Comparison of Biodiesel Production Using the Oil of Chlorella Vulgaris Micro-algae by Electrolysis and Reflux Methods Using CaO/KOH-Fe3O4 and KF/KOH-Fe3O4 as Magnetic Nano catalysts

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.