1.School of Chemistry ＆ Chemical Engineering, Jiangsu University, Zhenjiang, Jiangsu 212013, China; 2.Office of Light Industry and Textile Industry of Jining City, Jining, Shandong 272017, China)
Abstract：It takes 7-8 h to decrease the acid value(AV)of waste cooking oils from 125.46 mg·g-1 to 3 mg·g-1 for one step esterification reaction. Based on onestep process,two-step esterification process was adopted by separating intermediate to speed reaction equilibrium with normal acid and base catalysts. The optimal reaction condition is alcohol-oil ratio of 5 with catalyst amount of 1.0% at 110 ℃. The total reaction time is 4.5 h with first esterification time of 3.5 h and second esterification time of 1 h, which is shortened by 2.5-3.5 h.The AV can be decreased to 2.657 mg·g-1 after treatment. With 1% catalyst, the neutral oil was reacted with alcohol-oil ratio of 7 at 65 ℃ for 75 min. The conversion rate reaches 94% and the performance can meet the main index of 0# diesel.
2011, Vol. 32 
