The method of lifetime measurement is used to investigate the kinetics of spontaneous boiling-up of ethane-nitrogen solutions. Superheating temperatures T-n of solutions have been determined in experiments at pressure p = 1.0, 1.6 MPa and nitrogen concentration in ethane x = 0.5, 1.5 mol% in the nucleation. rate range J = 1 x 10(4)-2 x 10(8) s(-1) m(-3). At J > 3 x 10(6) s(-1) m(-3) one can observe a satisfactory agreement between experimental data and homogeneous nucleation theory with respect to the temperature dependence of the nucleation rate and a systematic disagreement in the superheating temperature. At x = 0.5 mol% attainable superheating temperatures achieved by experiment coincide within the experimental error with theoretical values, and at x = 1.5 mol% exceed them by approximately 1.7 K. It is shown that one possible reason of such "excess superheating" of a solution beyond the theoretical value of T-n may be the absence of adsorption equilibrium at the critical bubble-ambient solution interface. (C) 2015 Elsevier Ltd. All rights reserved.