Biodiesel has emerged as a popular alternative to conventional fossil fuel in transportation sector and thus producing low-cost biodiesel is a topic of interest for a large community of researchers. This study reports the preparation of an efficient and robust heterogeneous catalyst from dried L. (Guava) leaves and its application towards generation of biodiesel from soybean oil at room temperature. The biomass material was calcinated at variable temperature and the efficiency of each of the catalyst prepared was studied. The catalyst generated as well as the product biodiesel was thoroughly characterized using sophisticated analytical techniques. The catalyst was found to have mesoporous structure with active basic sites which contributed towards accelerating the transesterification process. Detailed characterization unveiled the occurrence of Ca as oxide and carbonate, in addition to a certain quantity of K in oxide and carbonate form, which contribute to the catalyst’s activity. Maximum biodiesel yield of 95.8 % was observed for reaction performed under optimum experimental conditions i.e., 1:17 oil-to-methanol ratio, 6 wt% loading of GL-850 (catalyst prepared by calcination at 850°C), and 15 % n-Hexane loading for 3 h at room temperature. GL-850 demonstrated exceptional recyclability for up to the fifth cycle exhibiting a mere 3.7 % decline in yield. The calculated expense for 1 kg catalyst was found to be $0.478, whereas the production cost of 1 kg biodiesel was found to be merely $1.120, indicating a strong economic feasibility of the process.

中文翻译：

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一种经济、环保的 Psidium guajava L. 在室温下为生物柴油生产留下催化剂：工艺优化和生命周期成本分析


生物柴油已成为交通运输领域传统化石燃料的流行替代品，因此生产低成本生物柴油是广大研究人员感兴趣的话题。本研究报告了从干番石榴叶中制备高效且稳定的多相催化剂及其在室温下从大豆油生产生物柴油中的应用。将生物质材料在不同的温度下进行煅烧，并研究了所制备的每种催化剂的效率。使用复杂的分析技术对生成的催化剂以及产品生物柴油进行了彻底的表征。发现该催化剂具有介孔结构和活性碱性位点，有助于加速酯交换过程。详细的表征揭示了Ca以氧化物和碳酸盐的形式存在，此外还有一定量的K以氧化物和碳酸盐形式存在，这有助于催化剂的活性。在最佳实验条件下进行的反应观察到最大生物柴油产率为 95.8%，即油与甲醇比为 1:17、GL-850 负载量为 6 wt%（催化剂在 850°C 下煅烧制备）和 15% n -室温下加载己烷3小时。 GL-850 在第五次循环中表现出出色的可回收性，产量仅下降 3.7%。经计算，1 公斤催化剂的费用为 0.478 美元，而 1 公斤生物柴油的生产成本仅为 1.120 美元，表明该工艺具有很强的经济可行性。