Large scale plantation of biofuel crops has lately been linked to the rise in food prices and environmental degradation. Experts now consider second generation bio-fuels extracted from microbial sources, lingo-cellulosic biomass, rice straw and bio-ethers a better option for addressing energy security and environmental concerns than large-scale plantation of biofuel crops like Jatropha. They were expressing their views during the 5th International Bio-fuels Conference organised by Winrock International-India, in Delhi.

According to Vijayanand S Moholkar of Indian Institute of Technology, Guwahati, who was one the   participants at the conference  preliminary experiments have shown tremendous potential for micro-algae derived oil feedstock for synthesis of bio-diesel. Proper cultivation of micro-algae can produce 10 times more oil than Jatropha on the same piece of land. Jatropha and Karanja yield not more than 1 to 1.5 tonne of oil per hectare of cultivation —a major limitation, which adversely affects the bio-diesel economy. Large scale production of micro-algae can be done in raceway ponds (closed loop recirculation channels) and photo-bioreactors.

Other experts at the conference favoured biochemical conversion of rice straw and other biomass into bio-ethanol. According to them, bio-ethanol production from cheaply available rice straw by separate enzymatic hydrolysis and fermentation can be economically viable. According to a scientist from the Dehradun-based Indian Institute of Petroleum, bio-ethers seem to be the most promising among all the bio-fuels due to their oxygenated molecular structure, better combustion characteristics, superior well-to-wheel efficiency, low GHG emissions and higher production efficiency.