CIESC Journal ›› 2018, Vol. 69 ›› Issue (5): 2233-2241.DOI: 10.11949/j.issn.0438-1157.20180048

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Simulation and experimental study on smelter off-gas desulfurization using calcium-based desulfurizer

CHANG Jing1, HU Xiude2, TIAN Hongjing3, YUAN Fuqi1, XU Jingwen3, GUO Qingjie2,3   

  1. 1. College of Resources and Environment, Qingdao Agricultural University, Qingdao 266109, Shandong, China;
    2. State Key Laboratory of High-efficiency Coal Utilization and Green Chemical Engineering, Ningxia University, Yinchuan 750021, Ningxia, China;
    3. College of Chemical Engineering, Qingdao University of Science & Technology, Qingdao 266042, Shandong, China
  • Received:2018-01-15 Revised:2018-01-23 Online:2018-05-05 Published:2018-05-05
  • Supported by:

    supported by the National Natural Science Foundation of China(51608291, 51106077), the Natural Science Foundation of Shandong Province(ZR2017QB019), the Qingdao Independent Innovation Plan (16-5-1-30-jch), the Ningxia Introduction Innovation Team Plan, and the Foundation of State Key Laboratory of High-efficiency Utilization of Coal and Green Chemical Engineering (2017-K19).

钙基脱硫剂用于冶炼烟气脱硫的模拟与实验

昌晶1, 胡修德2, 田红景3, 远富启1, 许静文3, 郭庆杰2,3   

  1. 1. 青岛农业大学资源与环境学院, 山东 青岛 266109;
    2. 省部共建煤炭高效利用与绿色化工国家重点实验室(宁夏大学), 宁夏 银川 750021;
    3. 青岛科技大学化工学院, 山东 青岛 266042
  • 通讯作者: 田红景
  • 基金资助:

    国家自然科学基金项目(51608291,51106077);山东省自然科学基金项目(ZR2017QB019);青岛市自主创新计划项目(16-5-1-30-jch);宁夏引进科技创新团队项目(煤炭清洁利用);煤炭高效利用与绿色化工国家重点实验室开放课题(2017-K19)。

Abstract:

A method was developed to recover elemental sulfur from smelter off-gas with high SO2 content. Based on thermodynamic simulation of reactions between some sulfides and SO2, calcium sulfide (CaS) was demonstrated to be a novel chemical desulfurizer. SO2 was reduced to elemental sulfur by reacting with CaS in temperature range from 400℃ to 650℃ and direct solid product was CaSO4 rather than CaO. The experimental desulfurization in a fixed bed reactor showed that reaction temperature had a strong effect on SO2 removal efficiency and sulfur recovery ratio. When temperature was increased within the range of 400℃ and 650℃, both SO2 removal efficiency and sulfur recovery ratio were raised gradually. When temperature was higher than 600℃, SO2 removal efficiency was approximately equal to sulfur recovery ratio. Increasing gas velocity reduced SO2 removal efficiency, sulfur recovery ratio, and difference between these two. SO2 removal efficiency remained at 99.8% at SO2 concentration below 1% but dropped sharply to 92.1% at SO2 concentration up to 3.45%. Average SO2 removal efficiency declined gradually when SO2 concentration was continuously increased. With increase of SO2 concentration, sulfur recovery ratio exhibited an optimal range. At late stage of desulfurization, large particle size of CaS decreased SO2 removal efficiency. SEM photos showed that desulfurizer particles agglomerated more obviously at increase of reaction temperature. XRD patterns verified sublimated elemental sulfur particles in the reduction of SO2 by CaS.

Key words: flue gas, recovery, reduction, SO2 removal efficiency

摘要:

提出了一种应用钙基脱硫剂脱除冶炼烟道气中高浓度SO2并回收硫单质的方法。通过热力学模拟多种硫化物与SO2之间的反应,筛选得出硫化钙(CaS)适合作为化学链脱硫技术的脱硫剂,它在400~650℃范围内可将SO2还原为单质硫,生成的固相产物为CaSO4而非CaO。通过固定床反应器内的脱硫实验,发现温度对脱硫率和硫单质回收率影响较大。在400~650℃范围内温度越高,脱硫率和硫单质回收率越大;当温度高于600℃时,脱硫率和硫单质回收率基本相等。提高空速,则会降低脱硫率和硫单质回收率,但两者的差值随空速增大逐渐减小。当烟气中SO2浓度小于1%时,脱硫率维持在99.8%基本不变;SO2浓度升至3.45%后,平均脱硫率急剧下降至92.1%;SO2浓度越高,平均脱硫率越低。硫单质回收率随SO2浓度增大存在一最佳范围。在脱硫反应后期,粒径较大的脱硫剂颗粒脱硫性能较低。SEM照片表明了脱硫剂颗粒随反应温度的升高团聚现象更为明显,XRD表征证明了反应中SO2气体被还原为升华硫颗粒。

关键词: 烟道气, 回收, 还原, 脱硫率

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