(684c) Production and Characterization of Biorenewable Thermal Deoxygenation Oil/ Ultra Low-Sulfur Diesel Blends

Thermal DeOxygenation (TDO) oil is a type of highly deoxygenated biocrude produced through non-catalytic thermochemical conversion of levulinate and formate salt mixtures. Properties of TDO oil such as low oxygen content (< 5 wt %), broad boiling point range (75-550 °C), and high aromaticity suggest that it is a suitable candidate for making fuel blends with petroleum products. In this study, TDO oil and upgraded TDO oil were blended with Ultra Low-Sulfur Diesel (ULSD) and analyzed for chemical and physicochemical properties. The TDO oil was produced using a mixture of calcium levulinate and formate salt mixture at 450 °C in a 50 L semibatch reactor and hydrogenated using Ni/SiO₂-Al₂O₃ (65 wt % Ni) catalyst in a continuous flow tubular reactor. The crude TDO oil and hydrogenated TDO (HDO) oil were distilled to produce 200- 325 ℃ diesel range distillate. Sixteen different fuel blends were prepared by blending four different blend stocks, namely, crude TDO oil, HDO oil, distilled TDO oil, and distilled HDO oil with ULSD in four different volume percent (5 %, 10 %, 15%, and 20%). The fuel blends blend stocks were analyzed for specific gravity/ API gravity, viscosity, heat of combustion, hydrogen content, cetane number, boiling range distribution, lubricity, carbon residue, acid and base number, and hydrocarbon types in middle distillate according to American Society for Testing and Materials (ASTM) methods.

Some of the properties such as specific gravity, viscosity, hydrogen content, and net heat of combustion change linearly with the blend percent. Specific gravity and viscosity of all the fuel blends exceed or fall within the specified range of ASTM D975 No.2 distillates and MIL-DTL-16884M fuel specifications. Hydrogen (H) content (wt %) of TDO oil and TDO oil distillate fuel blends are comparatively lower than that of HDO oil and HDO oil distillate fuel blends. However, H content of all the fuel blends except the 15 % and 20 % blends of TDO and TDO distillate oil meet the MIL-DTL-16884M specifications. Net heat of combustion of all the fuel blends are approximately 42 MJ/kg or above. Overall chemical and physicochemical properties of HDO oil fuel blends and HDO oil distillate fuel blends are closer to the properties of ULSD.