Wet peroxide oxidation and catalytic wet oxidation of stripped sour water produced during oil shale refining

Abstract

Catalytic wet oxidation (CWO) and wet peroxide oxidation (WPO) of stripped sour water (SSW) from an oil shale refinery was investigated. Greater than 70% total organic carbon (TOC) removal from SSW was achieved using Cu(NO 3) 2 catalysed WO under the following conditions using a glass lined reaction vessel: 200 °C, pO 2 = 0.5 MPa, 3 h, [Cu(NO 3) 2] = 67 mmol/L. Significant TOC removal (∼31%) also occurred in the system without added oxygen. It is proposed that this is predominantly due to copper catalysed oxidative decarboxylation of organics in SSW based on observed changes in copper oxidation state. Greater than 80% TOC removal was achieved using WPO under the following conditions: 150 °C, t = 1.5 h, [H 2O 2] = 64 g/L. Significantly more TOC could be removed from SSW by adding H 2O 2 in small doses as opposed to adding the same total amount in one single dose. It was concluded that WPO was a far more effective process for removing odorous compounds from SSW.