Developments in biodiesel production by photocatalytic method

This thesis provides a comprehensive examination of the photocatalytic method for biodiesel production in terms of environmental, economic, and engineering aspects. The photocatalytic process utilizes semiconductor photocatalysts (mainly TiO₂, ZnO, and g C₃N₄) to convert triglycerides into biodiesel under light irradiation. The use of renewable solar energy, non-toxic catalysts, and direct conversion of waste oils makes this method both eco-friendly and cost-effective. The study demonstrates that photocatalytic systems achieve high yields with lower energy input compared to conventional acid-base catalysts, reporting conversion rates exceeding 90% and up to 98.6% with composite catalysts such as ZnO/SiO₂, TiO₂/g-C₃N₄, and SrTiO₃. These reactions operate efficiently at low temperatures, with reusable catalysts reducing wastewater generation and carbon emissions. However, industrial scalability still requires further improvements in photoreactor design and catalyst stability. The findings indicate that the photocatalytic method offers a highly energy-efficient, sustainable, and environmentally friendly alternative for next-generation biodiesel production.