Enhancing the Synthesis of Biolubricant from Used Chicken Fat: Optimization of Operating Parameters Using Magnesium Oxide Nanoparticles as a Catalyst and Response Surface Methodology

Abstract

In light of the growing concerns regarding the environmental impact and sustainability of mineral oil-based lubricants, the use of biolubricants has been advocated as a renewable alternative. The double transesterification of used chicken fat oil involves two steps of converting the triglycerides into methyl esters (UCFME) using methanol and Magnesium oxide Nano Particles (MgO NPs) as catalyst, and utilizing Trimethylolpropane (TMP) and MgO NPs to produce the final biolubricant (UCFBL). This research aimed to optimize the reaction parameters for the transesterification process involving used chicken fat methyl ester (UCFME) and TMP using response surface methodology. A series of 20 individual experiments were conducted, focusing on the variables of reaction temperature, time, and UCFME-to-TMP molar ratio. Through statistical modeling, it was predicted that the transesterification process would yield a maximum conversion rate of 97.5% under the optimized conditions of a reaction temperature 114 °C, a reaction time 227 minutes, and a UCFME-to-TMP molar ratio 10.5:1. Experimental results, obtained from three independent replicates conducted under these optimal conditions, demonstrated an average yield of 98.3 % for the production of UCFBL, which aligned closely with the model's predicted range of 98.35%. The resultant biolubricant has remarkable lubrication qualities, such as a pour point of -5 °C, flash point of 289°C, viscosity index of 213, and kinematic viscosities (KV) of 38.5 and 9.2 cSt at 40 and 100 °C, respectively. These qualities revealed that the biolubricant generated fulfilled the ISO VG-32 criteria, making it an acceptable replacement for petroleum-based lubricants in industrial machine applications.