Waste banana stem has a high organic content (83%); with 15±20% (w/w) lignin and cellulose which gives it a sheath-like texture.
Banana stem slurries (BSS) at 2±16% total solids (TS) concentration were anaerobically digested under mesophilic (37±40°C) as well
as thermophilic conditions (50±55°C) in batch culture. The ®nal biogas yields, 267±271 l/kg TS fed, were observed with 2±4% TS
slurries, under mesophilic conditions. In the thermophilic range, the biogas yields, 212±229 l/kg TS fed, were found with 2±8% TS
slurries. However, thermophilic digestion rates were 2.4 times faster than mesophilic. Methane accounted for 59±79% of the total
biogas. Methane yield was maximum at 2% TS BSS in both the temperature ranges. The process led to 45±50% reduction in organic
solids and 40±55% reduction in COD. With 16% TS BSS inhibition resulted in 50±60% loss in biomethanation process eciency. Ó 2000 Elsevier Science Ltd. All rights reserved.