固定床活性炭脱硫动态传质过程分析

Dynamic mass transfer process of activated carbon desulfurization on fixed bed

对活性炭法烟气脱硫技术中SO2在活性炭催化剂中的传质过程进行分析,提出固定床SO2有效传质速率的概念,并建立相应的数学模型.以微孔扩散动力学方程为依据,对不同类型活性炭的SO2粒内扩散系数和内表面利用率进行了测定.结果表明,微孔型活性炭的SO2粒内扩散系数小于中孔型活性炭;活性炭的SO2粒内扩散系数在水洗脱附条件下降至无水情况时的34%-47%;粒内扩散阻力是活性炭的活性位大量失效的原因;小颗粒活性炭的内表面利用率高于大颗粒活性炭.

The mass transfer process of SO2 about activated carbon desulfurization is analyzed, effective mass transfer velocity of SO2 on fixed bed is proposed and mathematics model is established. Inner diffusivity and inner surface availability coefficient of different kinds of activated carbon are measured according to experiments on the basis of the micro-pore dynamics theory for which can guide parameter calculations of industrial application. Results show that the inner diffusivity of SO2 in micropore-type activated carbon is less than that in middlepore-type activated carbons; inner diffusivities of SO2 drops to 34%-47% when water exists; inner diffusion resistence is the reason why a large number of active sites of activated carbon lose efficacy; inner surface availability coefficients of small particle activated carbon are higher than those of large particle activated carbon.