TECHNOLOGY FOCUS - ORGANIC CHEMISTRY - Preferred Component: The oil is ricebran oil, cottonseed oil, soybean oil, sunflower oil, castor oil, or coconut oil. The alcohol is methanol, ethanol, n-propanol, n-butanol, or n-pentanol. The catalyst is sodium hydroxide, or potassium hydroxide. Preferred Method: The esterified oil is separated by decanting, centrifuging, gravity separation, and/or settling. The purification of the mixture is by bubble washing involving bubble size of 1-3 mm, micro filtration with not less than 5 microns filter, and/or centrifuging. The Reynolds number for maintaining turbulence is adjusted at not less than 4000 irrespective of the type of reactor. EXAMPLE - About 100 mL rice bran oil having a moisture content of 3% was heated at 120degreesC for 2 hours. Later the moisture content of the oil was found to be 0.5%. This oil was taken in the specially modified batch continuous stirred tank reactor with provision for alcohol recycle/recovery system, condenser, thermometer, and feeding funnel. About 20 mL methanol was taken in a beaker and 0.5 gm sodium hydroxide was added under continuous stirring. The resulting solution was added to the reactor rapidly. The reactor system was maintained at turbulent condition by stirring at 100 rpm to maintain the Reynolds number at the minimum of 4000. The reaction was continued for 30 minutes. The excess methanol of 4 mL used for above reaction was recovered. The resulting solution was taken in separating funnel, and two layers were found to form. The mixture was allowed to settle for 4 hours and the top layer was taken for further processing. This was then subjected to bubble washing by aeration with 15 mL distilled water for 8 hours and the resulting material was allowed to settle for 8 hours. It was taken for micro filtration to remove the micro particles present in the product. The bubble washing, settling and filtration operations were repeated for two more times to attain improved fuel properties. The resulting biodiesel was stored. About 97% of rice bran oil was estimated to have been converted into biodiesel, which was found to meet the specifications of conventional petroleum fuel. The biodiesel was used for running a test engines. The emission properties of this biodiesel were found to be better than of the conventional fuels.