Optimization of Vegetable Oil-Based Biodiesels by Multi-Response Surface Methodology (MRS) using Desirability Functions

Abstract

Environmental concerns associated with petroleum resources have propelled the development of sustainable and renewable alternatives to petroleum based products. Vegetable oil is one amongst the foremost abundant bio-based feedstocks. The interest in using vegetable oils and low molecular weight alcohols by direct transesterification have shown great potential as alternatives to petroleum-based diesel, and the production of bio-based diesel continues to increase. Utilization of multi-response surface methodology (MRS) for the most effective combination effect or response from the uses of input to output variables to optimize the yield and higher heating values (HHV) of biodiesels was investigated. In this work, utilizing variety of non-edible vegetable oils like castor (Ricinus communis L), jatropha (Jatropha curcas), and neem (Azadirachta indica) seeds and several process variables or inputs, including mixing time, mixing speed, process temperature and catalyst dosage to formulate high quality renewable fuels were further explored. The outputs were yield, viscosity, higher heating value, density and turbidity. The proposed optimization scenarios for biodiesel using the statistical (MRS) models was aimed to optimize the processes to achieved high conversion and higher heating values, while reducing the reaction time, turbidity, density, and viscosity in the samples. The results showed catalyst dosage as the most important variable for all the three samples. For maximum yield of 100%, the molar ratio of 6.25, catalyst of 0.75 wt.%, reaction speed of 499.99 rpm, reaction time of 19.88 min and temperature of 24.50 oC were found as optimal conditions; while the molar ratio of 5.60, catalyst of 1.01 wt.%, the reaction speed of 499.5 rpm, reaction time of 20.00 min and temperature of 35.50 oC were optimal conditions for maximum biodiesel yield.

Using Response Surface Methodology to Optimize Biodiesel Production from Sweet Almond (Prunusamygdalus Dulcis) and Jatropha (Jatropha Curcas) Seed Oils

“…Sample collection and preparation, pretreatment, refinement and trans-esterification processes followed by the physicochemical properties of crude sweet almond oil (CSAO), refined sweet almond oil (RSAO), crude jatropha oil (CJO) and refined jatropha oil (RJO) carried out using Association of Official Analytical Chemists -AOAC [9] and American Society for Test and Material -ASTM (D6751-09) standard methods. Pre-treatment and refinement to ensure the levels of the free fatty acids (FFAs) of the two feedstocks were carried out to ensure the percentages of FFAs were <0.5% [10][11].…”

“…The production variables for the production of biodiesels refined RSAO and RJO include NaOH catalyst doses, mixing speed, reaction temperature at fixed methanol to oil molar ratio, and time. The design of experiments (DoE) established input ranges were as provided in Table 1 to obtain the experimental outputs or responses (yield, specificgravit, and density) [10].…”

Optimization of Protection Condition on the Stability of Castor (Ricinus communis) Oil Based Biodiesel using Response Surface Methodology

“…The relationships between independent variables and response variables are established by the RSM method. Box and Wilson [32] were the pioneers that got a model or optimal response for experimental data, but its industrial application has increased with other techniques to optimize processes. The use of ANOVA for each of the models can be computed to give the Pvalue.…”

Optimization of process parameters for biodiesel production from three indigenous vegetable oils

“…Cold oil extraction was used to extract refined Jatropha oil (RJO), Sweet Almond oil (RSAO), and sesame oil (CSO) from crude Jatropha oil (CJO), Sweet Almond oil (CSAO), and sesame oil (CSO) (RSO). Following refinement, the oils were transesterified to obtain refined jatropha biodiesel (RJB), Sweet Almond biodiesel (RSAB), and sesame biodiesel (RSB) using the two-step method recommended by the American Standard for Testing Materials, the Association of Official Analytical Chemists and Mustapha et al [22][23][24][25][26].…”

“…A fixed sodium hydoxide dose of 1.0 wt. %, a molar ratio of 1:3, 1:6, 1:12, and a temperature of 60 o C were randomly tuned with variable time (20, 40, 60 min), and speed (500, 750, 1000 rpm) [26].…”