Hydrothermal treatment of empty fruit bunches for enhanced solid fuel production using palm oil mill effluent as a liquid stream

Abstract

The study investigates utilising palm oil mill effluent (POME), comprising over 95–96 % water, as a key liquid component in producing biocoal via the hydrothermal treatment of empty fruit bunches (EFB). This innovative approach reimagines POME, commonly viewed as a byproduct of palm oil production, as a potential resource. Evaluating POME as a substitute for water in the hydrothermal treatment at 180–220 °C, using varying POME-to-EFB ratios (PER) of 1, 3, and 5, and durations of 30, 60, and 90 min, the research employed Box Behnken and Response Surface Methodology via Design Expert® 10 software. Through 17 treatments, the optimal conditions—199.4 °C, PER 5, and 90 min—yielded the best EFB-POME mixture for solid fuel production. This discovery underscores POME's viability in replacing water effectively during HT, highlighting its potential despite its high water content as a plentiful waste stream.