A hybrid contact tray for a mass transfer column, the contact tray comprising: a tray deck for passage of liquid along a liquid flow path thereon, the tray deck having a plurality of orifices for passage of ascending vapor through the tray deck ; a cross-current vapor-liquid mixing section having a first portion of the plurality of orifices; a co-current vapor-liquid mixing section comprising at least one co-current mixing device and having a second portion of the plurality of orifices; and means for altering liquid head levels (440, 441, 540, 541,) with respect to the plurality of orifices i) by raising the first portion of orifices with respect to the second portion of orifices to provide an elevation difference between the cross-current vapor-liquid mixing section and the co-current vapor-liquid mixing section or ii) by lowering the second portion of orifices with respect to the first portion of orifices to provide an elevation difference between the cross-current vapor-liquid mixing section and the co-current vapor-liquid mixing section , such that the liquid head level (440, 441, 540, 541, with respect to the second portion of the plurality of orifices within the co-current vapor-liquid mixing section is greater than the liquid head level (440, 441, 540, 541,) with respect to the first portions of the plurality of orifices within the cross-current vapor-liquid mixing section , wherein the co-current vapor-liquid mixing device comprises a conduit having: a vapor inlet in fluid communication with one or more of the second portion of orifices; a froth inlet in fluid communication with the liquid flow path along the tray deck ; a fluid outlet ; and a co-current flow path of vapor and liquid within the conduit disposed after the vapor and froth inlets and before the fluid outlet . a tray deck for passage of liquid along a liquid flow path thereon, the tray deck having a plurality of orifices for passage of ascending vapor through the tray deck ; a cross-current vapor-liquid mixing section having a first portion of the plurality of orifices; a co-current vapor-liquid mixing section comprising at least one co-current mixing device and having a second portion of the plurality of orifices; and means for altering liquid head levels (440, 441, 540, 541,) with respect to the plurality of orifices i) by raising the first portion of orifices with respect to the second portion of orifices to provide an elevation difference between the cross-current vapor-liquid mixing section and the co-current vapor-liquid mixing section or ii) by lowering the second portion of orifices with respect to the first portion of orifices to provide an elevation difference between the cross-current vapor-liquid mixing section and the co-current vapor-liquid mixing section , such that the liquid head level (440, 441, 540, 541, with respect to the second portion of the plurality of orifices within the co-current vapor-liquid mixing section is greater than the liquid head level (440, 441, 540, 541,) with respect to the first portions of the plurality of orifices within the cross-current vapor-liquid mixing section , wherein the co-current vapor-liquid mixing device comprises a conduit having: a vapor inlet in fluid communication with one or more of the second portion of orifices; a froth inlet in fluid communication with the liquid flow path along the tray deck ; a fluid outlet ; and a co-current flow path of vapor and liquid within the conduit disposed after the vapor and froth inlets and before the fluid outlet . <EOS>