Transesterification of Non-Edible Oil Using Phase Transfer Catalyst via Response Surface Methodology

With the increasing demand for energy from the fossil fuels, the oil reserves are getting depleted and raising a serious concern over the future rising energy demand. Use of fossil fuels are becoming the environmental issue as the environment and its ecosystems are getting polluted by the emission of greenhouse gases such as carbon dioxide generated from use of fuels. Use of renewable alternative energy and chemical resources can reduce the problem. One such option is biodiesel. However, use of edible oil as a source of raw material for biodiesel directly competes with food processing industries affecting the cost of biodiesel and food industries. Use of non-edible oils can reduce the high cost of edible oil. Besides that, due to limited solubility between oil and alcohol phase leads to an increase of the cost of biodiesel. Use of reaction rate enhancement agent and microwave energy can reduce the processing costs. In the present project work, Caster oil as a source of non-edible oil sources was used to produce biodiesel. Alkaline cetyltrimethylammonium bromide (CTMAB) as a phase transfer catalyst (PTC) was utilized to enhance the rate of transesterification reaction. Optimum reaction condition was established using statistical tools of response surface methodology (RSM) central composite design (CCD) technique. At optimum condition, 89.85% w/w of fatty acid methyl esters (FAME) was produced in 25.91 minutes of reaction time as compared to 76.8% w/w FAME yield produced without the use of PTC in 31.3 minutes of reaction time. It can be observed that by the use of CTMAB as PTC about 13.05 wt% additional yield increment is achieved while reducing the reaction time. Model equation that predicts the yield of biodiesel was also developed using RSM of CCD. Model predicted yield compares well with experimentally observed FAME yield indicating that developed model equation is adequate enough to predict the yield of biodiesel.