摘要
以钢铁厂废弃钢渣为原料,以丙酮溶液为分散剂制备FeCl_3改性材料,在固定床吸附评价装置上考察了钢渣在FeCl_3改性前后对模拟烟气中Hg脱除效果的影响,并结合吸附试验与微观表征对改性催化剂的脱汞性能进行分析.结果表明:氯是FeCl_3改性钢渣吸附剂的主要活性组分,FeCl_3的掺入使钢渣的比表面积由1.06 m^2/g提高到1.32 m^2/g,进而提高吸附剂的汞吸附容量,经FeCl_3改性后废弃钢渣对汞的脱除效率比未改性前提升了3.2倍.SO_2的存在降低了FeCl_3改性钢渣材料的脱汞性能,持续通入的SO_2与吸附剂接触占据了部分孔道和表面活性位点,使得对单质汞的吸附效率下降,200℃时含有SO_2时的FeCl_3改性钢渣吸附剂吸附量比未通入SO_2气体的改性材料降低了75.57%;在含有HCl气体的烟气体系中,FeCl_3改性钢渣材料对汞的脱除效率从3 432.70 ng/g升至10 341.10 ng/g,并且随着反应温度的升高零价汞向氧化态汞转化的效率增加.研究显示,SO_2的存在降低了FeCl_3改性钢渣吸附剂的脱汞性能,而HCl气体有效地促进了FeCl_3改性钢渣吸附剂对零价汞(Hg^0)的脱除.
An FeCl3 modified material was prepared by acetone solution and steel slag from a steel plant. The effect of FeCl3 modification on Hg^0 removal of materials in the simulated flue gas was investigated in a fixed bed adsorption device. From the adsorption experiment and characterization results,it was found that Cl was responsible for mercury adsorption and oxidation. The doping of FeCl3 not only could increase the BET specific surface area of the sorbent from 1. 06 to 1. 32 m^2/g,but also enhance the reducibility of the sorbent,which might benefit the mercury adsorption and oxidation on sorbent surface（the mercury removal efficiency increased 3. 2 times after FeCl3modification）. The presence of SO2 decreased the mercury removal efficiency of FeCl3 modified steel slag material,which was due to the continuous access of SO2. During the reaction,a lot of SO2 occupied part of tunnel and surface active sites of the catalyst,which resulted in the reduction of mercury adsorption efficiency. At 200 ℃,the adsorption capacity of FeCl3 modified adsorbent in SO2-containing gases decreased 75. 57% times compared to that in SO2-free gases. In contrast,the presence of HCl gas promoted the adsorption performance of FeCl3 modified steel slag material. Furthermore,the conversion efficiency of zero-valent mercury to oxidation state increased with the increase of reaction temperature. Above all,the existence of SO2 decreased the mercury removal efficiency of FeCl3 modified adsorbent,while HCl gas promoted the removal efficiency of zero-valent mercury（Hg^0） effectively.
出处
《环境科学研究》
EI
CAS
CSCD
北大核心
2017年第3期450-456,共7页
Research of Environmental Sciences
基金
国家高技术研究发展计划(863)项目(2013AA065001)
2013年度国家环境保护公益性行业科研专项(201309018)
关键词
汞
钢渣
FeCl3改性
燃煤烟气
吸附剂
mercury
steel slag
FeCl3 modification
coal-fired flue gas
adsorbent
