1-Chloro-1,1-difluoroethane

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1-Chloro-1,1-difluoroethane
1-Chloro-1,1-difluoroethane.svg
Names
Preferred IUPAC name
1-Chloro-1,1-difluoroethane
Other names
Freon 142b; R-142b; HCFC-142b; Chlorodifluoroethane
Identifiers
3D model (JSmol)
ChemSpider
ECHA InfoCard 100.000.811 OOjs UI icon edit-ltr-progressive.svg
PubChem CID
UNII
  • InChI=1S/C2H3ClF2/c1-2(3,4)5/h1H3 Yes check.svgY
    Key: BHNZEZWIUMJCGF-UHFFFAOYSA-N Yes check.svgY
  • CC(F)(F)Cl
Properties
C2H3ClF2
Molar mass 100.49 g·mol−1
AppearanceColorless gas [1]
Melting point −130.8 °C (−203.4 °F; 142.3 K) [1]
Boiling point −9.6 °C (14.7 °F; 263.5 K) [1]
Slight [1]
Hazards
Occupational safety and health (OHS/OSH):
Main hazards
Asphyxiant
632 °C (1,170 °F; 905 K) [1]
Except where otherwise noted, data are given for materials in their standard state (at 25 °C [77 °F], 100 kPa).
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1-Chloro-1,1-difluoroethane (HCFC-142b) is a haloalkane with the chemical formula C H 3 C Cl F 2. 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. [2]

Contents

Physiochemical properties

1-Chloro-1,1-difluoroethane is a highly flammable, colorless gas under most atmospheric conditions. It has a boiling point of -10 °C. [1] [3] Its critical temperature is near 137 °C. [4]

Applications

HCFC-142b is used as a refrigerant, as a blowing agent for foam plastics production, and as feedstock to make polyvinylidene fluoride (PVDF). [5] It was introduced to replace the chlorofluorocarbons (CFCs) that were initially undergoing a phase-out per the Montreal Protocol, but HCFCs still have a significant ozone-depletion ability. As of year 2020, HCFC's are replaced by non ozone depleting HFCs within many applications. [6]

In the United States, the EPA stated that HCFCs could be used in "processes that result in the transformation or destruction of the HCFCs", such as using HCFC-142b as a feedstock to make PVDF. HCFCs could also be used in equipment that was manufactured before January 1, 2010. [7] The point of these new regulations was to phase-out HCFCs in much the same way that CFCs were phased out. HCFC-142b production in non article 5 countries like the United States was banned on January 1, 2020, under the Montreal Protocol. [6]

Production history

According to the Alternative Fluorocarbons Environmental Acceptability Study (AFEAS), in 2006 global production (excluding India and China who did not report production data) of HCFC-142b was 33,779 metric tons and an increase in production from 2006 to 2007 of 34%. [8]

For the most part, concentrations of HCFCs in the atmosphere match the emission rates that were reported by industries. The exception to this is HCFC-142b which had a higher concentration than the emission rates suggest it should. [9]

Environmental effects

Growth of HCFC-142b in Earth's atmosphere since year 1992. HCFC142b concentration.jpg
Growth of HCFC-142b in Earth's atmosphere since year 1992.
HCFC-142b 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. HCFC-142b mm.png
HCFC-142b 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.

The concentration of HCFC-142b in the atmosphere grew to over 20 parts per trillion by year 2010. [10] It has an ozone depletion potential (ODP) of 0.07. [11] This is low compared to the ODP=1 of trichlorofluoromethane (CFC-11, R-11), which also grew about ten times more abundant in the atmosphere by year 1985 (prior to introduction of HCFC-142b and the Montreal Protocol).

HCFC-142b is also a minor but potent greenhouse gas. It has an estimated lifetime of about 17 years and a 100-year global warming potential ranging 2300 to 5000. [12] [13] This compares to the GWP=1 of carbon dioxide, which had a much greater atmospheric concentration near 400 parts per million in year 2020.

See also

Related Research Articles

<span class="mw-page-title-main">Montreal Protocol</span> 1987 treaty to protect the ozone layer

The Montreal Protocol on Substances That Deplete the Ozone Layer is an international treaty designed to protect the ozone layer by phasing out the production of numerous substances that are responsible for ozone depletion. It was agreed on 16 September 1987, and entered into force on 1 January 1989. Since then, it has undergone nine revisions, in 1990 (London), 1991 (Nairobi), 1992 (Copenhagen), 1993 (Bangkok), 1995 (Vienna), 1997 (Montreal), 1999 (Beijing) and 2016 (Kigali). As a result of the international agreement, the ozone hole in Antarctica is slowly recovering. Climate projections indicate that the ozone layer will return to 1980 levels between 2040 and 2066. Due to its widespread adoption and implementation, it has been hailed as an example of successful international co-operation. Former UN Secretary-General Kofi Annan stated that "perhaps the single most successful international agreement to date has been the Montreal Protocol". In comparison, effective burden-sharing and solution proposals mitigating regional conflicts of interest have been among the success factors for the ozone depletion challenge, where global regulation based on the Kyoto Protocol has failed to do so. In this case of the ozone depletion challenge, there was global regulation already being installed before a scientific consensus was established. Also, overall public opinion was convinced of possible imminent risks.

<span class="mw-page-title-main">Ozone layer</span> Region of the stratosphere

The ozone layer or ozone shield is a region of Earth's stratosphere that absorbs most of the Sun's ultraviolet radiation. It contains a high concentration of ozone (O3) in relation to other parts of the atmosphere, although still small in relation to other gases in the stratosphere. The ozone layer contains less than 10 parts per million of ozone, while the average ozone concentration in Earth's atmosphere as a whole is about 0.3 parts per million. The ozone layer is mainly found in the lower portion of the stratosphere, from approximately 15 to 35 kilometers (9 to 22 mi) above Earth, although its thickness varies seasonally and geographically.

<span class="mw-page-title-main">Ozone depletion</span> Atmospheric phenomenon

Ozone depletion consists of two related events observed since the late 1970s: a steady lowering of about four percent in the total amount of ozone in Earth's atmosphere, and a much larger springtime decrease in stratospheric ozone around Earth's polar regions. The latter phenomenon is referred to as the ozone hole. There are also springtime polar tropospheric ozone depletion events in addition to these stratospheric events.

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

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">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 because of their toxicity and 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.

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

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 water, with a high thermal stability. Due to the low melting and boiling point, (−136.0 and −51.6 °C [−212.8 and −60.9 °F; 137.2 and 221.6 K] 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.

<span class="mw-page-title-main">Chlorodifluoromethane</span> Chemical propellant and refrigerant

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.

Chlorotrifluoromethane, R-13, CFC-13, or Freon 13, is a non-flammable, non-corrosive, nontoxic chlorofluorocarbon (CFC) and also a mixed halomethane. It is a man-made substance used primarily as a refrigerant. When released into the environment, CFC-13 has a high ozone depletion potential, and long atmospheric lifetime. Only a few other greenhouse gases surpass CFC-13 in global warming potential (GWP). The IPCC AR5 reported that CFC-13's atmospheric lifetime was 640 years.

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

2,2-Dichloro-1,1,1-trifluoroethane or HCFC-123 is considered as an alternative to CFC-11 in low pressure refrigeration and HVAC systems, and should not be used in foam blowing processes or solvent applications. It is also the primary component of the Halotron I fire-extinguishing mixture.

Natural refrigerants are considered substances that serve as refrigerants in refrigeration systems. They are alternatives to synthetic refrigerants such as chlorofluorocarbon (CFC), hydrochlorofluorocarbon (HCFC), and hydrofluorocarbon (HFC) based refrigerants. Unlike other refrigerants, natural refrigerants can be found in nature and are commercially available thanks to physical industrial processes like fractional distillation, chemical reactions such as Haber process and spin-off gases. The most prominent of these include various natural hydrocarbons, carbon dioxide, ammonia, and water. Natural refrigerants are preferred actually in new equipment to their synthetic counterparts for their presumption of higher degrees of sustainability. With the current technologies available, almost 75 percent of the refrigeration and air conditioning sector has the potential to be converted to natural refrigerants.

Refrigerant reclamation is the act of processing used refrigerant gas which has previously been used in some type of refrigeration loop such that it meets specifications for new refrigerant gas. In the United States, the Section 608 of the Clean Air Act of 1990 requires that used refrigerant be processed by a certified reclaimer, which must be licensed by the United States Environmental Protection Agency (EPA), and the material must be recovered and delivered to the reclaimer by EPA-certified technicians.

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

1,1-Dichloro-1-fluoroethane is a haloalkane with the formula C
2
H
3
Cl
2
F
. It is one of the three isomers of dichlorofluoroethane. 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.

<span class="mw-page-title-main">Hydrofluoroolefin</span> Class of chemical compounds

Hydrofluoroolefins (HFOs) are unsaturated organic compounds composed of hydrogen, fluorine and carbon. These organofluorine compounds are of interest as refrigerants. Unlike traditional hydrofluorocarbons (HFCs) and chlorofluorocarbons (CFCs), which are saturated, HFOs are olefins, otherwise known as alkenes.

Life Cycle Climate Performance (LCCP) is an evolving method to evaluate the carbon footprint and global warming impact of heating, ventilation, air conditioning (AC), refrigeration systems, and potentially other applications such as thermal insulating foam. It is calculated as the sum of direct, indirect, and embodied greenhouse gas (GHG) emissions generated over the lifetime of the system “from cradle to grave,” i.e. from manufacture to disposal. Direct emissions include all climate forcing effects from the release of refrigerants into the atmosphere, including annual leakage and losses during service and disposal of the unit. Indirect emissions include the climate forcing effects of GHG emissions from the electricity powering the equipment. The embodied emissions include the climate forcing effects of the manufacturing processes, transport, and installation for the refrigerant, materials, and equipment, and for recycle or other disposal of the product at end of its useful life.

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

Tetrachloro-1,1-difluoroethane or 1,1,1,2-tetrachloro-2,2-difluoroethane, Freon 112a, R-112a, or CFC-112a is an asymmetric chlorofluorocarbon isomer of tetrachloro-1,1-difluoroethane with formula CClF2CCl3. It contains ethane substituted by four chlorine atoms and two fluorine atoms. With a boiling point of 91.5°C it is the freon with second highest boiling point.

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

1,1-Dichlorotetrafluoroethane is a chlorofluorocarbon also known as CFC-114a or R114a by American Society of Heating, Refrigerating, and Air Conditioning Engineers. It has two chlorine atoms on one carbon atom and none on the other. It is one of two isomers of dichlorotetrafluoroethane, the other being 1,2-dichlorotetrafluoroethane, also known as CFC-114.

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

2-Chloro-1,1-difluoroethene (also known as R 1122, u-HCFC-1122 or HCFO-1122) is a toxic unsaturated hydrochlorofluorocarbon which can be written as CF2=CHCl. The HCFO portion of the name stands for hydrochlorofluoroolefin. Another constitutional isomer of it, 1-chloro-1,2-difluoroethylene, is known as HCFO-1122a.

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

2-Chloro-1,1-difluoroethane (HCFC-142) is a haloalkane and a hydrochlorofluorocarbon. It is produced as a byproduct of the production of 1-chloro-1,1-difluoroethane (HCFC-142b). According to a 2022 report by the WMO and other agencies, it has an ODP of 0.019 and a 100-year GWP of 189.

References

  1. 1 2 3 4 5 6 Record in the GESTIS Substance Database of the Institute for Occupational Safety and Health
  2. "Safety Data Sheet for 1-Chloro-1,1-difluoroethane" (PDF). Archived from the original (PDF) on 24 October 2018. Retrieved 24 February 2018.
  3. "Addenda d, j, l, m, and t to ANSI/ASHRAE Standard 34-2004" (PDF). ANSI/ASHRAE Standard 34-2004, Designation and Safety Classification of Refrigerants. Atlanta, GA: American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc. 2007-03-03. ISSN   1041-2336. Archived from the original (PDF) on 2011-10-12. Retrieved 2011-12-18.
  4. Schoen, J. Andrew, "Listing of Refrigerants" (PDF), Andy's HVAC/R Web Page, archived from the original (PDF) on 2009-03-19, retrieved 2011-12-17
  5. "Phaseout of Class II Ozone-Depleting Substances". Environmental Protection Agency. 22 July 2015.
  6. 1 2 "Overview of HCFC Consumption and Available Alternatives For Article 5 Countries" (PDF). ICF International. 2008. Retrieved 2021-02-12.
  7. U.S. Government Publishing Office Federal Register 2005 November 4, Protection of Stratospheric Ozone: Notice of Data Availability; Information Concerning the Current and Predicted Use of HCFC-22 and HCFC-142b Pages 67172 - 67174 [FR DOC # 05-22036].
  8. "Production and Sales of Fluorocarbons - AFEAS". Archived from the original on 2015-09-28. Retrieved 2018-02-13.
  9. "Good news from the stratosphere, sort of: Accumulating HCFCs won't stop ozone-hole mending". Archived from the original on 2016-03-03. Retrieved 2018-02-13.
  10. 1 2 "HCFC-142b". NOAA Earth System Research Laboratories/Global Monitoring Division. Retrieved 2021-02-12.
  11. John S. Daniel; Guus J.M. Velders; A.R. Douglass; P.M.D. Forster; D.A. Hauglustaine; I.S.A. Isaksen; L.J.M. Kuijpers; A. McCulloch; T.J. Wallington (2006). "Chapter 8. Halocarbon Scenarios, Ozone Depletion Potentials, and Global Warming Potentials" (PDF). Scientific Assessment of Ozone Depletion: 2006. Geneva, Switzerland: World Meteorological Organization . Retrieved 9 October 2016.
  12. "Chapter 8". AR5 Climate Change 2013: The Physical Science Basis. p. 731.
  13. "Refrigerants - Environmental Properties". The Engineering ToolBox. Retrieved 2016-09-12.