Enzymatic and Dilute Acid Hydrolyses of Maize Stalk Substrate in Bio-ethanol Production

Abstract

Biofuels have been identified as suitable in combating climate change as a result of green gas emissions from fossil fuels. Bioethanol is a biofuel from lignocellulosic biomass is considered a viable renewable energy alternative to fossil fuels. However, the recalcitrance of biomass feedstocks due to the presence of lignin, creates a barrier to glucose fermentation. This study compares enzymatic and dilute acid hydrolyses of cellulose substrates obtained from pretreated maize stalk. The cellulose substrates were hydrolysed into glucose using dilute H 2 SO 4 , dilute HCl and Cellulase enzyme. The glucose obtained was fermented using an active yeast strain (Saccaromyces cerevisae) and then distilled in accordance with ASTM D1078 to obtain bio-ethanol. High Performance Liquid Chromatography (HPLC) was used in quantitative analyses of the bio-ethanol produced while qualitative tests were done based on ASTM D7795-12 for physical tests (density, boiling point, miscibility, non-volatile residues, colour, flammability and distillation range) and chemical tests (Acidity, Alkalinity, Fusel oil, Readily carbonizable substances and readily oxidizable substances). Enzymatic hydrolysis gave a higher glucose yield, while there was no significant difference between hydrolysis using dilute acids. There was significant difference in extraction efficiencies between acid and enzymatic hydrolysis methods. The bio-ethanol produced has similar purity levels with qualitative properties to that of an industrial grade ethanol.

Saccharification and Fermentation of Cellulolytic Agricultural Biomass to Bioethanol using Locally Isolated Aspergillus niger S48 and Kluyveromyces sp. Y2, respectively

“…6 showed that highest concentration of sugars (1.07 mg/ mL) was produced from the rice chaff, followed by yam peel which produced 0.87 mg/mL while groundnut shell produced lowest sugar concentration of 0.75 mg/mL. Kolajo [39] mentioned in her report that cellulase enzymes yielded more (4.04 mg/mL) fermentable sugars than dilute acid or alkali that produced 3.76 mg/mL. This reaffirms the report being presented that crude cellulase produced by Aspergillus niger S48 hydrolyzed pre-treated lignocellulosic agricultural biomass to fermentable sugars.…”

Bioethanol production from coconut husk using DES-NADES pretreatment and enzymatic hydrolysis method

“…Fossil fuels are still the primary source of energy used commercially. The massive use of these fos-and plant waste, such as lignocellulose plants [2][3][4][5][6][7][8][9]. Low toxicity, fewer emissions, and biodegradability are bioethanol advantages compared to fossil fuels.…”