Production and application of ABE as a biofuel

The increasing energy demand and more stringent legislation for engine pollutant emissions with the use of carbon-neutral fuels have forced to use alcohol. ABE, a combination of acetone, butanol, and ethanol, is a potentially fuel that can be produced from waste biomass via fermentation. Recently, this fuel has attracted researchers' attention due to its better performance and less emission as a diesel blend when compared to ethanol. First, this article addresses past and recent research conducted in the field of biofuel (ABE) production from lignocellulosic materials. Second, the development in ABE production efficiency is reviewed and various methods of improving ABE production are presented. ABE from lignocellulosic materials (a green energy resource) can be improved through metabolic engineering of the fermenting yeast (Clostridia) and/or pre-treatment techniques. Furthermore, the application of ethanol, butanol and ABE as biofuel blends is compared and summarised considering three aspects (1) combustion characteristics; (2) as an additive blend of diesel fuel in compression engines; and (3) as an additive blend of gasoline in spark ignition engines related to engine performance and emission levels. This study shows that ABE has the potential to become an important second-generation biofuel that can be blended with diesel and gasoline for the following reasons: it is cheaper to produce compared to butanol, it is possible to improve engine performance and it reduces exhaust gas emissions. Moreover, engine power is comparable to diesel, and at the same time ABE releases fewer emissions such as CO and NOx than other fuel blends.