Bromine and Bromine compounds
Bromine was discovered by Ballard in 1820.
The French Academy picked the name bromine from the Greek word Bromos, which means: stinks.
The first use of bromine was in 1840 to produce AgBr for use as the active component in photography films.
Bromine is widespread in nature in rocks, but in low concentrations (Under 10 ppm). Slow leaching of bromine from rocks is the source of bromine in seas and lakes.
It is believed that the important purple die in biblical times that was extracted from certain snails was a bromine compound of indigo.
Bromine serves some, undiscovered yet function, in human physiology.
Bromides used to serve as sedatives,before the invention of Prozac.
Patients of schizophrenia have a greater than average concentration of bromine in their brains and in their blood.
The first commercial production of Bromine was at Germany, in 1865, from concentrated effluent brines of a potash plant.
Production
Most of the world bromine production is by three companies:
-Great Lakes Chemical (Now Chemtura)
-Albemarle in the USA.
-The Bromine Co in Israel.
-The Dow company which was the first bromine producer and had beenthe the largest producer of bromine in the world is currently only a minor producer.
The production methods typically have the following stages:
-Oxidizing the bromides in the feed brine to bromine, usually by chlorine.
-Vaporizing the bromine from the brine by air or steam.
-Condensation of the bromine, or direct reactions of the bromine vapor to bromides.
-Purification, if required.
Generally a chlorine production plant is physically close to a bromine plant.
Chlorine is produced, together with NaOH and hydrogen by electrolysis of purified NaCl solutions, in three types of plants:
-Diaphragm plants.
-Mercury plants.
-Membrane plants (Which are currently the preferred type)
Transport of bromine
Bromine is extremely poisonous and corrosive and has stringent rules of transport
The usual transport vessels are by steel vessels coated with lead.
Exports of bromine from Israel are by iso containers – special vessels of 14 tons or by glass bottles of 1 liter (About 3 kg).
Uses
The more important uses are:
-Ethylene di-bromide used with lead additive to gasoline, as an anti knock agent (Prohibited currently).
-Methyl bromide, the most important soil fumigant, which is gradually reduced in use due to World Health Organization rules, but no worthy substitute has sofar been found.
-Calcium bromide, as a high density component of oil drilling mud.
-Hydrobromic acid.
-Flame retardants (The fastest growing market).
About 150 bromine compounds are produced and sold. Production methods are, in most case, very simple: reactions of HBr with a base, or simple reaction of bromine with an organic compound, generally in batch reactors. For large volume production continuous processes are used.