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CO2 Carbon Dioxide Properties

Reference data and engineering information about co2 carbon dioxide properties for gases and compressed air applications.

CO2carbondioxidepropertiesData Table

Overview

Engineering reference data for CO2 Carbon Dioxide Properties in gases and compressed air.

Key Formulas

Ideal Gas Law

PV=nRTPV = nRT

Pressure × Volume = moles × gas constant × temperature.

Boyle's Law

P1V1=P2V2P_1 V_1 = P_2 V_2

At constant temperature.

Charles's Law

V1T1=V2T2\frac{V_1}{T_1} = \frac{V_2}{T_2}

At constant pressure.

Variables

SymbolDescriptionUnit
PPPressurePa
VVVolume
TTTemperatureK
RRGas constant8.314 J/(mol·K)

Carbon Dioxide Thermophysical Properties Data

18 rows
Selected thermophysical properties of carbon dioxide (CO₂) in various phases and units. Values at 25°C/1 atm unless specified.
Property
Value
Unit
Value
Unit
Value
Unit
Value
Unit
Acidity (pKa1)6.35
Acidity (pKa2)10.33
Boiling Point - sublimation point194.686K-78.464°C-109.24°F
Critical density10.63mol/dm3467.6kg/m30.9073slug/ft329.19lb/ft3
Critical pressure7.38MPa73.8bar72.8atm1070psi
Critical temperature304.13K30.98°C87.76°F
Critical volume94.12cm3/mol0.00214m3/kg1.102ft3/slug0.03426ft3/lb
Density (at 25°C, 1 atm)40.8mol/m31.795kg/m30.00348slug/ft30.1121lb/ft3
Density, gas at 0°C, 1 atm44.9mol/m31.977kg/m30.00384slug/ft30.1234lb/ft3
Density, liquid at -37°C25017mol/m31101kg/m32.136slug/ft368.73lb/ft3
Density, solid at -78.5°C35492mol/m31562kg/m33.031slug/ft397.51lb/ft3
FlammableNo
Gas constant - R188.92J/kg K0.0525Wh/(kg K)1130(ft lbf/slug °R)35.114(ft lbf/lb °R)
Molecular Weight44.0095g/mol0.09702lb/mol
Specific Gravity (relative to air)1.53
Specific Heat Ratio (Cp/Cv)1.29
Sound velocity in gas269m/s
Thermal Conductivity0.01663W/m°C0.009609Btu/hr ft °F

Source: engineeringtoolbox.com

Phase Behavior and Key Definitions

Carbon dioxide is a gas at standard conditions (STP). Its phase diagram shows distinct behavior:

  • Triple Point: The unique temperature and pressure where solid, liquid, and gas coexist. For CO₂: T = 216.58 K (-56.57 °C), P = 0.518 MPa (5.18 bar).
  • Critical Point: The end point of the liquid-gas equilibrium curve. For CO₂: T = 304.13 K (30.98 °C), P = 7.38 MPa (73.8 bar). Above this point, CO₂ becomes a supercritical fluid.
  • Sublimation Curve: The curve from the triple point to lower pressures/temperatures, showing the direct solid-gas transition.
  • Dry Ice: The common name for solid carbon dioxide, which sublimes directly at -78.5°C (-109.3°F) at 1 atm.

Further detailed properties can be explored across varying temperature and pressure:

  • Density and specific weight
  • Dynamic and kinematic viscosity
  • Prandtl number
  • Specific heat capacity
  • Thermal conductivity

Interactive Charts

CO2 phase diagram C

References