| 摘要 |
PURPOSE:To perform efficient denitration, by contacting NOx-containing gas with a catalyst in the presence of O2 to oxidize and absorb NOx by the catalyst and stopping the exhaust gas when absorbing efficiency is lowered to allow a reducing agent to flow and performing the reductive removal of accumulated NOx. CONSTITUTION:The exhaust gas from an engine is introduced into one of catalysts 1-a, 1-b and Nox is oxidized and absorbed by the catalyst in the presence of O2 while a gaseous reducing agent such as H2 is generated by a H2- generator 2 to be introduced into the catalyst, through which no exhaust gas flows, through a sump 5. NOx oxidized and absorbed by the catalyst is reduced and removed by the reducing agent and the catalyst is regenerated. The catalyst 1-a, 1-b are periodically changed over at the point of time when absorbing efficiency was lowered. By this method, because the reducing agent is used only in an amount necessary for reducing NOx absorbed by the catalyst, a small quantity of the reducing agent is sufficient. |
