Experimental study on supercritical water gasification of grease trap sludge in a continuous reactor

Grease trap sludge (GTS) is one of the main hazardous oily wastes produced from petrochemical industry. Supercritical water gasification (SCWG) technology is an attractive method for the resource utilization and treatment of organic waste. In this study, experiments on gasification of GTS in supercritical water (SCW) were carried in a continuous system with different temperatures (610–650 °C), concentrations of GTS (14 wt%-20 wt%) and preheat water flow rate (60 g/min to 100 g/min). Experimental results show that higher temperature, lower concentration and suitable preheat water flow rate all promote the gasification. The highest carbon gasification efficiency reached to 73.12 % with 4.90 mol/kg H₂ gas yield at 650 °C, 17 wt% GTS concentration and 100 g/min preheat water flow. The primary intermediate organic components identified in the liquid products were naphthalene, indene, acenaphthene, and phenols. This study offers experimental insights for the efficient and environmentally friendly industrial treatment of grease trap sludge using SCW.