Biorefinery is a center that melds biomass conversion processes and equipment to manufacture fuels, power, heat, and chemicals from biomass. The biorefinery concept is parallel to petroleum refinery, which makes various products and fuels from petroleum. The ethanol manufacturing methods applied are enzyme digestion (to release sugars from stored starches), distillation, fermentation of the sugars, and drying. It can be used in petrol engines as a substitute for gasoline and it can be blended with gasoline to any concentration. The present car petrol engines can operate on mixes of up to 15% bioethanol along with petroleum/gasoline.