Synthesis of sulfonated mesoporous carbon from <i>Calophyllum inophyllum</i> oil cake as heterogeneous transesterification catalyst for biodiesel production: a process optimization study

To address the concern of depleting resources and forge ahead toward sustainability, new renewable materials are being explored for multifarious applications. In this present study, sulfonated mesoporous carbon was synthesized using <i>Calophyllum inophyllum</i> oil cake by the process of carbonization, hydrothermal treatment, and KOH activation. Sulfonation of mesoporous carbon was characterized by BET, SEM, TEM, and FTIR. N₂ gas adsorption-desorption studies were performed with the synthesized solid sulfonated catalyst and the total surface area, average pore volume, and diameter were estimated to be 618.3 m² /g, 0.72 cm³ /g, and 5.27 nm respectively. The activated mesoporous carbon was then used in the catalysis of the transesterification reaction using <i>Calophyllum inophyllum</i> oil as a reactant. Finally, the biodiesel yield was found to be 93.2% with methanol: oil molar ratio of 1:14, the temperature of reaction 60°C, and 1.5 (wt %) of mesoporous catalyst.

为应对资源枯竭问题并推进可持续发展进程，科研人员正探索可应用于多元场景的新型可再生材料。本研究以琼崖海棠（*Calophyllum inophyllum*）油饼为原料，通过炭化、水热处理及氢氧化钾（KOH）活化工艺合成了磺化介孔碳材料。采用Brunauer-Emmett-Teller比表面积分析法（BET）、扫描电子显微镜（SEM）、透射电子显微镜（TEM）与傅里叶变换红外光谱仪（FTIR）对该介孔碳的磺化改性过程进行了表征。以合成的固体磺化催化剂开展氮气（N₂）吸附-脱附实验，测得其总比表面积、平均孔容及平均孔径分别为618.3 m²/g、0.72 cm³/g与5.27 nm。随后将所制备的活化介孔碳用作催化剂，以琼崖海棠油为反应物开展酯交换催化反应。最终在甲醇与油摩尔比为1:14、反应温度60℃、催化剂添加量为1.5 wt%的条件下，生物柴油产率可达93.2%。