Electrolytic membrane recovery of bromine from waste hydrogen bromide streams

✍ Scribed by Cary N. Wauters; Jack Winnick

• Publisher: American Institute of Chemical Engineers
• Year: 1998
• Tongue: English
• Weight: 476 KB
• Volume: 44
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690441003

✦ Synopsis

A novel electrochemical process was developed for the recoveiy of bromine from waste gas-phase hydrogen bromide streams. It uses a molten-salt-saturated membrane to electrolytically decompose hydrogen bromide into its molecular constituents, which are separated into a hydrogen-enriched waste stream and a pure bromine product stream. Single-cell studies were carried out in a configuration consisting of two cell housings (vitreous carbon), two gas-difision electrodes (reticulated vitreous carbon or graphite felt), and a molten salt [(Li0,5,5 Ko~~33Cso,292)Br] saturated membrane (zirconia). Single-cell results at 300°C, based on process stream concentrations ranging from 25 to 75% hydrogen bromide at 50 to 300 mL/min, demonstrated current densities exceeding 1 A / c m 2 and removals as high as 95%. Water and acetone (as a light organic contaminant) addition to the process feed, as well as exposure to thermal cycling, showed no deleterious effects on cell performance. Preliminary economics indicate this to be a viable process.