| AbstractThe development and research on the technologies of extracting bromine from brine were summarized in this paper.Technology feature and production status of domestic main technology of extracting bromine from brine—the sour method of the air stripping bromine were analyzed and problem existing in blow-out process were indicated.One was the lower stripping rate and higher energy consumption in lower bromine level which caused wasting of resources,and the other was that the stripping rate had made a breakthrough hardly when the gas-liquid ratio was more than 120m3/m3.On the above of this,the idea of enhancing blow-out process by high gravity technology in the view of interphase mass-transfer was put forward first.Higher mass-transfer and lower bed pressure drop of Rotating Packed Bed(RPB) increased stripping rate and decreased energy consumption.Simulated experiment was carried out with air and Br2—H2O system,free bromine was blown out from stimulant oxidized liquid in ambient temperature and pressure.The mathematical model for mass-transfer of air stripping free bromine was established.The results showed that it was an efficient mass transfer equipment,and liquid volumetric mass transfer coefficient Kxa was 0.1238 s-1,170 times larger than that of tower.Non-dimensional equation of Kxa was established,and the accuracy of the model was proved after the experimental data was analyzed.In this paper,experiments on the stripping rate of free bromine were carried out under different high gravity factor,gas flow rate,liquid flow rate,pH value,and total bromine concentration of oxidized liquid.The test results showed that single stage stripping rate of total bromine concentration with 150mg/L and 450mg/L were about 78.3%and 91% respectively under the feasible operation parameters:gas to liquid ratio 120m3/m3,pH value 3.5,high gravity factor 42.46.After three stage stripping,total stripping rate of them were about 81.27%and 95.3%respectively.The single stage stripping rate of total bromine concentration with 2000mg/L was 94.5%.High gravity technology was more beneficial to increasing stripping rate of higher concentration oxidized liquid.Compared with tower,stripping rate still had enhancement space in RPB when gas to liquid ratio over 120m3/ m3.At the same gas to liquid ratio,gas resistance in RPB was much lower than tower,total pressure of ventilator and investment cost decreased.Energy consumption of liquid conveyer reduced,for its height was about one fifth to tenth of tower. Wide operation flexibility,small occupation,lower cost,easy installation and maintenance, easy industrial experimentation were beneficial to distributed brine and new production line.
|
PDF Full Text Request