The present invention relates to the selective separation of methane (“CH4”) from higher carbon number hydrocarbons (“HHC”s) in streams containing both methane and higher carbon number hydrocarbons (e.g. ethylene, ethane, propylene, propane, etc.) utilizing a zeolitic imidazolate framework (“ZIF”) material. Preferably, the stream to be separated is fed to the present process in a substantially gaseous phase. In preferred embodiments, the current invention is utilized in a process to separate methane from higher carbon number hydrocarbons in natural gas streams.