Hi everyone
For calculating the vapour fraction and phase compositions of a hydrocarbon mixture at given Pressure, Temperature and overall compositions, the rachford-rice equation needs to be solved.
Because of the absence of phase composition (x-y) information in the beginning, we need starting values for the equilibrium K Ratios, (since the K values are composition dependent) for initialising the rachford rice solution procedure. Upon subsequent computation of phase composition, K values are reevaluated using the new information and the procedure is repeated until convergence.
I know about the raoult's approximation for K values (vapor pressure/System pressure) and the wilson correlation.
But they don't seem to be very helpful, because it often happens that for the initial estimated values of the K ratios, no feasible solution of the vapour fraction exists, which should ideally be between 0 and 1.
So I would like for any leads which would help me set good initial values for K ratios to ensure robust evaluation of the vapour fraction