Simultaneous particulates, NO(sub x), SO(sub x) removal from flue gas by all solid-state electrochemical technology. Final report, July 15, 1987-January 31, 1990.

摘要

The process control SO(sub x), NO(sub x), and particulate emission from coal combustion flue gases. It is based on a solid-state, electrochemical reactor which converts NO(sub x) and SO(sub 2) to nitrogen, sulfur, and oxygen. Sulfur is condensed downstream at a lower temperature. Particulates are removed with a filter or electrostatic precipitator. The process utilizes no other material input (flue gas is the only fluid), has no moving parts, and produces no sludge(s). The reactor consists of an electrochemical cell where the electrolyte is a solid oxygen ion conducting ceramic such as stabilized ceria or zirconia and the electrodes are electronically conductive material(s). Porous metal such as silver or gold were used as electrodes in the experimental work. Acceptable reduction rates and electric power requirements for sulfur dioxide and nitrogen oxide removal were obtained in up to 1% oxygen with ruthenium and strontium ruthenate electrocatalysts. Electrocatalytic improvements are needed for higher oxygen concentrations, with the NO reduction rates and efficiencies being most sensitive to oxygen concentration. The best electrocatalysts were ruthenium and the perovskite strontium ruthenate. 37 refs., 23 figs., 26 tabs.