K-value of Several Hydrocarbons versus Temperature and Pressure

Initializing live version
Download to Desktop

Requires a Wolfram Notebook System

Interact on desktop, mobile and cloud with the free Wolfram Player or other Wolfram Language products.

This Demonstration shows the contour plot of versus temperature expressed in °R and pressure expressed in psia, where and are the mole fractions of component in the liquid and vapor phases, respectively. For many systems, -values are approximately independent of composition and we have .


For light hydrocarbons, the approximate -values can be determined from DePriester charts, which have been fit to the following equation: , where the constants , , , , , and are tabulated [1]. Drag or click the locator to display the values of the temperature and pressure as well as the -value for various light hydrocarbons.


Contributed by: Housam Binous and Ahmed Bellagi (March 2011)
Open content licensed under CC BY-NC-SA



[1] M. L. McWilliams, "An Equation to Relate K-Factors to Pressure and Temperature," Chemical Engineering, 80(25), 1973 p. 138.

Feedback (field required)
Email (field required) Name
Occupation Organization
Note: Your message & contact information may be shared with the author of any specific Demonstration for which you give feedback.