Non-Catalytic Biodiesel Synthesis from Kemiri Sunan (Reutealis trisperma) Oil in a Semi-Batch Bubble Column Reactor

Abstract

The bubble column reactor (BCR) is intensive equipment used as a multiphase contactor and reactor in the chemical, biochemical, and petrochemical industries. BCR has advantages, including high mass and heat transfer rates, compactness, and low operating and maintenance costs. This research applied BCR to produce biodiesel from Kemiri Sunan (Reutealis trisperma) oil through non-catalytic and simultaneous esterification and transesterification reactions. Kemiri Sunan oil was fed into the reactor and heated to a specific temperature. During the heating process, nitrogen gas was flown to prevent oxidation. Liquid methanol was flown at various flow rates through a vaporizer and superheater so that it was delivered into the reactor in the form of the saturated condition (1 atm, 240 ºC). Experiments with variations in the methanol flow rate were carried out at a reaction temperature of 250 ºC, while experiments with various temperatures were carried out at a methanol flow rate of 2.5 mL/min. The best conditions were obtained at a 2.5 mL/min methanol flow rate with a reaction temperature of 290 ºC. The production rate was 3.47 g/min with an acid number of 0.69 mg KOH/g sample, and FAME content was 78.2% wt. These results indicate the occurrence of simultaneous esterification and transesterification reactions in one reactor.