Abstract
At present the production of biodiesel from castor oil (Ricinus communis L) has been restricted due to the high cost of vegetable oil. An alternative to reduce production costs is the blend of castor oil and waste cooking oil. This is a good alternative to improve the waste cooking oil which is a water contaminant and a health problem in many countries. Initially the two oils were characterized by density, viscosity, iodine index, saponification index and free fatty acids percentage, where the results were consistent with those reported in the literature. Subsequently the mixture between 0% and 20% of waste cooking oil with castor oil was conducted. The transesterification was performed under the conditions previously defined: temperature 60 °C, molar ratio of 6 mol of methanol / 1mol of oil, catalyst potassium hydroxide (KOH) at 1% w/w with respect to oil. The highest yield was 99% for 85% mixture of castor oil and 15% waste cooking oil, since the results of the other mixtures used were up to 89% yield. The results obtained in gas chromatography showed an average composition of 97.6 of methyl esters. The calorific value was 36,645 J / g for the 85% blends of castor oil and 15% waste cooking oil, it was found that the above mixture was the best of all blends made. Through this work it is concluded that it is possible, from a technical point of view, to use the mixture of castor oil and waste cooking oil for biodiesel production, which can reduce costs in the production of biodiesel from castor oil.
