Hydrothermal liquefaction of municipal sewage sludge: Effect of red mud catalyst in ethylene and inert ambiences

In this study, ethylene and nitrogen(inert) reaction environments were applied into the hydrothermal liquefaction (HTL) process of municipal sewage sludge with red mud catalyst to evaluate effects on biocrude other byproducts. Red in three oxidation states was used: calcined at 575 °C (CRM), reduced 500 (RRM500), 700 (RRM700). The RRM500 lowered acidity by 14%; whereas, RRM700 minimized viscosity 47% comparing non-catalytic-inert samples. ambience successfully maximized yield 41.6 wt% without any catalyst. biocrudes produced under environment showed lower differences compared nitrogen environment. RRM500-ethylene efficiently content 14%. These results suggested that atmosphere has potential for improved production during catalytic HTL treatment.