湿法脱硫工艺对烟气中二价汞吸收特性的模拟研究

Simulation Study on Absorption of Divalent Mercury in Flue Gas by Wet-Flue-Gas Desulfurization Process

利用湿法脱硫模拟实验装置,研究脱硫剂(CaO)、有机硫化物(TMT-15)以及不同实验因素(包括SO32-的浓度、反应温度、初始pH值、曝气条件中的O2浓度、初始Hg2+浓度以及Cl-的浓度)对溶液中Hg2+还原过程的影响。研究表明:CaO会抑制Hg2+向Hg0的还原转化,当CaO的加入量从0.3%增至0.7%时,Hg0的释放率会由51.6%降至19.9%;TMT-15对于Hg2+的还原具有明显的影响,TMT-15加入量从0增至0.06 mg/L时,Hg0的释放率可降低10倍左右;溶液中SO32-的浓度是Hg2+还原反应的主要影响因素之一,SO32-浓度的增加会明显促进Hg2+的还原;此外,温度和初始Hg2+的增加对Hg2+的还原亦具有促进作用,而初始pH值、O2百分含量以及Cl-浓度则对Hg2+的还原具有抑制作用。

This paper describes a simulation experiment using a bench-scale wet-flue-gas desulfurization device on which Hg2＋ reduction of flue gas affected by the factors were studied including CaO concentration,organic sulfide of TMT-15,SO32-,O2,reaction temperature and pH.It was found CaO apparently inhibited reduction of Hg2＋ decreasing the release rate of Hg0,and increase of TMT-15 concentration also declined the release rate of Hg0;on the other hand,the addition of SO32-would remarkably boost Hg2＋ reduction.Additionally,raising temperature and initial concentration of Hg2＋ promoted its reduction,while factors such as pH,concentrations of O2 and Cl-when increased would obviously hinder Hg2＋ reduction.