A modified Redlich-Kwong equation for supercritical helium and hydrogen

✍ Scribed by Walter F. Vogl; Kenneth R. Hall

• Publisher: American Institute of Chemical Engineers
• Year: 1970
• Tongue: English
• Weight: 620 KB
• Volume: 16
• Category: Article
• ISSN: 0001-1541
• DOI: 10.1002/aic.690160621

✦ Synopsis

Abstract

A modified Redlich‐Kwong equation of state is developed in which the two parameters are expressed as functions of temperature. The critical values for the two constants in the equation are completely determined by the values of the critical properties of the gas. The optimum values of the constants for each isotherm (Z vs. P) are found, followed by a curve‐fitting routine that obtains the constants as functions of temperature. The resulting equation of state predicts experimental helium compressibility data to within an average of 0.90% absolute error for data in the range 0 < pressure ⩽ 700 atm., 5.26°K. ⩽ temperature ⩽ 1,500°K. For hydrogen, the prediction is to within an average of 0.79% absolute error for temperatures from 34° to 600°K. and pressures up to 2,900 atm.