METHOD FOR PRODUCING HYDROGEN

Abstract

The invention provides a method for producing hydrogen which includes supplying a raw material gas and steam to a reactor filled with a reforming catalyst and a carbon dioxide gas absorbent containing a lithium composite oxide at a ratio of absorbent/catalyst by volume not lower than 9, and heating the inside of the reaction to a temperature range from 450° C. to 570° C., thereby carrying out reforming reaction.

Description

BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING

FIG. 1 is a partial cross-sectional view showing a hydrogen producing apparatus to be used for production of hydrogen according to an embodiment;

FIG. 2 is a characteristic graph showing the relation between the volume ratio of absorbent/catalyst and the composition of the product gas; and

FIG. 3 is a characteristic graph showing the relation between the reforming temperature and the composition of the product gas.

Claims

1. A method for producing hydrogen comprising: supplying a raw material gas and steam to a reactor filled with a reforming catalyst and a carbon dioxide gas absorbent containing a lithium composite oxide at a ratio of absorbent/catalyst by volume not lower than 9; andheating the inside of the reactor to a temperature range from 450° C. to 570° C., thereby carrying out reforming reaction.

2. The method according to claim 1, wherein the raw material gas is a hydrocarbon, oil, or alcohol.

3. The method according to claim 1, wherein the reforming catalyst has a structure where a catalyst metal particle of at least one selected from the group consisting of nickel, ruthenium, rhodium, palladium, platinum and cobalt is supported on a carrier selected from alumina, magnesia, ceria, lanthanum oxide, zirconia, silica and titania.

4. The method according to claim 1, wherein the reforming catalyst has a granular or pellet shape and has a diameter of 2 to 10 mm.

5. The method according to claim 1, wherein the lithium composite oxide is lithium silicate.

6. The method according to claim 1, wherein the carbon dioxide absorbent is a porous body having particles of 2 to 50 μm and a porosity of 30 to 70%.

7. The method according to claim 1, wherein the reactor is filled with the reforming catalyst and the carbon dioxide absorbent at a volume ratio of absorbent/catalyst not lower than 9 and lower than 17.

8. The method according to claim 1, wherein the reactor is filled with the reforming catalyst and the carbon dioxide absorbent at a volume ratio of absorbent/catalyst in a range from 11 to 13.

9. The method according to claim 1, wherein the heating is carried out at a temperature in a range from 500 to 550° C.

10. The method according to claim 1, wherein the product gas discharged out of the reactor is further supplied to a methanation reactor filled with a methanation reaction catalyst and carbon monoxide in the product gas is subjected to methanation reaction.

11. The method according to claim 10, wherein the methanation reaction catalyst has a structure comprising an alumina carrier and ruthenium deposited thereon.

12. The method according to claim 10, wherein the methanation reaction is carried out by heating the inside of the methanation reactor in a temperature range from 150 to 350° C.