Capillary constant and surface tension of ethane with small additions of hydrogen

One of the ways of increasing the ecological and economic performance of internal combustion engines is the addition of small amounts of hydrogen to hydrocarbon fuel. We used the differential capillary method to measure the capillary constant a2 and to determine the surface tension σ of ethane/hydrogen mixtures. Experiments were conducted in the temperature range from 93.15 to 283.15 K at pressures from that of the phase equilibrium of pure ethane to 4 MPa. The values of a2 and σ as functions of the temperature, pressure and concentration of hydrogen are described by analytical dependences. The effect of the nature of the substance being dissolved and the nonideality of the forming mixture on the value of its surface tension has been examined.