Application of Process Analysis for Esterification and Two-step Transesterification in the Biodiesel Production Plant

Esterification and transesterification reacting vessels are the care unit operations of typical industrial biodiesel production plants. Feedstock with a high free fatty acid is esteri-ed -1st in an acid condition before continuing to the transesterification under presence of an alkaline catalyst. Process analysis is an important tool to a plant engineer in the biodiesel plant operation to estimate the conversion of the palm oil to biodiesel and the yield. This paper describes the process analysis for the methanolysis of crude palm oil through the esterification and the subsequent two-step transesterification in the biadiesel production plan with a capacity of 1000 kg per batch. Physical pretreatment of the nude palm oil (CPO) is necessary to remove the unsaponifiable and other undesired trace components to become bleached palm oil @PO). Conversion at 85%(w/w) of 6ee fatty acid @FA) to biodiesel has been achieved in the esterification of BPO with methanol under acid catalyst reaction. The first transesterification is able to produce up to 88% (wlw) conversion of triglycerides (TG) to biodiesel. The remaining TG is carried out in the second step of the transesterification to complete the reactIan toward achieving a high methyl ester content. Analytical method using gas chromatography is used for validation against the theoretical results. GC analysis results confonns the conversion estimated by the process analyses based on the material balance, especially in the esterification and -mt-step transesterification, 81% and 88%. respectively. After one hour retention time of the secondstep transesterification, 95% conversion of TG to biodiesel has been achieved The process analytk applied at the- iquilibrium states shows consequently in accordance with the GC analysis results. Therefore it offers a useful compendium to a plant engineer for better understanding of the biadiesel processes.