Integrated Carbon Dioxide Capture and Conversion to Methanol Utilizing Tertiary Amines over a Heterogenous Cu/ZnO/AlO Catalyst.

Increasing carbon dioxide emissions has sparked a growing interest in capturing these emissions at the source of their release. For such processes, amines can be used as carbon dioxide capture agents. Herein, CO was captured under ambient conditions using solutions of amines and polyamines in ethylene glycol. The captured solutions were then successfully hydrogenated to methanol under hydrogen pressure with a heterogeneous Cu/ZnO/AlO industrial catalyst. An extensive amine scope found that tetramethyl-1,6-hexanediamine, with two tertiary amine sites, provided the highest methanol productivity. This reaction was then optimized to achieve up to 89% methanol yield under relatively mild conditions of 250 °C and 80 bar H pressure. The catalyst was shown to be recyclable over five reaction cycles.