Abstract: A mixed gas is separated with collection of at least one constituent gas. An inlet leads to a blower or other gas compression element through a valve. This blower feeds a chamber which contains media which selectively adsorbs the constituent gas to be collected, such as nitrogen from air. An exhaust from the chamber leads to an exhaust through a check valve. The blower can be reversed after nitrogen has been adsorbed within the chamber to desorb nitrogen and deliver nitrogen back through the blower. The inlet valve is closed after blower reversing and a separate diversion pathway is opened so that nitrogen is delivered from the blower to a nitrogen collection region. A variant system also includes an oxygen collection region on a side of the chamber opposite the blower for collection of both nitrogen and oxygen separated from air simultaneously, or collection of other constituent gases.