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A modified Redlich‐Kwong equation for supercritical helium and hydrogen
Author(s) -
Vogl Walter F.,
Hall Kenneth R.
Publication year - 1970
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.690160621
Subject(s) - supercritical fluid , thermodynamics , equation of state , chemistry , helium , compressibility , atmospheric temperature range , hydrogen , reduced properties , constant (computer programming) , real gas , range (aeronautics) , materials science , physics , organic chemistry , computer science , programming language , composite material
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.