Search for future fuels-pathway points to a 'boring' process

Abstract

The article compiles information on the efforts so far attempted for the production of clean fuels from potentially vast and diverse sources, like agricultural produce, algae, and also from the enormous quantities of lignocellulose wastes (woody material, crop residue, etc.). Among the several feedstocks, investigated upon in different laboratories as alternative sources for biofuels, are oils from soybean, palm, rapeseed, coconut, sunflower, peanut, cottonseed, linseed and rice bran; seeds from jetropha, neem, poon, rubber, mahua and karanj; and also maize, tapioca, castor oil, fish oil, animal fat, tallow, oleaginous fungi, microalgae and aquatic weeds. Among these, investigations on jetropha have now progressed well to the extent of commercial production. Utilization of these materials, however, is bereft with one or the other limitations, especially the non-availability of an efficient cost-effective method for their conversion into fuel in place of the presently employed thermal, physical, chemical and biochemical methods. It is suggested that microalgae, water hyacinth (with all their advantages including the manifold higher yield) and waste biomass have the potential to help us to overcome the energy crisis, for which added inputs in biotechnological research, aimed at developing a cheap, technically feasible and economically competitive methodology, holds the key. In this context, the possibility of utilizing the powerful cellulose-digesting enzymes of the marine wood-borer, Limnoria, to effectively break down any lignocellulose materials into simpler glucose, deserves special attention. Utilization of raw materials, mentioned above, involving an innovative process for their conversion into glucose and ethanol, based on the efficient cellulase enzyme system of Limnoria, can be our best option for future energy security. Research in this direction, initiated in UK, has been summarized.