A novel zero length column (ZLC) apparatus has been developed to provide rapid screening of CO2 capacities of adsorbent materials. The key features of the new apparatus are the use of 5-15 mg of sample, a purposely designed gas-dosing system, and low flow rates that extend the use of the ZLC to test adsorbents for postcombustion for carbon capture applications, The new ZLC system was first applied to provide rapid screening capacity ranking of more than 15 MOP materials and three representative zeolites. At the point of interest for flue gas application (38 degrees C, 0.1 bar CO2 partial pressure), Mg/DOBDC was found to outperform significantly all other MOFs and the benchmark zeolites.