Biodiesel has recently gained popularity due to its environmental issues and the fact that it is generated from renewable resources. However, the cost of the synthesis of biodiesel is the major impediment to commercialization. The utilization of leftover cooking oils as raw material, the adaptation of a continuous transesterification process, and the use of cheap catalysts are the major possibilities for investigating the cost of biodiesel. In this work, a dolomite catalyst was prepared from natural dolomite rocks and used for the evaluation of continuous transesterification of biodiesel from oleic acid as a model compound of waste cooking oil (WCO). The dolomite catalyst was prepared by activation under vacuum at a surface area of 34.5 m²/g. The characterization tests showed good thermal stability of the catalyst and evolution of the CaO and MgO compounds at high concentrations. A kinetic study was conducted to obtain kinetic parameters of catalytic transesterification of the WCO. The kinetic experiments were carried out at 298–333 K, and residence time up to 80 min. The results presented that the catalytic transesterification is the first-order reaction, and the activation energy was 43 kJ/mol. The oscillatory baffled reactor (OBR) was used to evaluate the dolomite catalyst for the continuous production of biodiesel via transesterification. The evaluation study was conducted at a methanol: oil mole ratio of 6:1 and the effect of different operation variables on oleic acid conversion to biodiesel was studied. These variables were temperature (323, 333, and 343 K), residence times (5–40 min), the amplitude of oscillation (2–8 mm), and frequency of oscillation (1, 2, 3, 4, and 4.3 Hz). The results showed an outstanding performance and stable activity of the dolomite catalyst as a conversion of 96% was obtained at 333 K, 4.3 Hz, 8 mm amplitude, and 40 min residence time.

中文翻译：

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白云石催化剂在振荡挡板反应器中废食用油酯交换生产生物柴油中的应用

生物柴油最近因其环境问题和由可再生资源产生的事实而受到欢迎。然而，生物柴油的合成成本是商业化的主要障碍。利用剩余的食用油作为原料，采用连续的酯交换过程，以及使用廉价的催化剂是研究生物柴油成本的主要可能性。在这项工作中，从天然白云石岩石制备白云石催化剂，并用于评价以油酸作为废食用油 (WCO) 模型化合物的生物柴油的连续酯交换反应。白云石催化剂通过真空活化制备，表面积为34.5 m ²/G。表征测试表明催化剂具有良好的热稳定性，并且在高浓度下会析出 CaO 和 MgO 化合物。进行动力学研究以获得 WCO 催化酯交换的动力学参数。动力学实验在 298-333 K 下进行，停留时间长达 80 分钟。结果表明，催化酯交换反应为一级反应，活化能为43 kJ/mol。振荡挡板反应器 (OBR) 用于评估白云石催化剂用于通过酯交换反应连续生产生物柴油。评估研究在甲醇：油摩尔比为 6:1 下进行，并研究了不同操作变量对油酸转化为生物柴油的影响。这些变量是温度（323、333 和 343 K），停留时间（5-40 分钟）、振荡幅度（2-8 毫米）和振荡频率（1、2、3、4 和 4.3 赫兹）。结果表明，白云石催化剂具有出色的性能和稳定的活性，在 333 K、4.3 Hz、8 mm 振幅和 40 min 停留时间下，转化率为 96%。