The Deactivation of Sulfonated Carbon Catalyst Derived from D-glucose on Amberlite XAD1180 During The Biodiesel Synthesis at High Temperature

Abstract

Biodiesel is an environmental friendly alternative for petrol-derived diesel. It can be produced fromthe transesterification reaction of triglycerides (TGs) with a low molecular weight alcohol using basic- oracidic- catalysts. Catalyst plays an important role on the production rate of biodiesel. Heterogeneouscatalyst, namely, sulfonated carbon catalyst derived from D-glucose on Amberlite XAD1180 (P-C-SO₃H)-solid acid catalyst, was used in this research for studying the cause of catalyst deactivation at hightemperature (120^oC) during the transesterification of triglycerides (TGs) with alcohol. Effects of alcoholsize and catalyst re-using were investigated. Its activity was compared with those of sulfated zirconiacatalyst (SZ) and Nafion 50, the commercially available catalysts.

From the results, size of alcohol had an effect on both the catalyst activity and deactivation. Methylalcohol gave the highest activity and lowest deactivation compared to ethyl and n-butyl alcohols. Similarresults were obtained for sulfated zirconia catalyst. Lower activity when using larger alcohol was related tothe steric hindrance effect of the larger alkyl chains. In addition, P-C-SO₃H was found to have higheractivity than the other two catalysts at the same reaction conditions due to its higher acid site concentration.The cause of catalyst deactivation was mainly from the leaching of sulfur functional group into the reactionmixture resulted in homogeneous catalytic transesterification reaction. The degree of leaching increasedwith alcohol size. In conclusion, for the transesterification of tricaprylin and alcohol at high temperature,P-C-SO₃H prepared in this work had higher activity compared to the commercial catalysts, and reactionwith methanol gave better activity and lower catalyst deactivation.

Keywords : Biodiesel / Solid Acid Catalyst / Sulfonated Carbon Catalyst Derived from D-glucoseon Amberlite Xad1180 / Catalyst Deactivation