PROCESS FOR PRODUCING BROMINE FROM SEAWATER

摘要

This invention is a combination process for producing elemental bromine using a seawater feed. The process involves a series of steps in which seawater is acidified, chlorinated, and air stripped to remove the bromine. The stripping effluent is reacted with an SO2 stream to convert the bromine to hydrogen bromine and H2SO4 in the air stream. The process continues by absorbing hydrogen bromide and H2SO4 from the resulting acidic fog to produce an aqueous H2SO4 stream containing HBr. The HBr is stripped from the liquid stream and passed to an oxidation reactor where it is catalytically oxidized with an oxygen-containing gas to produce a stream of Br2 and H2O. The hot reactor effluent is quenched and the product Br2 is separated from the H2O and inert gases such as air. In the figure 2 seawater enters pipeline (202) and is mixed with an H2SO4 stream (200). The resulting stream (214) is sent to a stripping column (218) where air stream (216) strips the bromine from the liquid. The vapor B22 stream (222) is mixed with SO2 (224) which is contacted with a water stream. The resulting aqueous H2SO4/HBr stream (236) is heated and mixed with a chlorine stream (240). A portion of the chlorine is introduced through line (241) to the bottom of stripping column (242) and separates with stream (244) into stream (246) containing H2O4 and HCl separates with stream (244) into stream (246) containing H2SO4 and HCl and stream (248) containing Br2. The Br2 product (260) is discharged from decanter (254) into the purification unit (255).