DEPRIESTER CHART ETHANE 100 KPA FREE
composition (P constant, T) – Ponchon-Savarit Plot Analytical expressions Thermodynamics: Equations of state/Gibbs free energy models Distribution coefficients, K values Relative volatility DePreister charts Curve fit of data Īnalytical Expressions for Equilibrium To date, we have looked at various ways to represent equilibrium behavior of binary systems graphically. x,y (P constant) – Saturated Liquid, Vapor Plot Enthalpy vs.
DEPRIESTER CHART ETHANE 100 KPA HOW TO
Composition – Enthalpy Determination 425 295 90Įquilibrium Data – How to Handle? Tabular Data Generate graphical plots Generate analytical expressions (curve fit) Graphical y vs. For example, if one were given a feed mixture of 35% ethanol (weight %) at T = 92 o C and P = 1 kg/cm 2 and the mixture was allowed to separate into vapor and liquid, what would be the enthalpies of the feed, vapor, and liquid? Įnthalpy vs. We will use enthalpies in energy balances later. Composition – Enthalpy Determination The major purpose of an enthalpy diagram is to determine enthalpies. Composition – Last Liquid Drop CompositionĮnthalpy vs. Composition – Dew Point Temperature 94.8 o CĮnthalpy vs. Composition – 1 st Bubble CompositionĮnthalpy vs. Composition – Bubble Point Temperature 82.2 o CĮnthalpy vs. An auxiliary line is used to assist in these determinations… Įnthalpy vs. The compositions of the 1 st bubble formed and the last liquid drop can be determined from the enthalpy vs.
Composition – Ponchon-Savarit Plot The bubble point temperature and dew point temperatures can be determined from the enthalpy vs. Ĭonverting Weight Fraction to Mole Fraction In General For a binary mixture: For a mixture of C components: Įnthalpy vs. Although slight, one can begin to see the effect of pressure on the azeotropic point. Weight Fraction Converting from wt fraction of the azeotrope to mole fraction: Thus, the azeotropic mole fraction is greater at P = 1 Kg/cm 2 than at 1 atm: 0.902 vs. For ethanol-water, this can be readily done using the molecular weights, MW EtOH =46.07 and MW w = 18.02. Weight Fraction Note that the enthalpy- composition plot is presented in terms of weight fractions – we will typically use mole fractions so one must convert between the two. Composition – Ponchon-Savarit Plot Note the boiling temperatures of the pure components, water and ethanol, and the temperature of the azeotrope are different due to the pressure at which the data was taken: P = 1 kg/cm 2 (0.97 atm) 1 atm Water 99.1 o C 100 o C Ethanol 77.8 78.30 Azeotrope 77.65 78.15 x,y plots for ethanol-water? Įnthalpy vs. Why is this different than that determined from the y vs. x,y plots for ethanol-water? The azeotrope for ethanol-water is indicated as T = 77.65 o C and a concentration of 0.955. Why? Why are the boiling point temperatures of the pure components different than those determined from the y vs. An azeotrope is indicated by the composition at which the isotherm becomes vertical. Points between the saturated liquid line and the saturated vapor line represent a two-phase, liquid-vapor system. Temperature is represented by isothermal tie lines between the saturated liquid (boiling) line and the saturated vapor (dew) line. Composition – Ponchon-Savarit Plot 3 phases are shown on the plot – solid, liquid, and vapor. Composition – Ponchon-Savarit PlotĮnthalpy vs.
composition plot to obtain this information. We will also need to employ energy balances, based on enthalpy, for certain separation problems. Composition – Ponchon-Savarit Plot We have begun to employ mass balances, both total and component.
0 kommentar(er)
