CIESC Journal ›› 2017, Vol. 68 ›› Issue (12): 4764-4773.DOI: 10.11949/j.issn.0438-1157.20170621

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Mercury adsorption characteristics of petroleum coke activated by SO2

WANG Chenping1, DUAN Yufeng1, SHE Min1, ZHU Chun1, YANG Zhizhong2   

  1. 1 Key Laboratory of Energy Thermal Conversion and Control of Ministry of Education, Southeast University, Nanjing 210096, Jiangsu, China;
    2 Technology Center of Dongfang Boiler Group Company Limited, Dongfang Electric, Zigong 643001, Sichuan, China
  • Received:2017-05-15 Revised:2017-06-26 Online:2017-12-05 Published:2017-12-05
  • Supported by:

    supported by the National Key Research and Development Program of China (2016YFB0600604).

SO2活化改性石油焦吸附剂的汞吸附特性

王晨平1, 段钰锋1, 佘敏1, 朱纯1, 杨志忠2   

  1. 1 东南大学能源热转换及其过程测控教育部重点实验室, 江苏 南京 210096;
    2 东方电气集团东方锅炉股份有限公司技术中心, 四川 自贡 643001
  • 通讯作者: 段钰锋
  • 基金资助:

    国家重点研发计划项目(2016YFB0600604)。

Abstract:

Petroleum coke as a kind of by-product in petrochemical industry was chosen to prepare the mercury removal adsorbent with high sulfur and activity by SO2 activation. The effects of adsorption temperature, inlet Hg0 concentration, flue gas composition and thermal regeneration on mercury removal characteristic were investigated in a fixed bed reactor system. Meanwhile, the removal mercury mechanism was put forward by applying characterization methods, including surface area and porosity analyzer, elemental analyzer and X-ray photoelectron spectroscopy (XPS). The experimental results showed that the physical and chemical properties of SAPC were significantly improved. And carbonyl, ester and non-oxidized sulfur were the main active sites of Hg0 capture. Furthermore, the mercury removal capacity decreased with increasing adsorption temperature. The mercury adsorption rate was faster, while the initial mercury removal efficiency became lower at elevated initial Hg0 concentration. SO2 had unconspicuous effect on mercury removal. Hg0 on or close to surfaces was oxidized by the adsorbed oxygen, and mercuric ions were more readily bound to sulfur via the Hg-S bond, while some will bind to oxygen. The absorption capacity of regenerated petroleum coke was weakened because of the loss of active sites in the regeneration process.

Key words: petroleum coke, mercury adsorption, sulfur dioxide, sulfur forms

摘要:

利用SO2气体对石化工业副产物石油焦进行活化改性以制成富硫高活性脱汞吸附剂(SAPC)。在固定床实验装置上进行SAPC吸附脱除汞的实验研究,考察吸附温度、入口Hg0浓度、烟气成分以及热再生等因素对脱汞特性的影响规律,同时结合比表面积及孔隙度分析、元素分析和X射线光电子能谱(XPS)等表征手段深入分析SAPC的汞吸附机理。结果表明,SO2活化改性石油焦的物理和化学特性得到极大改善,羰基、酯基以及非氧化态硫是Hg0的主要活性吸附位。吸附温度的升高会抑制对Hg0的吸附脱除,烟气中较高的Hg0浓度会降低汞脱除效率,但对其汞吸附速率有促进作用。SO2对SAPC的脱汞性能影响较小,O2易将Hg0氧化成为更容易与含氧、含硫官能团结合的氧化态汞,从而促进对Hg0的脱除。热再生时吸附态汞化合物受热分解的过程伴随着吸附剂表面化学活性位的损失,导致再生后汞吸附性能大幅下降。

关键词: 石油焦, 汞吸附, 二氧化硫, 硫形态

CLC Number: