BIOGAS PRODUCTION FROM CO-DIGESTION OF FOOD WASTE AND RAIN TREE LEAF USING SINGLE-STAGE AND TWO-STAGE ANAEROBIC DIGESTERS

Abstract

This research is aim to study the anaerobic digestion system of single-stage and two-stage anaerobic digester for biogas production and waste treatment. This research also study the possibility of co-digestion of food waste and rain tree leaf as a feed stock. The ratio of food waste and rain tree leaf was done in 85:15 90:10 95:5 and 100:0 respectively. Single-stage anaerobic digester has a horizontal cylinder shape located at the canteen of Chulachakrabongse building while two-stage anaerobic digester separated into two reactors. acid fermentation reactor and methane reactor. Two-stage anaerobic digester located at the canteen of Mahitaladhibesra building. The result obtain in feedstock was found that the ratio of co-digestion of food waste and rain tree leaf at 95:5 gave the significantly high in biogas production. Carbon to nitrogen ratio was measured, the result was 20.77 optimal C/N ratio for biogas production. The efficiency of COD removal found in single-stage was 61.95% – 89.44% while two-stage was 71.9% – 88.84% and the efficiency of total solid removal was found that ratio of co-digestion has significantly high in both single-stage and two-stage 73.54-81.7 and 59.03-83.10 respectively. The result found that separate reactor into two-stage gave more efficiency in waste reduction. Biogas production was found that two-stage anaerobic digestion had significantly high in biogas production rate at maximun 4.213 Nm3 and 1.965 Nm3 with average 3.194±0.189 Nm3 in two-stage while single-stage anaerobic digester can produced biogas average 1.612 ± 0.094 Nm3.