Transesterification of used cooking oil (UCO) catalyzed by mesoporous calcium titanate: Kinetic and thermodynamic studies
Transesterification of used cooking oil (UCO) catalyzed by mesoporous calcium titanate: Kinetic and thermodynamic studies
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DOI：
10.1016/j.enconman.2018.03.011
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发表时间：
2018-05
影响因子：
10.4
通讯作者：
N. Yahya;N. Ngadi;Syieluing Wong;Onn Hassan
中科院分区：
文献类型：
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作者：
N. Yahya;N. Ngadi;Syieluing Wong;Onn Hassan
由于氧化钙在通过酯交换制备生物柴油中的上级催化性能，因此有必要对此类催化剂进行改性以保留催化性能，同时克服与催化剂在该方法中的应用相关的缺点。研究了介孔钛酸钙（MCT）催化地沟油酯交换反应的动力学和热力学。实验在室温、65 °C和100 °C下进行。在所研究的各种模型中，拟一级动力学模型是描述反应动力学的最佳模型。数据分析表明，反应速率常数k在0.0233-0.058 s-1范围内变化，活化能Ea为21.25 kJ·mol-1。还得到了以下参数：焓（ΔH）为−24 kJ·mol− 1，熵（ΔS）为−0.16 kJ·mol−1.K− 1，吉布斯自由能（ΔG）为25.62-35.70 kJ·mol− 1。结果表明，该反应为放热反应（ΔH < 0），生物柴油氧化反应为非自发的吸能反应（ΔG > 0）。这项研究表明，MCT催化剂在促进UCO转化为具有高品质燃料特性的生物柴油方面具有潜力。
Due to the superior catalytic property of calcium oxide in biodiesel production via transesterification, it is necessary to modify such catalyst to retain the catalytic property while overcoming the disadvantages related to the catalyst application in the process. The present study focused on the kinetic and thermodynamic studies on the transesterification of used cooking oil (UCO) catalyzed by mesoporous calcium titanate (MCT). The experiments were performed at room temperature, 65 °C, and 100 °C. Among the various models being studied, the Pseudo First order is the best model to describe the reaction kinetic. Data analysis showed that the rate constants, k, varied in the range of 0.0233–0.058 s−1, while the activation energy, Eawas determined to be 21.25 kJ·mol−1. The following parameters were also obtained: −24 kJ·mol−1for enthalpy (ΔH), −0.16 kJ·mol−1.K−1for entropy (ΔS) and 25.62–35.70 kJ·mol−1for Gibb's free energy (ΔG). The results showed that the reaction was exothermic (ΔH < 0), and that the biodiesel oxidation reaction is non-spontaneous and endergonic in nature (ΔG > 0). This study demonstrates the potential of MCT catalyst in promoting the conversion UCO into biodiesel with high quality fuel properties.