Pretreatment of Palm Oil Mill Effluent (POME) Using Lipase and Xylanase to Improve Biogas Production

Abstract

The production process at biogas reactors from Palm Oil Mill Effluent (POME) often faces problems due to limited hydrolysis rates. This limitation occurs due to the formation of mud and lumps which reduce the effective volume of the biogas digester and reduce the potential for biogas produced. The sludge and lumps produced come from the high content and fiber present in the POME. Various treatments have been made such as manual extraction or mechanical stirring or by turbulence through strong fluid pumping. However, these treatments require additional tools, human resources, and energy so that the production process costs continue to increase. As an alternative, the use of lipase and xylanase is promising alternative for pretreatment that can minimize the content of hemicellulose and oil or fat in POME. Lipase can hydrolyze oil and grease into short-chain fatty acids, while xylanase can hydrolyze hemicellulose into its monomer, thus facilitating biogas production. In this study, it was proven that pretreatment with xylanase and lipase was able to reduce total suspended solid (TSS) by 49.21%; total solid (TS) by 34.52% and reducing sugar by 44.37%. Besides, it could reduce oil and grease (83.53%) at a concentration of 4%, increase biogas production by 52.17%, and remove chemical oxygen demand (COD) by 49.7%.