超重力旋转填料床中柠檬酸钠法脱除低浓度SO_2

在超重力旋转填料床中以柠檬酸-柠檬酸钠缓冲溶液为吸收液进行模拟烟气中SO2吸收的实验。考察了超重力因子(β)、液气比(L/m3)、入口烟气中SO2质量浓度、气体流量、吸收液中柠檬酸浓度、pH值等对SO2脱除率(η)和气相传质系数(KGa)的影响。实验结果表明,η和KGa随超重力因子、液气比(L/m3)、吸收液中柠檬酸浓度和pH的增加而增加,随入口烟气中SO2浓度的增加先增大后降低,随气体流量的增加而降低。采用超重力旋转填料床用柠檬酸-柠檬酸钠缓冲溶液吸收SO2的最佳工艺条件是:吸收液中柠檬酸浓度1.0mol/L,初始pH 4~5,液气比3L/m3~7L/m3,超重力因子54.53~90.14。在此条件下,出口气体中SO2质量浓度低于80mg/m3,η稳定在98%左右。

Removal of low concentration sulfur dioxide from flue gas by sodium citrate solution scrubbing in high-gravity rotating packed bed

The absorption of SO2 in simulated-flue gas in the citrate-sodium citrate buffer solution in a rotating packed bed was studied.The influences of high gravity factor,liquid/gas ratio,citrate concentration and initial pH of the scrubbing solution,gas flow rate and mass concentration of SO2 in feed gas on SO2 removal efficiency(η) and mass transfer coefficient(KGa) were investigated.Results showed that η and KGa increased with the increase of high gravity factor,liquid/gas ratio,citrate concentration and initial pH of the scrubbing solution,increased firstly and then decreased with the increase of the concentration of SO2 in feed gas,but decreased with the increase of gas flow rate.The optimum experimental conditions were citrate concentration of 1.0mol/L,absorption solution initial pH value of 4 to 5,high gravity factor of 54.53 to 90.14,liquid/gas ratio of 3L/m3 to 7L/m3.Under the optimized experimental conditions,SO2 concentration of exit gas was reduced to below 80 mg/m3,and η could reach around 98%.