The supercritical water gasification of phenolic wastewater without ox idant was performed to degrade pollutants and produce hydrogen-enriched gases. T he simulated o-cresol wastewater was gasified at 440—650℃ and 27.6 MPa in a co ntinuous Inconel 625 reactor with the residence time of 0.42—1.25 min. The infl uence of the reaction temperature, residence time, pressure, catalyst, oxidant a nd the pollutant concentration on the gasification efficiency was investigated. Higher temperature and longer residence time enhanced the o-cresol gasification. The TOC removal rate and hydrogen gasification rate were 90.6% and 194.6%, resp ectively, at the temperature of 650℃ and the residence time of 0.83 min. The pr oduct gas was mainly composed of H2, CO2, CH4 and CO, among which the total mola r percentage of H2 and CH4 was higher than 50%. The gasification efficiency decr eased with the pollutant concentration increasing. Both the catalyst and oxidant could accelerate the hydrocarbon gasification at a lower reaction temperature, in which the catalyst promoted H2 production and the oxidant enhanced CO2 genera tion. The intermediates of liquid effluents were analyzed and phenol was found t o be the main composition. The results indicate that the supercritical gasificat ion is a promising way for the treatment of hazardous organic wastewater.
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