减压膜蒸馏浓缩脱硫液试验研究

Study on Concentration of Desulfurization Solution by Vacuum Membrane Distillation

采用减压膜蒸馏(VMD)技术浓缩脱硫液,研究了减压膜蒸馏过程中脱硫液浓度、流速、热侧料液温度、冷侧真空度及膜组件装实密度对膜通量和截留率的影响。试验结果表明:当脱硫液浓度较低时,膜通量随脱硫液浓度的升高而下降缓慢,当脱硫液浓度较高时,膜通量随脱硫液浓度的升高呈抛物线式下降;随着热侧料液流速的增加,膜通量略有增加;热侧料液温度升高,膜通量线性增加;随着冷侧真空度的增加,膜通量先略有增加,当冷侧真空度超过一临界值时,膜通量显著增加;膜通量随着组件内膜丝数目的增加而线性减少;试验过程中截留率保持在99.0%以上,表明聚偏氟乙烯(PVDF)中空纤维膜具有良好的疏水性。

The concentration of desulfurization solution by vacuum membrane distillation was studied. The effects of concentration and flow rate of the feed, heat-side temperature, cold-side vacuum and membrane loading component density on the membrane flux and rejection rate were investigated. The ex- perimental results showed that the membrane flux decreased with the increase of the feed concentration, the flux decreased less at low feed concentration, but decreased in a parabolic manner at high feed concentration. The membrane flux increased slightly with the increase of the feed flow rate. When the heatside temperature increased, the membrane flux increased linearly. With the increase of the cold-side vacuum, the membrane flux increased very slowly at low cold-side vacuum, but when the vacuum was larger than a critical value, the flux increased significantly. The membrane flux decreased linearly with the increase of the membrane loading component density. The rejection rate of desulfurization solution was more than 99.0% in the experimental process which showed that the PVDF hollow fiber membrane had good hydrophobicity.