Process Safety and Environmental Protection, Vol.99, 159-166, 2016
Optimization by Box-Behnken experimental design fur synthesis of n-hexyl levulinate biolubricant over hierarchical H-ZSM-5: An effort towards agricultural waste minimization
The present study is devoted to develop efficient catalytic process for conversion of agricultural waste feedstock to value added chemicals. In this context, the n-hexyl levulinate, a renewable biolubricant was synthesized by esterification of biomass derived levulinic acid (LA) with n-hexanol in a closed batch system. Hierarchical-HZ-5 (modified H-ZSM-5) was used as a heterogeneous acid catalyst. There are no reports available on the synthesis of n-hexyl levulinate biolubricant using renewable levulinic acid. The process variables such as catalyst to LA ratio (X-1), n-hexanol to LA molar ratio (X-2), reaction time (X-3) and reaction temperature (X-4) were optimized by response surface methodology (RSM), using the Box-Behnken model. Analysis of variance was done to check the suitability and significance of the quadratic model. The yield of n-hexyl levulinate obtained was 97% with 100% selectivity at optimum process parameters. The RSM analysis predicted that catalyst to LA ratio is most significant (value of p < 0.0001) and n-hexanol to LA molar ratio is least significant (value of p = 0.0064) process parameter in esterification. The quadratic model established was revealed to be suitable and statistically precise with correlation value (R-2) of 0.9837 to predict the yield of n-hexyl levulinate. (C) 2015 The Institution of Chemical Engineers. Published by Elsevier B.V. All rights reserved.
Keywords:Agricultural waste feedstock;Esterification;Hierarchical-HZ-5;n-Hexyl levulinate;Optimization;Response surface methodology