ENGINEERING JOURNAL CHIANG MAI UNIVERSITY

Volume 26, No. 01, Month APRIL, Year 2019, Pages 107 - 120

Optimization of ethyl ester production from palm fatty acid distillate (pfad) using double-step esterification process: a response surface methodology approach

Dunyawat Phanyusoh, Krit Somnuk and Gumpon Prateepchaikul

Abstract Download PDF

In this study, a batch ethyl ester production process from palm fatty acid distillate (PFAD) was studied using a double-step esterification. The by-product from the refined palm oil (RPO) production process, PFAD was used as a raw material for ethyl ester production. The central composite design (CCD) was used to design the experiments to determine the predicted models of ethyl ester purities of each step. Results of ester purities were analyzed using a response surface methodology (RSM). Three parameters of both first-step and second-step processes were ethanol (4.77-55.23 wt.%), sulfuric acid (0.95-11.05 wt.%), and reaction time (6-74 min), were investigated to obtain the highest purity of ethyl ester under 75˚C of reaction temperature and 300 rpm of stirrer. Results showed that 74.22 wt.% ester purity was achieved under the recommended condition was 29.42 wt.% ethanol, 5.28 wt.% sulfuric acid, and 40 min reaction time for the first-step esterification. In the second-step esterification, 99.323 wt.% highest purity of ethyl ester was achieved under the optimal condition was 37.96 wt.% ethanol, 6.91 wt.% sulfuric acid, and 55.7 min reaction time.

Keywords

biodiesel; palm fatty acid distillate; ethanol; esterification; response surface methodology

---