Green lubrication: Mustard oil-based bio-lubricant enhanced with waste eggshell-derived CaO nanoparticles for sustainable and eco-friendly industrial solutions

The adoption of bio-lubricants derived from vegetable oils is pivotal in advancing environmental sustainability and mitigating the ecological impact of industrial machinery. This study introduces a groundbreaking biolubricant formulated with mustard oil as the base, augmented by CaO nanoparticles synthesized from waste eggshells. The CaO nanoparticles were synthesized through a sol-gel method and meticulously characterized via scanning electron microscopy (SEM) and X-ray diffraction (XRD). This investigation delves into the tribological, rheological, and thermal properties of the developed bio-lubricant, highlighting its potential as a sustainable alternative. Thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC) were employed to evaluate thermal stability and cold flow properties, revealing promising results. A comparative study with commercially available engine oil (SAE20W40) underscores the superior performance of the bio-lubricant. The key innovation lies in the incorporation of CaO nanoparticles, facilitated by a surfactant, which substantially enhances wear and friction reduction, lubrication qualities, shear stability, viscosity-temperature behavior, and thermal stability. These advancements position our bio-lubricant as a high-performance, environmentally friendly substitute for conventional lubricants. The study's findings underscore its potential for widespread industrial adoption, promising a transformative shift towards sustainable and eco-conscious lubrication practices.