NO_x Catalyst Performance on Mercury and SO₃ - Hot Topic April 14, 2011

The following speakers explained the current "state of the art" of SCR design and catalyst formulations relative to mercury oxidation and SO₂ to SO₃ conversion.

Mike Cooper, Vice President of Technology at CoaLogix explained the beneficial and detrimental reactions which impact the catalyst ability to oxidize elemental mercury. Promoters are the catalyst, lower temperatures, halogens, and V₂O₅. The inhibitors are NH₃, H₂O and SO₂. Catalyst regeneration results show beneficial impacts on Hg oxidation.

Karin Madsen of Haldor Topsoe discussed the effect of operating conditions and catalyst type on mercury oxidation across the SCR catalyst. Up to 90 percent mercury oxidation is achievable depending on the inlet Hg speciation and the chlorine concentration. Greater than 91 percent mercury removal is achievable using existing control devices (the combination of the SCR-FGD strategy). Adding additional HCl above a certain point does not improve oxidation. However, bromine acts differently and therefore may provide greater oxidation with increased amounts.

John Cochran of Ceram Environmental presented results of a mercury oxidation test program which will continue through 2013.  It is a result of a new major focus on mercury in Europe. The challenge is to balance the NO_x removal requirements with the goals for mercury oxidation and SO₃ minimization. Results were presented for one power plant with 91 percent NO_x removal and 95 percent mercury removal with a catalyst with an SO₂ to SO₃ conversion rate across the reactor of less than 0.5 percent.

Bio, Photo and Abstracts are shown below.
BIO, PHOTO AND ABSTRACTS - April 14, 2011.htm