摘要
对Mn2+,Fe2+,Zn2+3种过渡金属离子液相催化氧化低浓度烟气脱硫的效果进行了对比,并对Mn2+液相催化氧化烟气脱硫的相关工艺参数进行了优化;运用溶液化学原理,对SO2及Mn2+在溶液中的组分进行了计算,研究了Mn2+液相催化氧化烟气脱硫的机理.研究结果表明:Mn2+,Fe2+和Zn2+3种过渡金属离子对烟气脱硫都有催化作用,Mn2+的催化效果最佳;在烟气中,当SO2体积分数为1.4%,O2体积分数为10%,烟气流量为140L/h,吸收液体积为200mL,温度为24℃,吸收液pH为5～6及吸收液中Mn2+浓度为0.15mol/L时,经过一段吸收反应,SO2转化率大于80%,烟气脱硫率大于75%;当吸收液pH=5～6时,锰主要以Mn2+形式存在,SO2主要以HSO-3的形成存在;其催化反应的机理为:Mn2+与HSO-3反应形成络合物,成为反应链的引发剂来诱发氧化反应.
The effect of three kinds of transition metal ions Mn2+, Fe2+ and Zn2+ on the liquid catalyzed oxidation desulphurization of flue gas of low SO2 concentration was studied. The optimization of the process parameters of catalyzed oxidation desulphurization by Mn2+ was carried out, which includes volumetric fraction of SO2 and O2, and flow rate of flue gas, pH value , volume and concentration of Mn2+ of absorbent liquid. Based on the aqueous chemistry theory, the composition of SO2 and Mn2+ in aqueous is determined, and the mechanism of Mn2+ catalysis oxidation desulphurization in liquid is demonstrated. The results show that the three ions can all catalyze the desulphurization of flue gas in solutions, but manganese ion is the best. When the flue gas containing(volume fraction) 1.4% SO2 and 10% O2 at 140 L/h flow rate was desulphurized by absorbent solution at pH 5～6 and 0.15 mol/L Mn2+, above 80% of the transformation rate of SO2 into SO3 and 75% of desulphuriation rate were achieved only once. The results of aqueouschemistry calculation reveal that the mainly existing composition of manganese ion and SO2 are Mn2+ and HSO-3, respectively, at pH 56 of absorbent solution. The catalysis mechanism of Mn2+ is that Mn2+ triggers the oxidation of SO2 to occur by forming a complex with HSO-3, which induce a chain of oxidation reactions in the solution.
出处
《中南工业大学学报》
CSCD
北大核心
2003年第5期489-493,共5页
Journal of Central South University of Technology(Natural Science)
基金
全国高等学校优秀青年教师教学科研奖励基金资助项目(教人司2000 26)
关键词
二氧化硫烟气
过渡金属离子
液相催化氧化脱硫
环境保护
flue gas of SO_2 concentration
transition metal ions
liquid catalyzed oxidation desulphurization
environment protection
