Properties of Gases and Liquids 5th edition (RPP5)

Contents

• Properties of Gases and Liquids 5th edition (RPP5)

  • Source

  • Ideal Gas Molar Heat Capacity (Constant Pressure)

  • Ideal Gas Molar Enthalpy

  • Ideal Gas Molar Entropy

  • Saturation (Vapor) Pressure

Source

Methods for calculating pure component properties from:

The Properties of Gases & Liquids, 5th Edition Reid, Prausnitz and Polling, 2001, McGraw-Hill

All methods use SI units.

Ideal Gas Molar Heat Capacity (Constant Pressure)

Properties of Gases and Liquids uses the following correlation for the ideal gas molar heat capacity:

\[\frac{c_{\text{p ig}}}{R} = a0 + a1 \times T + a2 \times T^2 + a3 \times T^3 + a4 \times T^4\]

Parameters

Symbol	Parameter Name	Units	Description
\(a0\)	cp_mol_ig_comp_coeff_a0	None
\(a1\)	cp_mol_ig_comp_coeff_a1	\(\text{K}^-1\)
\(a2\)	cp_mol_ig_comp_coeff_a2	\(\text{K}^-2\)
\(a3\)	cp_mol_ig_comp_coeff_a3	\(\text{K}^-3\)
\(a4\)	cp_mol_ig_comp_coeff_a4	\(\text{K}^-4\)
\(R\)	gas_constant	Same as heat capacity	Universal gas constant

Ideal Gas Molar Enthalpy

The correlation for the ideal gas molar enthalpy is derived from the correlation for the molar heat capacity and is given below:

\[\frac{h_{\text{ig}} - h_{\text{ig ref}}}{R} = a0 \times (T-T_{ref}) + \frac{a1}{2} \times (T^2 - T_{ref}^2) + \frac{a2}{3} \times (T^3 - T_{ref}^3) + \frac{a3}{4} \times (T^4 - T_{ref}^4) + \frac{a4}{5} \times (T^5 - T_{ref}^5) + \Delta h_{\text{form, Vap}}\]

Parameters

Symbol	Parameter Name	Units	Description
\(a0\)	cp_mol_ig_comp_coeff_a0	None
\(a1\)	cp_mol_ig_comp_coeff_a1	\(\text{K}^-1\)
\(a2\)	cp_mol_ig_comp_coeff_a2	\(\text{K}^-2\)
\(a3\)	cp_mol_ig_comp_coeff_a3	\(\text{K}^-3\)
\(a4\)	cp_mol_ig_comp_coeff_a4	\(\text{K}^-4\)
\(\Delta h_{\text{form, Vap}}\)	enth_mol_form_vap_comp_ref	\(\text{J/mol}\)	Molar heat of formation at reference state

Note

This correlation uses the same parameters as the ideal gas heat capacity correlation.

Ideal Gas Molar Entropy

The correlation for the ideal gas molar entropy is derived from the correlation for the molar heat capacity and is given below:

\[\frac{s_{\text{ig}}}{R}= a0 \times ln(T/T_{ref}) + a1 \times (T - T_{ref}) + \frac{a2}{2} \times (T^2 - T_{ref}^2) + \frac{a3}{3} \times (T^3 - T_{ref}^3) + \frac{a4}{4} \times (T^4 - T_{ref}^4) + s_{\text{form, Vap}}\]

Parameters

Symbol	Parameter Name	Units	Description
\(a0\)	cp_mol_ig_comp_coeff_a0	None
\(a1\)	cp_mol_ig_comp_coeff_a1	\(\text{K}^-1\)
\(a2\)	cp_mol_ig_comp_coeff_a2	\(\text{K}^-2\)
\(a3\)	cp_mol_ig_comp_coeff_a3	\(\text{K}^-3\)
\(a4\)	cp_mol_ig_comp_coeff_a4	\(\text{K}^-4\)
\(s_{\text{form, Vap}}\)	entr_mol_form_vap_comp_ref	\(\text{J/mol}\cdotp\text{K}\)	Standard molar entropy of formation at reference state

Note

This correlation uses the same parameters as the ideal gas heat capacity correlation.

Saturation (Vapor) Pressure

Properties of Gases and Liquids 5th edition uses the following correlation to calculate the vapor pressure of a component:

\[Log{(P_{sat}) = A - \frac{B}{T+C}}\]

Units are bar and Kelvin.

Parameters

Symbol	Parameter Name	Units	Description
\(A\)	pressure_sat_comp_coeff_A	None
\(B\)	pressure_sat_comp_coeff_B	\(\text{K}\)
\(C\)	pressure_sat_comp_coeff_C	\(\text{K}\)