An Integrated Sequential Production of Bio-Ethanol, Biodiesel and Briquette from Spent Coffee GroundName : Dr. Muluken Eshetu Tefera
Affliation : Lecturer
University : Jimma University
Country : Ethiopia
Abstract: In this study, biodiesel, bioethanol and briquette samples were sequentially produced from spent coffee ground. The oil extracted from spent coffee ground with solvent extraction route at hexane to spent coffee ground ratio of 22.5g/g with an extraction time of 30.4min resulting in 11.892% of oil yield and subsequently used for biodiesel production experiments using a 1% by wt of NaOH at reaction temperatures and residence times ranging from 50 to 65 °C and 20 to 60min, respectively. The optimization carried out using central composite design methodology gave 81.507% of methyl-ester yield at a reaction temperature of 57.133 °C and reaction time (residence time) of 45.117 min with model determination coefficient (R2) of 0.9465 while the optimum reducing sugar yield for dilute acid hydrolysis experiments for ranges of operating parameters of temperature (70-100 °C) and (1-3M )of H2SO4 concentrations was found to be 39.161% at a temperature of 98.313°C and H2SO4 acid concentration of 2.962M. Experiments were conducted at the predicted optimum conditions and resulted 79.65% of biodiesel yield (out of 11.892g of oil) and reducing sugars yield of 37.28 %( out of the hydrolysate). The bio ethanol produced by simple distillation found to be 55% alcohol by volume. The Briquette produced from 75% wt of dilute acid hydrolysis residue and 25% wt of glycerol, resulted a calorific value of 13.35MJ/kg, with its easy mold -ability. This study signifies the value addition that can be affected from spent coffee ground and results obtained in this regard are discussed.
Muluken Eshetu Tefera has been working as a lecturer at Jimma University,Jimma Institute of Technology under the school of Chemical Engineering since Aug 2014. He has been working on giving lectures on Fluid Mechanics for Chemical Engineers, Mass Transfer Unit Operation and Entrepreneurship for Engineers courses, assisting undergraduate students in Thermal and Mass Transfer Unit Operations Laboratory, Advising graduating students, mentoring industrial intern students and many more activities.