In Situ production of fatty acid methyl esters from copra using methanol and tetrahydrofuran as co-solvent
Abstract/Summary
The conventional process for production of biodiesel often requires large amounts of energy and the use of toxic and flammable solvents like hexane. The low miscibility of oil in methanol reduces the contact between the reactants and slows down the overall reaction. In order to address these problems, this study applied an in situ process to transesterify the coconut oil in copra directly, without prior extraction of the oil, using H2SO4 catalyst and methanol and THF as co-solvents. Agitation and heating was continued until the system reached equilibrium, as indicated by successively constant readings of the refractive index. Gas chromatographic analysis was used to determine glycerol, mono-, di- and triglycerides in the upper phase. These results were used to determine yield. The results show that the in situ process produced biodiesel from copra can have a yield as high as 96.72%. The FAME yield increased significantly when the ratio of THF/methanol increased but only up to a THF/methanol ratio of 0.4. Beyond this ratio, there were no further increases in yield. The yield increased considerably from 87.2% to 96.72% when the temperature was changed from 400C to 600C. The yield was also dependent on the ratio of methanol to copra. The yield observed at a methanol:copra ratio of 150ml/100g was 93.81% whereas the yield observed at a methanol:copra ratio of 200ml/100g was 95.86%. However, there was no further change observed when the ratio is over 200ml methanol/100g copra. The amount of solvent bound on the marc decreased when the reaction temperature was change from 400C to 600C.
