Many countries have strict emission limits for nitrogen oxides(NO_(x));thus NO_(x) control systems are widely deployed.India has recently introduced NO_(x) emission limits,which require that pollution control technolo...Many countries have strict emission limits for nitrogen oxides(NO_(x));thus NO_(x) control systems are widely deployed.India has recently introduced NO_(x) emission limits,which require that pollution control technologies must be installed on most coal-fired plants.However,operational experience with NO_(x) control systems in India is limited to primary measures only.Additionally,Indian coals have a high level of inherent ash,which is also highly erosive and can influence the behaviour of some NO_(x) control systems and thus affect the selection process.Primary measures for NO_(x) control from coal-fired power plants include low NO_(x) burners(LNBs),overfire air systems(OFA),fuel reburning,flue gas recirculation,fuel biasing,low excess air and combustion optimization.Secondary NO_(x) control includes selective catalytic reduction,selective non-catalytic reduction and multi-pollutant control systems.Retrofit of primary measures(LNBs and OFA)in India has been recommended to take place during next-scheduled plant outages;for many plants this could occur by 2019.However,control strategies for individual plants will be needed to ascertain the appropriateness of installing post-combustion technologies or various combinations of NO_(x) control measures.Hence installation of secondary NO_(x) controls is not expected before test results from secondary controls on selected Indian power plants units are known.展开更多
文摘Many countries have strict emission limits for nitrogen oxides(NO_(x));thus NO_(x) control systems are widely deployed.India has recently introduced NO_(x) emission limits,which require that pollution control technologies must be installed on most coal-fired plants.However,operational experience with NO_(x) control systems in India is limited to primary measures only.Additionally,Indian coals have a high level of inherent ash,which is also highly erosive and can influence the behaviour of some NO_(x) control systems and thus affect the selection process.Primary measures for NO_(x) control from coal-fired power plants include low NO_(x) burners(LNBs),overfire air systems(OFA),fuel reburning,flue gas recirculation,fuel biasing,low excess air and combustion optimization.Secondary NO_(x) control includes selective catalytic reduction,selective non-catalytic reduction and multi-pollutant control systems.Retrofit of primary measures(LNBs and OFA)in India has been recommended to take place during next-scheduled plant outages;for many plants this could occur by 2019.However,control strategies for individual plants will be needed to ascertain the appropriateness of installing post-combustion technologies or various combinations of NO_(x) control measures.Hence installation of secondary NO_(x) controls is not expected before test results from secondary controls on selected Indian power plants units are known.
