Production of Biodiesel from Mixed Castor Seed and Microalgae Oils: Optimization of the Production and Fuel Quality Assessment

Abstract

The diminishing reserves and environmental consequences of the fossil fuel-based petrodiesel necessitate the exploration of an alternative fuel with better quality and minimum environmental impacts. The study explores the optimization of biodiesel production from nonfood and locally available mixed feedstocks as an effective and a sustainable approach to solve the insufficiency and high costs of single oil feedstock. The selection of suitable oil feedstocks and optimization of process variables are the prime issues for cost-effective industrial scale production of biodiesel from mixed feedstocks toward the industrial scale production of biodiesel. The objective of this study was to optimize process variables for the alkaline transesterification of mixed castor seed and microalgae oils to optimize the yield of biodiesel. Oils were extracted from dried microalgae (Chlorella vulgaris) biomass and castor seed kernel using methanol. The oils were purified, characterized, mixed in a 1 : 1 ratio, and converted to biodiesel. The transesterification experiments designed according to the central composite design (CCD) were used to optimize the yield of biodiesel through the response surface methodology (RSM). Experimental results were analyzed by response surface regression to produce a model for predicting biodiesel yield. Model significance, fitness, the effect of significant variables, and interactions between the variables on the yield of biodiesel were studied through the analysis of variance (ANOVA). The optimization of transesterification process variables revealed that the catalyst concentration of 1.23% (w/w), ethanol to mixed oil ratio of 5.94 : 1 (v/v), and reaction temperature of 51.0°C were the optimum conditions to achieve an optimum biodiesel yield of 92.88%. Validation experiments conducted under the optimum conditions resulted in the biodiesel yield of 92.36%, which is very close to the model predicted value. Various standard methods were used to characterize the biodiesel produced under optimum conditions, and it was found compatible with ASTM 751 and EN14214 biodiesel standards.

Removal of Hexavalent Chromium from Aqueous Solutions Using Natural Zeolite Coated with Magnetic Nanoparticles: Optimization, Kinetics, and Equilibrium Studies

“…This confirms that the model is highly significant and indicates a good agreement between the experimental and predicted data. The model adequate precision of response was >4.0, indicating a good agreement between the experimental and predicted values and high significance of the model [38, 41]. The predicted R 2 of 0.9528 shows that the model was adequate and offers 63.22% variability in predicting removal of Cr(VI) ions from aqueous solution.…”

“…The analysis of variance (ANOVA) results for the quadratic regression model were used to determine the suitability and sufficiency of the model. The statistical significance of the quadratic model was determined using the lack of fit (LOF) of F test, coefficient of determination ( R 2 ), and adjusted coefficient of determination ( R 2 Adj) between experimental and predicted values [41]. The significance of each terms of the quadratic model equation was evaluated using p value.…”

“…Sixteen factorial ( 2 n ) and 8 axial (2n) and 6 center point experimental runs were conducted (Table 2). The distance of axial points (± α ) to center point (CP) is calculated as follows [41, 42]: (1) ± α = 2 n 1 4 . …”

Biodiesel production: An updated review of evidence

“…This study explored the optimization of biodiesel production from non-food, locally available mixed feedstocks as an effective, a sustainable approach to solve the insufficiency and high costs of single oil feedstock .The selection of suitable oil feedstocks and optimization of process variables are the prime issues for cost-effective industrial scale production of biodiesel from mixed feedstocks toward the industrial scale production of biodiesel . This study optimized the process variables for the alkaline transesterication of mixed castor seed and microalgae oils and the yield of biodiesel was estimated [125]. Oils were extracted from dried microalgae (Chlorella vulgaris) biomass and castor seed kernel using methanol [125].…”

“…This study optimized the process variables for the alkaline transesterication of mixed castor seed and microalgae oils and the yield of biodiesel was estimated [125]. Oils were extracted from dried microalgae (Chlorella vulgaris) biomass and castor seed kernel using methanol [125]. The oils were purified, characterized, mixed in a 1 :1 ratio, and converted to biodiesel [125].…”