Evaluation of Mercury Control Technologies at a Power Plant without SCR Firing Eastern Bituminous Coal

摘要

Addition of calcium bromide to coal has been demonstrated to be effective at oxidizing mercury in flue gases derived from low-chloride coals such as Powder River Basin. The performance of this technology for eastern bituminous coal has not been documented. A twelve-day continuous full-scale calcium bromide addition test was conducted at Southern Company's Georgia Power's Plant Yates Unit 1, which fires a low sulfur eastern bituminous coal and is equipped with an ESP and Chiyoda CT-121 wet scrubber for SO_2 control. In a separate test, activated carbon was added directly to the wet scrubber with the objectives of learning how carbon affects mercury partitioning between liquid and solid phases of the scrubber slurry, evaluating how carbon affects gas-phase mercury re-emissions, and demonstrating separation of carbon from the gypsum. Carbon injection into the duct upstream of the scrubber was also tested as a stand-alone mercury control technology. This paper presents results from the bromide addition tests, carbon addition tests, and carbon injection tests. Results include flue gas mercury measurements across the scrubber, mercury partitioning within the scrubber, and the effect of hydroclone apex size on carbon partitioning within the scrubber.