Analysis of physicochemical and tribological properties of nano alumina-based gear oil developed from effluent of lube oil blending plant

Abstract

Industrial wastewater, also known as effluent has been identified as one of the leading sources of environmental pollutions worldwide. The establishment of lube oil blending plants in Nigeria has led to a continuous discharge of industrial effluent in densely populated areas. This threatens the well-being of humanity, plants, aquatic lives and construction soils. This research paper focused on developing a nano alumina-based effluent gear oil from effluent of lube oil blending plants as an alternative means of mitigating its threats on the environment. Nano lubricant are used in gearboxes for better thermal, friction and anti-wear properties. This is due to the small size and high specific surface area to volume ratio of the nanoparticles. Furthermore, due to their excellent mechanical and thermal properties, easy dispersal in most fluids, inexpensiveness, ease of manufacture, and aspect ratio, the Al2O3 nanoparticles are recently being used by researchers as an additive in gear oils to improve tribological properties, increase power efficiency, extend equipment lifetimes, and lower operating cost. In this work, the alumina nanoparticle was synthesized using co-precipitation method, after which it was characterized using Fourier Transform Infrared (FTIR) and X-ray Diffraction (XRD) analysers. After the development of Al2O3-based gear oil from the effluent, the physicochemical and tribological properties of the alumina-based effluent gear oil samples were investigated with varied weight percentages of Al2O3 nanoparticles. The Differential Scanning Calorimetry (DSC) and Computational Fluid Dynamics (CFD) thermal analyses of nano alumina-based gear sample was investigated after obtaining the suitable sample among the sample blends developed. The dispersion of the nanoparticle in the effluent oil improved the specific gravity and pour point whereas a slight reduction was observed in kinematic viscosity at 100 °C, viscosity index and flash point. However, viscosity index and flash point values are conforming to the minimum requirements of API EP 85W90 and ISO 100 standard values. The anti-wear property was observed to significantly improved by 26.14%, at 0.4 wt% nanoparticles concentration. The results showed that, the pure effluent oil recovered is more thermally stable than the 0.4 wt% nano alumina-based effluent gear oil sample, whereas the nano gear oil sample has a higher thermo-oxidative stability than the pure effluent oil. Finally, temperature profiles from the simulation results also ensured a better performance of the 0.4 wt% alumina-based effluent gear oil developed, at 1500 rpm speed of rotation by 6.7% and 8.9% and at 4000 rpm is by 5.9% and 7.8% than the API EP 85W90 and pure effluent oil samples respectively. Hence, based on the results obtained, the study indicated that the effluent oil from lube oil blending plants can be used as gear oil with the dispersion of alumina nanoparticles.