Patent ID: 8142745

Claim:
A process for separating CO 2 from a process feedstream, comprising: a) contacting an adsorbent bed comprised of a zeolitic imidazolate framework material with a process feedstream comprising CO 2 and N 2 at a first pressure and first temperature; b) adsorbing at least a portion of the CO 2 in the adsorbent bed, thereby producing a CO 2 -lean product stream, wherein the CO 2 -rich product stream has a higher concentration of CO 2 by vol % than the process feedstream; and c) producing a CO 2 -rich product stream at a second pressure and second temperature, wherein the CO 2 -rich product stream has a higher concentration of CO 2 by vol % than the process feedstream; wherein the zeolitic imidazolate framework material has a framework structure wherein each vertex of the framework structure is comprised of a single metal ion and each pair of connected adjacent vertices of the framework structure are linked by the nitrogen atoms of an imidazolate anion or its derivative, and wherein the zeolitic imidazolate framework material has an adsorptive loading ratio for CO 2 over N 2 of at least 5; wherein adsorptive loading ratio for Co 2 over N 2 is measured at 301 K and 106.6 kPa.