Cire methane a sararin samaniya

Cire methane na yanayi wani nau'i ne na hanyoyin da ake bincike don hanzarta rushewar methane wanda ke cikin yanayi, don rage wasu tasirin Canjin yanayi.2-1 Methane na yanayi ya karu tun lokacin da aka fara masana'antu daga 0.7 ppm zuwa 1.9 ppm, fiye da ninki biyu a cikin maida hankali. Karin methane daga masana'antu yana da alaƙa da gazawar methane na halitta wajen karɓar karuwar methane saboda ayyukan ɗan adam. Daga 2010 zuwa 2019, hayakin methane ya haifar da 0.5 ° C (kimanin 30%) na lura da dumamar duniya. Rashin hayaki na duniya ya kusanci rikodin 600 Tg CH4 a kowace shekara a cikin 2017. Methane gas ne mai karfi mai kula da gida tare da rayuwa har zuwa shekaru 12. Tare da ikon yin halayen canza methane zuwa carbon dioxide wanda ke da rayuwa a cikin daruruwan dubban shekaru, methane iskar gas ce mai tasiri. Methane na sararin samaniya ya fi ƙarfin gas fiye da carbon dioxide tare da yiwuwar dumama duniya sau 34 sama da sau 86 sama da shekaru 20.  Tunda methane ya fi karfi a cikin iskar gas, cire karamin methane na yanayi idan aka kwatanta da carbon dioxide daga yanayi zai haifar da irin wannan tasirin yanayi. Tare da matakan baya na carbon dioxide na yanayi kusan 420 ppm da matakan baya nke methane na yanayi kusan 1.92 ppm, ƙananan ƙididdigar methane yana haifar da karuwa a cikin wahalar kama methane idan aka kwatanta da carbon dioxide. Tare da karancin methane a cikin yanayi, kwanciyar hankali na methane da yanayin yanayi dangane da thermodynamics, kinetics, da canja wurin taro sune manyan abubuwan da ke ba da gudummawa ga wahalar cirewa. Cire carbon dioxide daga yanayi ya tabbatar da cewa yana da tasiri dangane da kokarin rage iskar gas, tare da kokarin bincike daban-daban da kuma tushen fasaha.  ** **

An yi nazarin hanyoyin cire methane da yawa na yanayi, gami da photocatalysts da metal catalysts da ke da alaƙa da zeolites da hanyoyin sadarwar polymer. Hanyoyin cire methane na tushen halittu waɗanda aka yi nazari sun haɗa da samar da gishiri na ƙarfe, hanyoyin masana'antu, da hanyoyin sarrafa ƙasa a cikin tsarin halittu daban-daban. Yawancin hanyoyin cire methane sun haɗa da ilmin sunadarai, kamar su thermal-catalytic, photocatalytic. Wuraren da aka yi niyya don lalata methane sun haɗa da iska mai muhalli, iska mai wadataccen methane, iska mai zurfi, da iska mai fashewa. Bayanan waɗannan manufofi da ƙididdigar haɗakar yanayi na yanayi ana iya gani a cikin tebur 1 tare da bayani kamar yadda aka bayar a Nisbet-Jones.

Tebur 1: Wannan teburin kai tsaye ya sake dawo da bayanai daga Nisbet-Jones yana ba da bayani game da manufofi daban-daban don gano methane da kuma daidaitattun haɗuwa da misalai da aka jera a cikin ra'ayi.

Don cire methane daga yanayi, makamashi wanda mai yiwuwa ya shafi fitar da iskar gas mai guba yana da hannu kai tsaye. Wannan ya sa wasu nau'ikan anthropogenic na cire methane da ke iya zama ƙasa da amfanin gona kuma mafi lalacewa fiye da barin methane a cikin yanayi. Ba tare da la'akari da tasirin muhalli ba, farashi da fa'idodi, da sauran sanannun dalilai, duk hanyoyin cire methane na yanayi za a tattauna su sosai a cikin wannan labarin ciki har da bayanan da suka shafi cire methane.

## Rashin ruwa na yanayi na yanayi

Methane yana da iyakantaccen rayuwar yanayi na kimanin shekaru 10 saboda yawan sinks na methane. Babban sink na methane shine oxidation na yanayi, daga hydroxyl radicals (OH) (~90% na jimlar sink) da kuma chlorine radicals (0-5% na jimlar nutk). Sauran ana cinye su da methanotrophs da sauran ƙwayoyin cuta masu methane-oxidizing da archaea a cikin ƙasa (~ 5%).  Halin sinadarai a cikin yanayi kamar halayen tropospheric, halayen stratospheric.

### Halin Tropospheric da stratospheric

#### Halin da ke faruwa a sararin samaniya
Halayen tropospheric waɗanda ke aiki azaman methane na yanayi na yanayi da farko waɗanda ke ƙarƙashin ikon halogen atom waɗanda ke oxidize methane. Atomic chlorine (Cl) halogen ne wanda ke ba da gudummawa sosai, musamman idan akwai babban aiki saboda bambancin yanayi na yanayi wanda ke faruwa a cikin iyakar iyaka.  Sodium chloride (NaCl) a cikin yankunan bakin teku da na ruwa yana ƙafewa daga digo na ruwan teku bayan amsawa tare da nitrogen dioxide (NO 2 ) don samar da diatomic chlorine (Cl 2 ), wanda ke fama da halayen photolytic don samar da sinadarin chlorine.  Atomic chlorine radicals suna da tasiri sosai kuma suna da ikon yin hulɗa da methane ta hanyar da ke lalata fili.

#### Halin Stratospheric
Methane ya ɓace a cikin yanayi ta hanyar halayen da ke da iskar oxygen (O ('D)), Cl, atomic fluorine (F), da OH. An ɗauka cewa na oxidation a cikin stratosphere, kusan 20% zuwa 35% na oxidation ne saboda halons, 25% ne saboda O ('D) a cikin babban stratosphere ne, kuma sauran oxidation a mu stratosphere shine saboda stratospheric OH.

### Yankin da aka samu
Samun ƙasa wanda ya haɗa da ƙasa mai ƙarancin oxic sune sinks na methane saboda kasancewar ƙwayoyin cuta na methanotrophic, waɗanda ke cinye methane a matsayin tushen makamashi. Wani samfurin da aka yi amfani da shi don nazarin ɗaukar methane a cikin ƙasa ya nuna ɗaukar kusan Teragrams 32 a kowace shekara. Samun ƙasa na methane yana da tasiri ta hanyar ƙarin hanyoyin watsa ruwa da jigilar shuka.

## Hanyoyin da za a iya amfani da su
Hanyoyi daban-daban don cire methane daga yanayi sun haɗa da ƙarancin zafi, ƙarancin photocatalytic, cire methane na methanotrophic na halitta, mai da hankali tare da zeolites ko wasu abubuwa masu ƙarfi, da rabuwa da membranes. Za'a iya rarraba hanyoyin da za a iya amfani da su ta hanyar tsarin haɓaka, ko kuma hanyar da za a yi amfani da ita.

### Ingantaccen Methane Oxidation na Yanayi
Ingantaccen yanayi na methane oxidation shine manufar inganta yawan oxidative methane sink a cikin yanayi ta hanyar tsara ƙarin OH ko Cl radicals. Hanyoyin ingantaccen yanayi na methane oxidation sun ƙunshi mafi yawan hanyoyin cire methane na yanayi.

#### Aerosols na gishiri na ƙarfe
Iron salt aerosols (ISA) wata hanya ce da aka gabatar don inganta yanayin methane oxidation wanda ya haɗa da ɗaga ƙwayoyin ƙarfe a cikin yanayi (misali daga jiragen sama ko jiragen ruwa) don haɓaka ƙwayoyin chlorine na yanayi, sink na halitta. Iska a kan Sahara tana tayar da ƙura a cikin troposphere kuma tana watsar da shi a kan Atlantic, tana ba da yanayi tare da kwayoyin da suka kunshi barbashi na ƙarfe. Binciken da aka yi a cikin 2023 ya nuna cewa wannan ya ba da gudummawa ga yanayin yanayi na methane. Har yanzu ba a gwada wannan hanyar a cikin filin ba, amma an yi nazarin bincike iri-iri da suka shafi ISA. An gudanar da hanyoyin bincike ta hanyar gwaje-gwaje na dakin gwaje-gaje, bincike na lura, da ƙididdigar lambobi don kimanta yiwuwar tasirin ISAs.

Ana nazarin ISAs don yiwuwar ƙarfe (III) chloride (FeCl3) don haɓaka samar da chlorine radical. Ana samar da atoms na Cl ta hanyar photolysis daga FeCl3 wanda ya samo asali ne daga ƙurar ƙurar ƙura mai ƙura a cikin iyakar teku.

FeCl3 + hv → FeCl2 + oCl

Kwayoyin Cl suna fara methane oxidation:

CH4 + o → HCl + oCH3

Sakamakon methyl radical ba shi da daidaituwa kuma yana da ƙwayoyin cuta ta halitta zuwa CO2 da ruwa:

3.5o2 + 2 → 2CO2 + 3H2O

Sakamakon tasirin ƙarfe (III) chloride

Inganta Cl a cikin troposphere yana da damar haifar da raguwar methane a cikin tropesphere. Ƙarin maida hankali na Cl a cikin troposphere na iya haifar da rage maida hankali ga OH, yana ƙara rayuwar nau'o'in da ke da lahani ga lafiyar ɗan adam. Tasirin ISAs a kan stratosphere na iya haifar da lalacewar ozone, lalata Layer na ozone. Abubuwan da suka shafi makomar Cl da ke cikin matakai na ISA ba su da tabbas kuma suna buƙatar ƙarin bincike, kamar yadda ƙarin Cl a cikin yanayi na iya zama barazana ga al'ummomin bakin teku, rayuwar halittu, da ƙarancin teku. A ƙarshe duk ƙwayoyin ƙarfe (III) chloride suna fuskantar wer-deposition kuma suna faɗuwa a ƙasa ko ruwa, inda suke narkewa cikin mahaɗan ƙarfe da gishiri. Bayan wankewa, gishirin ƙarfe na iya taimakawa ga takin ƙarfe. Kyakkyawan barbashi da aka warwatsa a cikin yanayi na iya zama ƙwayoyin girgije kuma ta haka ne ya haifar da haskaka girgije na ruwa kuma zai iya haifar da canje-canje ga albedo na Duniya.

Ƙarin binciken daga binciken ISA da ya gabata da sauran tushe sun ba da shawarar ƙarin bincike kan tasirin ISA akan lafiyar ɗan adam, yiwuwar, da ƙarin kimantawa game da tasirin abubuwan muhalli. Gudanarwa da tasirin zamantakewa game da cire methane na yanayi yana da mahimmanci wajen aiwatar da mafita masu yuwuwa.

### Ingantawar methanotroph na ƙasa
Kwayoyin cuta na ƙasa da archaea suna da kusan 5% na sink na halitta. Bincike na farko yana shiga cikin yadda za'a iya inganta aikin waɗannan ƙwayoyin cuta, ko dai ta hanyar amfani da gyare-gyaren ƙasa, ko gabatar da ƙwayoyin ƙwayoyin da aka zaɓa ko ƙwayoyin methane-oxidide.#cite_note-:12-4 [1] Microbes sun tabbatar da zama na biyu mafi girma na halitta don methane na yanayi, tara kusan 40 Teragrams na methane a kowace shekara. Anaerobic archaea da ƙwayoyin cuta na aerobic methanotrophs suna da enzymes waɗanda ke shayar da methane, waɗanda ke da methane monooxygenase da methyl coenzyme M reductase. Nazarin ya goyi bayan ra'ayin methanotrophs da ke iya haɗa kai tsaye anaerobic oxidation na methane zuwa denitrification na nitrate (NO3-).  Canjin methane-to-methane na ilimin halitta yana da sha'awa a cikin tsarin kamar maganin ruwa inda ake amfani da methanol don haɓaka ƙimar denitrification.

An yi bincike game da cire methane a cikin ƙasa ta noma, ƙasa da ba ta noma ba, da kuma kayan aikin wucin gadi. Wani binciken ya nuna cewa biochar da aka samo daga shinkafa ya rage hayakin methane daga ƙasa ta paddy da kashi 40% a cikin gwaje-gwaje na microcosm, tare da raguwar da ke da alaƙa da raguwar aikin methanogens da karuwar aikin methane oxidation na methanotrophs. An nuna ƙarin sulfate don rage hayakin methane daga shinkafa a cikin wannan binciken, yana nuna wani yiwuwar jagora don raguwa a cikin samar da methane.

An bincika matattarar ƙwayoyin cuta a matsayin hanyar cire methane daga sararin samaniya don gurɓataccen tushe. Tsarin tacewa yana amfani da ƙwayoyin cuta masu cin methane don yin oxidize da methane da ke cikin yanayi. Bio-covers da biofilters tare da methanotrophs a halin yanzu ana amfani da su don wasu wuraren gurɓataccen tushe kamar ƙananan da tsofaffi don rage methane.

### Tsarin injiniya na Catalytic
An tsara tsarin injiniyan injiniya don wuce iska daga yanayi, ko dai a hankali ko a hankali, ta hanyar tsarin injiniya wanda ke amfani da makamashi daga rana, haske na wucin gadi, ko zafi don yin amfani da methane. Wadannan abubuwan da ke haifar da zafi sun hada da masu saurin zafi, masu saurin hoto, da kuma radicals da aka samar ta hanyar photolysis (ta amfani da haske don karya kwayar halitta). 

Photocatalysts suna da ikon yin oxidize methane da sauran hydrocarbons ta hanyar heterogeneous catalysts.2" >[./Atmospheric_methane_removal#cite_note-:42-7 [1] titanium dioxide (TiO2) wani abu ne wanda ke aiki a lokacin da aka fallasa shi ga radiation na ultraviolet (UV) kuma yana iya haifar da irin wannan martani da ke faruwa lokacin da aka ƙone methane. "

CH4 + 2 2 + CO2

Ana amfani da kayan photocatalytic don yin amfani da fentin farfajiyar tare da TiO2 da zinc oxide (ZnO).  An yi nazarin wannan hanyar don oxidation na kwayoyin halitta (VOCs) da nitric oxide (NO) a cikin birane da cikin gida. Ba a yi nazarin amfani da wannan hanyar ba don cire methane, amma ƙarancin ingancin hanyar da ta shafi methane oxidation yana ba da shinge. Babban bincike da ya shafi kayan photocatalytic da hulɗar methane na iya haifar da manyan binciken da aka samu a cikin cire methane ta hanyar oxidation.

Masu haɓaka ƙarfe sun haɗa da Cu- da Fe- zeolites da cibiyoyin sadarwar polymer waɗanda ke da ikon yin oxidize methane da canza methane zuwa methanol (CH3), wanda ke da ɗan gajeren rayuwa fiye da methane. Hadin gwiwar methane tare da zeolites ya fi rauni, saboda ya dogara ne kawai akan hulɗar Van Der Waals tare da ƙwayoyin oxygen a bangon zeolite lattice. Ana iya ajiye ƙarfe da sauran abubuwan haɓaka a kan ko saka su a cikin cibiyoyin sadarwar polymer, waɗanda aka haɗa su don ƙungiyoyi masu aiki a kan kashin baya na polymer su yi hulɗa tare da methane a cikin micropores na cibiyar sadarwa.

### Methane reactors
Methane reactors sune tsarin da aka tsara don cire methane daga iska ta yanayi saboda ƙarancin inganci da matsalolin aiki waɗanda suka haɗa da guba da sake farfadowa. Methane reactors suna da iska shigarwa da kuma methane juyawa, yana aiki a matsayin tsada mai inganci da kuma ingantaccen hanya don cire methane. Masu haɓaka suna amfani da haske, zafi, da radicals don yin oxidize mai yawa na methane a cikin samfuran methyl. An yi amfani da wannan hanyar tun daga shekarun 1920 kuma ta tabbatar da inganci. Gabaɗaya, masu ba da amsa na methane suna iyakance farashi saboda rashin inganci a ƙananan ƙididdigar methane, yana mai da su da amfani a wuraren da ke da ƙididdigat mafi girma.

## Manazarta