Effects of blends on the physical properties of bioethanol produced from selected Nigerian crops

Abstract

Bioethanol fuel was synthesised from various Nigerian crops (palm (Elaeis Guineensis) wine, raffia (Raphia vinifera) trunk and sugar cane (Saccharum L.)) to serve as alternative fuels for internal combustion engines. Bioethanol was obtained through fermentation and distillation from these selected Nigerian crops and was then purified. Physical properties of the bioethanol and various petrol–bioethanol blends such as vapour pressure, octane number, flash point, heating values, auto ignition temperature and density were evaluated using the American Society for Testing and Materials methods. The calorific value of petrol decreased from 44.40 to 44.22 MJ/kg with a blend of 10% of alcohol (E10). The calorific value of the produced ethanol (E100) is 29.78 MJ/kg. The research octane number (RON) of petrol increased from 91 to 94 with a blend of 10% of alcohol (E10). The RON of the produced ethanol (E100) is 114. The flash point increased from -40°C at E10 to 12.6°C at E100. The results showed that the addition of bioethanol to petrol increases the octane number, flash point and auto ignition temperature, but on the other hand reduces the calorific value of the produced blend. The optimal petrol–bioethanol blends of E20 and below were recommended for vehicles running on spark ignition engines.