催化裂化烟气脱硝喷氨系统控制方案设计

Design of Control Scheme for Catalytic Cracking Flue Gas Denitrification and Ammonia Injection System

催化裂化再生烟气中含有大量的氮氧化物(NO_(x)),通常采用选择性催化还原(SCR)脱硝技术治理含NO_(x)再生烟气,以彻底解决再生烟气中的NO_(x)污染问题.介绍了SCR脱硝技术及流程,重点分析了液氨缓冲罐内温度、管壁温度、罐底实时液位,液氨蒸发器内介质的温度、液氨液位、环境中氨气浓度,氨气缓冲罐内的温度、压力,氨气吸收罐内液位等的控制方案.SCR脱硝装置投运后,再生烟气中的NO_(x)排放质量浓度由现有的240 mg/m^(3)降低至40 mg/m^(3)以下,每年可减排NO_(x)超过356.5 t,对建设创新环保友好型企业具有重要意义.

The catalytic cracking regeneration flue gas contains a large amount of nitrogen oxides(NO_(x)).The selective catalytic reduction technology(SCR)is usually used to treat the regenerated flue gas containing NO_(x)to completely solve the NO_(x)pollution problem in regeneration flue gas.The SCR denitration technology and process are introduced.The control scheme of inner temperature of liquid ammonia buffer tank,pipe surface temperature,tank bottom real-time liquid level,the temperature of medium in liquid ammonia evaporator,liquid ammonia level,the ammonia concentration in environment,the temperature and pressure in ammonia buffer tank and liquid level of ammonia absorption tank,etc are discussed with emphasis.After the SCR denitration installation is put into operation,the NO_(x)emission concentration is reduced from the existing 240 mg/m^(3)to less than 40 mg/m^(3),and the annual emission reduction of NO,will be more than 356.5 tons,which is of great significance for building innovative and environment-friendly enterprises.