DePriester chart

Last updated
A DePriester Chart DePriester Chart 1.JPG
A DePriester Chart

DePriester Charts provide an efficient method to find the vapor-liquid equilibrium ratios for different substances at different conditions of pressure and temperature. The original chart was put forth by C.L. DePriester in an article in Chemical Engineering Progress in 1953. These nomograms have two vertical coordinates, one for pressure, and another for temperature. "K" values, representing the tendency of a given chemical species to partition itself preferentially between liquid and vapor phases, are plotted in between. [1] [2] [3] [4] Many DePriester charts have been printed for simple hydrocarbons. [5] [6]

Example

For example, to find the K value of methane at 100 psia and 60 °F.

  1. On the left-hand vertical axis, locate and mark the point containing the pressure 100 psia.
  2. On the right-hand vertical axis, locate and mark the point containing the temperature 60°F.
  3. Connect the points with a straight line.
  4. Note where the line crosses the methane axis. Read this K-value off the chart (approximately 21.3).

Related Research Articles

Boiling point Temperature at which a substance changes from liquid into vapor

The boiling point of a substance is the temperature at which the vapor pressure of a liquid equals the pressure surrounding the liquid and the liquid changes into a vapor.

Vapor pressure Pressure exterted by a vapor in thermodynamic equilibrium

Vapor pressure or equilibrium vapor pressure is defined as the pressure exerted by a vapor in thermodynamic equilibrium with its condensed phases at a given temperature in a closed system. The equilibrium vapor pressure is an indication of a liquid's evaporation rate. It relates to the tendency of particles to escape from the liquid. A substance with a high vapor pressure at normal temperatures is often referred to as volatile. The pressure exhibited by vapor present above a liquid surface is known as vapor pressure. As the temperature of liquid increases, the kinetic energy of its molecules also increases. As the kinetic energy of the molecules increases, the number of molecules transitioning into a vapor also increases, thereby increasing the vapor pressure.

<span class="mw-page-title-main">Phase diagram</span> Chart used to show conditions at which physical phases of a substance occur

A phase diagram in physical chemistry, engineering, mineralogy, and materials science is a type of chart used to show conditions at which thermodynamically distinct phases occur and coexist at equilibrium.

<span class="mw-page-title-main">Psychrometrics</span> Field of engineering that studies gas-vapor mixtures

Psychrometrics is the field of engineering concerned with the physical and thermodynamic properties of gas-vapor mixtures.

This page provides supplementary data to the article properties of water.

This page provides supplementary chemical data on carbon dioxide.

This page provides supplementary chemical data on ammonia.

This page provides supplementary chemical data on methane.

A nitrogen rejection unit (NRU) selectively removes nitrogen from a gas. The name can be applied to any system that removes nitrogen from natural gas.

In thermodynamics and chemical engineering, the vapor–liquid equilibrium (VLE) describes the distribution of a chemical species between the vapor phase and a liquid phase.

This page provides supplementary chemical data on benzene.

This page provides supplementary chemical data on carbon tetrachloride.

This page provides supplementary chemical data on cyclohexane.

This page provides supplementary chemical data on 1,2-dichloroethane.

This page provides supplementary chemical data on tetrachloroethylene.

Relative volatility is a measure comparing the vapor pressures of the components in a liquid mixture of chemicals. This quantity is widely used in designing large industrial distillation processes. In effect, it indicates the ease or difficulty of using distillation to separate the more volatile components from the less volatile components in a mixture. By convention, relative volatility is usually denoted as .

Slug flow

In fluid mechanics, slug flow in liquid–gas two-phase flow is a type of flow pattern. Lighter, faster moving continuous fluid which contains gas bubbles - pushes along a disperse gas bubble. Pressure oscillations within piping can be caused by slug flow. The word slug usually refers to the heavier, slower moving fluid, but can also be used to refer to the bubbles of the lighter fluid.

References

  1. ↑ Dambal, Ajey. "DePriester Charts". Thermodynamics - Chemical Engineering (Washington University).
  2. ↑ "Pbub and Pdew calculation based on the DePriester chart for a fast pyrolysis and hydrotreating process" (PDF). Biofuelsacademy.org.
  3. ↑ McKetta Jr., John J. (24 September 1992). Unit Operations Handbook: Volume 1 (In Two Volumes). CRC Press, 1992. pp. 447–448. ISBN   0824786696.
  4. ↑ "Define and use K values, relative volatility, and x-y diagrams". The Pillars Curriculum for Chemical Engineering.
  5. ↑ McKetta Jr., John J. (24 September 1992). Unit Operations Handbook: Volume 1 (In Two Volumes). CRC Press, 1992. pp. 447–448. ISBN   0824786696.
  6. ↑ Thammasat University. "AE 335 Charts AE + SI" (PDF).
This page is based on this Wikipedia article
Text is available under the CC BY-SA 4.0 license; additional terms may apply.
Images, videos and audio are available under their respective licenses.