Yellow tungsten oxide can be sued as promoter in SCR catalyst, it takes about 10% of SCR total weight. It plays an important role in SCR catalyst:
1.Promote thermal stability of carrier, prevent it losing catalytic activity due to high temperature calcination.
2.Sulfur resistance. Oxidation property of V2O5 will convert SO2 into SO3, SO3 is easy to combine with moisture in the off-gas to generate sulfate. Sulfate is sticky and corrosive, it will attached on surface of SCR catalyst and lower its catalytic activity.
3.Anti alkali metal poisoning such as K, Li, Na.
SCR catalyst is the essential part of SCR denitration technology, it determines the effectiveness and economy of denitration technology. At present, V2O5 is the mostly used catalytic material. WO3 is used as promoter, titanium dioxide as carrier, According to its different appearance can be divided into plate, corrugated plate and honeycomb. Usually in high temperature denitration process, SCR catalyst containing yellow tungsten oxide has best reaction temperature under 350℃. With the development of SCR technology, low temperature catalytic and high effectiveness of WO3 SCR catalyst can largely reduce cost and energy comsumption.