Separation of methane from higher carbon number hydrocarbons utilizing zeolitic imidazolate framework materials

A process for separating CH4 from a process feedstream, comprising:

• a) contacting an adsorbent material comprised of a zeolitic imidazolate framework material with a process feedstream comprising CH4 and at least one C2+ hydrocarbon compound at a first pressure and first temperature;
• b) adsorbing at least a portion of the C2+ hydrocarbon compound in the adsorbent material, thereby producing a CH4-rich product stream, wherein the CH4-rich product stream has a higher concentration of CH4 by mol % than the process feedstream;
• and
• c) producing a CH4-lean product stream at a second pressure and second temperature, wherein the CH4-lean product stream has a lower concentration of CH4 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 C2+ hydrocarbon compound over CH4 of at least 5.