Transesterification of palm oil using KOH/ZrO2 and KOH/mordenite as a heterogeneous catalyst

Abstract

Due to the global oil demand and oil prices is forever increasing every years, and also environment concerns. There has been a search to come up with a newer and cheaper alternative energy source. Biodiesel is a non-toxic and biodiegradable fuel that is made from vegetable oil or fat oil, is currently manufactured by the transesterification of triglycerides with methanol using NaOH or KOH as a homogeneous catalyst. However, the main drawback to this process is that the difficult of catalyst separation and the catalyst needs to be neutralized and a purification process is necessary, therefore the heterogeneous catalyst is used to substitute the homogeneous catalyst. In this work, the transesterification of palm oil with methanol has been studied in a heterogeneous system using KOH/ZrO2 and KOH/mordenite catalyst and has been studied the reuse ability of catalysts. The operation variables studied were the catalyst size, reaction time, loading amount of K, molar ratio of methanol to oil, amount of catalyst and calcinations temperature. The results show that KOH/ZrO2 with 20 wt.% K carried out at 2 hours reaction time with a 15:1 methanol-to-oil ratio and 5 wt.% of the catalyst gave 99.69 wt.% methyl ester content and KOH/mordenite with 20 wt.% K carried out at 3 hours reaction time with a 15:1 methanol-to-oil ratio and 4 wt.% of the catalyst gave 98.40 wt.% methyl ester content. Beside KOH/Mordenite has more efficiency of reusability than KOH/ZrO2. Both fresh and spent catalysts were characterized by means of XRD, SEM with EDS and XRF.