| abstract |
This invention is an emission control system wherein the boiler hosts a reactor which contains one or more catalysts for the purpose of reducing NO x and/or CO in the emissions. The reactor containing the NOx/CO catalysts may be placed at a place where the temperature is in the range of 300-1000° F. The hot flue gas can be diverted using control dampers and blended with colder flue gas inside the boiler to achieve the desired flue gas temperature for the selected catalyst. NO x is removed by the SCR catalyst inside the boiler upon injecting a suitable reducing agent (e.g. ammonia, or hydrocarbons). The CO and NO x catalysts may be used in any order. The emission control system is an integral part of the boiler, and the existing capabilities of the boiler to recover the heat from flue gas, after the catalyst layers, is utilized such that the overall boiler efficiency remains high. |