Decomposition of N-nitrosamines formed in CO2 capture systems through electrochemically-mediated reduction on carbon xerogel electrode

Abstract

N-nitrosamines, as a class of compounds, have been reported to be mutagenic, cytotoxic, genotoxic and carcinogenic. N-nitrosamine formation and emission are a major concern for amine-based CO2 capture systems. A process using a stationary carbon electrode inside an electrochemical cell was developed and tested in this study to adsorb and decompose two N-nitrosamines, N-nitrosopyrrolidine and N-nitrosodiethylamine, from an aqueous amine solution. The carbon xerogel electrode material has a high N-nitrosamine adsorption capacity and can initiate an electrochemically-mediated reduction of N-nitrosamines to a secondary amine. A greater than 80% reduction of N-nitrosodiethylamine and 90% of N-nitrosopyrrolidine was observed from a simulated amine-based waterwash solution using an applied current up to 300 mA. N-nitrosamine decomposition was effective in solutions with relatively high amine or salt concentrations.