Bio-butanol production from permentation of oil palm frond liquid extract as potential fuel for spark ignition engines

Abstract

In recent years, the increasing concern for environmental issues such as greenhouse gas emissions, diminishing fossil fuel reserves, engine exhaust emission from engine burning fossil fuels and unstable fuel supply has rekindled interest in the search for an alternative and sustainable replacement to conventional fuel. Presently, use of oil palm agro-plantation waste for bio-butanol production as a substitute for gasoline is seen to have potential due to its richness in fermentable sugar, abundance and low cost. The study investigated the batch fermentation of oil palm liquid extract for biobutanol fuel production using Clostridium acetobutylicum (ATCC4259) in terms of metabolite, kinetic cell growth, sugar conversion and solvent production. Furthermore, effects of pH and inoculum size concentration on acetone-butanolethanol (ABE) production were investigated using analysis of variance statistical method. In addition, oil palm frond liquid extract chemical characterization was also studied. Result of statistical analysis of variance indicated that inoculum size concentration has significant effect on the yield of biobutanol from oil palm frond liquid extract. The use of 50 g/L glucose content obtained from oil palm frond extract as a sole carbon source produces 9.05 g/L bio-butanol. In addition, characterization results showed that oil palm frond liquid extract contained (50.0 ± 1.5 g/L) glucose concentration with higher nutrient contents of Nitrogen 1077 mg/L, Potassium 2459 mg/L, Magnesium 1590 mg/L and Phosphorus 89.5 mg/L. The biobutanol produced was then characterized to determine the basic fuel properties inclusive of specific gravity, refractive index, calorific value, density, kinematic viscosity, pour point and flash point. The results obtained for the basic fuel properties tested conformed to the set limit with little variation. This study has demonstrate that butanol technically can be produced from oil palm frond agro-plantation wastes and provide an alternative to the current use of alcohol-based fuel such as ethanol and methanol. The possibility of producing butanol will undoubtly enhance future sustainable fuel security and minimize environmental impact.