Chemical transesterification of soybean oil as a feedstock for stable biodiesel and biolubricant production by using Zn Al hydrotalcites as a catalyst and perform tribological assessment

Trimethylolpropane fatty acid triester (TFATE) is a potential biolubricant that could substitute mineral-based lubricants in an environmentally responsible way. Double transesterification from vegetable oils would play a key role in the development of biodiesel and biolubricants. However, there are difficulties associated with high-pressure maintenance, energy consumption, and substrate saponification caused by strong homogeneous alkaline catalysts. In this research, develop a novel method for using Zn Al hydrotalcite as heterogeneous catalysts in the production of fatty acid alkyl esters and TFATE-based biolubricants (biodiesel & biolubricants) from vegetable oils through a double transesterification with methanol and trimethylolpropane (TMP), respectively. As a result, high yields of biolubricant were formed under the following chemical conditions for the latter; alcohol to fame ratio is 4:1; the concentration of the catalyst is 5%; and the temperature is 140 °C. by using XRD, FTIR, TGA, and SEM-EDX, the Zn Al hydrotalcite was examined. The product was analyzed by using 1H NMR, FTIR, and Gas chromatography techniques. Moreover, physicochemical, along with tribological properties were also evaluated. the developed biolubricant's tribological characteristics indicated the lowest coefficient of friction.