Hydrobromic acid is an aqueous solution of hydrogen bromide and a strong acid. The concentration of saturated hydrobromic acid at room temperature is 68.85% (mass ratio).

Hydrobromic acid is an aqueous solution of hydrogen bromide with a pKa of −9. It is more acidic than hydrochloric acid but weaker than hydroiodic acid. It is one of the strongest inorganic acids.

Product uses

Hydrobromic acid is mainly used to produce inorganic bromides, remove alcohol salts and phenol salts, replace hydroxyl groups in substitution reactions, and add to olefins. It can also catalyze mineral extraction and certain alkylation reactions.

Recycling and utilization

The organic chemical industry produces a large amount of hydrobromic acid waste liquid while producing organic bromides. On the one hand, the waste liquid has a complex composition and is difficult to handle; on the other hand, direct discharge seriously pollutes the environment. Part of it is used to prepare dodecane bromide, but the effect is not ideal. The commonly used preparation methods for dodecane bromide are: hydrogen bromide gas method, red phosphorus bromination method, concentrated sulfuric acid/hydrobromic acid method, and hydrobromic acid/solid superacid catalysis method. Among them, the concentrated sulfuric acid/hydrobromic acid method is a more ideal method for synthesizing brominated alkanes. From the perspective of industrial synthesis, the less hydrobromic acid is used, the better, in order to reduce the pressure of wastewater treatment and reduce production costs. In addition, the higher the conversion rate, the better, because dodecanol is easily emulsified, resulting in difficulty in separation. Through a large number of experimental studies, it was found that the use of tetrabutylammonium bromide as a phase transfer catalyst for the preparation of dodecane bromide greatly accelerated the conversion rate of hydrobromic acid and greatly improved the yield.