NOVELTY - A gas-rich liquid is heated in desorption unit, to desorb gas from gas-rich liquid and form primary product stream (13) including gas and vapor and secondary product stream (14) including gas-lean liquid (23). The primary product stream is contacted with vapor permeable membrane condenser (22), to remove portion(s) of vapor from primary product stream. The primary product stream is passed through membrane condenser and heat is exchanged with portion(s) (21a) of gas-rich liquid entering desorption unit, to heat gas-rich liquid stream. Thus, stripping gas from gas-rich liquid is performed.    USE - Method for stripping gas e.g. carbon dioxide, hydrogen sulfide, carbon monoxide, methane, propane, butane, oxygen, nitrogen dioxide and sulfur dioxide from gas-rich liquid (all claimed) used during separation of paraffin-olefin mixture, carbon monoxide and volatile compounds from wastewater.    ADVANTAGE - The method enables efficient stripping of gas from gas-rich liquid using the apparatus.    DETAILED DESCRIPTION - A gas-rich liquid is heated in a desorption unit, to desorb the gas from the gas-rich liquid and form primary product stream including the gas and a vapor and a secondary product stream including a gas-lean liquid. The primary product stream is contacted with a vapor permeable membrane condenser, to remove portion(s) of vapor from the primary product stream through the permeable membrane interface (24). The primary product stream is passed through the membrane condenser and heat is exchanged with portion(s) of the gas-rich liquid entering the desorption unit, to heat the gas-rich liquid stream. Alternatively, the secondary product stream is contacted with vapor permeable membrane evaporator (17), to remove portion(s) of vapor from the secondary product stream through a membrane interface of the permeable membrane. The separated portion is returned from the secondary product stream to the desorption unit. Thus, stripping gas from gas-rich liquid is performed. An INDEPENDENT CLAIM is included for apparatus, which consists of a desorption unit including a gas-rich liquid inlet, a primary product stream outlet and a secondary product stream outlet, and a membrane condenser containing inlets to receive the primary product stream and gas-rich liquid stream, a membrane interface permeable to the vapor through which vapor transfers from the primary product stream to the gas-rich liquid stream, an outlet in fluid contact with the gas-rich liquid inlet of the desorption unit, and an outlet for a vapor-reduced primary product stream, and/or a membrane evaporator containing an inlet to receive portion(s) of the secondary product stream, a membrane interface permeable to the vapor through which vapor transfers to separate a vapor portion from the secondary product stream and an outlet for a vapor-reduced secondary product stream.    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of gas desorption unit.    Product streams (13, 14)    Membrane evaporator (17)    Heat exchanger (20)    Gas-rich stream (21)    Portion of gas-rich stream (21a)    Membrane condenser (22)    Gas-lean liquid (23)    Membrane interface (24)