水蒸气和α-Fe2O3对铈改性半焦脱除单质汞的影响研究

赵可; 牛庆欣; 王力; 张华伟

水蒸气和α-Fe₂O₃对铈改性半焦脱除单质汞的影响研究

山东科技大学化学与环境工程学院, 山东青岛 266590

基金项目:

国家自然科学基金 51406107

国家自然科学基金 21276146

山东省杰出青年基金 JQ201612

详细信息

通讯作者:
张华伟, E-mail:sdkdzhw@163.com

中图分类号: TQ534.9
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- 文章访问数: 97
- HTML全文浏览量: 38
- PDF下载量: 6
- 被引次数: 0
出版历程
- 收稿日期: 2016-12-13
- 修回日期: 2017-01-10
- 网络出版日期: 2021-01-23
- 刊出日期: 2017-03-10

Effect of water vapor and α-Fe₂O₃ on elemental mercury removal performance over cerium oxide modified semi coke

College of Chemical and Environmental Engineering, Shandong University of Science and Technology, Qingdao 266590, China

Funds:

the Natural Science Foundation of China 51406107

the Natural Science Foundation of China 21276146

Shandong Fund for Distinguished Young Scholars JQ201612

摘要

摘要: 采用浸渍法制备了铈改性半焦吸附剂（Ce/SC），在小型固定床反应器上考察了水蒸气和α-Fe₂O₃对Ce/SC脱除Hg⁰性能的影响，并利用X射线衍射、H₂程序升温还原、X射线光电子能谱等分析手段对其机理进行了探究。结果表明，水蒸气会明显抑制Ce/SC对单质汞的脱除效率，原因是H₂O分子在活性组分CeO₂表面发生解离，部分晶格氧转化成Ce-OH官能团，从而导致其氧化活性的降低；α-Fe₂O₃的加入对Ce/SC的脱汞性能无显著影响；当水蒸气和α-Fe₂O₃同时存在时，Ce/SC的脱汞效率虽然有所降低，但是其降低幅度明显低于水蒸气单独作用时的情况，这主要是因为水蒸气与α-Fe₂O₃作用增加了其表面化学吸附氧的含量，提高了α-Fe₂O₃的氧化活性，促进单质汞的氧化和脱除。
- 水蒸气 /
- Fe₂O₃ /
- 改性半焦 /
- 单质汞
Abstract: Cerium modified semi coke adsorbent (Ce/SC) was prepared by impregnation method and a bench-scale fixed bed reactor was used to study the effect of H₂O vapor and α-Fe₂O₃ on elemental mercury removal efficiency over Ce/SC. Characterizations of X-ray powder diffraction (XRD), Hydrogen temperature programmed reduction (H₂-TPR), and X-ray photoelectron spectroscopy (XPS) were conducted to investigate the mechanism of elemental mercury removal.The adsorption results showed that H₂O had a negative effect on the oxidation activity of the adsorbent. H₂O can be dissociated on the surface of CeO₂ with partial lattice oxygen transformation into Ce-OH functional groups which led to the decrease of its oxidation activity and thus resulted in the inhibitory effect of mercury removal efficiency. The addition of α-Fe₂O₃ had no significant effect on mercury removal over Ce/SC. The mercury removal efficiency of Ce/SC was decreased when the water vapor and α-Fe₂O₃ existed simultaneously. However, the decrease rate was much lower than that of water vapor conditions alone mainly due to the interaction between water vapor and α-Fe₂O₃ increased the content of the surface chemical adsorbed oxygen and thus the oxidation activity and elemental mercury removal performance of Fe₂O₃were promoted.
- water vapor /
- Fe₂O₃ /
- modified semi coke /
- elemental mercury

HTML全文

图 1 单质汞吸附实验装置示意图

Figure 1 Experimental device for the adsorption of elemental mercury

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图 2 水蒸气对Ce/SC脱汞性能的影响

Figure 2 Effect of water vapor on the adsorption of elemental mercury performance over Ce/SC

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图 3 水蒸气对SC和CeO₂脱汞性能的影响

Figure 3 Effect of water vapor on adsorption of elemental mercury performance over SC and CeO₂

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图 4 SC、Ce/SC和Ce/SC+10%H₂O的XRD谱图

Figure 4 XRD spectra of SC, Ce/SC and Ce/SC+10%H₂O

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图 5 CeO₂和CeO₂+10%H₂O的H₂-TPR谱图

Figure 5 H₂-TPR spectra of CeO₂ and CeO₂+10%H₂O

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图 6 CeO₂和CeO₂+10%H₂O的O 1s XPS谱图

Figure 6 O 1s XPS spectra of CeO₂ and CeO₂+10%H₂O

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图 7 水蒸气和α-Fe₂O₃对Ce/SC脱汞性能的影响

Figure 7 Effect of water vapor and α-Fe₂O₃ on adsorption of elemental mercury performance by Ce/SC

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图 8 水蒸气对α-Fe₂O₃脱汞性能的影响

Figure 8 Effect of water vapor on adsorption of elemental mercury performance by α-Fe₂O₃

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图 9 水蒸气处理前后α-Fe₂O₃的XRD谱图

Figure 9 XRD spectra of α-Fe₂O₃ before and after water vapor treatment

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图 10 水蒸气处理前后α-Fe₂O₃的H₂-TPR谱图

Figure 10 H₂-TPR spectra of α-Fe₂O₃ before and after water vapor treatment

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图 11 水蒸气处理前后α-Fe₂O₃的O 1s XPS谱图

Figure 11 O 1s XPS spectra of α-Fe₂O₃ before and after water vapor treatment

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表 1 CeO₂和CeO₂+10%H₂O样品中各种形态O的相对含量

Table 1 Relative contents of O in different forms of CeO₂ and CeO₂+10%H₂O

Sample	Relative content w/%
Sample	Ce-OH	H₂O	O^2-
Pure CeO₂	20.85	10.94	68.21
CeO₂+10%H₂O	39.99	14.18	45.83

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表 2 水蒸气处理前后α-Fe₂O₃中各种形态O的相对含量

Table 2 Relative contents of O in different forms of α-Fe₂O₃ before and after water vapor treatment

Sample	Relative content w/%
Sample	O_β	O_α	O_γ
Fe₂O₃-0%H₂O	23.84	32.07	44.09
Fe₂O₃-10%H₂O	44.06	19.72	36.22

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