The utilization of cotton stalks as a renewable feedstock for the production of bioethanol and its use as an additive to improve the properties of gasoline

Abstract

The objective of this study is to investigate the feasibility of producing bioethanol from cotton stalk waste, a lignocellulosic feedstock characterized by its abundance and low cost. The study involved preliminary chemical pretreatment of cotton stalk powder using sulfuric acid at a solid-to-liquid ratio of 1:6 and concentrations of 1.5%, 1.0%, and 0.5%, in order to break down the complex lignocellulosic structure and partially remove lignin and hemicellulose. This was followed by fermentation of the pretreated material for 3days using commercial dry yeast (Saccharomyces cerevisiae) to convert monosaccharides into bioethanol. The results showed significant variation in bioethanol production depending on the acid concentration used. The objective of this study is therefore to determine the optimal acid concentration that yields the highest bioethanol production.

The produced bioethanol was then used as an additive to pure gasoline at different volume fractions (0%, 5%, 7%, and 10%). Numerous experimental tests were conducted to evaluate the properties of the resulting fuel in accordance with American Society for Testing and Materials (ASTM) standards, in order to determine its physical and chemical properties. The results showed an increase in the research octane number of the fuel blend as the percentage of ethanol increased.