Effective production of hydrogen negative ions (H−) is one of the important issues in high power neutral beam injection (NBI) for fusion experimental devices. Cesium (Cs) vapor is seeded in the H− sources to enhance the H− production rate, which depends strongly on the amount of Cs inside the source. On the other hand, oxygen and water attenuate the production rate. In order to investigate the ...

the majority of rhizospheric bacteria, particularly fluorescent pseudomonads are able to stimulate plant growth by producing different metabolites including hydrogen cyanide and siderophores. to evaluate the effect of these metabolites on wheat growth, strains of fluorescent pseudomonads were isolated from the wheat rhizosphere in khorasan provinces, identified and studied for production of hyd...

The photocatalytic methanol reforming reaction has been studied using many different Pd/Pt loaded TiO2 powdered catalysts, focussing on the effect of weight loading and reaction phase on the rate of hydrogen production. The palladium/platinum weight loading dependence in the gas and liquid phase showed that independent of the phase of reaction, the amount of hydrogen produced from methanol refo...

■ This paper offers an overview of the technologies for hydrogen production. The technologies discussed are reforming of natural gas; gasification of coal and biomass; and the splitting of water by water-electrolysis, photo-electrolysis, photo-biological production and hightemperature decomposition. For all hydrogen production processes, there is a need for significant improvement in plant effi...

There is a growing need for hydrogen and a future hydrogen economy is high on the political agenda. But where should the hydrogen come from? The “sustainable” routes are still too expensive. Steam reforming of hydrocarbons is the most feasible route today. If CO2-sequestration is accepted, fossil fuels may play an important role in a starting future “hydrogen economy”. This will happen by use o...

This study evaluated the use of an anaerobic packed-bed reactor for hydrogen production at different hydraulic retention times (HRT) (1-8 h). Two reactors filled with expanded clay and fed with glucose (3136-3875 mg L(-1)) were operated at different total upflow velocities: 0.30 cm s(-1) (R030) and 0.60 cm s(-1) (R060). The effluent pH of the reactors was maintained between 4 and 5 by adding Na...

The photocatalytic production of hydrogen from aqueous systems is reviewed, stressing the very promising features of the process as an environmentally friendly, perfectly renewable way to produce hydrogen, the ideal fuel for the future. Starting with a brief historical background, the most recent achievements in the field are discussed, both in the development of innovative materials able to ca...

The limited fossil fuel prompts the prospecting of various unconventional energy sources to take over the traditional fossil fuel energy source. In this respect the use of hydrogen gas is an attractive alternate source. Attributed by its numerous advantages including those of environmentally clean, efficiency and renew ability, hydrogen gas is considered to be one of the most desired alternate....

Biogas production technologies commonly involve the use of natural anaerobic consortia of microbes. The objective of this study was to elucidate the importance of hydrogen in this complex microbial food chain. Novel laboratory biogas reactor prototypes were designed and constructed. The fates of pure hydrogen-producing cultures of Caldicellulosiruptor saccharolyticus and Enterobacter cloacae we...

At the University of Hawaii (UH), the approach to developing high-efficiency, low-cost photoelectrochemical (PEC) processes for the direct production of hydrogen has included the use of integrated electrochemical/optical models to design photoelectrodes based on multijunction thin-film technology; materials research to identify critical issues on photoelectrode efficiency and stability; and the...