INVESTIGATION OF POTATO PEELS AS A RAW MATERIAL BASE FOR BIOFUELS PRODUCTION
SHAABAN OMAR1,2, POLINA VELICHKOVA1*, TODOR IVANOV1, IVO LALOV1
1 – Faculty of Chemical System Engineering, Department of Biotechnology, University of Chemical Technology and Metallurgy, Sofia, Bulgaria
2 – Faculty of Science and Health, Department of Medical Microbiology, Koya University, Iraq
*Corresponding author: p.velichkova_BT@uctm.edu
Keywords: biochemical methane potential, biogas, bioethanol, bioenergy, biofuels, potato peels, fermentation
Abstract: This study deals with improvement of the energy potential of potato peels via different types of modification. Proper pretreatment methods can increase concentrations of fermentable sugars, thereby improving the efficiency of the whole bioconversion process. As pre-treatment methods, hydrochloric acid hydrolysis at high temperature and pressure and enzymatic hydrolysis at high temperature using an amylolytic complex were selected. Both modifications have led to an increase in biochemical methane potential of potato peels - 0.33 dm3CH4/gVSS by 24 % in the acid hydrolysate (0.41 dm3CH4/gVSS) and by 67 % in the enzymatic hydrolysate (0.55 dm3CH4/gVSS), respectively. Additionally pretreatments of the potato peels resulted in expanded spectrum of produced biofuels, as it was proved by subjecting the modified substrates to successful alcohol fermentation. The total energy potential of the modified substrates was revealed using combined anaerobic bioconversion process. Such approach allowed us to determine that the energy density of the enzymatically modified potato peels exceeds that of the untreated biomass more than 2.2 times.