Problem Solving in Chemical and Biochemical Engineering with POLYMATH,

Chapter 12. Phase Equilibria and Distillation

Three Stage Flash Evaporator for Recovering Hexane from Octane

Concepts Demonstrated

Bubble and dew point temperature calculations for a binary mixture. Isothermal and adiabatic flash calculations. Vapor and liquid enthalpy estimations for pure components and ideal mixtures.

Numerical Methods Utilized

Solution of systems of nonlinear algebraic equations.

Problem Statement

Seader and Henley^[1] (p. 171) investigated the process shown in Figure 12-1 where n-hexane (designated as component 1) is separated from n-octane by a series of three flash units at 1 atm. The feed to the first stage is an equimolar bubble point liquid at a flow rate of 100 kg-mol/h. The flash evaporator stages operate isothermally at the ...