Abstract

Today, most of the biodiesel is made by using vegetative or animal oils as raw materials, so, the cost of biodiesel production is arising from raw materials. By considering problems raised from raw materials price and process time, cost of the catalysts and reducing food resources, in this study, it is attempted to reduce these costs by using magnetic nano catalysts (CaO/KOH-Fe₃O₄ and Fe₃O₄-KF/KOH) and nonedible oils (micro-algae strain, namely Chlorella Vulgaris) to compare two methods of producing biodiesel (Transesterification with reflux and electrolysis, magnetic nano catalysts were prepared using sedimentation and centrifugation methods and characterized by X-Ray Diffraction patterns. Different condition for reflux method were investigated, Due to the magnetic properties of these catalysts, they have a high interaction in the reaction medium and also have a high surface area which results in increased reaction efficiency and reducing the reaction time in order to achieve the highest efficiency, Furthermore, Magnetic nano catalysts are recoverable and can be recovered by using an external magnetic field and, at the same time, it maintains a high catalytically activity and this property reduces the reaction costs and ultimately the cost of biodiesel production. The results showed the optimum values were 1.5 wt% of the catalyst weight, molar ratio of alcohol to oil (6:1), and the reaction time of 360 min to achieve the maximum yield of 80% using KF/KOH-Fe₃O₄ nano catalyst along with saponification side reaction. In addition, using electrolysis method resulted in the maximum process yield of 98.1% with the same nano catalyst and non-saponification side reaction. Therefore, using electrolysis method with KF/KOH-Fe₃O₄ magnetic nano catalyst and micro algae as the feed, showed the higher mass yield in transesterification reaction. Furthermore, the prepared biodiesel was in accordance with the world standard of fuel.

Graphic Abstract

中文翻译：

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CaO / KOH-Fe 3 O 4和KF / KOH-Fe 3 O 4为磁性纳米催化剂的小球藻微藻油电解和回流法生产生物柴油的比较

摘要

如今，大多数生物柴油都是以植物油或动物油为原料制成的，因此，生物柴油的生产成本来自原材料。通过考虑由原材料价格和处理时间，催化剂成本以及减少食品资源引起的问题，本研究尝试通过使用磁性纳米催化剂（CaO / KOH-Fe ₃ O ₄和Fe ₃ O）来降低这些成本。_4- KF / KOH）和非食用油（微藻菌株，即小球藻）为了比较两种生物柴油的生产方法（回流和电解的酯交换反应），采用沉降和离心方法制备了磁性纳米催化剂，并通过X射线衍射图进行了表征，研究了回流条件的不同，由于这些催化剂的磁性，它们在反应介质中具有较高的相互作用，并且具有较高的表面积，从而提高了反应效率并缩短了反应时间，从而实现了最高效率。此外，磁性纳米催化剂可回收，并可通过使用外部催化剂进行回收磁场，并同时保持很高的催化活性，这种特性降低了反应成本，最终降低了生物柴油的生产成本。结果表明最佳条件是催化剂重量的1.5 wt％，醇与油的摩尔比（6：1）和360分钟的反应时间，以使用KF / KOH-Fe实现最大产率80％₃ O ₄纳米催化剂与皂化副反应一起。此外，使用电解方法在相同的纳米催化剂和无皂化副反应的情况下，最大工艺收率为98.1％。因此，采用KF / KOH-Fe ₃ O ₄磁性纳米催化剂和微藻类为原料的电解法，在酯交换反应中具有较高的产率。此外，所制备的生物柴油符合世界燃料标准。

图形摘要