1-5　脱硝触媒におけるSi化合物付着特性

抄録

In coal-fired power generation, De NOx catalysts are known to deteriorate over time, but its mechanism has not been clarified yet. According to the previous research, it has been found that amorphous silica forms a thin layer on the catalyst surface, which composition are much different from those of coal ash. It implies that coal ash itself does not adhere on the surface of the catalyst, but Si compounds in the gas deposits to the catalyst. In order to confirm this consideration, deposition behaviors of vapor Si compounds to the catalyst surface were examined, and its effect on the catalyst performance was investig ated. High volatile siloxane was selected to simulate vapor Si compounds in exhaust gas. Two kinds of experiments are conducted, such as exposure and immersion tests. In the former, test pieces of the catalyst were exposed to siloxane vapor. In the latter, test pieces were immersed in liquid siloxane and calcined afterward. The amount of silica deposition on the surface of the catalyst was analyzed by SEM / EDX. In the catalyst performance evaluation test, dete rioration of the catalyst by silica adhesion wa s confirmed.