Portable pressure swing adsorption method and system for low flow rate gas processing

A method of processing hydrocarbon gas comprising:

• feeding heated and pressurized hydrocarbon gas at a feed flowrate for a feed time through a first adsorption bed of a pressure swing adsorption (PSA) system;
• recovering a light product from the first adsorption bed during the feed time;
• obtaining a heavy product from a second adsorption bed of the PSA system during the feed time;
• compressing the heavy product to obtain natural gas liquid (NGL) and NGL storage tank vapor from the heavy product;
• sending a volume of reflux gas through the first adsorption bed after the feed time to obtain additional light product;
• and
• adjusting one of the feed flowrate, the feed time, the volume of reflux gas, or a combination thereof based on a gross heating value of the heated and pressurized hydrocarbon gas, wherein adjusting the volume of reflux gas comprises combining the NGL storage tank vapor with the volume of reflux gas.

A pressure swing adsorption system for recovering hydrocarbon gas from a well, the pressure swing adsorption system comprising:

• four adsorbent beds coupled together and configured to asynchronously cycle through an eight-step adsorption process;
• a pair of pumps fluidly coupled to the four adsorbent beds;
• a first pump of the pair of pumps configured to remove heavy product from a first bed of the four adsorbent beds during a first time increment and a second time increment;
• a second pump of the pair of pumps configured to remove buffer gas from a second bed of the four adsorbent beds during the first time increment;
• and
• the first pump and the second pump configured to remove heavy product during the second time increment.