Dow process

The Dow process is the electrolytic method of bromine extraction from brine, and was Herbert Henry Dow's second revolutionary process for generating bromine commercially.

Before Dow got into the bromine business, bromine-rich brine was evaporated by heating with wood scraps and then crystallized sodium chloride was removed. An oxidizing agent was added, and bromine was formed in the solution. Then bromine was distilled. This was a very complicated and costly process.

His first process involved eliminating the heating. First he oxidized the bromine with a bleaching agent, then dripped it onto burlap, and blew air under the burlap. The air had bromine gas, which was then reacted with iron (or alkalis) producing ferrous bromide.

He then became the first to use an electrolytic method of extracting bromine from brine in a commercial process. He used a 15-volt generator powered by a steam engine.