Pentafluoroethane

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Pentafluoroethane
1,1,1,2,2-Pentafluoroethane-2D-skeletal.png
1,1,1,2,2-Pentafluoroethane.svg
Names
Preferred IUPAC name
Pentafluoroethane
Other names
Pentafluoroethane, Genetron HFC 125, Khladon 125, Suva 125, Freon 125, Fc-125, R-125
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.005.962 OOjs UI icon edit-ltr-progressive.svg
EC Number
  • 206-557-8
PubChem CID
UNII
  • InChI=1S/C2HF5/c3-1(4)2(5,6)7/h1H X mark.svgN
    Key: GTLACDSXYULKMZ-UHFFFAOYSA-N X mark.svgN
  • InChI=1/C2HF5/c3-1(4)2(5,6)7/h1H
    Key: GTLACDSXYULKMZ-UHFFFAOYAX
  • FC(F)C(F)(F)F
Properties
C2HF5
Molar mass 120.02 g/mol
AppearanceColourless gas. Has a faint, almost imperceptible odor
Density 1.53 g/cm3 (liquid at −48.5 °C) [1]
Melting point −103.0 °C (−153.4 °F; 170.2 K)
Boiling point −48.5 °C (−55.3 °F; 224.7 K)
Vapor pressure 1414.05 kPa (at 25 °C)
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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Pentafluoroethane is a fluorocarbon with the formula CF3CHF2. Pentafluoroethane is currently used as a refrigerant (known as R-125) and also used as a fire suppression agent in fire suppression systems.

Contents

Pentafluoroethane does not deplete ozone so it has replaced earlier fluorinated chemicals that did. However while it has zero ozone depletion potential, it has high global warming potential, reported by the United States Environmental Protection Agency (EPA) as 3450 times that of carbon dioxide. [2]

Refrigerant

Shipping container for the gas, shown in Japan Container [( 2079 )] CCRU 538017(0) [( Pictures taken in Japan )] .jpg
Shipping container for the gas, shown in Japan

Pentafluoroethane in a near azeotropic mixture with difluoromethane is known as R-410A, a common replacement for various chlorofluorocarbons (commonly known as Freon) in new refrigerant systems.

Fire suppression systems

HFC-125 (ECARO-25 / FE-25 / NAF S 125) is a gaseous fire suppression agent which can be used in clean agent fire suppression systems. In addition, HFC-125 leaves no residue on valuable equipment and material after discharge. [3] It is generally used in situations where water from a fire sprinkler would damage expensive equipment, or where water-based fire protection is impractical, such as museums, banks, clean rooms and hospitals. The HFC-125 clean agent is stored in a pressurized container and introduced into the hazard as a gas. The agent is odorless, colorless, electrically non-conductive, non-corrosive, and leaves no residue. It is used in occupied enclosed areas that contain high-value assets.

HFC-125 suppresses fire by absorbing heat energy at its molecular level faster than the heat can be generated, so the fire cannot sustain itself. It also forms free radicals to chemically interfere with the chain reaction of the combustion process. This makes it a highly effective fire fighting agent that is safe for people and causes no damage to equipment.

HFC-125 is considered a Clean Agent and is therefore included in the National Fire Protection Association's 2001 - Standard for Clean Agent Fire Extinguishing Systems.

Environmental impact

HFC-125 measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) in the lower atmosphere (troposphere) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion. HFC-125 mm.png
HFC-125 measured by the Advanced Global Atmospheric Gases Experiment (AGAGE) in the lower atmosphere (troposphere) at stations around the world. Abundances are given as pollution free monthly mean mole fractions in parts-per-trillion.
Atmospheric concentration of pentafluoroethane at various latitudes since year 2007. HFC125 concentration.jpg
Atmospheric concentration of pentafluoroethane at various latitudes since year 2007.

HFC-125 is a non-ozone depleting replacement for chlorine- or bromine-containing chemicals such as Halon 1301. Due to its global warming potential (GWP) of 3500 times that of CO₂ and atmospheric lifetime of 29 years, it is included in the list of controlled substances of the Montreal Protocol. [4] [5]

When introduced to the market HFC-125 was not considered safe for use in occupied spaces. The US EPA Significant New Alternative Policy (SNAP) listing reflected this. Following the introduction and acceptance of the PBPK model in the NFPA standard 2001 on Clean Agent Fire Extinguishing Systems 2004 Edition, the restriction was relaxed and now HFC-125 can be used in occupied hazards. Generally, class B (flammable liquid) hazards require concentrations that exceed the agent's no-observed-adverse-effect level (NOAEL) so extra precautions must be taken to avoid prolonged exposure to the agent.

At high temperatures, pentafluoroethane will decompose and produce hydrogen fluoride. This is observable as presence of sharp, pungent odour, which can be perceived in concentrations far below a dangerous level. Other decomposition products include carbonyl fluoride, carbon monoxide and carbon dioxide. Prior to re-entry of a room where HFC-125 system has been activated to suppress a fire, the atmosphere should be tested. An Acid Scavenging Additive added to pentafluoroethane is able to reduce the amount of hydrogen fluoride.

Brands

ECARO-25 is a registered trademark of Fike Corporation. FE-25 is a registered trademark of E. I. du Pont de Nemours and Company or its affiliates. NAF S 125 (HFC-125 plus Acid Scavenging Additive) is a trademark of Safety Hi-Tech.

Related Research Articles

<span class="mw-page-title-main">Chlorofluorocarbon</span> Class of organic compounds commonly used as refrigerants

Chlorofluorocarbons (CFCs) and hydrochlorofluorocarbons (HCFCs) are fully or partly halogenated hydrocarbons that contain carbon (C), hydrogen (H), chlorine (Cl), and fluorine (F), produced as volatile derivatives of methane, ethane, and propane.

<span class="mw-page-title-main">Bromochlorodifluoromethane</span> Chemical compound

Bromochlorodifluoromethane (BCF), also referred to by the code numbers Halon 1211 and Freon 12B1, is a haloalkane with the chemical formula CF2ClBr. It is used for fire suppression, especially for expensive equipment or items that could be damaged by the residue from other types of extinguishers. It is stored as a liquid under pressure and vaporizes when discharged to suppress fires. The use of halons, including Halon 1211, has decreased over time due to their adverse impact on the ozone layer. Alternatives have been developed to mitigate environmental concerns while still providing effective fire suppression capabilities.

Bromotrifluoromethane, commonly referred to by the code numbers Halon 1301, R13B1, Halon 13B1 or BTM, is an organic halide with the chemical formula CBrF3. It is used for gaseous fire suppression as a far less toxic alternative to bromochloromethane.

<span class="mw-page-title-main">Refrigerant</span> Substance in a refrigeration cycle

A refrigerant is a working fluid used in the refrigeration cycle of air conditioning systems and heat pumps where in most cases they undergo a repeated phase transition from a liquid to a gas and back again. Refrigerants are heavily regulated due to their toxicity, flammability and the contribution of CFC and HCFC refrigerants to ozone depletion and that of HFC refrigerants to climate change.

<span class="mw-page-title-main">Halomethane</span> Halogen compounds derived from methane

Halomethane compounds are derivatives of methane with one or more of the hydrogen atoms replaced with halogen atoms. Halomethanes are both naturally occurring, especially in marine environments, and human-made, most notably as refrigerants, solvents, propellants, and fumigants. Many, including the chlorofluorocarbons, have attracted wide attention because they become active when exposed to ultraviolet light found at high altitudes and destroy the Earth's protective ozone layer.

Halocarbon compounds are chemicals in which one or more carbon atoms are linked by covalent bonds with one or more halogen atoms resulting in the formation of organofluorine compounds, organochlorine compounds, organobromine compounds, and organoiodine compounds. Chlorine halocarbons are the most common and are called organochlorides.

Difluoromethane, also called difluoromethylene, HFC-32Methylene Fluoride or R-32, is an organic compound of the dihalogenoalkane variety. It has the formula of CH2F2. It is a colorless gas in the ambient atmosphere and is slightly soluble in the water, with a high thermal stability. Due to the low melting and boiling point, (-136.0 °C and -51.6 °C respectively) contact with this compound may result in frostbite. In the United States, the Clean Air Act Section 111 on Volatile Organic Compounds (VOC) has listed difluoromethane as an exception (since 1997) from the definition of VOC due to its low production of tropospheric ozone. Difluoromethane is commonly used in endothermic processes such as refrigeration or air conditioning.

1,1,1,2-Tetrafluoroethane (also known as norflurane (INN), R-134a, Klea 134a,Freon 134a, Forane 134a, Genetron 134a, Green Gas, Florasol 134a, Suva 134a, HFA-134a, or HFC-134a) is a hydrofluorocarbon (HFC) and haloalkane refrigerant with thermodynamic properties similar to R-12 (dichlorodifluoromethane) but with insignificant ozone depletion potential and a lower 100-year global warming potential (1,430, compared to R-12's GWP of 10,900). It has the formula CF3CH2F and a boiling point of −26.3 °C (−15.34 °F) at atmospheric pressure. R-134a cylinders are colored light blue. A phaseout and transition to HFO-1234yf and other refrigerants, with GWPs similar to CO2, began in 2012 within the automotive market.

Trichlorofluoromethane, also called freon-11, CFC-11, or R-11, is a chlorofluorocarbon (CFC). It is a colorless, faintly ethereal, and sweetish-smelling liquid that boils around room temperature. CFC-11 is a Class 1 ozone-depleting substance which damages Earth's protective stratospheric ozone layer.

<span class="mw-page-title-main">Gaseous fire suppression</span>

Gaseous fire suppression, also called clean agent fire suppression, is the use of inert gases and chemical agents to extinguish a fire. These agents are governed by the National Fire Protection Association (NFPA) Standard for Clean Agent Fire Extinguishing Systems – NFPA 2001 in the US, with different standards and regulations elsewhere. The system typically consists of the agent, agent storage containers, agent release valves, fire detectors, fire detection system, agent delivery piping, and agent dispersion nozzles.

Chlorodifluoromethane or difluoromonochloromethane is a hydrochlorofluorocarbon (HCFC). This colorless gas is better known as HCFC-22, or R-22, or CHClF
2. It was commonly used as a propellant and refrigerant. These applications were phased out under the Montreal Protocol in developed countries in 2020 due to the compound's ozone depletion potential (ODP) and high global warming potential (GWP), and in developing countries this process will be completed by 2030. R-22 is a versatile intermediate in industrial organofluorine chemistry, e.g. as a precursor to tetrafluoroethylene.

Fluoroform, or trifluoromethane, is the chemical compound with the formula CHF3. It is a Hydrofluorocarbon as well as being apart of the haloforms, a class of compounds with the formula CHX3 with C3v symmetry. Fluoroform is used in diverse applications in organic synthesis. It is not an ozone depleter but is a greenhouse gas.

R-410A, sold under the trademarked names AZ-20, EcoFluor R410, Forane 410A, Genetron R410A, Puron, and Suva 410A, is a zeotropic but near-azeotropic mixture of difluoromethane (CH2F2, called R-32) and pentafluoroethane (CHF2CF3, called R-125) that is used as a refrigerant in air conditioning and heat pump applications. R-410A cylinders were colored rose but are no longer specially color-coded, now bearing a standard light gray color.

<span class="mw-page-title-main">1,1,1,2,3,3,3-Heptafluoropropane</span> Chemical compound

1,1,1,2,3,3,3-Heptafluoropropane, also called heptafluoropropane, HFC-227ea, HFC-227 or FM-200, as well as apaflurane (INN), is a colourless, odourless gaseous halocarbon commonly used as a gaseous fire suppression agent.

PhostrEx is a fire suppression agent developed for use in aviation applications to replace halon, a greenhouse gas (GHG). It was developed by Eclipse Aviation for use aboard their Eclipse 500 very light jets as an engine fire suppression system, and is now being marketed to other aviation manufacturers.

<span class="mw-page-title-main">Automatic fire suppression</span> Fire suppression systems that operate without human control

Automatic fire suppression systems control and extinguish fires without human intervention. Examples of automatic systems include fire sprinkler system, gaseous fire suppression, and condensed aerosol fire suppression. When fires are extinguished in the early stages loss of life is minimal since 93% of all fire-related deaths occur once the fire has progressed beyond the early stages.

<span class="mw-page-title-main">1-Chloro-1,1-difluoroethane</span> Chemical compound

1-Chloro-1,1-difluoroethane (HCFC-142b) is a haloalkane with the chemical formula CH3CClF2. It belongs to the hydrochlorofluorocarbon (HCFC) family of man-made compounds that contribute significantly to both ozone depletion and global warming when released into the environment. It is primarily used as a refrigerant where it is also known as R-142b and by trade names including Freon-142b.

<span class="mw-page-title-main">Clean agent FS 49 C2</span> Fire suppression agent

Clean agent FS 49 C2 is an environmentally engineered, human safe, fast acting Clean Agent fire extinguishing gas for gaseous fire suppression installed in a suited fire suppression system. The gas consists of tetrafluoroethane, pentafluoroethane and carbon dioxide.

Zyron is a registered trademark for specialty gases marketed to the global electronics industry by DuPont.

The Significant New Alternatives Policy is a program of the EPA to determine acceptable chemical substitutes, and establish which are prohibited or regulated by the EPA. It also establishes a program by which new alternatives may be accepted, and promulgates timelines to the industry regarding phase-outs of substitutes.

References

  1. ↑ Kirk-Othmer Encyclopedia of Chemical Technology. Wiley. ISBN   9780471238966.
  2. ↑ "Protection of Stratospheric Ozone: Notice 20 for Significant New Alternatives Policy Program". Federal Register Environmental Documents. Environmental Protection Agency. March 29, 2006. Archived from the original on 29 Jul 2012.
  3. ↑ "ECARO-25® Clean Agent Fire Suppression - HFC-125". Fike. Archived from the original on Aug 6, 2020.
  4. ↑ Montreal Protocol Section 1.1. including 2016 Kigali amendment (in effect in 2019)
  5. ↑ P. Forster; V. Ramaswamy; P. Artaxo; T. Berntsen; R. Betts; D.W. Fahey; J. Haywood; J. Lean; D.C. Lowe; G. Myhre; J. Nganga; R. Prinn; G. Raga; M. Schulz; R. Van Dorland (2007). "Chapter 2: Changes in Atmospheric Constituents and in Radiative Forcing". In Solomon, S.; Miller, H.L.; Tignor, M.; Averyt, K.B.; Marquis, M.; Chen, Z.; Manning, M.; Qin, D. (eds.). Climate Change 2007: The Physical Science Basis. Contribution of Working Group I to the Fourth Assessment Report of the Intergovernmental Panel on Climate Change. Cambridge, United Kingdom and New York, NY, USA: Cambridge University Press. Archived from the original on 1 December 2016. Retrieved 9 October 2016.
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