Start
Sep 26, 2013 - 17:00
End
Sep 26, 2013 - 18:00
Venue
Creativity Hall Room 118
Event Type
Speaker
Saeikh Zaffar Hassan
Title
Reaction Kinetics for Biodiesel Synthesis from Low-Cost Feed-stocks: A Taguchi Approach
Abstract: Biodiesel is produced by esterification of fatty acids or trans-esterification of glycerides or the former followed by the latter for low-cost feed-stocks containing free fatty acids (FFA). Typically one-factor-at-a-time (OFAT) experiments are performed to study the effects of process parameters on kinetics of biodiesel production. However statistically designed experiments have advantages over OFAT experiments: the latter require more number of experiments than the former to obtain same amount of information; the latter cannot detect interactions between the parameters and may miss optimal settings of the parameters. The overall aim of our work is to understand in detail the parametric effects on the kinetics of the esterification and the trans-esterification reactions for biodiesel synthesis from low-cost feed-stocks using orthogonal array design of experiments and its properties with the help of Taguchi approach. Theoretically equilibrium constant (Keq) depends on temperature only but reported measurements for esterification reactions show that it also depends on reactant concentration and amount of catalyst. The sensitivity-analysis of Keq showed that Keq is indeed a function of temperature only and not of molar ratio (MR) of the reactants and catalyst loading; reported dependency of Keq on reactants concentrations and catalyst loadings is due to errors in analysis of equilibrium composition. Dependency of the apparent rate constant on temperature reactants concentration and catalyst loading is also studied for H2SO4-catalyzed esterification-kinetics. Taguchi approach guided modification of second-order rate constant (SRC). The modified rate constant is shown to be independent of the reactants concentration unlike SRC. The rate law obtained with modified rate constant is consistent with the general mass action rate law reported by Blum and Luus (1964) and Pekar (2011). The modified rate constant is shown to be equivalent to Brønsted–Bjerrum relation; it is more general than the reported rate constants for esterification of fatty acids and predicts kinetics over a wide range of reaction parameters. Parametric-effects on esterification-kinetics of FFA are evaluated at different intervals of reaction. The relative effects of parameters for our system are also compared with the results of the detailed Taguchi analyses of esterification-kinetics data of published works for biodiesel synthesis. The relative parametric-effects on esterification-kinetics are found to be function of reaction duration. For KOH-catalyzed trans-esterification of sunflower oil with methanol parametric-effects on the kinetics of biodiesel (FAME) tri-glycerides (TG) di-glycerides (DG) and mono-glycerides (MG) are presented and discussed. Catalyst loading is found to be a significant parameter for FAME TG and DG and insignificant for MG. Temperature is insignificant for TG and DG reduction but it has an important influence in the minimisation of MG. The combination of parameters which yielded ~95% of FAME with reasonable purity is 0.5 wt% KOH 50 °C and 7 MR.About the Speaker: Saeikh Zaffar Hassan has been a PhD student in this department since July 2008. He finished his B.Tech in Petrochemical Engineering in 2005 from Aligarh Muslim University Aligarh (U.P) and M.Tech in Polymer Technology in 2007 from Institute of Chemical Technology Mumbai. He has worked in R & D division Asian Paints Pvt. Ltd. before joining the PhD program. His supervisor is Prof. Madhu Vinjamur; title of his PhD thesis is "Reaction kinetics for biodiesel production from low-cost feed-stocks – A Taguchi Approach". His research interests include reaction kinetics and catalysis biomass conversion Taguchi method and design of experiments.