Lightdependant Processes

The low energy density of solar energy places severe economic restrictions on potential light-dependant biohydrogen processes. For example, at very favorable locations the yearly average solar irradiation could be as high as 5 kWh m2 day which would give 6.6GJ year. At a very optimistic conversion efficiency of 10 and a price for H2 of 15 per GJ only 10 worth of H2 m2 year would be obtained thus severely constraining construction and operational expenditures. Obviously, the situation worsens if...

Watersplitting Systems By Renewable Energy

Presently, more than 98 of the hydrogen gas consumed by the industries are provided by reforming coal, naphtha, and natural gas, and will be unable to bear the future demand 7 , It is strongly required to supply the hydrogen produced from water by renewable energy sources. Table 1 shows the water-splitting methods -lysis by the different kinds of energies. Hydrogen produced by water electrolysis is the traditional way since M. Faraday, however it cannot be qualified as clean energy carrier...

Hydrogen Utilization Systems

The precious ways of hydrogen utilization have the principles based upon the two non substitutive properties of hydrogen, that is, hydrogen energy systems are not only ecological but also energetic. Energetic means that hydrogen combustion has the high power chemical wattage that generates a big energy per unit time, which has been applied to the second stage of rocket launching. Ecological means that hydrogen can make not only the on site recycle by reversible physical reaction and or by...

Cyanobacterial Biohydrogen

Basically, two strategies are possible for cyanobacterial biohydrogen 1 H2 produced by nitrogenase, and 2 H2 produced by the bidirectional hydrogenase. Individual strains may harbor both a bidirectional hydrogenase though this is not a universal cyanobacterial enzyme , and none to several nitrogenase s , encoded by different structural genes. There is no report describing the existence of either several uptake hydrogenases or several bidirectional hydrogenases in a single cyanobacterial strain....

Photobiological Hydrogen Production Utrilizing Cyanobacteria

Merits of photobiological hydrogen production utilizing cyanobacteria Solar energy is the most abundant renewable alternative, and hydrogen is the most likely environmentally friendly future fuel. The amount of solar energy received on Earth's surface amounts to more than 6,000 times of the world social energy consumption Tab. 1 . However, solar energy is diffuse in intensity and its economical utilization is not easy Tab. 2 . In order that H2 substitutes for or supplements fossil fuels, its...

Hydrogen Enzyme Electrode For Renewable Energy

The hydrogen enzyme electrode is a device, which able to activate reversibly hydrogen molecule using catalytic activity of hydrogenase for energy interconversion between H2 and electricity. The effective electron exchange between the enzyme active site and electrode surface is required for function of this device, for example, in water electrolyzer, hydrogen fuel cells and other energy conversion systems. Several approaches were used to develop hydrogen enzyme electrodes based on direct and...

Materials And Methods

Biohydrogen

Rb. sphaeroides KD 131 wild type and its mutant strains 17 were obtained from Dr. J. Lee Sogang University, Korea . Rb. sphaeriodes KD131 was pre-cultured in the modified Sistrom's broth containing NH4 2S04 and L-aspartic acid as nitrogen sources and 35 mM succinic acid as a carbon source at 30 C for 20-24 hr under 7-8 klux m2 irradiance using halogen lamps 12V, 20W by illuminating at one side of serum bottles. The pre-cultures were centrifiiged to collect the cells and the cells collected were...

Introduction To Biohydrogen

The spurred impetus has been given to developing non pollutant vehicles, and consequently, the clean cars driven by the fuel cells loading proton exchange membranes PEMFC , which based upon Nafion, have been surprisingly developed. A promising less pollutant and economical system is also expected, which will be the on site cogeneration system of electric power and the hot water supply with use of fuel cells combined with city gas pipe-lines. Such a spreading trend of non pollutant systems by...