Treatment of impurities in process streams

A system for power production, the system comprising:

• a combustor configured for receiving a hydrocarbon fuel, an oxidant, and a stream comprising compressed CO2 and configured for output of a combustion process stream;
• a turbine configured to expand the combustion process stream to produce power and output a turbine exhaust process stream including one or more species, the one or more species including at least NOx and SOx;
• a process stream line configured for passage of the turbine exhaust process stream including the one or more species;
• a recuperative heat exchanger configured to receive and cool the turbine exhaust process stream;
• an oxidation reaction unit arranged downstream from the recuperative heat exchanger and configured to receive a vapor phase of the turbine exhaust process stream and further cool the vapor phase to a desired temperature;
• a water input line configured for passage of a recirculating stream of water to the oxidation reaction unit;
• a sensor configured to indicate a concentration of NOx and SOx in the oxidation reaction unit and determine when a concentration limit for one or both of NOx and SOx is met;
• an advanced oxidant line controlled by the sensor and configured for continuous injection of an advanced oxidant to one or more of the process stream line, the water input line, and the oxidation reaction unit when the concentration limit for one or both of NOx and SOx is met and at a rate to reduce the concentration of the one or both of NOx and SOx to below their concentration limit;
• and
• a compressor arranged downstream of the oxidation reaction unit and configured to receive a recycle stream;
• wherein SOx and NOx at least partially convert to acids in the presence of the advanced oxidant and the recirculating stream of water.