Abstract
Typically, sludge palm oil (SPO) which discharged from the palm oil refining process, is a low cost material of potential value, due to its high free fatty acid content. Accordingly, there is potential for upgrading low grade oil into valuable biofuel. In this work, we present a novel method for biodiesel production from SPO. The process consists of two steps (i) free fatty acid (FFA) extraction (ii) enzymatic esterification. Firstly, SPO was saponified by hydroalcoholic solution into soap and glycerol. Secondly, the FFAs obtained were further converted into biodiesel via enzymatic esterification catalyzed by immobilised alginate-PVA lipase beads. •Biodiesel production from sludge palm oil could be completed.•A modified fatty acid extraction was used for SPO fatty acid preparation.•Immobilised alginate-PVA lipase beads were used as biocatalyst for esterification reaction.