Thermal process and NO emission reduction characteristics of a new-type coke oven regenerator coupled with SNCR process

Abstract Based on the cascade utilization of high-temperature waste heat and selective non-catalytic reduction (SNCR) technology, a new-type coke oven regenerator with ammonia injection space was proposed. By changing the structure and operating parameters, the high-temperature heat storage and NO emission reduction are achieved synergistically. A three-dimensional model was used to study the flow, heat transfer, and SNCR process inside the regenerator. The validity of the model was verified. Results showed that the new-type regenerator had a significant cascade utilization characteristics of waste heat. There was a competitive reaction between NH3 + NO → N2 and NH3 → NO during the coupled SNCR process. The optimal reaction temperature window was 911 ~ 984°C, and the residence time was 0.21 ~ 0.38 s. The mixing of the reductant with the flue gas and the complete contact of NH3 with NO determined high NO reduction efficiency. Furthermore, combining multiple operating parameters, a strategy was proposed to ensure the outlet NO/NH3 concentration meets the emission standard requirements.