(127e) Integrated Process of CO2 Capture and Conversion to Alkyl Carbonates

A new generation of CO₂-capture and utilization technologies that are being separately developed by federally funded projects would show market-driven adoption if CO₂ were used to manufacture value-added products competitively. Dimethyl carbonate (DMC), one such product, has an expanding world market: a) for polycarbonate production; b) as electrolyte in lithium-ion batteries; c) as intermediate in polyurethane production; and d) as environmentally friendly solvent replacing ketone-based solvents. DMC also is being evaluated as an additive to reduce emissions from diesel engines.

Integrating the process of CO₂ capture and conversion to DMC should significantly enhance both the economics as well as energy efficiency when compared to separate processes for CO₂ capture followed by conversion. The direct reaction of CO₂ with methanol for synthesis of DMC is thermodynamically difficult, requiring innovative catalyst development. Therefore, E3Tec is actively pursuing two separate integrated processes based on chemical carriers for CO₂ utilization to manufacture high-value DMC; one with the SBIR Phase II (DE-SC0013233) and the other one with an ERA, Alberta grant. The two DMC processes are based on two alternate chemical pathways 1) using ammonia as a carrier while consuming CO₂ and methanol feeds; and 2) using CO₂, methanol and ethylene oxide (EtO) as feeds to co-produce DMC and mono-ethylene glycol (MEG).

E3Tec is now pursuing integration of the DMC process with this new generation of CO₂ capture technologies, i.e., membrane separations; solid adsorbents; non-aqueous solvents; a new generation of amine solvents; and hybrid processes. The technology challenges and opportunities of integrating the DMC process with the new generation of CO₂ capture technologies are discussed with the focus on different membrane separations and solid adsorbents. The ASPEN Plus® analysis of the integrated process is based on prototype testing of the DMC process and reported performance of the CO₂ capture processes.