| Three parameters important to the transesterification reaction of soy waste cooking oil to ethyl esters were optimized: molar ethanol concentration, weight fraction of the potassium hydroxide catalyst, and reaction temperature. In the course of optimizing the parameters, applicable analytical techniques which quantify the free fatty acid and water content of waste cooking oils and the components of the reaction mixture with minimal manipulation were developed and verified.; The acid number and the water content of the waste cooking oil were determined to be as 3.61 +/- 0.06 and 0.018 vol%, respectively. Hence, the pretreatment of waste cooking oil was not explored. The optimal conditions for the production of ethyl esters from waste cooking oil were identified to be: 145 mol% excess ethanol based on stoichiometric requirements, 1.3 wt% potassium hydroxide based on the waste cooking oil used, and a reaction temperature of 27°C. Using these optimized parameters, the mass-based ethyl ester yield was found to be 85.6%. |
