Abstract In this study, oil was extracted from underutilized sandbox seeds and converted into biodiesel via transesterification process using KOH as a base catalyst. The impact and optimum values of the essential process variables (methanol-to-sandbox seed oil (SSO) ratio, KOH loading, reaction temperature and reaction time) on the sandbox oil methyl esters (SBOME) yield were established via Taguchi orthogonal array design method. Kinetic modeling of the transesterification process was carried out by monitoring the pH of the reaction. Maximum SBOME yield of 97.10 ± 0.03 wt% could be achieved under optimal condition of methanol-to-SSO molar ratio of 6:1, KOH loading of 0.5 wt%, reaction temperature of 35 °C and reaction time of 25 min. The kinetics of the process followed a unimolecular pseudo-second order rate law with reaction rate of 0.0016 L/mol.min at 35 °C. The activation energy and frequency factor of the reaction were calculated to be 11.40 kJ/mol and 0.1362 L/mol.s, respectively. The ΔH‡, ΔS‡ and ΔG‡ for the process were determined as 8.76 kJ/mol, – 0.270 kJ/mol.K and 92.02 kJ/mol, respectively. The quality of the SBOME demonstrates that it could serve as a replacement for diesel as its properties complied with standard specifications for biodiesel. The kinetic data obtained in this study could be used in reactor design for the process.

中文翻译：

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清洁沙箱（Hura crpitans）油甲酯合成：通过 pH 监测方法进行的动力学和热力学研究

摘要 在这项研究中，从未充分利用的沙箱种子中提取油，并使用 KOH 作为碱催化剂，通过酯交换过程将其转化为生物柴油。通过田口正交阵列设计方法建立了基本工艺变量（甲醇与沙箱种子油（SSO）比、KOH负载量、反应温度和反应时间）对沙箱油甲酯（SBOME）产率的影响和最佳值. 酯交换过程的动力学模型是通过监测反应的 pH 值进行的。在甲醇与 SSO 摩尔比为 6:1、KOH 负载量为 0.5 wt%、反应温度为 35 °C 和反应时间为 25 min 的最佳条件下，SBOME 的最大产率为 97.10 ± 0.03 wt%。该过程的动力学遵循单分子准二级速率定律，反应速率为 0。0016 L/mol.min 在 35 °C。计算出反应的活化能和频率因子分别为 11.40 kJ/mol 和 0.1362 L/mol.s。该过程的 ΔH‡、ΔS‡ 和 ΔG‡ 分别测定为 8.76 kJ/mol、– 0.270 kJ/mol.K 和 92.02 kJ/mol。SBOME 的质量表明它可以作为柴油的替代品，因为其特性符合生物柴油的标准规范。本研究中获得的动力学数据可用于该过程的反应器设计。SBOME 的质量表明它可以作为柴油的替代品，因为其特性符合生物柴油的标准规范。本研究中获得的动力学数据可用于该过程的反应器设计。SBOME 的质量表明它可以作为柴油的替代品，因为其特性符合生物柴油的标准规范。本研究中获得的动力学数据可用于该过程的反应器设计。