痕量元素在气化产物中分布规律的研究

STUDY ON THE DISTRIBUTION OF TRACE ELEMENTS IN GASIFICATION PRODUCTS

采用氢化物发生器和原子荧光光谱法联用(HG-AFS)和电感耦合等离子发射光谱法(ICP-AES),测定了常压流化床煤气化产物中As、Cd、Co、Cr、Cu、Mn、Mg、Ni、Hg、Pb、V、Se、Sr、Zn 14种痕量元素含量,基于质量平衡原理,得到痕量元素在气化产物中的分布规律.研究结果表明:除Mg之外,几乎所有痕量元素在布袋低温焦中的含量均高于旋风高温焦;As、Hg、V、Se质量平衡率为75%～83%,Co、Cr、Cu、Pb、Sr、Zn质量平衡率为88%～105%,Cd、Mn、Mg、Ni质量平衡率为115%～118%:Hg、Se、As、Co、Cr、Cd、Cu、Zn在煤气中的份额依次减小;除Hg、Se、As外,其它元素在旋风高温焦中份额最大;旋风除尘器和布袋除尘器对Mn、Mg、Ni、Pb、V、Sr的捕集效率接近于除尘效率,对其它元素的捕集效率小于除尘效率,大小顺序为Zn＞(Cd、Cr、Cu)＞(Co、Se、As)＞Hg.布袋除尘器对Zn、Cd、Cr、Cu、Co、Se、As、Hg的捕集效率低于旋风除尘器.

By using HG-AFS and ICP-AES, the contents of 14 trace elements(As、Cd、Co、Cr、Cu、Mn、 Mg 、Ni、Hg、Pb、V、Se、Sr、Zn) in gasification products were measured quantitatively in an atmospheric fluidized bed gasifier. According to the principle of mass balance, the distribution of trace elements in gasification products was studied. The results may be summarized as follows: Most of contents of trace elements in the low temperature coke are larger than those in the high temperature coke (except Mg). The mass balance degrees of As, Hg, V, Se are in 75%-83%, Co, Cr, Cu, Pb, Sr, Zn in 88%-105% and Cd, Mn, Mg, Ni in 115%-118%.The order of percents of trace elements in gas is Hg>Se>As>Co> Cr>Cd>Cu>Zn. The fractions of Cd, Co, Cr, Cu, Mn, Mg, Ni, Pb, V, Sr and Zn in the high temperature coke are larger than those in other gasification products. The removal efficiencies of Mn, Mg, Ni, Pb, V and Sr are nearly equal to those of fine particles in cyclone and bag filter, while other trace elements are less and the order is Zn>(Cd, Cr, Cu)>(Co, Se, As)>Hg. The removal efficiencies of Zn, Cd, Cr, Cu, Co, Se, As and Hg in bag filter are less than those in cyclone.