ADIABATIC FLASH CALCULATIONS FOR CONTINUOUS OR SEMICONTINUOUS MIXTURES USING AN EQUATION OF STATE

This work presents a thermodynamic framework for adiabatic flash calculations for continuous or semicontinuous mixtures using an equation of state. A Gaussian quadrature method is used to solve phase-equilibrium and enthalpy-balance equations containing integrals of continuous distribution functions. First, comparisons between the quadrature method and the pseudocomponent method are presented for a single-stage calculation using an assumed mixture. Second, a multistage gas absorber using a continuous solvent is considered. The results using the quadrature method compare favorably with those using the exact method where all considered in the calculation. By contrast, the pseudocomponent method gives different results which depend on the selection of pseudocomponents.