Evaluating the properties of a novel diesel-like fuel produced by biochar-assisted catalytic cracking of waste motor oil

In light of the need for sustainable and eco-friendly alternatives to conventional fuels, waste-based diesel-like fuels have emerged as a promising solution. This study explores the chemical, physical, and rheological properties of a diesel-like fuel (DLF) produced via chemical recycling of waste motor oil (WMO) using an alkali-treated rice husk biochar as a catalyst. DLF from biochar-assisted cracking (DLFB) resembles commercial diesel hydrocarbon distribution better than DLF from thermal cracking, which shows to many molecules in the gasoline range. DLFB meets the minimum requirements for commercial diesel as per ASTM standards. The study also presents the rheological properties of the DLFB and its blends with commercial diesel, assessing their flow behavior under various operating conditions. The results indicate that all samples exhibit Newtonian behavior. The shear stress rises with the shear rate in a linear manner. Moreover, rheograms indicate that viscosity gradually decreasing with temperature. The obtained DLFB resembles commercial diesel in chemical composition when analyzed via through FTIR and GC-MS analysis, though with a small presence of low-molecular-weight hydrocarbons. In summary, these results demonstrate the potential of this novel DLFB as a sustainable fuel, given its favorable properties and the circular approach applied to the valorization of WMO. Highlights Biomass-based catalytic recycling of waste motor oil to obtain diesel-like fuels (DLFs). DLFB meet commercial diesel standards and exhibit favorable rheological properties. DLFB potential as sustainable fuel with a similar composition to commercial diesel.