Imvelaphi

Uvavanyo lomjikelo wobomi (LCA) sisixhobo sokulinganisa ukusetyenziswa komthombo wamandla kunye nefuthe lokusingqongileyo kwimveliso, ubugcisa bokuvelisa. Isixhobo siyakulinganisa ukusuka kwingqokelela yemathiriyeli ekrwada ukuya kwimveliso, ukuthuthwa, ukusetyenziswa, kwaye ekugqibeleni ukuya ekuchithweni kokugqibela. I-LCA yasekwa ukususela ngo-1970.

l Umbutho we-Environmental Toxicology and Chemistry (SETAC) uchaza iSETAC njengendlela yokuhlola ukuba imveliso, imveliso kunye neentshukumo zinefuthe njani kokusingqongileyo ngokuvavanya ukusetyenziswa kwempahla ekrwada, ukusetyenziswa kwamandla kunye nokukhutshwa kwenkunkuma.

l Ngo-1997, i-ISO yakhupha uthotho lwe-ISO 14000, yaze yachaza i-LCA njengokuhlanganiswa kunye novavanyo lwamagalelo, iziphumo kunye neempembelelo ezinokubakho zokusingqongileyo zenkqubo yemveliso kumjikelo wobomi bayo bonke. Impembelelo yokusingqongileyo ibandakanya ukusetyenziswa kobutyebi, impilo yabantu kunye ne-ikholoji. I-ISO 14040 ichaza inqununu kunye nesakhelo, kwaye i-ISO 14044 ichaza iimfuno kunye nesikhokelo.

Uvavanyo lweLCA lunezigaba ezi-4:

1) injongo kunye nobubanzi. Oku kumalunga nenjongo yophando, imida yenkqubo, yeyiphi iyunithi ekhethiweyo ukuyisebenzisa, kunye nemfuneko kwidatha.

2) Uhlalutyo lwe-inventri. Oku kubandakanya ukuqokelelwa kunye nokulahlwa kwedatha.

3) Uvavanyo lwempembelelo. Oku kukuhlalutya izinto ezichaphazela okusingqongileyo.

4) Ukutolikwa. Oku kukugqiba uvavanyo kunye nokuhlalutya umphumo.

Injongo kunye nobubanzi

Injongo yokufunda

Injongo yokufunda yindawo yokuqala yeLCA. Oku kukuvavanya ngcono ukusebenza kwenkqubo, kwaye kukwanceda nobungqina bokusingqongileyo kwenkqubo ukuze kufakwe isicelo sesiqinisekiso sohlaza.

Imida yenkqubo

Imida yenkqubo kufuneka iqulathe ezi zigaba zilandelayo zomjikelo wobomi kunye nenkqubo efanelekileyo (Ngezantsi kukho imida yenkqubo yemveliso yebhetri)

Oku kubizwa ngokuba yi-cradle-to-grave. I-Cradle ithetha isiqalo, esibhekisa ekufumaneni imathiriyeli ekrwada. Ingcwaba lithetha isiphelo, esibhekisa ekuchithweni nasekusetyenzisweni ngokutsha.

Iyunithi yokusebenza

Iyunithi yokusebenza ngumgangatho wokubala wegalelo kunye nesiphumo ngexesha lokujikeleza kobomi benkqubo. Ngokwesiqhelo kukho iiyunithi zokusebenza ezimbini. Enye bubunzima (iyunithi: kg), enye ngamandla ombane (iyunithi: kWh). Ukuba sithatha amandla njengeyunithi, ke la mandla achazwa njengamandla ewonke abonelelwa yinkqubo yebhetri kumjikelo wobomi bayo. Amandla ewonke abalwa ngokuphindaphinda amaxesha omjikelo kunye namandla omjikelo ngamnye.

Umgangatho wedatha

Kuphononongo lwe-LCA, umgangatho wedatha yempembelelo kwisiphumo se-LCA. Ke ngoko kufuneka sinike ingxelo kunye nengcaciso kwidatha esiyamkelayo ngexesha lophononongo.

Uvavanyo lwe-inventri

I-Life Cycle Inventory (LCI) sisiseko seLCA. Kufuneka silinganise izibonelelo ezifunekayo kumjikelo wobomi weemveliso, ukusetyenziswa kwamandla, kunye nokuphuma. Izibonelelo apha ziquka imigodi, ukusetyenzwa, ukuthengiswa kweemveliso, ukusetyenziswa, ukuthuthwa, ukugcinwa, ukuchithwa kunye nokuphinda kusetyenziswe, umjikelo wobomi bonke. Amandla aquka ukusetyenziswa kombane, ikhemistri kunye namandla elanga. Ukukhutshwa kubandakanya ungcoliseko, ubushushu kunye nemitha.

(1) Ukuseka imodeli yenkqubo yemveliso esekelwe kwimida yenkqubo echazwe kwinjongo kunye nobubanzi.

(2) Ukuqokelela idatha efanelekileyo, njengezinto eziphathekayo kwinkqubo nganye, ukusetyenziswa kwamandla, ukuthutha, ukukhutshwa, kunye nedatha engaphezulu.

(3) Bala ukukhutshwa ngokweyunithi yomsebenzi.

UVavanyo lweMpembelelo

Uvavanyo lwempembelelo yomjikelo wobomi (LCIA) luqhutywa ngokusekelwe kuhlalutyo lwe-inventri. I-LCIA ibandakanya iindidi zempembelelo, ipharamitha, imodeli yophawu, ukuhlelwa kweziphumo, ukubalwa kwepharamitha yodidi (ukulinganisa kunye nokulinganisa).

Iindidi zovavanyo lweempembelelo zeLCA ziquka:

• Ukusetyenziswa kwemithombo ye-Abiotic ixabiso elinokubakho kunye nexabiso elinokubakho lokusebenzisa amafutha eefosili. Ukusetyenziswa kwemithombo ye-abiotic kuhambelana nokuphuculwa kwe-ore kwigalelo lenkqubo. Iyunithi yi-kg Sb eq. Ukusetyenziswa kwe-abiotic yesibaso sefosili kunxulumene nexabiso lobushushu. Iyunithi nguMJ.
• Ixabiso lokufudumala kwehlabathi. IPhaneli yoRhulumente kuTshintsho lweMozulu (IPCC) iphuhlise imodeli eneempawu zokubala izinto eziphawuliweyo. Izinto ezibonakalisiweyo zibonisa amandla okufudumala kwehlabathi kwiminyaka eyi-100. Iyunithi yi-kg CO₂eq.
• I-ozone sphere yokuncipha ixabiso elinokubakho. Lo mzekelo uphuhliswe yiGlobal Meteorological Organisation. Ichaza amandla okutshatyalaliswa kwe-ozone yegesi eyahlukeneyo. Iyunithi yi-kg CFC-11 eq.
• I-ozone ye-photochemical. Iyunithi yi-kg C₂H₂eq.
• I-Acidification. Imele amandla okukhutshwa ngokulinganisa i-SO₂yekhilogram nganye yokukhutshwa. Iyunithi yi-kg SO₂eq.
• I-Eutrophication. Iyunithi yi-kg PO₄eq.
• Ukutolikwa
• Utoliko sisigaba sokugqibela seLCA. Ukudibanisa injongo kunye nobubanzi, uhlalutyo lwe-inventri kunye novavanyo lwempembelelo, sinokuba novavanyo olubanzi kwimveliso, kwaye sifumane umlinganiselo wokuphucula imveliso okanye ukukhutshwa kwe-lifecycle. Umzekelo, sinokukhuthaza imveliso yezinto ezikrwada, sitshintshe ukhetho lwemathiriyeli ekrwada, sikhuthaze ukusetyenzwa kwemveliso, sitshintshe uhlobo lwamandla, silungise izixhobo zokurisayikilisha, njl.

Ukuqukumbela

• Zininzi kakhulu iindidi zedatha ezibandakanyekayo kwiLCA. Umgangatho kunye nokuthembeka kwedatha kuya kuba nefuthe elikhulu kwisiphumo. Ukuba sinokwakha iqonga lokulandelela idatha, apho sinokubamba khona uluhlu lwempahla njengamacandelo abalulekileyo kunye nemveliso, kwaye senze isiseko sesiseko sokubuyisela kwakhona, kuya kunciphisa kakhulu ubunzima besatifikethi se-carbon footprint.
• Ukunciphisa ukukhutshwa kwekhabhoni, kukho imilinganiselo ngolu hlobo lulandelayo: 1. Ukusungula inkqubo yemathiriyeli yebhetri ukunyusa uxinano lwamandla kunye nobomi bomjikelezo. Oku kuya kunciphisa ukukhutshwa kwekhabhoni. 2. Xa kuthelekiswa nebhetri ye-lithium-ion, ibhetri ye-sodium-ion inefuthe eliphantsi kwindalo. 3. Ibhetri eqinile inokukhutshwa kwekhabhoni ephantsi kunebhetri ye-lithium-ion ngexesha lokuvelisa. 4. Izinto zokurisayikilisha kunye nokuveliswa kwakhona kunokuphucula ungcoliseko kunye nokukhutshwa kwekhabhoni esezantsi.