Generalized calculation of pure saturation properties using cubic
equations of state
Abstract
Little attention has been given to the bubble temperature problem of a
pure component in academic field. A robust methodology for solving the
pure saturation temperature (vapor temperature) is proposed by using
cubic equations of state. The methodology is based on a Newton-Raphson
iterative technique for solving phase equilibrium criteria, coupled with
initialization procedures. This methodology is free of numerical
pitfalls from the critical point to very low reduced pressure. The fact
that the given pressure is equal to the pressure at the inflection point
of the initial temperature isotherm yields an automatic initialization
of the calculations inside a region of convergence where the EOS can
always predict vapor temperatures. In addition, the initialization
method can also be used to calculate vapor pressures. Examples for vdW,
RK, SRK and PR EOS show that the methodology can give perfect
predictions for saturation properties even at very low reduced pressure
and temperature.