The energy crisis of the 1970s was followed by increased for the environment, with paticular emphasis on protection of the global ecosystem. The RAPAD estabished in japan investigated the development of technologies for biomass conversion and utilization, in particular, the production of ethanol from cellulosic biomass. Various forms of biomass resources exist. Among these, sugar and stsrch croos are inappropriate for use as energy sources since they are primary food sources, and are unstable from the viewpoints of long-term supply and cost. Cellulosic resources, on the other hand, represent the most abundant global source of biomass, and have been largely unutilized[17].
Development of technologies that efficiently produce biomass and convert it to more convernient forms of energy is therefore very important [18]. Microalgas heve been investigated for the production of a number of different biofuels including bio-diesel, bio-oil, bio-syngas, and bio-hydrogen. the production of these bio-fuels can be coupled with flue gas Co2 mitigation, wastewater treatment and the production of high-value chemicals. Developments in micro-algal cultivation and downstream processing (e.g.,harvesting,drying, ang thermo-chemical processing) are expected to further enhance the cost-effectiveness of the bio-fule from micro-algae strategy [19]. Biofule is a renewable energy source produced from biomass, ehich can be used as a substitute for petroleum fuels [20]. biofuels are expected to play an increasingly important role throughout 21th century [21][22]. Algae based biofuels are considered as a viable option as the oil productivity of many algse exceeds that of oil crops.