Bioproduction of Hydrogen with the Assistance of Electrochemical Technology

摘要: The depletion of fossil fuel diverts us to the use renewable resources as supplement for fuel. Solar, hydroelectric power and microbial system are known be abundant production. Hydrogen has a energy yield 122 kJ/g, which is 2.75 times greater than hydrocarbon fuels (Kapdan & Kargi, 2006). together with oxygen key element in biological cycle on earth. In all organic matter hydrogen atoms bound carbon, nitrogen, sulphur other elements. Biological processes production hydrogen, environment-friendly less intensive, may categorized into bio-photolysis, photo-fermentation dark fermentation. Bio-photolysis occurs organisms such green algae or cyanobacteria, carry out plant-type photosynthesis, using captured solar split water. Non-sulphur purple photosynthetic bacteria undergo perform an anaerobic photosynthesis. By fermentation, variety different microbes anaerobically breaks down carbohydrate rich substrates by-products (Das Veziroglu, 2001; Hallenbeck Benemann 2002). Gaseous produced well consumed by living microorganisms presence absence (under both oxic anoxic conditions). condition observed during fermentation microbes. Among processes, presents high rate production, fermentative bacteria, Enterobacter species (Palazzi et al., 2000; Kumar Das, Nakashimada 2002; Kurokawa T Zhang 2005; Shin 2007), Clostridium (Chin 2003; Lee 2004; Levin 2006; Jo 2008) Escherichia coli (Yoshida 2005). through bacterial currently limited maximum 4 moles per mole glucose, under these conditions results end product (acetate; 2 mol/mol glucose) that were unable further convert hydrogen. Thermophiles up 60–80% theoretical maximum, demonstrating higher yields can reached extremophiles mesophilic anaerobes 2003). oxidative pentose phosphate pathway alternative metabolic route exists example microalgae, produce stoichiometric amount H2 from glucose. However, this usually not functional energetic reasons (Lee 2004). Several problems still remain commercial scale bio-hydrogen including low yield. Alternatively used