催化裂化装置低NO_x再生技术的工业应用

Industrial application of NO_x reduction regeneration technology in FCCU

介绍了低NOx再生技术在中石油华东设计院有限公司设计或改造的5套催化裂化装置的应用情况。该技术通过在再生器床层中分层配置催化剂和主风、调控烧焦过程促进CO还原NO反应来降低再生烟气中NOx浓度。结果表明:①DL1.4和LH2.2装置在高烧焦负荷、烟气过剩氧的体积分数大于3.5%和不使用脱硝助剂的条件下,NOx的质量浓度小于85mg/m3;CQ1.4装置配合使用脱硝助剂,NOx的质量浓度降到30mg/m3以下;DL0.8装置使用脱硝助剂量不变,另DL3.5装置助剂量减少25%,改造后NOx降幅均超过50%;②根据烧焦负荷高低相应调整关键工艺参数。通过该技术的应用解决了单纯依靠选择性还原(SCR)进行深度脱硝不易保持长周期运行的难题,避免了SCR因氨逃逸问题造成锅炉压力降升高,降低了装置的运行及设备投资费用。

The application of NO x reduction regeneration technology in five sets of FCCU designed or revamped by CNPC East China Design Institute Co., Ltd., is introduced. The technology can reduce NO x concentration in regenerated flue gas by layering catalyst and main air in regenerator bed, regulating coke burning process and promoting the reduction of NO by CO to reduce the concentration of NO x in the regenerated flue gas. The results show that :①for two units (DL1.4 and LH2.2), the mass concentration of NO x is less than 85 mg/m 3 under the conditions of high coke burning load, excess oxygen content in flue gas more than 3.5% and no denitrification additives;for one unit (CQ1.4),the mass concentration of NO x with denitrification additives is less than 30 mg/m 3;for one unit (DL0.8), with denitrification additives amount unchanging, for the other unit (DL3.5), with denitrification additives amount reducing by 25%, the mass concentration of NO x decreases by more than 50% after revamping;②the key process parameters are adjusted according to the coke burning load, the application of this technology solves the problem that it is not easy to maintain long-term operation by relying solely on SCR for deep denitrification, avoids the increase of boiler pressure drop caused by ammonia escape of SCR, and reduces the operation cost of the plant and the investment cost of equipment.