Study On The Separation Of Bromine-Water By Pervaporation Technology

In recent year, more and more demand of bromine was occurred with the development of industrial. The current domestic production of bromine still can not meet industrial demand. Meanwhile, there existed some disadvantages in the bromine industrial production such as high-energy consumption, high cost and low production, etc. Based on the advantages of pervaporation, such as high separation efficiency, low-energy consumption and sample device, etc., the separation of bromine-water mixture by pervaporation technology was studied in this paper.Firstly, due to swelling degree principles, the polyurethane (PU) was employed to prepare different types flat membranes. These according to the characterization of the surface and section morphologic structures and composition of membranes were characterized by Scanning Electron Microscope (SEM) and Fourier Transform Infrared Spectroscopy (FTIR), which was shown dense and-NHCOO-containing membranes.Secondly, the swelling properties of different PU membranes in bromine-water system were studied. According to the swelling degree curves produced in qualitative experiment, the separation performances of membranes were researched, and the type-6190x and type-6190y PU membranes, in which the PU concentration were10%and15%, respectively, were selected to participate in the subsequent quantitative experiment.Then, the pervaporation performance and relationship between separation factor, permeation flux and feed concentration of type-6190x and type-6190y PU membranes in the separation of bromine-water by pervaporation were studied. The feed concentrations were100mg/l～400mg/l and3g/l～14g/l at25℃and100ml/min feed flow rate. The results showed that the permeation flux and separation factor increased with increasing feed concentration when the bromine concentration in bromine-water was in100mg/l～400mg/l; and when it was in3g/l-14g/l, there was a slight increase in permeation flux with increasing feed concentration, but the separation factor increased firstly and then decreased with increasing feed concentration. In addition, it showed that10%type-6190x PU membrane had better comprehensive separation property.Finally, based on the solution-diffusion model, a mathematical model of transfer process in the separation of bromine-water mixture by pervaporation using PU membranes was established to study the theoretical relationship between separation factor, permeation flux and concentration. The results of simulation were identical with the experiments.