Optimization of pretreatment and saccharification processes of empty fruit bunches (efb) for bioethanol production / Ukaegbu Chinonso Ishmael

Faculty of Industrial Sciences and Technology

Thesis (Master of Science) -- Universiti Malaysia Pahang – 2016

Bibliograpgy : p. 102-109

Environmental degradation and episodes of global warming have facilitated studies into alternative sources of energy carriers for economic use. Green energy carriers such as bioethanol and biodiesel have waged the gap but not without a snag. Pretreatment of biomass for the production of biofuel has conventionally been done using energy and chemical agents which are not sustainable to the environment as well. Hence, in this study, a novel pretreatment method for the pretreatment of Empty fruit bunches (EFB) was studied and statistically optimized. The optimization of the process parameters for the pretreatment and saccharification of EFB using laccase and cellulase enzymes (enzyme and substrate concentrations, size of EFB, time, pH and temperature) were studied using one-factor-at-a-time (OFAT) and response surface methodology (RSM). The results of the study showed that the activity of laccase enzyme was more affected by the temperature of the reaction than any other factor. The optimized condition for the pretreatment of EFB with laccase enzyme was achieved as: temperature 35 oC, duration 4 h, enzyme concentration 20 IU/g of EFB, EFB concentration 5 % (w/v), and a reaction buffer of pH 5. The optimized saccharification condition of the enzyme pretreated EFB was studied and achieved as: temperature 50 oC, duration 24 h, enzyme concentration 30 IU/g of EFB, EFB concentration 5 % (w/v), and pH 5. Furthermore, the analysis of variance (ANOVA) of the statistically optimized parameters showed that temperature of pretreatment has higher significant effect (P < .05) compared to pH, while the pH during saccharification has higher significant effect (P < .05) compared to temperature. Ethanol production was evaluated at the optimized pretreatment and saccharification conditions and a yield of 29.13 % by total sugar content was achieved, as well as 31.12 % by biomass content. The pretreatment of EFB with laccase enzyme at the above modelled pretreatment conditions could contribute to the sustainability efforts aimed towards reduction of greenhouse gas emission from chemical agents and keep the environment safe from the harmful effect of global warming