Concentrating Aqueous Solution of Sulfuric Acid and Phosphoric Acid by Multiple-Effect Membrane Distillation
LI Xiao-Jun1, QIN Ying-Jie1, LIU Rong-Ling1, CUI Dong-Sheng2, LIU Li-Qiang2
1. School of Chemical Engineering and Technology, Tianjin University, Tianjin 300072, China;
2. Chembrane Engingeering and Technology, Inc., Tianjin 300308, China
Abstract：
Multipleeffect membrane distillation (MEMD) was used to concentrate dilute aqueous solution of sulfuric acid or phosphoric acid by using selfmade membrane module containing both micropous hydrophobic hollow fibers and densewall hollow fibers. Effects of heated feedin temperature, feedin flow rate and feedin concentration on the MEMD performance were experimentally investigated. The experimental results demonstrated that permeation flux and performance ratio increased with the increase of heated feedin temperature; permeation flux increased with the increase of feedin flow rate, while performance ratio decreased at the same time; permeation flux and performance ratio decreased with the increase of feedin concentration. Compared with phosphoric acid, the effects of the concentration of sulfuric acid on the performance of MEMD process were more evident. The maximum permeation flux and performance ratio were 5.3 L/(m2·h) and 11.5, respectively. Aqueous solution of sulfuric acid or phosphoric acid of 2 wt% could be concentrated to 40 wt% or above, while the electrical conductivity of the permeate was still less than 200 μS/cm. By using two AGMD modules, a long-term operational stability of the MEMD process was investigated using aqueous solution of 10% sulfuric acid solution as feed. The MEMD process showed excellent operation stability in a longterm test lasting for 30 days.
LI Xiao-Jun, QIN Ying-Jie, LIU Rong-Ling, CUI Dong-Sheng, LIU Li-Qiang.Concentrating Aqueous Solution of Sulfuric Acid and Phosphoric Acid by Multiple-Effect Membrane Distillation[J]. Chemcial Industry and Engineering, 2013,30(4): 55-62
2013, Vol. 30 
