A theoretical analysis of non-linear mass transfer kinetics based on similarity variables method for a gas-liquid opposite-current flow in the conditions of large concentration gradients has been done. The obtained numerical results for the energy dissipation in laminar boundary layers with flat phase boundary and mass transfer rate are compared with analogous results for co-current flows. The ratio between the mass transfer rate and energy dissipation is determined. The induced secondary flow in the gas phase influences mass transfer kinetics significantly when the interphases mass transfer is limited by the mass transfer in gas phase.