Hydrogen evolution by fermentation is very general metabolism for bacteria. Almost 25% of generalisted in the Bergey’s Manual of Determinative Bacteriology, 8^th edition, were recognized to evolve hydrogen, no matter what the amount of evolution. The reason is mainly to re-oxidize NADH to NAD⁺ to get more energy for their growth and living like follows; NADH+H⁺→ NAD⁺+H₂. For the case of Clostridium butyricum, the evolution was clearly explained from the point of chemical thermodynamics. The metabolism is regulated by the redox potential of H₂ at the cultural pH. Maximum values on hydrogen production properties were estimated from the theoretical point of view.

To produce hydrogen from biomass, gasification from biomass followed by reforming of the product gas is usually employed. Since reforming of the product gas, mainly composed of hydrogen, methane, carbon dioxide, and carbon monoxide into hydrogen-rich gas is a well-developed technology, efforts on technology development now targets biomass gasification. There are several technologies available for biomass gasification, each favoring specific type of biomass. This paper reviews the status quo and prospects of these biomass gasification technologies in terms of hydrogen production from biomass.

To produce hydrogen from woody biomass, steam gasification using a CO₂ sorbent has been investigated. The principle of the steam gasification using a CO₂ sorbent is shown the following equation; C+H₂O+M→H₂+MCO₂, here M is a CO₂ sorbent. The R&D project, named “Clean gas production from biomass”, has been performed. A continuous bench scale unit has been designed and constructed. A reactor and hoppers of woody powder and calcium oxide powder are set in pressure vessels. The capacity is 10 kg of wood a day.

The laboratory scale examination has been also performed. The powder of Japanese Oak was gasified by using a batch reactor with 50 mL capacity into a clean gas at the reaction conditions of 600 to 700 °C and 0.1 to 5 MPa using calcium hydroxide as a CO₂ Sorbent. The clean gas, mainly hydrogen was obtained at the yield of 1.5 L/g-wood, and it contained 97 vol% of H₂, 3 vol% of CH₄ and 0.1 vol% of hydrocarbons. No CO₂ nor CO was detected in the clean gas.

The excergy regeneration from low quality energy sources combined with various chemical reaction processes is the potential option to realize a highly sophisticated new energy system. This new concept can be realized based on material conversion processes closely related to multi-pass energy recycling among electric, chemical, and thermal energy sources. In order to realize future excergy regeneration systems and their further optimization, we especially focus on the excergy enhancement from low temperature (100-300ºC) heat sources including waste steam. Here, as an example, we propose excergy regeneration system based on hydrogen-rich biomass gasification with self-heat recirculation. The possibility of realizing this system was evaluated by using Aspen Plus software combined with our experimental data for each component. This process could be further improved with the combination of various chemical reactions such as fuel cell and methanol and DME syntheses.

The Teflon® composite membranes were fabricated with the room temperature molten salt (RTMS) in order to operate a fuel cell over 100℃ without humidification. The cell performance was evaluated with hydrogen and oxygen. It was improved by the addition of 2EtHImBF₄ to the catalyst layer. This might be due to the formation of the proton channels in the electrode by 2EtHImBF₄. When the quantity of 2EtHImBF₄ in the catalyst layer was about 5 vol.%, the cell had the maximum current density. The internal resistances of the cell with the RTMS were analyzed by the AC impedance method. The resistance of electrolyte is small, but the resistance of oxygen reduction reaction is large. The large cathode resistance would be the major reason for the low cell performance. It is also found that water content is important for oxygen reduction reaction.

Mechanical milling of graphite,carbon black,zirconium metal and ZrMn₂ alloy was performed under hydrogen to synthesize hydrogen sorbing composites. Hydrogen capacity of milled graphite depended on milling time,but variation of the former with specific surface area was not monotonous. Among the studied carbonaceous composites,cooperative effect to enhance hydrogen capacity was only observed for zirconium-carbon black composite. This would be owing to some specific sites on carbon black that were effectively created and were not consumed during the milling process. Another effect of the composite formation was stabilization of zirconium and ZrMn₂.

Fuel cell application for mobile electronic devices such as portable computer and cellular phone requires miniaturization of the cell system, not to mention the price reduction. While electronic devices in general are driven by a small electric current, a single fuel cell generates electric power of comparatively high electric current density at the voltage lower than 1 V. Boosting its output voltage with a dc/dc converter can therefore reduce the size of fuel cell power supply system. We have conducted a design study to assess the effectiveness of this scheme in reducing the size and cost of the fuel cell power source for a cellular phone. It was shown that 5 cells were required for the fuel cell to provide duty power of a cellular phone, and that an equivalent power was available with the fuel cell consisted of 2 cells and dc/dc voltage booster reducing the size by 36%, the cost by 35%, and increasing the energy efficiency by 20%.

The paper describes transmission cost of nuclear off-peak power for water electrolysis. The cost of transmission could be evaluated ca. 1.5¥/kWh when the electrolyser receives the power from a 6kV wire and ca. 0.7¥/kWh from a several ten kV wire. Marked reduction of the transmission cost of the off-peak power arose from enlarged capacity factor of the power transmission system.

Dimethyl ether (DME) has been considered as a promising fuel because theoretical electromotive force and theoretical efficiency of direct DME fuel cell (DDFCs) are almost equal to those of direct methanol fuel cell (DMFC), and it can be stored in high-density liquid phase at modest pressures of around 0.6MPa (25ºC). In addition, DME is less toxic than methanol.

In this paper, the electro-oxidation of DME was carried out using stripping voltammetry (SV) and cyclic voltammetry (CV) on Pt electrode in aqueous H₂SO₄. The results of SVs indicated e.p.s. (electron per site) of DME oxidation reactions (DOR) was 1.5~2 at adsorption potentials (0.05~0.5V vs. RHE). CVs showed that adsorbates of DOR were similar to those of formic acid, the predominant species are suggested to be *CO (linear), **CO (bridge) and ***COH. However, it was found that the product potential of the strong adsorbates was different by the varying the potential range.

It is very important to develop the international standard for hydrogen technologies in view of the fact that hydrogen technologies are being utilized internationally and have a wide spread impact on top of the consideration for world common safety and environmental standard. Engineering Advancement Association of Japan undertook the development of international standardization activities for hydrogen technologies - ISO/TC197- under the National Hydrogen Development project;WE-NET

project dedicated by NEDO from 1994 through 2002 and has continued to work under the new National project; ‘Development of Basic Technologies for the Safe Use of Hydrogen’ from 2003.

To establish codes and standards for fuel cell vehicle safety Japan Automobile Research Institute (JARI) has been evaluating safety issue about hydrogen fuel cell vehicles such as hydrogen diffusion property in the air, ignition, flame propagation released from high pressure cylinders and so on. Although hydrogen is thought to be very dangerous gas, these results shows that, in some cases, hydrogen is rather safe compare with exisiting energy sources such as gasoline and compressed natural gas.

For spread and promotion of a fuel cell power generation system, it is important to further technical development, such as high reliability, miniaturization and cost reduction.Simultaneously deregulation and standardization such as performance test and safety are required as technical conditions for successful and safe market introduction. The Japan Electrical Manufactures’ Association (JEMA) is advancing them. This paper introduces the activity of deregulation and standardization for stationary Fuel Cells, moreover for micro Fuel Cell.

Features and technologies to produce hydrogen using nuclear energy are reviewed. For the world under constraint of environment and resource, the sustainable bulk supply capability is one of the important features of producing hydrogen as well as generating electricity from nuclear energy. Production technologies, such as the electrolysis of water by nuclear electricity, thermochemical decomposition of water by nuclear heat, and nuclear-heated steam reforming of natural gas, are under development in Japan and other countries. These hydrogen production technologies and also the nuclear reactors to supply energy to them are in differing stages of development. It is technologically possible to produce hydrogen at present using the nuclear electricity from Light-Water Reactors and the conventional electrolysis. Hydrogen production through nuclear-heated steam reforming of natural gas is viewed as an intermediate step to the ultimate target of clean and efficient hydrogen production by the water splitting using nuclear heat and/or electricity.