Bio-diesel Production from Kapok Seed Oil

Abstract

Indonesia’s rapid growth of people and industries causes the rising demand of fuel oil. Consequently, the lack of fuel oil availability in the future will become a very serious problem and facing the challenges to find out some alternative resources for producing fuel oil will be a must. Conversion
fatty acid to fatty acid methyl ester (FAME) can be used to substitute the diesel oil (bio-diesel). Fatty acid as raw material for production bio-diesel is mainly selected from non-edible oils such as castor oil, nyamplung oil, and kapok seed oil.This research was aimed to find out the optimum conditions for esterification process of kapok seed oil as substrate for producing bio-diesel, including reaction time and the amount of catalyst added, and to study its purification processes. The low content of free fatty acid (FFA) in initial oil (< 5%) caused the bio-diesel production in this research was carried out only by a transesterification process.Bio-diesel was produced with oil-to-methanol molar ratio of 1:6. Kapok seed oil and solution of KOH in methanol were mixed together at 60oC. This reaction was conducted at
stirring speed of 800 rpm in a three-neck flask equipped with a condenser. After certain time periods of reaction, bio-diesel produced was sampled, purified, and analyzed. Optimum conditions obtained from these experiments at oil-to-methanol molar ratio of 1:6 and temperature of 60oC were the reaction time of 30 minutes and the amount of catalyst of 1.25% weight of KOH/volume of oil. At this condition, oil conversion of 86.20% was obtained. From the kinetics viewpoint, this reaction was pseudo-first order
with respect to oil concentration and with the specific rate (k) of 0.0283 min-1. The bio-diesel product met the SNI (Standar Nasional Indonesia) specification, except the carbon content (that is still high enough, i.e. 0.21%) and the free glycerol content (0.05%).