Disclosed is a method for running natural gas powered stationary combustion systems, such as an internal combustion engine, a furnace, a fired heater, a power plant, an incinerator, and the like. In one embodiment of the present method, ethane and heavier hydrocarbons or propane and heavier hydrocarbons (29) are removed (90) from a natural gas feedstream (3) to provide the methane-rich natural gas stream (5) used to fuel the stationary combustion system (100). One embodiment of this method provides for the use of a regenerable adsorbent media to remove the higher hydrocarbons which is regenerated by a microwave heating system. Said regeneration step may be operated as a batch process, a semi-continuous process, or a continuous process.