碱性硫酸铝溶液吸收SO_2试验研究

Experimental study on SO_2 absorption in basic aluminum sulfate solution

试验研究了不同参数碱性硫酸铝溶液和硫酸铝溶液吸收SO_2的过程。结果表明:随着SO_2吸收量的增加,碱性硫酸铝溶液和硫酸铝溶液的pH均呈下降趋势,但碱性硫酸铝溶液中的活性Al3+对溶液的p H下降具有较强的缓冲作用。同参数碱性硫酸铝溶液,无论SO_2吸收量多少,SO_2吸收率均随着吸收液温度的升高而降低,且吸收液温度越高,降低程度越大;当吸收液温度低于50℃,且每升碱性硫酸铝溶液SO_2吸收量不超过5 L时,SO_2吸收率最低也能达到95.18%,吸收效果良好。

The process of SO2 absorption by basic aluminum sulfate solution and aluminum sulfate solution with different parameters was experimentally studied. The results show that, with the increasing SO2 absorption, the pH value of both the basic aluminum sulfate solution and aluminum sulfate solution declined, But the active Al3＋ in the basic aluminum sulfate solution has a strong buffering effect on the pH value＇s drop.In the basic aluminum sulfate solution, SO2 reacted with the active Al3＋ firstly, when the active Al3＋ was exhausted, the gaseous SO2 would dissolve into the water. However, in the basic aluminum sulfate solution, due to the absence of active Al3＋, the gaseous SO2 directly dissolved into the water. Therefore, in the basic aluminum sulfate solution with the same parameters,the SO2 absorption rate decreased with the increasing temperature in absorption liquid, and the reduction degree turned higher when the absorption liquid temperature increased.When the absorption liquid temperature was lower than 50℃ and the SO2 absorption amount in per liter basic aluminum sulfate solution was less than 5 L, the SO2 absorption rate could reach at least 95.18 %, so the absorption effect is good.