系统论述了当前主要的脱硝技术、流化催化裂化(FCC)再生工艺及FCC再生过程NOx产生和转化规律。O2是影响催化剂脱硝活性的主要因素,从反应器尺度精确控制烧焦再生反应,严格控制过剩氧含量,是提高脱硝效率的一条可行途径。提出了通过再生器内部结构和工艺设计创造出具有氧化区和还原区多层多区的新型再生工艺脱硝思路。从降低NOx角度考虑,再生温度应不高于700℃,再生烟气中CO浓度不低于4%,O2浓度至少低于1%。这种新的再生器脱硝是一种经济、高效的脱硝技术,已在中石油大港石化FCC工业装置得到了初步验证,为FCC再生装置和其他化工过程脱硝提供了新思路。
The development of NOx reduction strategy, the fluid catalytic cracking (FCC) regeneration process and the formation and conversion of NOx are summarized. O2 is a strong inhibiter of the reaction of NO reduction by CO. It should be an efficient NOx reduction way by controlling O2 concentration of the regenerator. A new type of a multi-layer multi-zone with oxidation zone and reduction zone NOx reduction technology is proposed. This new regeneration process could have characteristics of low carbon content, short regeneration time, high burning intensity, and counter-current contact with catalyst and air. In view of NOx reduction, regeneration temperature should be less than 700℃, CO concentration in regenerator no less than 4% and O2 concentration in regenerator less than 1% at least. This novel FCC regenerator technology is a highly efficient and economical NOx reduction technology, which has been demonstrated in the FCC plant of PetroChina Dagang Petrochemical Company, and might be applied to other FCC process or coal combustion for NOx reduction.