Statistical analysis of experimental factor optimization in acid esterification of rubber seed oil

Abstract

Statistical analysis for esterification of high viscous rubber seed oil (RSO) (feed stock) with a high free fatty acids (FFA) content was presented in this work. Initially a high acid value of 67.6 mg KOH/g oil was observed from raw RSO analysis, which is not in a favorable range. After complete esterification reaction, a reasonable acid value of 3.55 mg KOH/g oil was detected at reaction conditions of 15:1 methanol: oil molar ratio (mol/mol), 3 vol% of catalyst concentration, and 2 hr of reaction time. Statistical analysis of factors affecting the final value is performed using response surface methodology. From the statistical analysis, a significant second-order quadratic model with a p value <0.0001 was observed. It is also noticed that molar ratio and reaction time are the most significant factors affecting the final product (esterified oil). The coefficient of determination, R 2 of value, 0.9672 indicates that there exists a minimum error between predicted and experimental acid values observed.

Acid value minimization in continuous biodiesel production from a high viscous nonedible oil

“…Application of high viscous and high fatty acid content biodiesel directly into internal combustion (IC) engine is not advised because it may lead to carbon deposition and engine fouling (Debalaxmi et al., 2017; Saifuddin et al., 2009). Esterification of raw RSO is performed as per the procedure mentioned in our recent work (Sai Bharadwaj et al., 2020). After esterification the acid value of the treated oil is found to be 3.55 mg KOH/g oil at optimum process conditions of 15:1 alcohol:feedstock (mol/mol), 3 (vol%) of catalyst concentration, and 2 h of reaction time.…”