Abstract

Corncobs are lignocellulosic biomass that has received widespread attention as a promising raw material for bioethanol production because of its abundance and low-cost. They also relieve the predicament and ethics involved in using consumable food crops such as corn for bio-ethanol production when there are serious food shortages in many parts of the world. Corncobs have a high cellulose and hemicellulose content, high-molecular-weight constituents of lignocellulosic residues that can break down into simple sugars for microbial growth. Pretreatment of corncobs is necessary for lignin removal and the breakdown of cellulosic matter. Enzymes or acids act on the lignocelluloses to break down the cellulose into glucose monomers which are utilized by micro-organisms for conversion into ethanol through metabolic pathways. Large-scale production of bio-ethanol is stalled, attributed to the cost of production. The selection of a suitable pretreatment strategy will offset costs but is challenging as different methods offer different advantages over others in improving the overall efficiency of enzymatic saccharification and downstream processing costs. The current review accounts for strategies developed for bio-ethanol production using corncobs since pre-treating corncobs have been thoroughly researched and documented. The review hopes to establish the future of corncobs as a valuable commodity in the bioethanol industryby acting as knowledge or material source of the important processes to assist in designing a cost-effective ethanol production for industrial-scale production.

Graphic Abstract