Maafa Ibrahim M
Department of Chemical Engineering, College of Engineering, Jazan University, Jazan 45142, Saudi Arabia.
Polymers (Basel). 2022 Feb 8;14(3):643. doi: 10.3390/polym14030643.
A heterogeneous solid acid catalyst was synthesized using tire polymer waste (TPW) for the esterification of waste chicken fat (CF) enriched with fatty acids. The TPW was carbonized and functionalized with concentrated sulfuric acid under various sulfonation conditions to obtain a sulfonated tire polymer char (TPC-SOH) catalyst. The TPC-SOH catalyst was further characterized via acid-base titration (to ascertain the total concentration of acid), X-ray diffraction, scanning electron microscopy (SEM), energy dispersive X-ray analysis (EDAX), and Brunauer-Emmett-Teller (BET) analysis. The esterification reaction conditions of extracted chicken fat with methanol and the viability of catalyst reuse were also investigated. The composition of the free fatty acid (FFA) decreased to below 1% under optimum reaction conditions of 5% TPC-SOH catalyst, the methanol-to-CF molar-ratio of 15:1, and a reaction time of 120 min at 70 °C. The catalyst preserved its conversion efficiency above 90%, even after three cycles. The results demonstrate that the catalyst is applicable and efficient in the esterification of raw materials containing various fatty acid compositions since different carbonized materials have distinct abilities to combine acid groups. Furthermore, after de-acidification of CF-FFA by the as-prepared TPC-SOH catalyst, the neutral CF was transesterified completely to biodiesel and characterized via Fourier Transform Infrared (FTIR) spectroscopy, proton nuclear magnetic resonance (H NMR) spectroscopy and physicochemical analysis. This work unveils a promising technique for utilizing tire waste generated in large quantities for the development of a novel heterogeneous acid catalyst for biodiesel production.
利用废旧轮胎聚合物（TPW）合成了一种多相固体酸催化剂，用于富含脂肪酸的废弃鸡脂肪（CF）的酯化反应。在不同的磺化条件下，将TPW碳化并用浓硫酸进行功能化处理，以获得磺化轮胎聚合物炭（TPC-SOH）催化剂。通过酸碱滴定（以确定酸的总浓度）、X射线衍射、扫描电子显微镜（SEM）、能量色散X射线分析（EDAX）和布鲁诺尔-埃米特-泰勒（BET）分析对TPC-SOH催化剂进行了进一步表征。还研究了提取的鸡脂肪与甲醇的酯化反应条件以及催化剂重复使用的可行性。在5% TPC-SOH催化剂、甲醇与CF的摩尔比为15:1以及在70℃下反应时间为120分钟的最佳反应条件下，游离脂肪酸（FFA）的组成降至1%以下。即使经过三个循环，该催化剂仍保持其90%以上的转化效率。结果表明，由于不同的碳化材料结合酸基团的能力不同，该催化剂在含有各种脂肪酸组成的原料的酯化反应中适用且高效。此外，用制备的TPC-SOH催化剂对CF-FFA进行脱酸后，中性CF完全酯交换为生物柴油，并通过傅里叶变换红外（FTIR）光谱、质子核磁共振（H NMR）光谱和物理化学分析进行了表征。这项工作揭示了一种有前景的技术，可利用大量产生的轮胎废料开发用于生物柴油生产的新型多相酸催化剂。
