Bioethanol is a renewable energy source produced through fermentation of sugars. A dramatic increase in ethanol production using the agriculture waste is currently been practical because production for ethanol will compete for the limited agricultural waste. A potential source for low cost ethanol production is to utilize lignocellulosic materials such as crop residues, grasses, sawdust, wood chips, solid animal waste and industrial wastes. The objective of this work was to evaluate the feasibility of ethanol production and optimization from coffee husk by using commercial bakery yeast, i.e., S. cereviciae. The study was conducted, at fermentation temperature 30 °C and pH 5, and treated using different acid concentrations and residence times. Coffee husk was hydrolyzed by refluxing, a solid to liquid ratio of 1:10, using dilute sulfuric acid (1 to 5 %) and distilled water at hydrolysis time of 1 to 11 hours keeping boiling temperature. 90 % maximum total sugar concentration was obtained at 5 h acid free hydrolysis. Based on these hydrolysis results, fermentation process was performed.
Keywords: Biomass, bioenergy, fuel, suitability, transportations