Extraction and Trans-Esterification of Jatropha Oil into Fatty Acid Methyl Esters.

Abstract

Biodiesel is a fuel that may be made from renewable resources, such as vegetable oil or animal fats, through the process of trans-esterification. It is non-polluting, accessible, sustainable, and reliable. On a bulk basis, its energy content is around 12% lower than that of petroleum-based diesel. When burned, biodiesel emits fewer pollutants than petroleum diesel. It reduces the severity of the greenhouse effect and does not increase the amount of carbon dioxide in the atmosphere.

The oil content is 25-30% in the seed making it potential for biodiesel production. The oil contains 21% saturated fatty acids and 79% unsaturated fatty acids. Oil has very high saponification value and being extensively used for making soap in some countries. Also oil is used as an illuminant in lamps as it burns without emitting smoke. It is also used as fuel in place of, or along with kerosene stoves. The oil was extracted using solvent extraction using n hexane as the solvent using 105g of the kernel powder. The mixture of the oil was separated using distillation and the oil (60ml) was residue. The oil extraction yield was 52.23% from this study. The biodiesel from jatropha oil is produced by trans-esterification from the extracted oil. This study was carried out to compare the biodiesel yield when trans-esterification is done in 2 steps with that of literature where only base catalyzed trans-esterification was used.

The fatty acid were reduced by reacting the 50ml of jatropha oil with a heated mixture of concentrated H2 SO4 and methanol (600 C), stirred for 1 hour and left to settle. The separated oil was then used for trans-esterification which was carried out on using prepared sodium methoxide, stirred for an hour and left to settle for 24 hours. The quantity of biodiesel was recorded to be 14.5ml.The yield was above average. Jatropha seed oil is a good feedstock potential for the production of biodiesel and at conditions of 1:6 methanol to oil ratio, 1 hour reaction time and 0.5g catalyst load the reaction yielded 14.9ml of the fuel. And 21ml of the product from the first step of trans-esterification were used to produce the final 14.9ml of FAME to give to give a yield of 70.952%. And the reduction of free fatty acids before trans-esterification increases the productivity.