ENHANCEMENT OF UTILIZATION OF DECANTER CAKE AND CRUDE GLYCEROL IN BIOGAS CO-FERMENTATION

Abstract

This study focuses on the optimization of biogas production and the maximization of waste management efficiency. Co-digestion of decanter cake and crude glycerol (GLC) on biohydrogen fermentation was carried out in the first stage and then the effluent was collected and pretreated for the batch fermentation in the second stage. This work was divided into 2 parts. 1) The semi-continuous fermentation in 20 L reactor showed the optimal HRT of 2 days could maintain the fermentation process and dilute the acidity condition. The maximum yield of hydrogen production of 43.33 L/kgTSadded, hydrogen production rate of 0.89 L/L.d and energy recovery of 0.11 kWh/kgTSadded were obtained from the controlled HRT of 2 days with 1.5% GLC co-digestion. 2) Pre-treatment of hydrogenic effluent from the single stage of biogas fermentation by ozonation and thermal steam were conducted in 100 mL serum bottles (working volume of 80 mL). Thermal steam pre-treatment of hydrogenic effluent strongly resulted in the overall two-stage fermentation process. Results showed that the maximum methane production (P) of 385 mL in the second stage was observed at the condition of hydrogenic effluent pretreated by thermal steam. This work demonstrated the practical pretreatment by thermal steam, byproduct from the Palm Oil Mill, to improve the efficiency of biogas production in the second stage.