A GREEN METHOD TO PRODUCE BIODIESEL FROM PALM OLEIN OIL

The current transesterification method to produce biodiesel from palm oil uses NaOH as the homogeneous catalyst. NaOH has several disadvantages. It is corrosive, can not be reused, and separation from biodiesel is time-consuming. The objective of the present work was to replace NaOH with a greener and efficient heterogeneous catalyst, calcium diglyceroxide. The potential contamination of biodiesel by Ca2+ was minimised by incorporating Na2CO3 into the transesterification mixture. The work aimed to identify the optimum reaction conditions which would minimise the production cost of biodiesel complying with the quality prescribed by ASTM standards. Optimum conditions were oil: methanol ratio of 1: 6 (molar), catalyst 0.2% (w/w oil), Na2CO3 2.5% (w/w oil), and 3 hr reaction period at 65 degrees C. The yield was 92.2%. All the studied properties of biodiesel except kinematic viscosity conformed with recommended levels by ASTM. Reusing the catalyst which was used twice previously, increased the biodiesel yield from 92.2% to 94.3%. The production of good quality biodiesel from palm olein by this novel method is greener. It is more efficient because the catalyst is not corrosive and easy to separate. Also, the catalyst can be reused at least twice, thus minimising the amounts of chemicals used.