刘俊杰, 苏伟, 邢奕, 刘卫民, 赵青涛, 庞升果, 蒋兟, 卫祥民, 历新燕. 改性兰炭烟气SO2吸附材料的制备及其再生性能[J]. 工程科学学报, 2021, 43(2): 223-231. DOI: 10.13374/j.issn2095-9389.2020.02.21.001
引用本文: 刘俊杰, 苏伟, 邢奕, 刘卫民, 赵青涛, 庞升果, 蒋兟, 卫祥民, 历新燕. 改性兰炭烟气SO2吸附材料的制备及其再生性能[J]. 工程科学学报, 2021, 43(2): 223-231. DOI: 10.13374/j.issn2095-9389.2020.02.21.001
LIU Jun-jie, SU Wei, XING Yi, LIU Wei-min, ZHAO Qing-tao, PANG Sheng-guo, JIANG Shen, WEI Xiang-min, LI Xin-yan. Preparation and regeneration performance of modified semi-carbon for flue gas SO2 adsorbent[J]. Chinese Journal of Engineering, 2021, 43(2): 223-231. DOI: 10.13374/j.issn2095-9389.2020.02.21.001
Citation: LIU Jun-jie, SU Wei, XING Yi, LIU Wei-min, ZHAO Qing-tao, PANG Sheng-guo, JIANG Shen, WEI Xiang-min, LI Xin-yan. Preparation and regeneration performance of modified semi-carbon for flue gas SO2 adsorbent[J]. Chinese Journal of Engineering, 2021, 43(2): 223-231. DOI: 10.13374/j.issn2095-9389.2020.02.21.001

改性兰炭烟气SO2吸附材料的制备及其再生性能

Preparation and regeneration performance of modified semi-carbon for flue gas SO2 adsorbent

  • 摘要: 利用活性炭(焦)等吸附剂将烟气中的污染物分离出来是一种有效的烟气治理与资源化方式。兰炭作为一种廉价半焦碳素材料,是一种有潜力代替现有商用活性焦的多孔材料。本文采用陕西兰炭作为研究对象,研究炭化时间、炭化温度、黏结剂添加量等改性工艺对所制备的吸附剂性能的影响,考察了微观形貌变化,利用X射线光电子能谱(XPS)探究在吸附解吸过程中的表面官能团的变化。结果表明,炭化温度对耐磨强度、耐压强度指标影响显著,炭化时间对饱和脱硫值和穿透脱硫值影响显著;在煤焦油添加比例50%,700 ℃炭化20 min,900 ℃活化60 min条件下制得改性兰炭参数为:耐磨强度95.81%,抗压强度536.1 N·cm−1,每克兰炭饱和脱硫值45.71 mg,每克兰炭穿透脱硫值23.45 mg;经历多次吸脱附过程第一次失活时,表面被大面积刻蚀,孔隙与小颗粒增多。兰炭吸附剂失活后可以通过二次活化的方式提高其吸附性能,但衰减速度比新改性兰炭要快。二次失活后,在酸蚀刻、水蒸气扩孔等共同作用下致使骨架结构过度烧蚀而坍塌;改性兰炭表面含氧基团的量和构成比例会影响吸附性能。含氧与含碳基团的比值与吸附性能相对应,含氧基团比例越高,吸附性能越差。二次活化再生改变了各含氧基团所占比例,令C=O显著下降,O−C=O显著增加,C−O变化不大。O−C=O官能团尽管含氧,但可能对吸附抑制作用不显著。本研究将为工业烟气治理提供一种新型吸附剂的制备方法,同时也为兰炭表面改性以及二氧化硫吸附解吸机制的研究提供参考。

     

    Abstract: The use of adsorbents such as activated coke to separate pollutants from flue gas is an effective flue gas treatment method. As a cheap carbon material, semi-carbon is a potential porous alternative material to the existing commercial activated coke. In this work, the effects of the carbonization time, carbonization temperature, and binder addition on the properties of prepared adsorbents from Shanxi semi-coke were studied. The microstructure changes were investigated, and the changes in the surface functional groups in the adsorption and desorption process were explored via X-ray photoelectron spectroscopy (XPS). The results show that the carbonization temperature has a significant effect on the wear resistance and compressive strength index, and the carbonization time has a significant effect on the saturated desulfurization value and the breakthrough desulfurization value. In addition, under the conditions of 50% coal tar addition ratio, 700 ℃ carbonization for 20 min, and 900 ℃ activation for 60 min, the modified semi-coke parameters were as follows: abrasion resistance 95.81%, compressive strength 536.1 N·cm−1, saturated desulfurization value per g of semi-carbon is 45.71 mg, and breakthrough desulfurization value per g of semi-carbon is 23.45 mg. When the first failure occurred in the adsorbents after 10 thermal regeneration processes, the activated carbon surface was etched over a large area with severe changes in the surface morphology under the above conditions. Some large granular activated carbons were etched and pulverized into small particles. The activated carbon surface structure was also etched out of pores, which may be caused by the C consumption resulting from the interaction of C and H2SO4. The results also show that the secondary activation could increase the adsorption capacity in a short time, but the activated carbon performance degradation is also significant. The amount and composition ratio of the oxygen-containing groups on the surface of the modified semi-coke affected the adsorption performance. The ratio of oxygen to carbon groups corresponded to the adsorption performance: the higher the proportion of oxygen-containing groups, the worse the adsorption performance. The proportion of oxygen-containing groups was changed by the second activation regeneration, and C=O decreased significantly, O−C=O increased significantly, while C−O changed slightly. Although the O−C=O functional group contains oxygen, it may not significantly inhibit adsorption. This study provides a new adsorbent-preparation method for industrial flue gas treatment and also provides a reference for the research on the surface modification of semi-coke and the adsorption and desorption mechanisms of sulfur dioxide.

     

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