Optimization of Rubber Seed Oil Transesterification to Biodiesel Using Experimental Designs and Artificial Neural Networks

Abstract

The development of biofuels is driven both by concern about the greenhouse effect and by interest in the opportunities for exploitation of biomass of agricultural origin. In order to improve the yield and quality of biodiesel through modeling and optimization, several studies are in progress. In this paper, biodiesel produced from rubber seed oil in the homogeneous transesterification is studied using a Plackett-Burman experimental design, a full factorial design, a central composite design and an Artificial Neural Network (ANN) coupled with a Genetic Algorithm (GA).Variables such as temperature, stirring speed, reaction time, type of alcohol, and type of catalyst are studied to obtain the best specific gravity and kinematic viscosity. Type of alcohol and type of catalyst have the greatest effect on the two responses, with ethanol (alcohol) and sulphuric acid (catalyst) producing the best results. The specific gravity and kinematic viscosity changes recorded during the transesterification process followed the first and second order polynomial models, respectively. The ANN coupled with GA was used to optimize the two responses simultaneously. Global optimal values of specific gravity (0.883) and kinematic viscosity (6.76 cSt) were recorded when a temperature of 90˚C, a stirring speed of 305 rpm, and a treatment time of 141 min were imposed.

Optimization of Biofuel Formulation by Mixture Design

“…Under these conditions, the specific gravity value is 0.84 and that of the kinematic gravity is 2.97 cSt. The responses (specific gravity and kinematic viscosity) obtained under optimal conditions show that these values comply with the Ivorian specification for diesel [5]. These values are of the same order as that of Uzun et al [14].…”

“…For mixture data, the contour plot shows the relationships between constituent proportions and specific gravity. Throughout the experimental domain, the specific gravity values respect the Ivorian diesel standard [5]. In the zone where the specific gravity values are between 0.830 and 0.850 the proportion of UFO is 40%.…”

“…The kinematic viscosity of the mixture increases with UFO content and decreases with bioethanol content incorporated. In this ternary mixture, some samples whose values of kinematic viscosity are between 1.6 and 5.9 cSt (at the temperature of 40˚) comply with the Ivorian diesel standard [5]. In this comparison, it emerges that some mixtures have a viscosity which respects this standard such as: HAG (9-20-21), HAG (9-10-31), HAG (5-25-20), HAG (20 -25-5), HAG (5-5-40), HAG (13-15-22) and HAG (16-20-14).…”

“…All these reasons have led researchers to focus their work on new energy resources. Biofuels have emerged as an interesting solution, especially in recent years [1] [4] [5]. There are numerous biofuels that can be sorted as biofuels in pure form, and mixtures with fossil fuels.…”