Oily Wastewater Treatment Process via Supercritical Water Gasification

Abstract Oily wastewater generated by various industries such as petroleum refining and oil extraction poses significant environmental and economic challenges due to its complex composition and hazardous nature. There are several physical and chemical methods for the treatment of oily wastewater. However, these conventional methods have their own drawbacks such as high cost, using toxic compounds and generation of secondary pollutants. Supercritical water gasification has emerged as a promising concept for thermo-chemical conversion of oily waste water by using water as a reaction medium at elevated pressure and temperature conditions to generate H2 rich fuel gas accompanied by the recovery of water. This study involves a conceptual development of supercritical gasification process for oily wastewater feedstock. A steady state process simulation is developed and employed to calculate the material and energy balance targeting hydrogen production. A sensitivity analysis has been conducted to study the effect of key parameters on product composition over a broad range i.e. temperature (540-700 °C), pressure (150-350 bar) and feed concentration (2.5-20 %) to identify the optimum process conditions. Energy analysis of the process has also been conducted to assess the overall energy efficiency and energy output of the SCWG process. This preliminary energy analysis highlights the potential benefits of the proposed concept.