Kunoma iyiphi inqubo yezimboni yokukhiqiza i-syngas, kuyisixhumanisi esibalulekile sokusebenzisa inqubekela phambili yokusabela kokushintsha kwegesi yamanzi ukuguqula i-CO ibe yi-hydrogen.
Lokhu kusabela kuyindlela yokusabela exothermic eguqukayo. Uma izinga lokushisa liphakeme, kulapho ukuguqulwa kwe-equilibrium okuhambisanayo kwehla khona. Ngesikhathi esifanayo, lokhu kusabela kuyindlela ejwayelekile yokusabela. Uma kungekho catalyst, kunzima ukusabela ku-700. Uma kukhona i-catalyst, izinga lokushisa lokusabela liyancipha kakhulu. Uma usebenzisa i-catalyst yokushintsha izinga lokushisa eliphezulu, izinga lokushisa lokusabela lingu-300 ~ 500 ° C; Uma kusetshenziswa i-catalyst yokushintsha izinga lokushisa eliphansi, izinga lokushisa lokusabela lingu-200-400 ° C (ithebula 22). Ngenxa yokuthi ukusabela kuyi-isomolecular reaction, ingcindezi ayinawo umthelela ku-reaction equilibrium, kodwa ukusebenza kwengcindezi kungathuthukisa ukuqina kokukhiqiza kanye nesilinganiso sokusabela.
Esigabeni sokuqala sokusabela, inqubo ikude kakhulu nomkhawulo wokulingana futhi ilawulwa yi-kinetics. Ukwandisa izinga lokushisa kungathuthukisa kakhulu izinga lokusabela futhi kuthuthukise ukusebenza kahle kwenqubo. Esigabeni sokugcina sokusabela, ukuguqulwa kwenqubo kunqunyelwe yi-thermodynamic equilibrium. Ukuguqulwa kwe-thermodynamic equilibrium ekushiseni okuphezulu kuphansi kakhulu. Ngakho-ke, esigabeni sokugcina sokusabela, ukusebenza kwezinga lokushisa eliphansi kufanele kwamukelwe ukuthuthukisa ukuguqulwa kwe-CO. Izici ze-thermodynamic kanye ne-kinetic zenqubo zinquma ukuthi inqubo yokuguqulwa kwe-CO kufanele isebenzise ukusebenza kwezinga lokushisa eliguquguqukayo.
Esigabeni sokuqala sokusabela, inqubo ikude kakhulu nomkhawulo wokulingana futhi ilawulwa yi-kinetics. Ukwandisa izinga lokushisa kungathuthukisa kakhulu izinga lokusabela futhi kuthuthukise ukusebenza kahle kwenqubo. Esigabeni sokugcina sokusabela, ukuguqulwa kwenqubo kunqunyelwe yi-thermodynamic equilibrium. Ukuguqulwa kwe-thermodynamic equilibrium ekushiseni okuphezulu kuphansi kakhulu. Ngakho-ke, esigabeni sokugcina sokusabela, ukusebenza kwezinga lokushisa eliphansi kufanele kwamukelwe ukuthuthukisa ukuguqulwa kwe-CO. Izici ze-thermodynamic kanye ne-kinetic zenqubo zinquma ukuthi inqubo yokuguqulwa kwe-CO kufanele isebenzise ukusebenza kwezinga lokushisa eliguquguqukayo.
Ngenxa yokuvinjelwa kwebhalansi yokusabela, yize i-CO iguqulwa ngokujulile ngemva kokuguqulwa kwegesi yamanzi enokushisa okuphansi, okuqukethwe kwayo kusengu-1%, okungakwazi ukuhlangabezana nezidingo zokusetshenziswa kwezinqubo eziningi ezilandelayo. Embonini, ivame ukususwa ngezinye izindlela zamakhemikhali. Ukushiswa kwe-CO kanye ne-O2 lapho kukhona inani elikhulu le-hydrogen kukhiqiza i-CO2, kanti i-hydrogen kanye ne-O2 kulula ukusabela. Ngakho-ke, inqubo incike kakhulu ekushiseni kokusabela kanye nohlobo lwe-catalyst [29301].
Enye inqubo yezimboni ukufakelwa kwe-CO2 ngenani elikhulu le-hydrogen elikhona ngqo ku-catalyst esekelwe ku-nickel ukuze kukhiqizwe i-methane.
Ngemva kokuguqulwa kwegesi yamanzi nokususwa kwe-CO2, izingxenye eziyinhloko zegesi ziba yi-H2 ne-CO2. Embonini ye-ammonia yokwenziwa, i-CO2 idinga ukuhlukaniswa kuqala. Le CO2 ingaqhubeka nokusabela ne-ammonia ekhiqizwa yi-hydrogen esigabeni esilandelayo ukuze ikhiqize i-ammonium bicarbonate, i-ammonium carbonate noma i-urea kanye neminye imifino yamakhemikhali ukuze kufezwe ukusetshenziswa okuphezulu kwe-CO2. Kule nqubo, ubuchwepheshe bokuhlukanisa be-CO2 ne-H2 ngokuyinhloko ukuqinisekisa ukuthi i-CO2 ingaphinde isetshenziswe.
Ekusetshenzisweni kwe-hydrogen njengamaseli kaphethiloli e-proton membrane, kusetshenziswa i-hydrogen kuphela esikhundleni se-CO2. I-CO2 iba ukukhishwa okungenamsebenzi, okungase kudingeke kuhlanganiswe nezinye izinqubo zokumbiwa phansi (njengokukhiqizwa kwe-calcium carbonate yezinga lokudla).
Kodwa-ke, kuzo zonke izinqubo zokuhlukaniswa kwe-CO2, kuyindlela engcono yokusebenzisa i-amine noma i-methanol ephilayo ukuze imunce i-CO2. Ikakhulukazi enkambisweni yokumuncwa kwe-CO2 yi-methanol ekushiseni okuphansi, ukuncibilika kwamagesi amaningi kuzoba phezulu ekushiseni okuphansi. Ukuncibilika kwe-hydrogen kuphela okunganqunyelwe yizinga lokushisa, futhi uma izinga lokushisa liphansi, kulapho ukuncibilika kwehla khona. Kubonisa ukukhetha okuhle kokuhlukaniswa kwe-H2.
Enkambisweni yokubuyisa i-CO2, ngenhloso yokugwema umonakalo ekuvuneni kwe-hydrogen, zama ukugwema ukusebenzisa ama-reagent abizayo (njenge-caustic soda) angahlangana kakhulu ne-CO2, ukuze kuqinisekiswe umnotho wenqubo.
Isikhathi sokuthunyelwe: Disemba 10-2021