Chlorodifluoromethane

Chlorodifluoromethane ko difluoromonochloromethane hydrochlorofluorocarbon ne (HCFC). Wannan iskar gas mara launi an fi sani da HCFC-22, ko R-22, ko CHClF2. An yi amfani da shi azaman mai amfani da man fetur da mai sanyaya. Wadannan aikace-aikacen an cire su a karkashin Yarjejeniyar Montreal a cikin Kasashe masu tasowa a cikin 2020 saboda yiwuwar lalacewar ozone (ODP) da kuma yiwuwar dumama duniya (GWP), kuma a cikin Kasashe masu tasowa wannan tsari za a kammala shi a shekarar 2030. R-22 matsakaici ne mai amfani a cikin masana'antu organofluorine sunadarai, misali a matsayin mai gabatarwa ga tetrafluoroethylene. 

 Fitarwa da aikace-aikace na yanzu 
A duniya samar da R-22 a cikin 2008 ya kasance game da 800 Gg a kowace shekara, daga kimanin 450 Gg a kowane shekara a cikin 1998, tare da mafi yawan samarwa a kasashe masu tasowa. Ana amfani da R-22 a cikin kasashe masu tasowa, inda ake amfani da shi sosai don aikace-aikacen sanyaya iska.

An shirya R-22 daga chloroform:

 HCCl3 + 2 HF → HCF2Cl + 2 HCl

Wani muhimmin aikace-aikacen R-22 shine a matsayin mai gabatarwa ga tetrafluoroethylene. Wannan juyawa ya haɗa da pyrolysis don ba da difluorocarbene, wanda ke dimerizes: 

 2 CHClF2 → C2F4 + 2 HCl

Har ila yau, fili yana samar da difluorocarbene a kan magani tare da tushe mai ƙarfi kuma ana amfani dashi a cikin dakin gwaje-gwaje a matsayin tushen wannan matsakaici.

Pyrolysis na R-22 a gaban chlorofluoromethane yana ba da hexafluorobenzene.

 Tasirin muhalli 
Sau da yawa ana amfani da R-22 a matsayin madadin CFC-11 da CFC-12 masu raguwa sosai, saboda ƙarancin yiwuwar raguwar ozone na 0.055,  daga cikin mafi ƙasƙanci ga haloalkanes masu ƙunshe da chlorine. Koyaya, ko da wannan ƙarancin yiwuwar ƙarancin ozone ba a ɗauka a matsayin abin karɓa ba.

A matsayin ƙarin damuwa game da muhalli, R-22 gas ne mai karfi tare da GWP daidai da 1810 (wanda ke nuna sau 1810 kamar yadda carbon dioxide yake). Hydrofluorocarbons (HFCs) galibi ana maye gurbin su don R-22 saboda ƙananan yiwuwar lalacewar ozone, amma waɗannan refrigerants galibi suna da GWP mafi girma. R-410A, alal misali, sau da yawa ana maye gurbinsa, amma yana da GWP na 2088. Wani maye gurbin shine R-404A tare da GWP na 3900. Sauran madadin refrigerants suna samuwa tare da ƙananan GWP. Ammoniya (R-717), tare da GWP na <1, ya kasance sanannen maye gurbin a kan jiragen kamun kifi da manyan aikace-aikacen masana'antu. Ammoniya mai guba a cikin babban taro yana iyakance aikace-aikacensa a cikin ƙananan aikace-aikace na sanyaya.

Propane (R-290) wani misali ne, kuma yana da GWP na 3. Propane shine mai sanyaya a cikin tsarin da ya fi karami fiye da sikelin masana'antu kafin gabatarwar CFCs. Sunan firiji na propane a matsayin haɗarin wuta ya ci gaba da isar da kankara da akwatin kankara babban zaɓi na mabukaci duk da rashin jin daɗinsa da tsada mafi girma har sai tsarin CFC mai aminci ya shawo kan mummunan ra'ayi na firiji. Ba bisa ka'ida ba ne a yi amfani da shi azaman firiji a Amurka na tsawon shekaru, yanzu an ba da izinin amfani da propane a cikin iyakantaccen taro wanda ya dace da ƙananan firiji. Ba doka ba ce a yi amfani da shi a cikin masu sanyaya iska ko manyan firiji saboda ƙonewa da yiwuwar fashewa.


 Mataki a cikin Tarayyar Turai 
Tun daga 1 ga Janairun 2010, ba bisa ka'ida ba ne a yi amfani da sababbin HCFCs don ba da sabis ga firiji da kayan sanyaya iska; kawai za a iya amfani da HCFC da aka dawo da su da sake amfani da su. A aikace wannan yana nufin cewa dole ne a cire iskar gas daga kayan aiki kafin a yi aiki kuma a maye gurbin ta daga baya, maimakon a sake cika ta da sabon iskar gas.

Tun daga 1 ga Janairun 2015, ba bisa ka'ida ba ne a yi amfani da kowane HCFCs don ba da sabis ga firiji da kayan aikin sanyaya iska; kayan aikin da suka lalace waɗanda suka yi amfani da firiji na HCFC dole ne a maye gurbin su da kayan aikin da ba sa amfani da su.

 Phaseout a Amurka 
An fi fitar da R-22 a cikin sabbin kayan aiki a Amurka ta hanyar aiki na EPA a karkashin Shirin Sabon Sabon Sabbin Sabon Sabanin Sabon Sabobin Sabon Sabin Sabon Sabutun Sabon Saben Sabon Saboton Sabon Sabõda ka'idojin 20 da 21 na shirin,  saboda babban damar dumama duniya. Shirin EPA ya yi daidai da Yarjejeniyar Montreal, amma dole ne Majalisar Dattijan Amurka ta tabbatar da yarjejeniyar kasa da kasa don samun sakamako na doka. Wani yanke shawara na 2017 na Kotun daukaka kara ta Amurka don Gundumar Columbia  ya yanke shawarar cewa EPA ta Amurka ba ta da ikon tsara amfani da R-22 a karkashin SNAP. Ainihin kotun ta yanke hukuncin cewa ikon doka na EPA  shine don rage ozone, ba dumamar duniya ba. EPA daga baya ta ba da jagora ga tasirin cewa EPA ba za ta sake tsara R-22 ba. Wani hukunci na 2018  daga wannan kotun ya yanke shawarar cewa EPA ta kasa bin tsarin da ake buƙata lokacin da ta ba da jagoranta bisa ga hukuncin 2017, ta soke jagorar, amma ba hukuncin da ya gabata da ya buƙaci shi ba. Masana'antar sanyaya da sanyaya iska sun riga sun dakatar da samar da sabbin kayan aikin R-22. Sakamakon amfani na waɗannan hukunce-hukuncen shine rage farashin R-22 da aka shigo da shi don kula da kayan aiki masu tsufa, tsawaita rayuwar sabis ɗin, yayin hana amfani da R-22 a cikin sabbin kayan aiki.

 R-22, sake fasalin ta amfani da madadin refrigerants 

Kyakkyawan makamashi da ƙarfin tsarin da aka tsara don R-22 ya ɗan fi girma ta amfani da R-22 fiye da maye gurbin da ke akwai.

R-407A ana amfani dashi a cikin sanyaya mai sauƙi da matsakaici. Yana amfani da man polyolester (POE).

R-407C don amfani ne a cikin sanyaya iska. Yana amfani da mafi ƙarancin kashi 20 cikin dari na man POE.

R-407F da R-407H suna amfani da su a cikin aikace-aikacen sanyaya na matsakaici da ƙananan zafin jiki (supermarkets, ajiyar sanyi, da tsarin sanyaya); ƙirar tsarin fadada kai tsaye kawai. Suna amfani da man POE.

R-421A ana amfani dashi ne a cikin "tsarin rarraba iska, famfo na zafi, tsarin pak na supermarket, masu sanyaya madara, ajiyar kai, aikace-aikacen burodi, jigilar firiji, ɗakunan nuni masu zaman kansu, da masu sanyaya". Yana amfani da man ma'adinai (MO), Alkylbenzene (AB), da POE.

R-422B ana amfani dashi a aikace-aikacen low-, matsakaici-, da high-zafin jiki. Ba a ba da shawarar amfani da shi a aikace-aikacen ambaliyar ruwa.

R-422C don amfani ne a cikin aikace-aikacen matsakaici da ƙananan zafin jiki. Za a buƙaci canza wutar lantarki ta TXV zuwa kashi na 404A/507A kuma ana iya buƙatar maye gurbin hatimi mai mahimmanci (elastomers).

R-422D don amfani ne a cikin aikace-aikacen low-lokaci, kuma yana da man fetur mai jituwa.

R-424A ana amfani dashi a cikin sanyaya iska da kuma matsakaicin yanayin sanyaya na 20 zuwa 50 ̊F. Yana aiki tare da MO, alkylbenzenes (AB), da mai POE.

R-427A don amfani ne a cikin sanyaya iska da aikace-aikacen sanyaya. Ba ya buƙatar cire duk man ma'adinai. Yana aiki tare da mai na MO, AB, da POE.

R-434A ana amfani dashi a cikin ruwa mai sanyaya da kuma aiwatar da masu sanyaya don sanyaya iska da aikace-aikacen matsakaici da ƙananan zafin jiki. Yana aiki tare da mai na MO, AB, da POE.

R-438A (MO-99) ana amfani dashi a aikace-aikacen low-, matsakaici-, da high-zafin jiki. Ya dace da duk mai. 

R-458A don amfani ne a cikin sanyaya iska da aikace-aikacen sanyaya, ba tare da iyawa ko asarar inganci ba. Yana aiki tare da mai na MO, AB, da POE.

R-32 ko HFC-32 (difluoromethane) ana amfani dashi a cikin sanyaya iska da aikace-aikacen sanyaya. Yana da ƙarancin ƙarancin ozone (ODP)  da kuma yiwuwar dumama duniya (GWP) sau 675 na carbon dioxide.[2]

 Abubuwan jiki 
DukiyaDarajarDensity (ρ) a -69 °C (ruwa)  1.49 g⋅cm-3−3Density (ρ) a -41 °C (ruwa)  1.413 g⋅cm-3−3Density (ρ) a -41 °C (gas)  4,706 kg⋅m−3 Density (ρ) a 15 °C (gas)  3.66 kg⋅m−3 Takamaiman nauyi a 21 °C (gas)  3.08 (iska ita ce 1) Takamaiman girma (ν) a 21 °C (gas)  0.275 m3-1−1Density (ρ) a 15 °C (gas)  3.66 kg⋅m−3 Yanayin zafin jiki na uku (t)  -157.39 °C (115.76 K)  c="mw-redirect cx-link" data-linkid="143" href="./Critical_temperature" id="mw_w" rel="mw:WikiLink" title="Critical temperature">Yanayin zafi mai tsanani (Tc) 96.2 °C (369.3 K)  Matsi mai mahimmanc (pc) 4,936 MPa (49.36 bar) Matsi na tururi a 21.1 °c (pc)  0.9384 MPa (9.384 bar) Matsakaic yawa (ρc) 6.1 mol⋅l-1 −1Rashin zafi na tururi (lv) a wurin tafasa (−40.7 °C)  233.95 kJ⋅kg-1−1[./S<sub id= p_heat_capacity" id="mwASU" rel="mw:WikiLink" title="Specific heat capacity">Ikon zafi] a matsin lamba (Cp) a 30 ° C (86 ° F)   0.057 kJ.mol-1⋅K-1−1Ikon zafi a madaidaiciyar girma (Cv) a 30 ° C (86 ° F)   0.048 kJ⋅mol-1⋅K-1−1Rashin ƙarfin zafi (γ) a 30 °C (86 °F)   1.178253Abubuwan da ke tattare da matsawa (Z) a 15 °C 0.9831Abubuwan da ke tattare da ƙwayoyin cuta (ω) 0.22082Lokaci na dipole na kwayoyin1,458 DViscosity (η) a 0 °C 12.56 μPa⋅s (0.1256 cP) Rashin yiwuwar lalacewar ozone (ODP) 0.055 (CCl3F shine 1) Halin dumama na duniya (GWP) 1810 (CO2 shine 1) 
Yana da allotropes guda biyu: crystalline II a ƙasa da 59 K da crystallin I a sama da 59 K kuma a ƙasa da 115.73 K.
+Yanayin zafi da na jiki na saturated ruwa refrigerant 22:Yanayin zafi (K) Density (kg/m^3) Takamaiman zafi (kJ / kg K) Tsinkaye mai ƙarfi (kg/m s) Kinematic viscosity (m^2/s) Gudanarwa (W / m K) Rashin zafi (m^2/s) Lambar PrandtlBabban modulus (K^-1) +23014161.0873.56E-042.51E-070.11457.44E-083.40.002052401386.61.13.15E-042.27E-070.10987.20E-083.20.002162501356.31.1172.80E-042.06E-070.10526.95E-0830.002292601324.91.1372.50E-041.88E-070.10076.68E-082.80.002452701292.11.1612.24E-041.73E-070.09626.41E-082.70.002632801257.91.1892.01E-041.59E-070.09176.13E-082.60.002862901221.71.2231.80E-041.47E-070.08725.83E-082.50.003153001183.41.2651.61E-041.36E-070.08265.52E-082.50.003513101142.21.3191.44E-041.26E-070.07815.18E-082.40.0043201097.41.3911.28E-041.17E-070.07344.81E-082.40.004693301047.51.4951.13E-041.08E-070.06864.38E-082.50.00575340990.11.6659.80E-059.89E-080.06363.86E-082.60.00756350920.11.9978.31E-059.04E-080.05833.17E-082.80.01135360823.43.0016.68E-058.11E-080.05312.15E-083.80.02388

 Tarihin farashi da wadata 
EPA's analysis indicated the amount of existing inventory was between 22,700t and 45,400t. []
Shekara201020112012201320142015–20192020R-22 Budurwa (t) 0R-22 Maidowa (t)  -- -- -- -- --R-22 Jimillar (t)  -- --
   A cikin 2012 EPA ta rage adadin R-22 da kashi 45%, wanda ya sa farashin ya tashi sama da 300%. A shekara ta 2013, EPA ta rage adadin R-22 da kashi 29%.

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