Process Modelling and Optimization of Green Lube Oil Synthesis

Abstract

Modeling and optimization of trans-esterification of palm kernel oil (PKO) to trimethylolpropone ester (TMP ester- a bio-lubricant) via palm kernel oil methyl ester (PKOME-a biodiesel) synthesis were investigated. The central composite design (CCD) component of the response surface methodology (RSM) was adopted for the optimization of the process parameters, where temperature and weight ratio of PKOME to TMP were held constant at 130 °C and 3.9 : 1 respectively, to generate 20 experimental runs. Bio-lubricant yield was calculated for each experimental run. A quadratic-like model was generated that related the yield to the process parameters (Reaction time, Stirring Speed, and Catalyst concentration). The predicted and actual R2 value were 0.9856 and 0.9959 respectively, which indicate an excellent agreement between experimental and predicted bio-lubricant yield. The predicted maximum bio-lubricant yield was 98.11 % at reaction time of 99.9084 mins, stirring speed of 863.794 rpm, and catalyst concentration 0.84522 wt. %. The experimental value obtained under same conditions was 96.996 %. Physico-chemical analysis of the bio-lubricant synthesized at optimum conditions were found to be within the range of the ASTM standard for bio-lubricants