Unit Operations Handbook: Volume 1 (In Two Volumes).

РІвЂ вЂ 'Pbub and Pdew calculation based on the DePriester chart for a fast pyrolysis and hydrotreating process'.

Read this K-value off the chart (approximately 21.3).

Note where the line crosses the methane axis.

Connect the points with a straight line.

On the right-hand vertical axis, locate and mark the point containing the temperature 60РІВРЏ.Ideal Behavior 2.5.5 Equilibrium relation: K-value. A chart was provided for each hydrocarbon, in which K-value could be obtained by knowingT andPof thesystem. On the left-hand vertical axis, locate and mark the point containing the pressure 100 psia. charts constructed by DePrister, then called Depriester charts.ExampleР”Р‡or example, to find the K value of methane at 100 psia and 60Р’В РІВРЏ. Many DePriester charts have been printed for simple hydrocarbons. 'K' values, representing the tendency of a given chemical species to partition itself preferentially between liquid and vapor phases, are plotted in between. These nomograms have two vertical coordinates, one for pressure, and another for temperature. A feed that is 45 mole ethane, 30 mole n-buta ne and 25 mole n-pentane is flashed distilled. DePriester in an article in Chemical Engineering Progress in 1953. Use the DePriester c hart for equilibrium data, Figure 2-12 from Wankat 2007 2.

This variable K is define: KK(T,P) y/x where y and x are the mole fractions of that component in vapor and liquid respectively. Understanding the concept behind Flash Distillation, the vapor-liquid equilibrium. For methane and ethane, you can use a DePriester Chart to determine the vapor/liquid equilibrium ratio of each component for any temperature and pressure. It is also one of the most important processes to learn in Mass Transfer / Separation Process Technologies as it is a fundamental unit operation. using the Depriester chart (b) Calculate the compositions of the liquid and vapor for a mixture of n-butane and n-pentane at equilibrium at 40 C and 46,5. DePriester Charts provide an efficient method to find the vapor-liquid equilibrium ratios for different substances at different conditions of pressure and temperature. Flash Distillation is one of the most important Mass Transfer Operations used extensively in the Chemical industry.

Depriester chart for equilibrium