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.

中文翻译：

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从混合蓖麻籽油和微藻油生产生物柴油：优化生产和燃料质量评估

以化石燃料为基础的石油柴油的储量不断减少和对环境的影响需要探索一种质量更好、对环境影响最小的替代燃料。该研究探讨了从非食品和当地可获得的混合原料中优化生物柴油生产，作为解决单一油原料不足和高成本的一种有效且可持续的方法。选择合适的油原料和优化工艺变量是从混合原料到生物柴油工业规模生产的经济高效的工业规模生产生物柴油的主要问题。本研究的目的是优化混合蓖麻籽油和微藻油的碱性酯交换反应的工艺变量，以优化生物柴油的产量。小球藻) 使用甲醇的生物质和蓖麻籽仁。将油纯化、表征、以 1:1 的比例混合，并转化为生物柴油。根据中心复合设计（CCD）设计的酯交换实验用于通过响应面法（RSM）优化生物柴油的产量。通过响应面回归分析实验结果以产生预测生物柴油产量的模型。通过方差分析 (ANOVA) 研究了模型显着性、适应度、显着变量的影响以及变量之间的相互作用对生物柴油产量的影响。酯交换过程变量的优化表明催化剂浓度为 1.23% (w/w)，乙醇与混合油的比例为 5.94:1 (v/v)，反应温度为 51。0°C 是实现 92.88% 的最佳生物柴油产率的最佳条件。在最佳条件下进行的验证实验得出的生物柴油收率为92.36%，与模型预测值非常接近。各种标准方法用于表征在最佳条件下生产的生物柴油，发现它与 ASTM 751 和 EN14214 生物柴油标准兼容。