ABSTRACT
Renewable biofuels emerge as attractive alternates to conventional fossil fuels because they are sustainable, reduce greenhouse gas emissions, and aid in economic security. The focus so far has been put on bioethanol production, which is presently used in a blended form with gasoline in many countries. However, the inherent disadvantage of using ethanol as fuel has led to the search for alternate biofuels. Biobutanol has gained considerable attention as an advanced renewable biofuel due to its superior characteristic features over ethanol. It has higher energy content, is less miscible with water, has low vapor pressure, and is compatible with the existing oil infrastructure. It is naturally produced by Clostridium species, which follows the acetone-butanol-ethanol (ABE) fermentation pathway. Currently, there are several issues that challenge biobutanol production at commercial scales such as low yields, product inhibition, incomplete sugar use, and high feedstock costs. Furthermore, the separation of butanol from the fermentation broth is costly. This chapter provides a comprehensive review about the biobutanol production and its potential use as a biofuel. The various ongoing studies for the improvement of the ABE fermentation process are highlighted and the recent advancements and challenges are emphasized.
