Catalytic and Non-catalytic Supercritical Water Oxidation of DBU

摘要

Non-catalytic and catalytic supercritical water oxidation (SCWO) of 1,8-diazobicyclo [5.4.0]undec-7-ene (DBU) experiments were carried out in a continuous plug flow reactor operated at the following conditions: 23.0 and 25.0 MPa and 653 - 923 K. Catalytic SCWO (CSCWO) was conducted in a fixed-bed reactor packed with Pt/γ-Al{sub}2O{sub}3. The study confirmed temperature to be the main controlling variable, and complete SCWO of a solution of 0.3 mmol DBU/L was achieved at 723 K, 25.0 MPa, SR of 2 and a residence time of 8 s. Yet TOC under these conditions was 65% indicating the presence of intermediates, despite high pressure and oxidant concentration. Based on the results DBU is easily oxidized but it still produces considerable amounts of TOC. Catalytic SCWO allowed the reduction of TOC content, at milder operating conditions. At 653 K, 23.0 MPa, SR of 1 and residence time of 2.0 s and using a solution of 0.3 mmol DBU/L, 100% removal of the organic compound was achieved and TOC content was less than 3.5%. Again, temperature was the controlling operating condition during the catalytic oxidation. DBU initial concentration and oxygen concentration did show a negative effect in the oxidation.