advanced mwcnt-cooh@zno nano catalyst for biodiesel production from used cooking oil enhancing fuel quality and reducing engine wear

In response to the rising global demand for renewable energy solutions, biodiesel has emerged as an excellent ecological alternative to fossil fuels. this study aims to develop and evaluate mwcnt-cooh@zno, a novel nanocatalyst synthesized by functionalizing multiwalled carbon nanotubes (mwcnts) with zno2 to produce high-quality biodiesel from waste cooking oil. optimal reaction parameters (70 °c, 30 minutes, 600 rpm, oil-to-methanol ratio of 1:8, and 400 mg catalyst) were determined using the taguchi method. under these conditions, a yield of 96.3% of biodiesel was obtained. the mwcnt-cooh@zno nanocatalyst enabled biodiesel synthesis that met astm d6751 standards for a flash point of 146 °c, a viscosity of 3.8 mm²/s,  a density of 872 kg/m³ at 16 °c, a pour point of -1 °c, and a cloud point of -2 °c. the mwcnt-cooh@zno nanocatalyst demonstrated 89% recyclability after three cycles and reduced friction and wear rates by up to 15% under extreme pressure. this study establishes mwcnt-cooh@zno as a scalable nanocatalyst for sustainable biodiesel production, offering improved environmental friendliness and engine protection.