Electrochemical membrane process for flue gas desulfurization

✍ Scribed by Dennis J. McHenry; Jack Winnick

• Publisher: American Institute of Chemical Engineers
• Year: 1994
• Tongue: English
• Weight: 845 KB
• Volume: 40
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690400116

✦ Synopsis

A flue gas desulfurization process being developed for coal-fired power plants removes and concentrates sulfur oxides (SO,). The key element is an electrochemical cell using a sulfur oxide selective membrane. It achieves 90% sulfur oxide removal with near 100% electric current efficiency.

Recent research has focused on improving the structure of the electrochemical membrane and its interface with the electrodes. The capillary forces of the membrane and porous electrodes establish an equilibrium. To maintain electrode surface area enhancement, it is necessary to retain the electrolyte in the membrane and allow only wetting of the electrode pores. Chemically-stable matrix materials for the membrane have been identified; several fabrication techniques were used to prepare the actual membrane structure. A new electrode material, (LiO),NiO, possesses the proper chemicalstability and electricalproperties in the corrosive environment. These modifications have led to an order of magnitude increase in flux and operating lifetime.