In recent years, global warming is seen as a problem, and a fuel cell system attracts attention as a new clean energy as an alternative to fossil fuels which have been widely used. The fuel cell system uses hydrogen as fuel, and only water is discharged during generating electric power. Thus, it is expected to spread widely as an energy technology which is most environmentally friendly and clean.
On the other hand, in the gasoline automobiles, diesel generators for ships/locomotives, etc., “hydrogen-oil co-combustion technique” adding hydrogen to the fuel oil such as gasoline has been proposed. This technique is expected to improve the fuel consumption and reduce the generation of substances becoming environment loads, e.g. CO2, NOx, CO and the like. In such technological innovation, therefore, there is a growing demand for hydrogen.
Meanwhile, hydrogen has problems with storage and transportation which are difficult because hydrogen is combustible and is a substance causative of hydrogen embrittlement of metallic materials. Accordingly, as for the production, storage and transportation of hydrogen, all sorts of provisions are required.
In view of the above-mentioned problems, studies have been made on a hydrogen storage-supply system capable of supplying hydrogen quickly responding to the demand.
For example, as such system,
A) a method for obtaining hydrogen from raw materials including hydrogen e.g. natural gas, propane gas, methanol and the like through a technique such as steam reforming and hydrogen separation,
B) a method utilizing a catalytic body formed in the form of a plate, ribbon or honeycomb and provided with a catalyst supported by γ-alumina layer on the surface thereof, and
C) a method utilizing photosynthesis bacteria, anerobic hydrogen bacteria and the like
have been proposed. (see, for example, patent documents 1 and 2)
As for storage means for the obtained hydrogen, for example, a storage system utilizing a hydrogen storage alloy, and a system development utilizing carbon materials e.g. carbon nanotube, carbon nanofiber and the like have been proposed. (see, for example, patent documents 3 and 4)
[Patent documents1]
    Japanese patent application publication 2007-117992[Patent documents2]    Japanese patent application publication H02-144154[Patent documents3]    Japanese patent application publication H07-192746[Patent documents4]    Japanese patent application publication H05-270801