BASF Mercury Sorbent ZX™ for Control of Coal-fired Power Plant Hg Emissions

摘要

Electric utilities that operate coal-fired generating units continue to seek new, cost-effective sorbents for controlling mercury emissions to meet regulatory requirements while also preserving the value of salable fly ash for concrete applications as a partial replacement for Portland cement.The latest innovative BASF Mercury Sorbent platform technology - ZX - is a patent-pending1'2 brominated mineral-based mercury adsorbent with an organic flow modifier constituent. The flow modifier has been confirmed in third-party testing to be an effective means to overcome sorbent agglomeration issues seen previously in other mineral-based sorbents.Full scale, parametric field trial results from Xcel Energy's Pawnee Generating Station in Brush, Colorado, a nominal 500MW PRB coal-fired generating unit equipped with a fabric filter, demonstrated that BASF Mercury Sorbent ZX110~(™) controlled baghouse outlet vapor-phase mercury emissions to the levels stated in the 2012 and 2018 Colorado mercury control regulations for this plant of 0.0174 Ib/GWh and 0.0087 lb/GWh respectively. BASF Mercury Sorbent ZX110 also achieved greater than 90% vapor phase mercury removal at the baghouse outlet at sorbent injection rates comparable to those of a commercially available brominated powdered activated carbon, which was tested parametrically at the site as a comparative reference.Fly ash samples retrieved during extended full scale testing of BASF Mercury Sorbent ZX110 were submitted for concrete property testing. Test results confirmed that the fly ash retained salable properties for concrete applications, including satisfactory air entrainment admixture dosing levels, concrete entrained air retention levels, and concrete compressive strengths.