Bio-ethanol production from a mixture of rice hull and orange peel wastes

Abstract

Bioethanol, as a renewable fuel with a plant base, has a molecule of oxygen in its molecular structure which can improve engine performance and emissions. In the present study, rice hull and orange peel (RHOP) wastes were used to produce bioethanol. First, equal shares of dried rice hulls and orange peels were mixed and milled. Then, 10 L of distilled water was added to the mixture for better hydrolysis and fermentation. Finally, 11 kg of substrate was prepared for hydrolysis to produce sugar. For hydrolysis, three concentrations of sulfuric acid (1, 2 and 3%) were used. The hydrolysis temperature was set at 121 °C for three times of 20, 40 and 60 minutes in the reactor. Finally, 55 g of Saccharomyces cerevisiae was used for fermentation. The fermentation times were set between 4 and 32 hours. The results showed that 22.77 g of bioethanol is obtained per L of RHOP substrate in the best condition. Also, according to the optimum conditions of the experiment, the yield of bioethanol production was 0.295 L/kg of dry matter of RHOP.