NOVELTY - A processing plant (G1) comprises a control circuit operationally coupled to a thermal sensor that is thermally coupled to a refluxed demethanizer (57) and a flow control element. The refluxed demethanizer is configured to receive a temperature-controlled expander discharge. The control circuit is configured such that the flow control element controls a flow volume of a bypass loop from an expander discharge stream (3) through a heat exchanger to form the temperature-controlled expander discharge in response to a temperature sensed by the thermal sensor in the demethanizer.    USE - For processing carbon dioxide-containing feed gas (claimed) useful in ethane and propane recovery.    ADVANTAGE - The processing plant efficiently separates the ethane, propane and higher hydrocarbons from a carbon dioxide-containing feed gas without the need for upstream carbon dioxide removal. The process increases in column temperature in top trays to avoid freezing of carbon dioxide; and decreases in column overhead temperature to increase ethane recovery.    DETAILED DESCRIPTION - An INDEPENDENT CLAIM is included for processing (P1) a carbon dioxide-containing feed gas involving providing a control circuit and operationally coupling the control circuit to a thermal sensor that is thermally coupled to a refluxed demethanizer and to a flow control element; feeding a temperature-controlled expander discharge to the refluxed demethanizer; and configuring the control circuit such that the flow control element controls a flow volume of a bypass loop from an expander discharge stream through a heat exchanger to thereby form the temperature-controlled expander discharge in response to a temperature sensed by the thermal sensor in the demethanizer.    DESCRIPTION OF DRAWING(S) - The figure shows a schematic diagram of ethane recovery plant.    expander discharge stream (3)    subcooled reflux stream (7)    expander suction drum (52)    demethanizer (57)    temperature control system. (60)