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Carbon dioxide
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Carbon dioxide
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CO2
Carbon dioxide

Physical Properties

Under solid (grey), liquid (blue) and vapor states (white) along the equilibrium curves

  • General properties
  • Solid phase
  • Liquid Phase
  • Gas Phase
(P)
log(P)
Download
  • Molecular weight
    44.01
    g/mol
  • Content in air
    400
    ppm
    400 ppm 0.04 vol/% 4.E-4 vol/vol

Critical Point

  • Temperature
    30.98
    °C
    87.764 °F 304.13 K
  • Pressure
    73.773
    bar
    7.3773E6 pa 1069.9865 lbf/in2 72.8083 Atm 7377.3 Kpa 5.5334E4 mmHg
  • Density
    467.6
    kg/m³
    29.1912 lb/ft³

Triple Point

  • Temperature
    - 56.56
    °C
    - 69.808 °F 216.59 K
  • Pressure
    5.1867
    bar
    5.1867E5 pa 75.227 lbf/in2 5.1189 Atm 518.672 Kpa 3890.3707 mmHg
Pressure 1.013 bar
  • Melting point
    - 56.57
    °C
    - 69.826 °F 216.58 K
  • Latent heat of fusion (at melting point)
    204.93
    kJ/kg
    88.1632 Btu/lb 48.9794 kcal/kg
  • Solid density
    1562
    kg/m³
    97.5123 lb/ft³
Pressure 1.013 bar
  • Liquid density (at triple point (216.59 K, 5.18 b))
    1178.4
    kg/m³
    73.5649 lb/ft³
  • Boiling point
    /
  • Latent heat of vaporization (at boiling point)
    /
Pressure1.013barTemperature
  • Compressibility factor Z
    9.9326E-1
    9.9435E-1
    9.9496E-1
  • Cp/Cv ratio γ
    1.3083
    1.2995
    1.2941
  • Dynamic viscosity
    1.3711E-4
    Po
    13.711 µPa.s 1.3711E-5 PA.S 9.2134E-6 lb/ft/s
    1.4446E-4
    Po
    14.446 µPa.s 1.4446E-5 PA.S 9.7073E-6 lb/ft/s
    1.4932E-4
    Po
    14.932 µPa.s 1.4932E-5 PA.S 1.0034E-5 lb/ft/s
  • Gas density at boiling point
    2.813
    kg/m³
    1.7561E-1 lb/ft³
    2.813
    kg/m³
    1.7561E-1 lb/ft³
    2.813
    kg/m³
    1.7561E-1 lb/ft³
  • Gas density
    1.9763
    kg/m³
    1.2338E-1 lb/ft³
    1.8714
    kg/m³
    1.1683E-1 lb/ft³
    1.8075
    kg/m³
    1.1284E-1 lb/ft³
  • Heat capacity at constant pressure Cp
    8.2684E-1
    kJ/(kg.K)
    1.9762E-1 BTU/lb∙°F 826.835 J/kg∙K 1.9762E-1 kcal/kg∙K
    8.4124E-1
    kJ/(kg.K)
    2.0106E-1 BTU/lb∙°F 841.241 J/kg∙K 2.0106E-1 kcal/kg∙K
    8.5085E-1
    kJ/(kg.K)
    2.0336E-1 BTU/lb∙°F 850.852 J/kg∙K 2.0336E-1 kcal/kg∙K
  • Heat capacity at constant volume Cv
    6.3202E-1
    kJ/(kg.K)
    1.5106E-1 BTU/lb∙°F 632.015 J/kg∙K 1.5106E-1 kcal/kg∙K
    6.4738E-1
    kJ/(kg.K)
    1.5473E-1 BTU/lb∙°F 647.376 J/kg∙K 1.5473E-1 kcal/kg∙K
    6.5749E-1
    kJ/(kg.K)
    1.5714E-1 BTU/lb∙°F 657.487 J/kg∙K 1.5714E-1 kcal/kg∙K
  • Liquid (at boiling point)/gas equivalent
    /
    /
    /
  • Solubility in water
    /
    8.21E-4
    mol/mol
    6.15E-4
    mol/mol
  • Specific gravity
    1.53
    1.53
    1.53
  • Specific volume
    5.06E-1
    m³/kg
    8.1053 ft³/lb
    5.344E-1
    m³/kg
    8.5603 ft³/lb
    5.532E-1
    m³/kg
    8.8614 ft³/lb
  • Thermal conductivity
    14.674
    mW/m∙K
    8.4841E-3 Btu/ft/h/°F 1.2626E-1 cal/hour∙cm∙°C 3.5072E-5 cal/s∙cm∙°C 1.4674E-2 W/(m∙K)
    15.844
    mW/m∙K
    9.1606E-3 Btu/ft/h/°F 1.3633E-1 cal/hour∙cm∙°C 3.7868E-5 cal/s∙cm∙°C 1.5844E-2 W/(m∙K)
    16.643
    mW/m∙K
    9.6226E-3 Btu/ft/h/°F 1.432E-1 cal/hour∙cm∙°C 3.9778E-5 cal/s∙cm∙°C 1.6643E-2 W/(m∙K)
  • Vapor pressure
    34.9054
    bar
    3.4905E6 pa 506.2598 lbf/in2 34.449 Atm 3490.54 Kpa 2.6181E4 mmHg
    50.9921
    bar
    5.0992E6 pa 739.5776 lbf/in2 50.3253 Atm 5099.21 Kpa 3.8247E4 mmHg
    64.4789
    bar
    6.4479E6 pa 935.187 lbf/in2 63.6357 Atm 6447.89 Kpa 4.8363E4 mmHg
CO2
Carbon dioxide

Liquid / Gas Volumes

Calculate a liquid or gas volume or a mass

Liquid Phase

At triple point at -56.57 °C and 5.112 atm

m3(Volume)
kg(Mass)

Gas Phase

At 15°C and 1 atm

m3(Volume)
kg(Mass)
CO2
Carbon dioxide

Applications

Examples of uses of this molecule in Industry and Healthcare

Aeronautics

Carbon dioxide is used as a shielding gas for arc welding. Carbon dioxide snow is used to remove particles and organic residues from metals, polymers, ceramics and glasses. Calibrated mixtures of carbon dioxyde and nitrogen are used for the calibration of measuring equipments used for emission tests of engines.

Aeronautics

Automotive

Carbon dioxide is used as a shielding gas for arc welding. Carbon dioxide snow cleaning removes particles and organic residues from metals, polymers, ceramics, glasses Carbon dioxide in nitrogen is used as span gas calibration mixtures in engine emissions testing.

Automotive

Beverage

Carbon dioxide is used to carbonate beverages such as soft drinks, mineral water or beer and for wine maturation. Carbonic ice is used for controlling temperature during the distribution. Supercritical carbon dioxide is used to extract caffein from coffee.

Beverage

Chemicals

Carbon dioxide is used as a raw material in chemical process like urea or methionine synthesis. Carbon dioxide is used in chemistry for controlling reactor temperatures. CO2 is also employed to neutralize alkaline effluents. Carbon dioxide is used under supercritical conditions for purifying or dying polymer, animal or vegetal fibers.

Chemicals

Electronic components

Carbon dioxide is used as a cooling medium for the testing of electronic devices

Electronic components

Waste & Water management

Carbon dioxide is used in many industries to master pH of liquid effluents, especially as an excellent alternative to sulfuric acid for pH balance control. It is used in water treatment to control pH of waste waters, swimming pools etc.

Waste & Water management

Food

The food industry employs carbon dioxide for food processing applications such as chilling and freezing, modified atmosphere packaging and temperature control for products being stored and transported. Carbon dioxide increases the life of many food products thanks to it fungistatic and bacteriostatic properties. Food products are conditioned under Modified Atmosphere Packaging (MAP). Carbon dioxide is also used in greenhouses to increase vegetal and plant growing.

Food

Hospital care

Medical devices: carbon dioxide is used for laparoscopy (diagnostic performed in the abdomen), colonoscopy and cryo-dermatology. It is also used for the cryopreservation of cells cultures. Drug: carbon dioxide is used for prevention of hypocapnia (reduced carbon dioxide in the blood) during hyperventilation.

Hospital care

Laboratories & Research Centers

Supercritical carbon dioxide is used as mobile phase in both chromatography and extraction applications.

Laboratories & Research Centers

Metal

Carbon dioxide is used for environment protection : CO2 is used for red fume suppression during scrap and carbon charging, for nitrogen pick-up reduction during EAF tapping and for bottom stirring, in the non ferrous metallurgy, carbon dioxide is used for fume suppression during ladle transfer of matte (Cu/Ni production) or bullion (Zn/Pb production). Small amount of liquid CO2 can be used in recycling of waters from Acid Mine Drainage (AMD). CO2 lasers are fed with special grades of carbon dioxide

Metal

Pharma & Biotech

Supercritical carbon dioxide is used to extract components (oils) from natural products. It is used to control the atmosphere (inerting) of processes. Carbon dioxide is a reactant in chemical synthesis. It is also used to transport products at low temperature (-78 °C/-108.4 °F/195.15K).

Pharma & Biotech
CO2
Carbon dioxide

Safety

Information to safely use this molecule

  • Major hazards
  • Material compatibility
  • GHS04
    Gas under pressure

Odor

none

Metals

  • Aluminium
    Satisfactory
  • Brass
    Satisfactory
  • Monel
    Satisfactory
  • Copper
    Satisfactory
  • Ferritic Steel
    Satisfactory
    corrosive in presence of water
  • Stainless steel
    Satisfactory
  • Zinc
    Satisfactory
  • Titanium
    no data

Plastics

  • Polytetrafluoroethylene
    Satisfactory
  • Polychlorotrifluoroethylene
    Satisfactory
  • Polyvinylidene fluoride
    Satisfactory
  • Polyvinyl chloride
    Satisfactory
  • Ethylene tetrafluoroethylene
    Satisfactory
  • Polycarbonate
    Satisfactory
  • Polyamide
    Satisfactory
  • Polypropylene
    Satisfactory

Elastomers

  • Buthyl (isobutene- isoprene) rubber
    Not recommended
    significant swelling
  • Nitrile rubber
    Not recommended
    significant loss of mass and swelling
  • Chloroprene
    Not recommended
    significant loss of mass and swelling
  • Chlorofluorocarbons
    Not recommended
    significant loss of mass and swelling
  • Silicon
    Acceptable
    strong rate of permeation
  • Perfluoroelastomers
    Satisfactory
  • Fluoroelastomers
    Satisfactory
  • Nitrile rubber
    Satisfactory
  • Neoprene
    Satisfactory
  • Polyurethane
    Not recommended
  • Ethylene-Propylene
    Acceptable
    significant loss of mass and swelling

Lubricants

  • Hydrocarbon based lubricant
    Satisfactory
  • Fluorocarbon based lubricant
    Satisfactory

Materials compatibility

Recommendations : Air Liquide has gathered data on the compatibility of gases with materials to assist you in evaluating which materials to use for a gas system. Although the information has been compiled from what Air Liquide believes are reliable sources (International Standards: Compatibility of cylinder and valve materials with gas content; Part 1- Metallic materials: ISO11114-1 (March 2012), Part 2 - Non-metallic materials: ISO11114-2 (April 2013), it must be used with extreme caution and engineering judgement. No raw data such as these can cover all conditions of concentration, temperature, humidity, impurities and aeration. It is therefore recommended that this table is only used to identify possible materials for applications at high pressure and ambient temperature. Extensive investigation and testing under the specific conditions of use need to be carried out to validate a material selection for a given application. Contact the regional Air Liquide team for expertise service.

CO2
Carbon dioxide

Learn More

General information

More information

Jean-Baptiste Van Helmont, a Flemisch chemist and physicist of the 17th century observed that the burning of wood coal in a closed vessel produces ashes of a mass inferior to the material introduced. His conclusion is that coal has been transformed into some invisible substance he called "gas". Carbon dioxide gas is formed by two elements: carbon and oxygen. Carbon dioxide is a part of Natural Carbon Cycle (NCC) where carbon dioxide is exchanged among three main carbon pools – land, atmosphere and ocean. The process, where carbon dioxide is consumed by plants and other organisms and converted into biomass is called photosynthesis. The process where CO2 is released by living species (humans, animals, plants) is called respiration. Apart of NCC there is an Anthropogenic Carbon Cycle (ACC or Manmade Carbon Cycle) where fossil fuels (coal, natural gas, crude oil) or biomass are burned to produce energy and carbon dioxide is released. Carbon dioxide is an essential gas for life. It functions as a Green House Gas (GHG) maintaining livable conditions on Earth. Carbon dioxide gas has a slightly irritating odor, is colorless and heavier than air. It freezes at -78.5 °C to form carbon dioxide snow, used in fired extinguishers.