SYSTEMS AND METHODS FOR MEMBRANE-FREE ELECTROLYSIS

摘要

A system for treatment of brines includes one or more membrane-less electrolyzers. An influent flow chamber flows an influent stream to a porous anode and cathode. electrochemical reactions at the anode and cathode result in acidic and alkaline effluent streams respectively, including liquid and gaseous streams. The alkaline effluent can be combined with a brine feed stream, resulting in precipitation of alkali earth metals cations by reaction with hydroxyls to form alkali earth metal hydroxides (M(OH)2, M=Mg2+, Ca2+). These M(OH)2 are of interest as a carbon-free feedstock material for cement manufacturing. Additionally, carbon dioxide, such as from flue gas, can be combined with the alkaline effluent to form alkali earth metal carbonates or be concentrated and released upon neutralization of carbon dioxide saturated alkaline effluent with the acidic effluent. Chlorine gas evolved at the anode can also be utilized with hydrogen gas evolved at the cathode as feed streams for a fuel cell for the generation of electricity.