufacturing apparatus according to the first embodiment of the present invention.

  A substance (for example, halogen such as iodine) 21 to which hydrogen atoms are given is injected into the reaction tank 2 from the pipe 1. A reducing substance (for example, an organic acid such as oxalic acid) 22 is injected from the pipe 3, and is circulated through the reaction tank 2 using the pump 4 to react the reducing substance 22 with the substance 21 to which hydrogen atoms are imparted. The reducing substance 22 reduces the substance 21 to which a hydrogen atom is imparted and generates a hydrogen generating substance 23 (for example, hydrogen iodide) that is a substance to which a hydrogen atom is imparted, and then the circulation is stopped. Thereafter, the valve 5 is opened, and the hydrogen generating material 23 is transferred to the storage container 7 through the pipe 6. In the storage container 7, after separating the changed substance from the hydrogen generating substance 23 and the reducing substance 22, which are substances to which hydrogen atoms have been added, only the hydrogen generating substance 23 to which the hydrogen atoms have been added is separated from the pipe 8. And take it out.

  In the present embodiment configured as described above, the hydrogen atom of the reducing substance 22 or the hydrogen atom of the solvent such as water is chemically reacted with the substance 21 to which the hydrogen atom is imparted in the reaction tank 2. It can be given by. At this time, the reducing substance 22 and the substance 21 to which hydrogen atoms are imparted are circulated using the pump 4 so as to be sufficiently mixed. The reaction product transferred to the storage container 7, that is, the hydrogen generation material 23, which is a substance provided with hydrogen atoms, and the material changed from the reduction material are separated using the physicochemical properties such as the respective density, The hydrogen generating material 23, which is a material provided with hydrogen atoms, is isolated from the pipe 8.

  According to the present embodiment, by using the pump 4 to circulate and mix the reducing substance 22 and the substance 21 to which hydrogen atoms are provided in the reaction tank 2, the production amount of the hydrogen generating substance 23 is increased. be able to. Further, by utilizing the difference in physicochemical properties of each reaction product in the storage container 7, it is possible to increase the recovery rate of the hydrogen generating material 23, which is a material to which a hydrogen atom is added.

  FIG. 2 is a configuration diagram showing the configuration of the hydrogen generating raw material manufacturing apparatus according to the second embodiment of the present invention.

  In the second embodiment of the present invention, means for treating the substance 24 changed from the reducing substance 22 is added to the first embodiment, and the same reference numerals denote the same components. The description which overlaps is abbreviate | omitted.

  The reducing substance 22 injected into the reaction tank 2 reacts with the substance 21 to which hydrogen atoms are imparted in the reaction tank 2 by the pump 4 during circulation mixing, and moves to the gas phase. At this time, the substance (for example, carbon dioxide) 24 changed from the reducing substance 22 transferred to the gas phase is released into the atmosphere through the exhaust tank 9. At the same time, the reaction product adhering to the inner wall of the exhaust tank 9 is washed by circulating the solvent supplied from the solvent storage tank 12 through the valve 11 by the circulation pump 10 and is collected in the reaction tank 2. After the reaction in the reaction tank 2, the hydrogen-producing substance 23, which is a substance to which hydrogen atoms transferred to the storage container 7 are added, is transferred to the next process via the pipe 8 without passing through the separation process.

  In the present embodiment configured as described above, in the reaction tank 2, a hydrogen atom possessed by a reducing substance 22 or a hydrogen atom possessed by a solvent such as water is chemically reacted with a substance 21 to which a hydrogen atom is imparted. At the same time, the reducing substance decomposes and shifts to the gas phase, and the reducing substance 22 does not remain in the reaction product in the liquid phase.

  An oxalic acid that is an organic acid, formic acid, hydrazine that is a nitrogen compound, or the like is selected as a reducing substance that has an action of imparting hydrogen atoms and is decomposed as a gas.

The reaction formula when iodine is selected as a substance to which a hydrogen atom is given is as shown in the following formulas (1) to (3).
I ₂ + H ₂ C ₂ O ₄ → 2HI + 2CO ₂ (1)
I ₂ + HCOOH → 2HI + CO ₂ (2)
2I ₂ + N ₂ H ₄ → 4HI + N ₂ (3)
In the present embodiment configured as described above, a carbon compound such as an organic acid changes to carbon dioxide after decomposition and shifts to the gas phase. Further, hydrazine, which is a nitrogen compound, becomes nitrogen after decomposition and shifts to the gas phase.

  According to the present embodiment, by using a reducing substance that decomposes into a gas and moves to the gas phase, the changed substance from the reducing substance is separated from the hydrogen generating substance 23 to which a hydrogen atom is attached. Therefore, a substance to which hydrogen is added as a raw material for generating hydrogen can be obtained without isolation.

  FIG. 3 is a configuration diagram showing the configuration of the hydrogen generating raw material manufacturing apparatus according to the third embodiment of the present invention. The third embodiment of the present invention is the same as the second embodiment except that a means for injecting a reducing substance is added to the substance 21 to which unreacted hydrogen atoms are added. The same reference numerals are given to the configurations of, and duplicate descriptions are omitted.

  The valve 13 is opened with respect to the hydrogen-producing substance 23 and the substance 21 to which unreacted hydrogen atoms are added, which are substances to which the hydrogen atoms transferred to the storage container 7 are added. The reducing substance 22a is injected through the pipe 15. In the storage container 7, the reducing substance 22a and the substance 21 to which a hydrogen atom is added are reacted to generate a hydrogen generating substance 23 that is a substance to which a hydrogen atom is added, and then a substance to which a hydrogen atom is added. The hydrogen generating material 23 is transferred to the next process via the pipe 8.

  In the present embodiment configured as described above, when iodine is selected as the substance imparting hydrogen and hydrazine is used as the reducing substance, the reaction shown in the above formula (3) occurs. At this time, in the liquid phase in the storage container 7, only hydrogen iodide is generated as a substance to which hydrogen atoms are added. When the hydrogen iodide reaches a predetermined concentration, the hydrogen iodide is transferred to the next process, that is, a process (not shown) for producing hydrogen by concentrating or decomposing hydrogen iodide via the pipe 8.

  According to the present embodiment, when the substance 21 to which unreacted hydrogen atoms are added is changed to the hydrogen generating substance 23 that is a substance to which hydrogen atoms are added by the reducing substance 22, the reducing substance is transferred to the gas phase. Since it does not remain in the liquid phase, it is possible to raise only the hydrogen generating material 23, which is a raw material for hydrogen production, to a predetermined concentration. In addition, since only one liquid phase is dissolved in the hydrogen-producing substance 23, which is a raw material for hydrogen production, there is no fear that the substance changed from the reducing substance due to the side reaction will be changed to another substance. Is simple.

  In the case where hydrogen iodide is produced by chemically reacting conventional iodine, sulfur dioxide and water in the reaction tank 2, it is transferred to the storage container 7 as a two-phase liquid of hydrogen iodide and sulfuric acid. At this time, the concentration of hydrogen iodide in the lower phase liquid can be increased by allowing hydrazine as a reducing substance to act on unreacted iodine. At the same time, the simple sulfur produced by the side reaction can be dissolved. The dissolution of the sulfur alone can prevent the piping from being blocked due to the sulfur alone.

  Furthermore, the present invention is not limited to the above-described embodiments, and various modifications can be made without departing from the spirit of the present invention.

The block diagram which shows the structure of the hydrogen production raw material manufacturing apparatus of the 1st Embodiment of this invention. The block diagram which shows the structure of the hydrogen production raw material manufacturing apparatus of the 2nd Embodiment of this invention. The block diagram which shows the structure of the hydrogen production raw material manufacturing apparatus of the 4th Embodiment of this invention.

Explanation of symbols

  DESCRIPTION OF SYMBOLS 1 ... Piping, 2 ... Reaction tank, 3 ... Piping, 4 ... Pump, 5 ... Valve, 6 ... Piping, 7 ... Storage container, 8 ... Piping, 9 ... Exhaust pipe, 10 ... Pump, 11 ... Valve, 12 ... Solvent Storage tank, 13 ... Valve, 14 ... Reduced substance storage tank, 15 ... Piping, 21 ... Substance to which hydrogen atoms are applied, 22 ... Reduced substance, 23 ... Hydrogen generating substance, 24 ... Substance changed from reducing substance.

Claims (15)

A substance supply step for supplying a substance to which hydrogen atoms are added to the reaction tank;
A reducing substance supply step of supplying a reducing substance that decomposes when chemically reacting to the reaction tank;
A chemical reaction step in which a reducing substance is chemically reacted with the substance to which the hydrogen atom is imparted to generate a hydrogen generating substance;
A method for producing a hydrogen generating material, comprising:   The method for producing a hydrogen generating substance according to claim 1, wherein the substance supplying step uses halogen as the substance to which the hydrogen atom is added.   3. The method for producing a hydrogen generating substance according to claim 1, wherein the substance supplying step uses iodine as the halogen.   The method for producing a hydrogen generating material according to any one of claims 1 to 3, wherein the reducing material supply step is a gas phase transition when the reducing material chemically reacts.   5. The method for producing a hydrogen generating material according to claim 1, wherein the reducing material supply step uses an organic acid as the reducing material.   6. The method for producing a hydrogen generating substance according to claim 5, wherein the reducing substance supplying step uses at least one selected from oxalic acid and formic acid as the organic acid.   5. The method for producing a hydrogen generating substance according to claim 1, wherein the reducing substance supplying step uses a nitrogen compound as the reducing substance.   8. The method for producing a hydrogen generating material according to claim 7, wherein hydrazine is used as the nitrogen compound in the reducing material supply step.   3. The method for producing a hydrogen generating material according to claim 2, wherein, in the chemical reaction step, a reducing agent is allowed to act on the halogen to generate hydrogen halide as a hydrogen generating material.   The method for producing a hydrogen generating material according to claim 9, wherein the chemical reaction step generates hydrogen iodide as the hydrogen halide.   11. The method for producing a hydrogen generating material according to claim 10, wherein, in the chemical reaction step, the reducing material is transferred to a gas to generate an aqueous solution containing the hydrogen iodide.   12. The method for producing a hydrogen generating material according to claim 11, further comprising a hydrogen iodide concentration control step of controlling a concentration of hydrogen iodide by causing a reducing material to act on the iodine after the chemical reaction step. .   13. The method for producing a hydrogen generating material according to claim 12, wherein, in the hydrogen iodide concentration control step, hydrazine is allowed to act as the reducing material.   In the method for producing a hydrogen-producing substance that generates hydrogen iodide by chemically reacting iodine, sulfur dioxide, and water, hydrazine is allowed to act on the unreacted iodine as a reducing substance to suppress the production of sulfur. A method for producing a hydrogen-producing substance. A reaction vessel for producing a hydrogen-generating substance by chemically reacting a reducing substance with a substance to which hydrogen atoms are imparted;
An exhaust pipe provided at the top of the reaction vessel for exhausting the gas changed from the reducing material;
A storage container for storing an aqueous solution containing a hydrogen-producing substance changed from the substance to which the hydrogen atom is imparted;
An apparatus for producing a hydrogen generating material, comprising:

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