Microwave Energy Assisted Transesterification Reaction

Biodiesel is gaining increasing attention due to the versatility of raw material available for its production. However, currently more than 95% of biodiesel is made from edible oil sources affecting the cost of food as well as biodiesel industries as both industries compete for edible oil sources. Use of non-edible oil source such as jatropha and neem trees for the production of biodiesel can potentially reduce the high cost of biodiesel produced from edible oil sources. Long reaction time due to the low solubility of oils and alcohol also increased the cost of biodiesel processing. However, the use of microwave energy can increase the rate of reaction and yield of biodiesel. In the present work, these two concepts were utilized together to investigate transesterification of pre-treated neem oil with microwave energy. A two-step reaction was carried out on neem oil due to high free fatty acid content. It was observed that the use of neem oil pre-treated with microwave have substantially increased the reaction rate of transesterification reaction. Optimum conditions for the reaction were established using Response Surface Methodology (RSM). With microwave energy pre-treatment, the maximum yield was observed to be 99.1% in 15 minutes at 50 oC while without microwave energy treatment, the maximum yield achieved was 95.2% in 30 minutes at 50 oC reaction temperature.