MULTICOMPONENT NUCLEATION AND DROPLET GROWTH IN NATURAL-GAS

The first quantitative experimental results are presented on homogeneo us nucleation and droplet growth in a multicomponent gas-vapor mixture . Using the pulse-expansion wave tube technique, we investigated the c ondensation behavior of natural gas consisting of over 30 components. Data were obtained in the pressure range between 6 and 24 bar and at t emperatures ranging from 221 to 237 K. The observed droplet growth: ra tes are quantitatively explained using a multicomponent model for diff usion controlled growth. The nucleation rate data are for the moment m ainly presented as a challenge to theoreticians, although some qualita tive arguments are presented that could be helpful in the interpretati on. The data appear to agree at least qualitatively with theoretical v alues (according to the revised binary classical nucleation theory) fo r a mixture of n-octane and methane, a model mixture which also shows the same macroscopic phase behavior as natural gas. (C) 1998 American Institute of Physics.