NOVELTY - A contact and separation column (1) comprises a column wall (2) encasing a stack of one or more contact and separation cells; a downcomer (16) defining a liquid discharge; and a liquid supply (17) for supplying liquid to the contact and separation cell.    USE - The contact and separation column, and the process are useful for treating gas with a liquid (all claimed).    ADVANTAGE - The contact and separation column is highly improved; enables improved mass transfer, allows recycle of the liquid, and can be used with floating applications.    DETAILED DESCRIPTION - A contact and separation column (1) comprises a column wall (2) encasing a stack of one or more contact and separation cells, where each cell comprises: a tray (4) with a number of gas flow openings (6) opening into one or more contact and separation units (7) positioned on an upper side of the tray (4), where each contact and separation unit (7) comprises an upstream contact zone (8, 9) with liquid inlets (12), and one or more downstream separation zones (10) provided with a swirler (13) and a top end with a gas outlet (14); a downcomer (16) defining a liquid discharge; and a liquid supply (17) for supplying liquid to the contact and separation cell, where the contact zone (8, 9) has a larger cross-sectional area than the one or more separation zones of the contact and separation unit in question (10). INDEPENDENT CLAIMS are:    (1) a contact and separation tray for use in a contact and separation column, where the tray (4) comprises a base plate (5) with a number of gas flow openings (6) opening into one or more contact and separation units (7) positioned on an upper side of the tray (4), where each contact and separation unit (7) comprises an upstream contact zone (8, 9) with liquid inlets (12), and one or more downstream separation zones (10) provided with a swirler (13) and a top end with a gas outlet (14) bordered by a liquid flow deflector (15); where the contact zone (8, 9) has a larger cross-sectional area than the separation zone (10); and    (2) a process of treating gas with a liquid comprising introducing the gas at the gas inlet (6) and liquid at the liquid inlet (12) in a lower contact and separation cell (3) of a contact and separation column (1).    DESCRIPTION OF DRAWING(S) - The drawing shows a schematic view of the interior of the column.    Contact and separation column (1)    Column wall (2)    Tray (4)    Gas flow openings (6)    Contact and separation units (7)    Upstream contact zone (8, 9)    Downstream separation zones (10)