Abstract: The catalyst is the key element of the SCR denitrification system in the coal-fired power plant. It deactivates gradually during the running process. In-time replacement or supplement of the catalyst not only guarantees the denitrification efficiency, but also reduces the system reaction costs. In this work, with the ammonia slip amount as the evaluation indicator, the catalyst life management model in line with the actual conditions of the denitrification is established based on the basic model of the SCR reactor and the deactivation model of the catalyst. The actual conditions of the ammonia-nitrogen ratio less than 1 are adopted as the modeling conditions, with the changes of the ammonia-nitrogen ratios at the reactor inlet and each catalyst layer in the reactor in consideration. Through comparing with the actual catalyst deactivation time, it is concluded that the model is proved to be accurate and the catalyst operating conditions are assumed properly. On this basis, combining with the catalyst replacement or supplement situation, 12 feasible catalyst management schemes are proposed. The optimal scheme is obtained when the service life of the catalyst is set as the evaluation indicator.

Key words: coal-fired power plant, flue gas denitrification, SCR catalyst, ammonia slip, denitrification efficiency, catalyst life management