Comparison of Biogas Production from Oil Palm Empty Fruit Bunches of Post-Mushroom Cultivation Media (EFBMM) from Semi Wet and Dry Fermentation

摘要

The high content of organic substances (25.56%) in solid waste post-mushroom cultivation (EFBMM) has the potential to be processed into biogas . Comparative research of biogas production from EFBMM with semi wet and dry fermentation aims to know the potential of biogas using 20% ??cow dung solution (inoculum) which is mixed by way of circulation. Semi-wet anaerobic digestion is performed on WC/TS ratio (4.0 - 5.7) and dry digestion is performed on the WC/TS ratio (1.5 - 3.5) . Anaerobic fermentation method was developed using a circulation system by observing the physical-chemical characteristics of raw materials and products produced. The results showed that the fermentation of dry and semi-wet fermentation for 65 days decreased the C/N ratio by 5.27% and 19.31%, respectively. Biogas production in semi-wet fermentation produces 18.60 L/kg of EFBMM biogas with CH 4 131.85 L/kgVSr gas productivity with biogas composition 40.69% CH 4 , 49.96% CO 2 and 7.58% nitrogen. In dry fermentation, biogas produced 5.98 L/kg EFBMM with CH 4 38.71 L/kgVSr gas productivity and biogas composition 35.58% CH 4 , 46.12% CO 2 and 17.31% nitrogen. Semi-wet and dry fermentation process produces carbon (released as biogas) respectively 3.90 kgC (26.88%) and 3.40 kgC (23.44%). The result of lignocellulose analysis showed that dry fermentation of EFB using fungus media was able to degrade 6.00% hemicellulose, 10.60% cellulose and 6.74% lignin. Where as semi-wet fermentation was able to degrade 9.26% hemicellulose, 13.02% cellulose and 9.28% lignin. Imaging results with SEM show the fermentation process alters the EFBMM lignocellulosic morphology structure into more open, hollow and fragile textures.