Hydrogen generation from oily wastewater via supercritical water gasification (SCWG)

Gasification of oily wastewater in supercritical water (SCW) was investigated in a reactor at 773–923 K, 25–41 MPa and residence time of 180–220 s. Pressure change had no significant influence on gasification efficiency. Higher temperature and longer residence time enhanced gasification efficiency, and lower temperature favored the production of H2. The effects of KOH catalyst on gas product composition were studied, and gasification efficiency was analyzed. The total organic carbon (TOC) removal, carbon gasification ratio and hydrogen gasification ratio were up to 98%, 97.88% and 128% at 923 K and 220 s, respectively, which demonstrated that oily wastewater can be completely gasified in SCW.