石油炼制与化工 ›› 2022, Vol. 53 ›› Issue (11): 117-122.

• 节能减排 • 上一篇    下一篇

催化裂化装置选择性催化还原脱硝技术应用中的问题及解决方案

余璐,高勇强,范玉龙,徐梦飞   

  1. 中国石油长庆石化公司
  • 收稿日期:2022-05-26 修回日期:2022-07-16 出版日期:2022-11-12 发布日期:2022-11-02
  • 通讯作者: 余璐 E-mail:yulu_petrochina@163.com

PROBLEMS AND SOLUTIONS IN THE APPLICATION OF SCR DENITRIFICATION TECHNOLOGY IN FCC UNIT

  • Received:2022-05-26 Revised:2022-07-16 Online:2022-11-12 Published:2022-11-02
  • About author:[1] 水春贵. 催化裂化烟气脱硫脱硝技术应用现状及存在问题[J]. 石油石化绿色低碳, 2019,4(5):49-55 [2] 杨宗鑫,王兵,林孟雄,等. 大气污染过程中氮氧化合物对大气的危害及防治[J]. 内蒙古石油化工,2008,34(21):24-26 [3] 石油炼制工业污染物排放标准:GB 31570—2015[S] [4] 郭伟,李宁,白锐,等. 影响催化裂化烟气NOx浓度的因素及控制方法[J]. 石油炼制与化工,2020,51(1):97-100 [5] 高海山. FCC烟气SCR脱硝装置运行问题分析及解决方案[J]. 石油化工腐蚀与防护,2021,38(4): 39-41 [6] 孙博文,陈银平,张顺平. 催化裂化装置SCR脱硝技术应用问题及处理措施[J]. 石油化工应用,2020,39(7):105-107 [7] 王伟. 催化裂化再生过程碳、硫、氮燃烧及相关研究[J]. 炼油技术与工程,2021,51(8):18-22 [8] 李超,王楷,王志强,等. 余热锅炉省煤器结盐原因分析及对策[J]. 石化技术与应用,2017,35(3):225-228 [9] 朱少杰. 脱硫脱销在催化裂化装置的应用[J]. 科技风,2015,1(6):63-65 [10] Bouziden G, Gentile K, Kunz R G. Selective Catalytic Reduction of NOx From Fluid Catalytic Cracking Case Study: BP Whiting Refinery[C]. NPRA National Environmental and Safety Conference, Washington: 2002: 1-31 [11] Jensen-Holm H, Lindenhoff P. Combating NOx from refinery sources using SCR[C]. 2nd Annual World Refining Technology Summit & Exhibition, Abu Dhabi: 2010: 1-31 [12] 马双忱, 金鑫, 孙云雪,等. SCR烟气脱硝过程硫酸氢铵的生成机理与控制[J]. 热力发电,2010,39 (8):12-17 [13] 刘喜平,高庆军,杨大伟,等. SDJF-A1脱硫脱硝CO助燃剂在催化裂化装置的应用[J]. 齐鲁石油化工,2021,49(3):194-199 [14] 燃煤烟气脱硝喷氨混合系统: GB/T 34339—2017[S]. 2017 [15] 刘鹏宇,李德波,刘彦丰,等. 燃煤电厂SCR脱硝系统数值模拟研究进展[J]. 环境工程,2022,1(1):1-12 [16] 王云刚,于飞. 低热值垃圾焚烧发电机组设计和选型研究[J]. 发电设备,2017,31(4):250-253 [17] 张小金. 锅炉吹灰器的选择与技术应用[C] 全国火电100 MW级机组技术协作会第五届年会,成都:2006

摘要: 为保障催化裂化装置长周期运行,分析选择性催化还原(SCR)模块所在余热锅炉压降持续增加的原因,并针对性的提出解决方案。结果表明:黏性较强、易沉积的硫酸氢氨(NH4HSO4)的生成是余热锅炉压降增大的主要原因;使用脱硫脱硝助剂降低SCR脱硝模块入口烟气中氮氧化物(NOx)和硫氧化物(SOx)浓度,可大幅减少SCR模块喷氨量,有效抑制NH4HSO4的生成。工业应用结果表明:使用SDJF-A1型脱硫脱硝助剂后,反应-再生系统中NOx转化率高达69.08%~81.27%,烟气中NOx、SO2的浓度均大幅降低,余热锅炉的吹灰系统优化运行和提升省煤器温度分解NH4HSO4等方法在控制余热锅炉压降升高方面均有一定成效。进一步可采取优化SCR喷氨系统、提高SCR模块反应温度和改进吹灰系统的措施来保障装置的长周期运行。

关键词: 催化裂化, 烟气, 选择性催化还原, 余热锅炉, 省煤器, 脱硫脱硝助剂

Abstract: In order to ensure long-term operation of catalytic cracking unit, the reasons of increasing the pressure drop of the waste heat boiler in selective catalytic reduction (SCR) unit were analyzed, and the solutions were put forward. The results indicated that the formation of ammonia hydrogen sulfate (NH4HSO4) with strong viscosity and easy deposition was the main reason for the increase of pressure drop of waste heat boiler. Reducing the concentration of nitrogen oxide (NOx) and sulfur oxide (SOx) in the inlet flue gas of SCR unit could greatly reduce the amount of ammonia injected into the SCR unit and effectively inhibit the formation of NH4HSO4. The results of industrial application showed that the NOx conversion rate in the reaction-regeneration system was 69.08%-81.27%, and the concentration of NOx and SO2 in flue gas was significantly reduced after the use of SDJF-A1 type desulfurization and denitrification auxiliary agent. The methods of optimizing operation of the soot blowing system and increasing the temperature of economizer to decompose NH4HSO4 are effective in controlling the pressure drop rise in the waste heat boiler. Further measures such as optimizing SCR ammonia injection system, increasing the reaction temperature of SCR and improving soot blowing system can be taken to ensure the long-term operation of the plant.

Key words: catalytic cracking, flue gas, selective catalytic reduction, waste heat boiler, economizer, desulfurization and denitration agent