Bench-scale experimental evaluation of carbon performance on mercury vapour adsorption
Bench-scale experimental evaluation of carbon performance on mercury vapour adsorption
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DOI：
10.1016/j.fuel.2004.06.031
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发表时间：
2004-12
期刊：
影响因子：
7.4
通讯作者：
R. Yan;D. T. Liang;L. Tsen;Yeh Ping Wong;Yong Kian Lee
中科院分区：
文献类型：
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作者：
R. Yan;D. T. Liang;L. Tsen;Yeh Ping Wong;Yong Kian Lee
由于汞的毒性和高挥发性，燃烧烟气中的汞排放是一个重大的环境问题。对于蒸气中的元素汞（Hg0）来说，这一问题尤为严重，因为使用目前的空气污染控制装置无法有效地将其去除。活性炭吸附是一种在控制气相汞排放方面具有巨大潜力的技术。本文概述了一个实验室规模的固定床进行的参数研究的结果，对使用活性炭从模拟烟气中捕获痕量汞蒸气。评价了五种市售活性炭对汞的吸附性能。研究的参数包括碳负载，反应温度，入口汞浓度，和AC的颗粒尺寸。利用BET、SEM、XRF和XRD对五种炭的物理性质进行了全面的筛选，有助于更好地理解吸附的本质。实验数据表明，汞的吸附在很大程度上取决于操作条件。对于硫浸渍碳，吸附涉及物理和化学过程。随着温度的升高，物理吸附由于膨胀吸附过程的性质而降低，而化学吸附可能会增强，这可以通过碳在较高温度下的更好性能来证明。AC的外表面积对AC的高性能具有显著贡献。该研究为在广泛的条件下筛选用于处理实际烟气中气态汞的商业候选炭提供了很好的参考。
Mercury emission in combustion flue gases is a significant environmental concern due to its toxicity and high volatility. The problem is particularly severe for elemental mercury (Hg0) in vapour since it cannot be effectively removed using current air pollution control devices. Activated carbon (AC) adsorption is a technology that offers a great potential for the control of gas-phase mercury emissions. This paper outlines the results of a parametric study conducted with a bench-scale fixed bed, on the capture of trace mercury vapour from simulated flue gas using ACs. The performances of five commercially available ACs, which are claimed to be effective sorbents of mercury, are evaluated. The parameters investigated include carbon loading, reaction temperature, inlet mercury concentration, and particle size of ACs. A full screening of the physical properties of the five carbons using BET, SEM, XRF, and XRD, facilitates a better understanding to the nature of adsorption. The experimental data suggest that the adsorption of mercury is greatly dependent upon the operation conditions. For sulphur-impregnated carbon, adsorption involves both physical and chemical processes. With increasing temperature, physical adsorption decreases due to the nature of exothermal adsorption process whilst chemisorption might be enhanced, evidenced by the better performance of carbon at a higher temperature. The external surface area of AC has a significant contribution to the high performance of ACs. This study provides a good reference for screening the commercial carbon candidates to be used for treating vapour Hg in the actual exhausted flue gas over a wide range of conditions.