Ester-Based Biofuels from Wastes

Abstract

Nowadays, an increasing worldwide interest in the use of renewable energy sources and the production of biofuels through the use of agro-industrial waste biomass as substrate for biofuels has become a necessity. Therefore several studies have reported the use of wastes for biofuel production including ethanol, methane and hydrogen. Another biorefinery concept for wastes exploitation includes its use as a substrate for anaerobic acidogenesis, to produce organic acids (OAs). Low molecular weight OAs have many applications, including biogas and biodiesel production, and their production through anaerobic fermentation of waste biomass has the advantage of being a cost-effective and environmentally friendly process. The produced OAs can be esterified with the produced ethanol or/and with an added alcohol, to esters that may be used as a new biofuel. The use of such esters in a homogeneous charge compression ignition engine, gave promising results for the use of such alternative liquid biofuel. This chapter presents different aspects of the production of an ester-based biofuel from wastes. Agro-industrial waste is being used as the raw material for organic acid production through microbial processes, which after passing through the esterification process, will lead to the production of a 2nd generation biofuel.