Current methods for bromine production use chlorine to oxidize bromide to bromine. The principal processing steps follow:
- Oxidize bromide to bromine.
- Strip bromine from the aqueous solution.
- Separate the bromine from the resulting vapour.
- Purify the bromine.
At SBPL, Steaming-Out Process will be used wherein the current process used for producing bromine from bromide containing brines (5 gpl Br–). It consists of simultaneous chlorination and steam blowing. The brine is preheated, usually to 75°–80°C, before its introduction into the reaction column, and then heated inside the tower by live steam to near boiling. The bromine is steam-distilled as it is being set free by the chlorine. The distillation steam is a small fraction of the live steam supplied to heat the brine. The steaming-out process requires heating the brine to near boiling and reducing the partial pressure of bromine (and chlorobromide) in the effluent brine to nearly zero to improve the stripping of the bromine from the brine.
The advantage in the steaming-out process is that bromine is condensed directly from the steam, as opposed to the air blowing out process, in which the bromine is trapped in an alkaline or reducing solution to concentrate it.