earticle

영어

The study was focused to extract oil from spent coffee grounds(SCG) and to convert into biodiesel. In addition, the residue after oil extraction was examined for bioethanol production by saccharification liquid using acid hydrolysis. Oil from SCG contained 15~17% and acid value of SCG oil was 3.3%(6.6mgKOH/g). After sodium hydroxide treatment to remove the free fatty acids, SCG oil was converted into biodiesel. Several studies on transesterification of SCG oil with methanol have been carried out for the production of biodiesel. The reaction parameters such as catalyst concentration, methanol/oil molar ratio, temperature were optimized for SCG oil methyl ester (COME). The fatty acid methyl esters content in the reaction mixture were quantified by GC. The yield of methyl esters from SCG oil under the optimal condition was 82– 83%. SCG residue hydrolyzed by acid was analyzed by HPLC and TLC. SCG contained sugars of 52.2%(w/w), of which hemicellulose (constituted by mannose, galactose) and cellulose (glucose) corresponded to 42.4%(w/w) and 9.8%(w/w), respectively. Sugars composition in SCG was found to be glucose 9.8, glactose 11.8, mannose 30.6. It was thought that reducing sugar concentration of 378 g/L in the hydrolyzed liquid was suitable as a feedstock for bioethanol production.