This report examines incorporating a mild oxidation process, in traditional Hydrothermal Liquefaction (HTL). The focus is on improving efficiency through heat recovery and autothermal operations. In WAO, pressurized and heated sludge, mixed with air, undergoes combustion reactions, generating CO2 and other gases. A novel aspect is using reactor effluent heat to pre-heat incoming sludge, minimizing energy needs and enabling autothermal reactions at specific solids concentrations. The report discusses many advantages of this embodiment of the HTL process, which could eliminate heat exchangers by leveraging heat from oxidation. This approach simplifies operations.