Development of bio based nano-lubricant from walnut shell for refrigeration system

• Main Authors: Afolalu, Sunday A., Ikumapayi, Omolayo M., Ogundipe, Adebayo T., Oloyede, Olamilekan R., Yusuf, Olabisi O.
• Format: Conference Proceeding
• Language: English
• Subjects: Agricultural wastes; Biosynthesis; Copper oxides; Lubricants; Microstructural analysis; Mineral oils; Mixing ratio; Nanoparticles; Natural resources; Reducing agents; Refrigeration; Walnuts
• ISSN: 0094-243X; 1551-7616
• DOI: 10.1063/5.0161078

The biosynthesis of nanoparticles (NPs) from agro-waste has not been explored thoroughly by the scientific research world. This synthesis method was brought about as a solution to the problem of the high pollution rate that results from the conventional methods of nanoparticle preparation. Biosynthesis using agro-waste eliminates this pollution by using readily available natural resources whose decomposition further enriches the environment, coupled with safe practices and processes. NPs have been known to enhance the performance of refrigerating systems. In this work, walnut shell ash was used as a reducing agent to synthesise copper oxide NPs. The NPs were mixed with mineral oil to investigate its effects on the refrigeration system and see if it ensured better performance than the conventional mineral oil. Microstructural and spectroscopical tests were carried out on the NPs to verify their properties, such as size and element build. Spectroscopical analysis using an electron microscope revealed 30% of Oxygen, 7% of Carbon and 63% of copper, making Copper the most abundant element. The microstructural analysis put the average size within the accepted nanometric range. The mixing ratio used for this project started with 250ml of mineral oil to 0.50g of the NP, while the concentration of the NPs increased by 0.25g as the samples progressed. The control sample of pure mineral oil was used to get a baseline for which the performance of each sample was based. Coefficient of Performance (CoP) was the parameter used in determining the performance of all the samples and control. The result showed improved performance when specific samples were used when compared to the control. Samples such as 0.75g of NP showed a CoP increase by 23.9%, and 1.25g of NP showed an increase in CoP by 125%. The other samples that showed improvements in various aspects include 0.5g of NP and 1.5g of NP.