Tertiary Amine-Ethylene Glycol Based Tandem CO Capture and Hydrogenation to Methanol: Direct Utilization of Post-Combustion CO.

Carbon dioxide capture using tertiary amines in ethylene glycol solvent was performed under ambient conditions. Subsequently, the CO captured as alkyl carbonate salts was successfully hydrogenated to methanol, in the presence of H gas and Ru-Macho-BH catalyst. A comprehensive series of tertiary amines were selected for the integrated capture and conversion process. While most of these amines were effective for CO capture, tetramethylethylenediamine (TMEDA) and tetramethylbutanediamine (TMBDA) provided the best CH OH yields. Deactivation of the base due to side reactions was significantly minimized and substantial base regeneration was observed. The proposed system was also highly efficient for CO capture from a gas mixture containing 10 % CO , as found in flue gases, followed by tandem conversion to CH OH. We postulate that such high boiling tertiary amine-glycol systems as dual capture and hydrogenation solvents are promising for the realization of a sustainable and carbon-neutral methanol economy in a scalable process.