Anaerobic Mono-Digestion of Palm Oil Empty Bunches Residue (EFB) Results of Acid Hydrolysis and Enzyme Hydrolysis Muhammad Daffa Rialto Assidiq, Nimas Mayang Sabrina Sunyoto, Sri Suhartini
Universitas Brawijaya
Abstract
Palm oil empty fruit bunches (OPEFBs) have been widely used for bioethanol and xylitol production. However, during hydrolysis step, solid residues are generated, which contain high organic materials. Yet, these hydrolysis residues are underutilized and investigation with integrated biorefinery approach is essential. This study aimed to evaluate characteristics and methane potential of OPEFBs, acid and enzymatic hydrolysis residues. The biochemical methane potential (BMP) test was employed using AMPTS II, operated at 37oC for 28 days with ratio inoculum to substate (RI/S) of 3:1 and 4:1. The results showed that all samples have high volatile solids (VS) content, thus potential as feedstock for methane production. The pH value during AD process was well within the ideal value of 6.0-8.0. At RI/S of 3:1, the highest specific methane potential (SMP) value was from treated OPEFB (0.177 m3 CH4/kgVS) followed by acid hydrolysis residue (0.138 m3 CH4/kgVS). At RI/S of 3:1, enzymatic hydrolysis residues gave the highest SMP of 0.367 m3 CH4/kgVS, followed by treated OPEFBs and acid hydrolysis residues of 0.130 and 0.123 m3 CH4/kgVS, respectively. The treated OPEFBs and hydrolysis residues have higher electrical potential than untreated OPEFBs. Furthermore, all digestate samples contain macronutrients, thus potential as biofertilizer.
