Patent ID: 8192709

Claim:
A process for separating CH 4 from a process feedstream, comprising: a) contacting an adsorbent material comprised of a zeolitic imidazolate framework material with a process feedstream comprising CH 4 and at least one C 2+ hydrocarbon compound at a first pressure and first temperature; b) adsorbing at least a portion of the C 2+ hydrocarbon compound in the adsorbent material, thereby producing a CH 4 -rich product stream, wherein the CH 4 -rich product stream has a higher concentration of CH 4 by mol % than the process feedstream; and c) producing a CH 4 -lean product stream at a second pressure and second temperature, wherein the CH 4 -lean product stream has a lower concentration of CH 4 by mol % 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 is linked by nitrogen atoms of an imidazolate anion or its derivative, and wherein the zeolitic imidazolate framework material has an adsorptive loading ratio measured at 301 K and 106.6 kPa for the C 2+ hydrocarbon compound over CH 4 of at least 5.