The Potential of Elephant Grass (Pennisetum Purpureum Schum), a Nigerian Indigenous Grass, in Bioethanol Production: A Decarbonization Alternative for the Maritime Industry

Abstract

It is true that fossil based energy has contributed immensely to global economic growth. Unfortunately, its usage is accompanied by the emission of carbon dioxide (CO2), a principal greenhouse gas. Studies using business as usual (BAU) model, has predicted that CO2 emission into the atmosphere will increase by 50-250% by the year 2050. The transportation industry has remained one of the highest contributors to this global carbonization. About 40% of all CO2 emissions by 2050 will be caused by shipping and aviation if left unregulated, a study published by the European Parliament revealed. The above scenario has heightened the interest in energy crops development as resources for alternative/renewable energy purpose. Elephant grass (Pennisetum Perpureum Schum), an African indigenous grass, is an abundant, C4 grass, investigated for its potential as a renewable energy source. Elephant grass feedstock (stem & leaves) was subjected to laboratory analysis for its total carbohydrate content (TCC) via proximate composition analysis. For ethanol production experiments, feedstock acidic hydrolysis, using 0.5M of dilute H2SO4 was adopted. The pH of the hydrolyzed supernatant was adjusted to 5.0 using 10M NaOH solution. Fermentation medium was prepared using 10g of dextrose, 0.2g yeast extract and 1g urea. The fermentation process using 0.5g of Saccharomyces cerevisae at 350C for a period of 1 to 5 days was subjected to distillation process at 78.30C. Proximate composition analysis showed a 74.2% TCC, a huge content for conversion to bioethanol. The fermentation process showed increase in ethanol yield with increase in feedstock concentration. From the foregoing, elephant grass has the potential to serve as energy crop for biofuel production for automobiles including some auxiliary engines of ships if not major ones.