Biodiesel Production using Oil Extracted from Cooling Pond Wastewater by Esterification of Sulfonated Carbon Catalyst and Transesterification of Na₂CO₃ Catalyst

Abstract

While high production of palm oil improves the community economy, it has the potential to damage the environment because it produces the waste containing quite a lot of residual oil. The wastewater generated by this production process flows into the cooling pond before it is further processed in aerobic and anaerobic ponds. The residual oil contained in the cooling pond can be collected and used, e.g. as raw material for biodiesel production. This research aimed to produce biodiesel by utilizing the oil extracted from cooling pond wastewater through the esterification method with a sulfonated carbon catalyst and a transesterification method with the Na 2 CO 3 catalyst. The sulfonated carbon catalyst was made from the palm kernel shells as a solid waste of the palm oil plant. In order to study the optimum amount of catalyst usage, the catalyst ratio was varied, i.e. 8-16% for the esterification process and 1-3% for the transesterification process. The reuse performance of sulfonated carbon catalysts was varied three times. On the basis of the research results, sulfonated carbon catalysts were proven to be effective as heterogeneous catalysts in the esterification process because they can reduce acid level to below 5 mg KOH/g oil. The sulfonated carbon catalyst ratio of 12% was the optimum ratio which can reduce the acid level to 4.62 mg KOH/g oil. The reuse of sulfonated carbon can reduce the acid level to 6.9 mg KOH/g oil at the first reuse. In the transesterification process, the optimum ratio of the Na 2 CO 3 catalyst of 3% was found. The biodiesel produced has met the biodiesel characteristics of National Indonesian Standard (SNI of 7182:2015) with the saponification number of 197.18 mg KOH/g oil, free glycerol of 0.09%, FAME content of 96.79%, and density of 886 kg/m 3 .

Biodiesel Production of Palm Oil Mill Effluent by Using Hydrotalcite Catalyst

“…Biodiesel is fatty acid methyl esters produced from reaction of oils and fats with an alcohol in the presence of a catalyst (Putra, 2021). Catalysts are used in biodiesel processing to make the process run faster under low operating conditions (Kolakaningrum et al, 2021).…”