TiO₂ nanotubes have been used as practical heterogeneous nano‐catalyst for biodiesel production from waste cooking olive oil using solar energy. Several critical parameters namely the reaction time and temperature and volume ratio of methanol to oil were optimized to obtain high‐quality biodiesel fuel. By using an optimum volume ratio of methanol to WCOO of 8.0:1.0 at 60°C within 4 h, the highest conversion of 91.2 ± 0.7% was obtained. Solar energy was applied to heat the reaction vessel by parabolic trough reflectors, and photovoltaic panels were employed to power a small electric motor for the stirring of the reaction mixture. After completion of the reaction, the nanocatalyst was separated by a centrifuge. The catalyst could be reused up to four times with a 3% reduction in yield of the final product. The variation of five pollutant emissions for a blend of biodiesel: diesel (20:80 vol/vol %) showed a net decrease of the total hydrocarbons, carbon monoxide, and carbon dioxide emissions compared to the pure diesel fuel.

中文翻译：

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太阳能和TiO2纳米管：烹饪废橄榄油生产生物柴油

二氧化钛₂纳米管已被用作实用的多相纳米催化剂，用于利用太阳能从烹饪废橄榄油中生产生物柴油。优化了几个关键参数，即反应时间，温度和甲醇与油的体积比，以获得高质量的生物柴油燃料。通过在60°C下4小时内使用8.0：1.0的甲醇与WCOO的最佳体积比，可获得91.2±0.7％的最高转化率。太阳能通过抛物线形槽式反射器加热反应容器，光伏板用于为小型电动机提供动力，以搅拌反应混合物。反应完成后，通过离心分离纳米催化剂。该催化剂最多可重复使用四次，最终产品的收率降低3％。