In the current research, biodiesel production was investigated in the presence of solid catalysts of K₂CO₃/Al₂O₃ by transesterification of rapeseed oil. The specifications of produced fatty acid methyl esters like viscosity and flash point were studied, and it was noted that they complied with the requirements of ASTM D6751. In addition, the kinetic and thermodynamic parameters were explored considering the temperature changes between 318.15 and 348.15 K. Mass transfer resistance (external diffusion or internal diffusion) over the catalyst was neglected with regard to theWeisz‐Prater criterion and Mears criterion. The kinetic models containing Eley‐Rideal, Langmuir‐Hinshelwood, pseudo–first‐order, pseudo–second‐order, and α‐order models were investigated. Corrected Akaike information criterion was utilized to find the best model fitted with the experimental data. The greatest illustration for the K₂CO₃/Al₂O₃‐catalyzed reaction was the nonlinear model with an order of α = 1.287 and the activation energy of 12.12 kJ/mol. Using transition state theory (Eyring‐Polanyi equation), the activation Gibbs free energy, activation enthalpy, and activation entropy were calculated at different temperatures. The equilibrium thermodynamic properties depicted that this process is endothermic and spontaneous toward biodiesel production and tends to be irreversible.

中文翻译：

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氧化铝非均相催化剂存在下的生物柴油生产：动力学和热力学研究

在当前的研究中，在存在K ₂ CO ₃ / Al ₂ O ₃固体催化剂的情况下研究了生物柴油的生产。通过菜籽油的酯交换反应。研究了生产的脂肪酸甲酯的粘度和闪点等规格，并注意到它们符合ASTM D6751的要求。此外，考虑了温度在318.15和348.15 K之间的变化，研究了动力学和热力学参数。关于魏斯-普拉特准则和米尔斯准则，忽略了催化剂上的传质阻力（外部扩散或内部扩散）。研究了包含Eley-Rideal，Langmuir-Hinshelwood，伪一阶，伪二阶和α阶模型的动力学模型。校正后的Akaike信息标准被用来找到与实验数据相匹配的最佳模型。K ₂ CO ₃的最大图解/ Al ₂ O ₃催化的反应是非线性模型，其阶数为α= 1.287，活化能为12.12 kJ / mol。使用过渡态理论（Eyring-Polanyi方程），计算了在不同温度下的活化吉布斯自由能，活化焓和活化熵。平衡热力学性质表明，该过程是吸热的，并且对生物柴油的生产是自发的，并且趋于不可逆。