Evaluation of gas reburning and low NO{sub x} burners on a wall-fired boiler

An evaluation of Gas Reburning (GR) and Low NO{sub x}, Burners (LNB) has been completed at Public Service Company of Colorado`s Cherokee Station Unit 3. The goal of the demonstration, which was carried out in a US DOE Clean Coal Technology Round 3 Program, was to reduce NO{sub x} emissions by 70%. The reduction was to be achieved from the pre-project level, prior to LNB retrofit. The GR system was supplied by Energy and Environmental Research Corporation (EER) and the LNBs were supplied by the Foster Wheeler Energy Corporation. The project was carried out in three phases in which EER designed the GR system and obtained necessary permits (Phase 1), constructed the system and completed start-up tasks (Phase 2), and evaluated its performance with both Optimization Tests and a Long-Term Demonstration (Phase 3). As directed by the cooperative agreement, environmental monitoring was conducted in each phase. Measurements were taken by plant personnel and an EER Field Testing Team and were divided into two types. ``Compliance Monitoring`` was conducted by plant personnel to satisfy requirements of regulatory agencies, while ``Supplemental Monitoring`` was conducted by EER personnel to develop a database of environmental impacts of the technology and to ensure environmental acceptability of the project. This document presents environmental monitoring data obtained during the Long-Term Testing period, April 27, 1993 to January 27, 1995. During this period, ten months of testing of the GR-LNB system was followed by a modification into a ``second-generation`` GR-LNB system, which was evaluated for six months. Compliance Monitoring was conducted primarily in two areas, air emissions and aqueous discharges