Ms Chidiebere Millicent Igwebuike from Energy Systems and Environment Department (DSEE) and GEPEA laboratory, will present her research about :
"Experimental Study on the Potential of Different Feedstock on Second Generation Bioethanol Production: Setting a Methodology"
Biofuels are clean and renewable energy resources that are gaining increased attention as a potential replacement for non-renewable petroleum-based fuels. It is so-called because it is derived from biomass which could either be animal-based or belong to any of the three generations of plant biomass (agricultural crops, lignocellulosic materials, or algae). Different methods and techniques have been tested by scientists and researchers in this field, and the most optimal conditions adopted for the generation of biofuels from biomass. This has ultimately led to subsequent scale-up of procedures and the establishment of a pilot, demo, and large-scale plants/biorefineries in some regions of the world. Nevertheless, this biomass has not been fully exploited in many parts of the world for biofuel production, especially in developing countries, and as such little or no relevance has been attached to agricultural and forest residues and waste in this regard. Hence, there is still much work to be done in largely replacing fossil fuels with biofuels from biomass. Lignocellulosic waste biomass such as cassava peels, sugar beet pulp, and Ulva lactuca are suitable materials for bioethanol synthesis. Their compositions are presented in this study. Total soluble carbohydrates and carbohydrate yield were evaluated using dilute acid hydrolysis of biomass and reference materials (starch and cellulose) under different conditions. To explore two-factor interactions, the Plackett-Burman design of experiments was used in the statistical screening of variables and then transformed to a full-factorial design based on the significant variables. According to the experimental findings, dilute acid hydrolysis can yield a considerable amount of soluble carbohydrates. The goodness of fit of the model was evaluated using the coefficient of determination. The optimized carbohydrate yields of the biomass were 0.76 g/g cassava peels, 0.35 g/g sugar beet pulp, and 0.36 g/g Ulva lactuca. The actual values of the optimized points were close to the predicted values. Bioethanol production from optimized hydrolysis conditions using Saccharomyces cerevisiae and Scheffersomyces stipitis DSM 3651, led to a maximum ethanol yield of 0.286 g/g from cassava peels and 0.033 g/g from sugar beet pulp while using Neurospora intermedia DSM 1265 led to a maximum ethanol yield of 0.076 g/g from Ulva lactuca. Hence, cassava peels, sugar beet pulp, and Ulva lactuca are considered valuable feedstock for the production of second-generation bioethanol with cassava peels having the highest potential.
Thesis acreditation from IMT Atlantique with the Doctoral School SPIN
keywords: Waste biomass, dilute acid hydrolysis, carbohydrates, fermentation, bioethanol