Anaerobic digestion of fungally pre-treated oil palm empty fruit bunches: energy and carbon emission footprint

Oil palm empty fruit bunches (OPEFB) is one of the abundant lignocellulosic biomass in Indonesia. However, high lignin content in EFOB has becoming one of the obstacles in valorising it as bioenergy resources, as it is hardly broken down by the microorganisms. Therefore, pre-treatment is often needed to enhance the biodegradation process of organic content in OPEFB. The biological pre-treatment is besieged to enhance the utilisation of OPEFB as bioenergy resources. This study was aimed to investigate the impact of fungal pre-treatment on the OPEFB characteristics and its methane potential, and to estimate the energy and carbon emission saving from anaerobic digestion (AD) of OPEFB. In this study, OPEFB was treated using Phanerocheate chrysosporium under the standard condition and incubated for 7 and 14 days. The energy and carbon emission footprint were calculated using AD Assessment Tool (ADAT) software. The results showed that fungal pre-treatment was able to increase organic matter and enhance methane potential. Estimation on energy (i.e. electrical and heat), however, indicated a lower energy balance and carbon emissions saving for fungal pre-treated OPEFB. The higher moisture content (MC) on treated OPEFB may reduce the biogas and methane production. Yet, further research is still required to have an in-depth understanding of improving the efficacy of biogas production from OPEFB by incorporating other green pre-treatment approaches.