Biomethane Production from Co-digestion of Banana Peel and Waste Glycerol

Abstract

Banana peel and biodiesel derived glycerol are one of the most abundant agricultural waste in Southeast Asian countries. This current research demonstrated potential biomethane production from co-digestion of agricultural wastes under mesophilic fermentation. The wastes used include (1) banana peel (varying total solids in the range 2.5-10% w/v) and (2) Banana peel mixed with pure or waste glycerol. All treatments were setup in duplicate in 0.5 L batch reacotr. Gas and liquid samples were collected every 12 and 24 hr, respectively. Maximum methane production potential and yield were 181 mL and 188mL g-1 TS at 7.5% banana peel. The maximum methane production potential and yield of 7.5% banana peel mixed with 7.5 g L-1 pure glycerol (in the presence of buffer) were 467 mL and 151 mL g-1 COD, respectively, while those of 7.5% banana peel mixed with 7.5 g L-1 waste glycerol (in the presence of buffer) were 652 mL and 281 mL g-1 COD, respectively. Small amount of VFAs and ethanol was accumulated in the reactor content. The current findings indicate the potential use of glycerol waste as a co-substrate in biomethane production.