With the production of renewable biofuels, concerns about the end of fossil fuels have been partially eliminated. On the other hand, the utilization of low-cost and waste materials to provide the raw essential substances to manufacture these fuels is of paramount importance. Biodiesel is one of these fuels and the required raw materials for the reaction are oil (triglycerides), alcohol and catalyst. In this work, travertine stone powder (as waste in the manufacture of building materials) was used as a catalyst and waste frying oil as a source of triglyceride for biodiesel production. Using thermogravimetric and X-ray diffraction analysis, optimum temperature for catalyst calcination was selected at 900°C. Furthermore, X-ray fluorescence, Fourier transform infrared spectroscopy, Brunauer–Emmett–Teller, transmission electron microscopy and scanning electron microscopy analyses were performed. Using the design of experiments Response Surface Methodology, the optimum reaction conditions for biodiesel production yield of 97.74% were: reaction temperature 59.52°C (~60°C), time 3.8 h (228 min), catalyst concentration 1.36 wt.% and the methanol to oil molar ratio of 11:6. After reusing four times, the catalyst efficiency was reduced a little, and the biodiesel yield was 89.84%, indicating high strength and stability of the catalyst.

随着可再生生物燃料的生产，对化石燃料终结的担忧已部分消除。另一方面，利用低成本和废料提供原始必需物质来制造这些燃料至关重要。生物柴油是这些燃料之一，反应所需的原料是油（甘油三酸酯），醇和催化剂。在这项工作中，石灰华石粉（建筑材料生产中的废料）被用作催化剂，废煎炸油被用作生产生物柴油的甘油三酸酯来源。使用热重分析和X射线衍射分析，选择催化剂煅烧的最佳温度为900°C。此外，X射线荧光，傅里叶变换红外光谱，Brunauer–Emmett–Teller，进行透射电子显微镜和扫描电子显微镜分析。使用响应表面方法的实验设计，生产生物柴油的最佳反应条件为97.74％的产率为：反应温度59.52°C（〜60°C），时间3.8 h（228分钟），催化剂浓度1.36 wt。％和甲醇与油的摩尔比为11：6。重复使用四次后，催化剂效率略有降低，生物柴油产率为89.84％，表明该催化剂具有较高的强度和稳定性。