Kinetic Modelling of Heterogeneous Methanolysis Catalysed by Iron Induced on Microporous Carbon Supported Catalyst

Abstract

The investigation describes detailed kinetic modelling of biodiesel synthesis catalysed by waste derived carbonaceous catalyst in a batch reactor. The modelling is conducted via three approaches i.e. power law equation, Eley–Rideal (E–R) and Langmuir–Hinshelwood (L–H) mechanism. Reversible and irreversible pathways with respect to triglycerides (TG) and fatty acid methyl esters (FAME) for first and second order reactions were considered for developing model equations. The kinetics of heterogeneous catalysis is studied using E–R and L–H mechanism to assess the exact rate controlling step by considering all the possible resistances offered by solid catalyst. The rate expressions for adsorption and desorption of individual reactant and product and surface chemical reaction were also developed. The influence of diffusional resistance offered by solid catalyst on conversion is also determined. The best fitted model is identified from calculated regression coefficients. The results revealed that glycerol desorption from catalyst surface given by E–R and L–H mechanisms is controlling the biodiesel synthesis process. The best suited model equation is considered for evaluating the kinetic parameters of the transesterification process. Thus, the study gives exact rate controlling step for heterogeneous catalysis to be used for reactor design and cost-effective production of biodiesel.