Technical-Scale Evaluation of Scrubber-Based, Co-Removal of NOx and SOx Species from Flue Gases via Gas-Phase Oxidation

The coabsorption of SO x and NO x supported by the enhanced oxidation of NO by ClO 2 (g) from flue gases is investigated through technical-scale experiments and simulations. In focus is NO x absorption and the oxidation of S(IV) to S(VI). The concept was tested using the flue gases from a 100 kW gas-fired furnace, to confirm findings previously obtained at the technical scale. The chemical interactions that occurred between NO x, SO x, and ClO 2, used as an oxidizing agent, were investigated. The measurements confirm that the absorption of SO 2 in the scrubber is efficient and mainly determined by saturation in the scrubber liquid. The absorption of NO 2 peaked at 82%, when Na 2 SO 3 and Na 2 CO 3 were added to the scrubber liquid. The results indicate that the efficiencies of removal of NO x and SO x can be high (>90% and >99%, respectively). This work provides a first proof-of-concept on a technical scale and validates the reaction mechanism proposed in previous studies.