减压膜蒸馏法处理MDEA脱硫液的试验研究

Experimental Study on Treatment of MDEA Desulfurization Solution by Vacuum Membrane Distillation

选用聚丙烯(PP)中空纤维膜组件为再生器,以吸收了SO2的甲基二乙醇胺(MDEA)富液为研究对象,引用分离因子分析SO2的分离效果,分别考察富液流速、温度、初始SO2浓度及膜两侧真空度对聚丙烯(PP)中空纤维膜分离因子以及脱硫率的影响,并确定最佳工艺参数。实验得出了分离因子随温度、真空度增大而减小,流速以及初始SO2浓度对分离因子影响不大;减压膜蒸馏再生MDEA脱SO2富液的最佳工艺参数为:温度60℃,进料流速250 mL/min,冷侧真空度为60 kPa,初始SO2浓度为0.1 mol/L,在该工艺下脱硫率可达92%以上。实验结束后对减压膜蒸馏实验的膜组件进行清洗,清洗过程完成后,考察膜通量的恢复率,平均膜通量恢复率在75%以上。

Polypropylene(PP)hollow fiber membrane module was used as regenerator,and methyl diethanolamine(MDEA)rich liquid absorbed SO2 was taken as the research object.The separation effect of SO2 was analyzed by using separation factor analysis.The effects of liquid flow rate,temperature,initial SO2 concentration,the vacuum degree on the separation factors of polypropylene(PP)hollow fiber membrane and the effect of desulfurization rate were investigated,and the best process parameters were determined.The experimental results show that the separation factor decreases with the increase of temperature and vacuum,and the flow rate and initial SO2 concentration have little effect on the separation factor.The optimum technological parameters of MDEA desulfurization rich liquor regeneration by vacuum membrane distillation are as follows:temperature 60℃,feed flow rate 250mL/min,cold side vacuum 60 kPa,initial SO2 concentration 0.1 mol/L.The sulphur rate can be over 92%.After the experiment,the membrane module of vacuum membrane distillation was cleaned.After the cleaning process was completed,the recovery rate of pure water membrane flux was investigated.The average recovery rate of membrane flux was more than 75%.