(665e) Molecular Simulation Study of CO2 Selectively Capture From Pre- and Post-Combustion Mixture Using Latent Porous Crystal Copper-Organic Framework Adsorbents

CO2 emission sources like coal power plants accounts for nearly one third of total CO2 emission of the US thus make them a logical target for Carbon capture and storage (CCS) strategy to address the increasing trend of CO2 emissions from large and stationary sources. CCS involves separating CO2 from pre- or post-combustion process gasses, compressing CO2 to high density for pipeline transport, and injecting CO2 in to geological formations for long-term sequestration. Conventional CO2 capture is often accomplished using chemical absorption with amine solvents. However recovery of the CO2 and solvent is energy-intensive. Porous materials are thus sought for cost-effective CO2 capture using physical adsorption at power plants utilizing coal or natural gas.

Latent porous crystal metal-organic frameworks (MOFs) are an intriguing class of inexpensive adsorbents for high-capacity, high-selectivity capture of CO2 from flue gas. Certain copper-based MOFs exhibit highly selective ?gated? CO2 adsorption and desorption at temperatures and pressures relevant for flue gas treatment. We report molecular simulation results for CO2 isotherms and isosteric heats of adsorption on copper-organic framework materials. Sorption selectivities for CO2/H2 and CO2/N2 mixtures in excess of 600 are observed at conditions representative of pre-combustion coal gasification syngas mixtures and post-combustion flue gas. Ideal adsorbed solution theory (IAST) prediction on the adsorption selectivity has also been employed to compare with the GCMC binary mixture simulation data. It was found that IAST predictions are quantitatively accurate in the high temperature and low partial pressure region and can be used as a qualitative prediction on the adsorption selectivity of CO2-H2 mixture.