In-situ reactive extraction of castor seeds for biodiesel production using the coordinated ultrasound – microwave irradiation: Process optimization and kinetic modeling

Abstract

The present study demonstrates innovative and industrially viable in-situ biodiesel production process using coordinated ultrasound-microwave reactor. Reactive extraction process has been carried out by mixing grinded castor seeds with methanol in the presence of base catalyst (KOH). Response surface methodology coupled with central composite design has been applied for process optimization to achieve maximum yield. The result shows that maximum biodiesel yield of 93.5 ± 0.76% was obtained under favorable conditions of: molar ratio (350:1), catalyst (w/w) (1.74%), reaction temperature (43 °C) and reaction time (30 min). Regression equation obtained for the model having (R), and (R) equal to 0.9737 and 0.9507 respectively shows goodness of fit. First time reaction kinetics as well as oil extraction kinetics studies have been performed on coordinated ultrasound-microwave reactor. Assuming pseudo first order reaction activation energy was found to be 28.27 kJ·mol and activation energy for oil extraction was observed to be 9.11 kJ mol. Estimated activation energy for the reaction kinetics and extraction kinetics was reduced by 27%, reaction rate constants were eight to ten times higher and diffusion coefficient was found to be two times higher in case of hybrid system as compared to conventional mechanical stirring technique. Estimated thermo-physical properties of biodiesel were found in agreement with ASTM and DIN standards in comparison to gasoline diesel.

Biodiesel production in the presence of heterogeneous catalyst of alumina: Study of kinetics and thermodynamics

“…To simplify the equations in the present investigation, the following assumptions were considered, where [TG], [DG], [MG], [A], [GL], and [ME] are the concentration of triglyceride, diglyceride, monoglyceride, alcohol, glycerol, and methyl ester, respectively: Higher methanol to oil molar ratio (more than stoichiometry) is used and therefore concentration of alcohol is constant 4,44 Since the consumption of diglycerides and monoglycerides is faster than triglycerides, the concentration of MG and DG was ignorable and reaction (6) was considered as the overall transesterification reaction 45 …”

“…Higher methanol to oil molar ratio (more than stoichiometry) is used and therefore concentration of alcohol is constant 4,44 …”

A Control Algorithm for the Optimization of Batch Reactor-Based Processes

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Microwave-Assisted Noncatalytic Esterification of Fatty Acid for Biodiesel Production: A Kinetic Study

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