Abantu abaningi bayazibuza ukuthi izinkomo ze-methane zikhiqiza malini. Okuningi kokungcoliswa kwemvelo kusekelwe ekukhishweni kwe-carbon dioxide kanye ne-methane. Lawa magesi yizona zimbangela eziyinhloko zokwanda komphumela we-greenhouse. Izinkomo zibhekene nengxenye enkulu yokukhishwa kwe-methane, okunomthelela omkhulu ekufudumaleni komhlaba.
Ngenxa yalesi sizathu, kulesi sihloko sizokhuluma ngokuningiliziwe mayelana ingakanani i-methane ekhiqizwa yizinkomo nokuthi lokhu kuyithinta kanjani indawo ezungezile, futhi ukuhlola izixazululo eziphakanyiswe ukunciphisa umthelela wazo omubi.
Izinkomo zikhiqiza i-methane engakanani?
Mayelana nokukhishwa kwe-methane, izinkomo zifaka isandla cishe esisodwa I-5% yokukhishwa kwe-methane emhlabeni jikelele. Uma sicubungula imboni yemfuyo iyonke, ikhiqiza cishe u-18% we-greenhouse emissions. Ngaphakathi kulo mkhakha, izinkomo zibhekene nazo Ama-40% amagesi abamba ukushisa. Kodwa, ngokungafani nalokho abaningi abakucabangayo, igesi ekhishwa izinkomo ayiyona i-carbon dioxide (CO2), kodwa i-methane (CH4), igesi enamandla kakhulu ngokwethonya lokushisa.
Ukukhishwa kwe-methane kukhulu kakhulu kumabelche ezinkomo. Nsuku zonke, inkomo ingaphuma cishe amalitha angama-300 ye-methane, elingana ne- about I-120 kilograms ye-methane ngonyaka. Lokhu kungase kumangaze abaningi ngenxa yesilinganiso esincane sokudla abakudlayo uma kuqhathaniswa nezinye izilwane ezinobukhulu obufanayo.
Kwenzeka kanjani lokhu kukhishelwa futhi iyiphi inqubo ewumsuka ngemuva kwakho?
Ukukhishwa kwe-methane okuvela ezinkomeni kukhiqizwa phakathi nenqubo yokugaya, eyaziwa ngokuthi i-enteric fermentation. Le nqubo yenzeka ngenxa yama-microorganisms akhona ku-rumen (ingxenye yokuqala yesisu se-ruminants), ephula ama-carbohydrate ayinkimbinkimbi atholakala emifino edliwa izinkomo.
Lawa ma-microorganisms, aziwa ngokuthi ama-methanogen, akhiqiza i-methane njenge-byproduct lapho ephula ushukela. Ngesikhathi sokugaya, igesi ye-methane ikhishwa ngokuyinhloko ngokubhodla, okuphikisana nenkolelo evamile yokuthi le gesi ikhishwa ngokuthuthumela. Eqinisweni, inani elincane kuphela le-methane likhishwa ngethumbu elikhulu futhi likhishwe ngokugcwala umoya.
Ngaphezu kwe-methane ekhiqizwa ohlelweni lokugaya ukudla, umquba wenkomo nawo unomthelela ekukhiqizweni kwe-methane, ikakhulukazi uma ugcinwe ngobuningi emachibini noma emachibini ukuze ulashwe. Lokhu kwakha umthombo owengeziwe we-methane okufanele ulawulwe.
Umthelela we-methane kumphumela we-greenhouse
Nakuba i-methane ichitha isikhathi esincane kakhulu emkhathini kune-CO2 (cishe iminyaka eyi-12 uma iqhathaniswa neminyaka eyi-100), amandla ayo okubamba ukushisa makhulu kakhulu. Kulinganiselwa ukuthi i-methane ine- ukufudumala kwembulunga yonke okunamandla okuphindwe izikhathi ezingama-28 kune-carbon dioxide esikhathini esiyiminyaka emi-100.
Leli qiniso ligqamisa ukuphuthuma kokunciphisa ukukhishwa kwe-methane, ngoba nakuba isikhathi esihlala emkhathini sisifishane, imiphumela yayo ekushiseni kokufudumala ishesha kakhulu futhi inzima kakhulu.
Amamaski kanye nesiphakeli ukunciphisa ukukhishwa kwekhabhoni
Ukuze kuliwe ne-methane ekhishwa izinkomo, kuye kwathuthukiswa ubuchwepheshe obuhlukahlukene. Enye yezinto ezithakazelisa kakhulu imaski eguqula i-methane ibe isikhutha, okuholela ekukhiphweni okuyingozi okuncane kakhulu. Lezi zimaski zisebenza ngendlela efanayo kuziguquli ze-catalytic ezimotweni, zithwebula i-methane ekhishwe emakhaleni ezinkomo futhi ziyiguqule ngamakhemikhali ibe yi-CO2.
Kuphinde kwakhiwe ukudla okukhethekile okuklanyelwe ukunciphisa ukukhiqizwa kwe-methane ngokushintsha ukudla kwezinkomo. Lokhu kudla kuhlanganisa izithako ezifana ne-algae ebomvu, okuye kwaboniswa ukunciphisa kakhulu ukukhishwa kwe-methane ekuhlolweni kokuhlola kanye nomkhakha. Ucwaningo lwakamuva lwezinkomo zobisi lubonise ukuncipha kokufika I-60% ekhishwayo lapho benikezwa ukudla okufakwe ulwelwe.
Yiziphi ezinye izixazululo ezikhona zokunciphisa ukungcola okuvela ezinkomeni?
Esinye isixazululo esithembisayo yi ukuzalanisa okukhethiwe wezinkomo ezikhiqiza amanani aphansi e-methane. Lokhu kuhilela ukukhetha izilwane ezinezici zofuzo ezinciphisa ukukhiqizwa kwe-methane ohlelweni lwazo lokugaya ukudla. Ngefa lofuzo, isizukulwane ngasinye sezinkomo kulindeleke ukuthi sikhiphe i-methane encane kuneyangaphambili.
Ngaphezu kwalokhu, i- ukugaya kwe-anaerobic isibe yithuluzi elibalulekile lokunciphisa ukukhishwa komquba. Le nqubo isetshenziswa emapulazini ukuguqula ubulongwe biogas (ingxube ye-methane ne-carbon dioxide), engasetshenziswa njengomthombo wamandla avuselelekayo. Ngenqubo yokuhlanza, ukugcwala kwe-methane ku-biogas kungakhuliswa ukuze kuguqulwe ibe yi-biomethane, engenakuhlukaniswa negesi yemvelo.
Yini esingayenza njengabathengi ukunciphisa ukukhishwa kwe-methane?
Nakuba intuthuko yezobuchwepheshe iyasiza, abathengi nabo badlala indima ebalulekile ekwehliseni ukukhishwa kwe-methane. Ukunciphisa ukusetshenziswa kwemikhiqizo yezilwane, njengenyama nemikhiqizo yobisi, kungasiza ekunciphiseni isidingo semfuyo ngakho-ke ukukhishwa kwe-methane.
Ukudla okulinganiselayo nokuphakathi emikhiqizweni yezilwane, okuhlanganisa izinketho zezitshalo, akusizi nje ukunciphisa ukukhishwa kwegesi, kodwa futhi kunezinzuzo empilweni yabantu. Ukwengeza, kubalulekile ukunciphisa ukumosha ukudla. Yonke imikhiqizo yokudla emoshwayo ibe nomthelela ekukhiqizweni kwesisi esibamba ukushisa, okuhlanganisa naleyo evela kwezokuthutha, amandla asetshenziswa ekukhiqizeni kwayo, futhi endabeni yemikhiqizo yezilwane, ukukhishwa kwe-methane.
Ukusekela amapulazi emfuyo asebenzisa ubuchwepheshe obufana nokukhiqizwa kwe-biogas kanye nokuzalanisa okukhethiwe nakho kungenza umehluko. Ukukhuthaza ukusetshenziswa kwemikhiqizo evela emapulazini esimeme kuzovumela le mikhuba ukuthi yande.
Kubalulekile ukuthi kokubili amazinga enqubomgomo yomuntu ngamunye kanye neyomphakathi asekele lobu buchwepheshe obusha kanye nezindlela zokunciphisa ukukhishwa kwegesi, okuhloswe ngayo ukulwa nokushintsha kwesimo sezulu.
Ngamafuphi, izinkomo, nakuba zidlala indima ebalulekile ekukhiqizweni kwe-methane, akuzona kuphela ezinecala lokufudumala kwembulunga yonke. Kunezixazululo ezitholakalayo zokunciphisa lo mthelela, kokubili kwezobuchwepheshe kanye nezinguquko ekusetshenzisweni. Ukunciphisa ukukhishwa kwe-methane kumele kube yinto ehamba phambili uma sifuna ukunqanda imiphumela yokufudumala kwembulunga emashumini eminyaka ezayo.