Investigation of the phorbol ester content in high quality biodiesel production process

Abstract

Jatropha oil is an attractive alternative fuel as it is not concerned with edible oil crops. However, it is found that Jatropha oil contains some phorbol esters, which are a toxic compound. In this work, phorbol ester distribution of jatropha portions, including seed, seed cake, seed oil, kernel seed, seed hull, kernel cake and kernel oil, were firstly studied. The results found that a majority of phorbol ester was found in kernel oil and seed oil at 0.45 and 0.33 mg/g, respectively. These compounds can cause some biological effects such as inflammation and tumor promotion. Therefore, detoxification of phorbol ester must be performed. High quality biodiesel continuous production plant under JST-JICA SATREPS collaboration project was established with capacity to produce biodiesel that meets the EAS-ERIA standard [1]. The biodiesel plant consists of raw material dehydration, esterification, transesterification, biodiesel washing, dehydration and upgrading, which has affected the phorbol ester differently. Consequently, the changes of phorbol ester content were examined in each process by using High Performance Liquid Chromatogram (HPLC) technique. The results show that some of these processes can reduce the toxic content of biodiesel. Phorbol ester quantity was decreased by 77.55 % after esterification process, and this toxic content could be significantly eliminated after transesterification by 89.80%. Furthermore, the phorbol ester of 0.03 mg/g in biodiesel was detected after partial hydrogenation unit. The percentage removal of hydrogenation process was 95.92%.