A Variety of Hg Capture Solutions Are Available

摘要

While vacating the Clean Air Mercury Rule has postponed implementation of mercury capture to some extent, improvements in ways to capture -- and monitor -- Hg have continued to wend their way through the pilot testing phases and into the commercial market. One way of enhancing Hg capture from flue gas desulfurization and selective catalytic reduction at power plants that cannot meet their mercury emission limits through co-benefits alone is to treat the coal by adding something to it. Alstom's KNX process uses calcium bromide. Bromide can be added to the boiler or to the coal to oxidize the mercury and facilitate its capture in wet scrubbers. There are also variations of sorbent injection that provide ways to introduce activated carbon into flu gas. There are also ways to agglomerate the carbon or grind it finer on site to achieve better mass transfer. The post combustion Mer-Cure process Alstom offers is a combination of some of those methods.