Yiziphi Izisefo Zemolekyuli Ezisetshenziswa Ku-Petroleum Refining FCC Catalysts?
Ama-FCC (Fluid Catalytic Cracking) ama-catalysts ayikilasi lezinto ezisebenzayo eziningi ezisetshenziswa ezinqubweni zokucwenga i-petroleum ukuze kuguqulwe ngempumelelo ama-hydrocarbon asindayo abe-inani eliphezulu{1}}imikhiqizo eyengeziwe efana nophethiloli, i-liquefied petroleum gas, nama-olefin alula. Ngokuvamile zakhiwe izingxenye ezisebenzayo, izinto ze-matrix, izibophezelo, nezigcwalisi.
Izinhlobo Nemisebenzi Yezisefo Ze-Molecular Ye-FCC Catalysts
Ama-catalyst e-FCC ane-asidi ephezulu, ukuqina okuhle kwe-hydrothermal, kanye nezakhiwo eziqinile zokulwa-nezakhi zokugqoka, eziwavumela ukuthi akhuthaze ukusabela okufana nokuqhekeka, i-isomerization, nokudluliswa kwe-hydrogen yama-macromolecular hydrocarbons ngaphansi{1}}kwezimo ze-high fluidization. Ngaphezu kwalokho, ngokulungisa uhlobo lwesisefo samangqamuzana, okuqukethwe komhlaba okungavamile, i-acidity, kanye nesakhiwo se-pore, isivuno nokukhetha kwemikhiqizo eqondiwe njengophethiloli, i-propylene, ne-LPG kungathuthukiswa.
Ngakho-ke, izisefo zamangqamuzana ezihlukile kuma-catalysts e-FCC zidlala ikakhulukazi izindima ezisizayo. Y-izisefo ze-molecular kanye namafomu azo ashintshiwe ayizingxenye ezisebenzayo zama-catalysts e-FCC. Isisefo samangqamuzana e-Beta singasetshenziselwa ukuthuthukisa ukuqhekeka, ukuhlukaniswa kwe-isomerization, nokukhethwa komkhiqizo wama-hydrocarbon athile. Njengesengezo esisebenzayo, i-ZSM-5 ingathuthukisa ukukhiqizwa kwama-olefin alula. Futhi isisefo se-molecular ZSM-11 sisetshenziselwa ukuqhekeka okukhetha ukuma kwama-hydrocarbon kanye nokulawulwa kwama-olefin alula.
I-USY Molecular Sieve: Isakhi Esisebenzayo Esibaluleke Kakhulu
Y-uhlobo lwesisefo se-moleculariyingxenye eyisisekelo yokuqhekeka-ye-FCC, futhiI-Ultrastable Y (USY)iwuhlobo olugqamile lwe-zeolite oluqhekekayo. High-silica Y nomaI-Dealuminated Y (DAY)zombili izisefo ze-molecular ze-USY. I-USY ingaqondwa njengo-Y-uhlobo lwe-zeolite oluthole ukwelashwa kokuzinzisa okufana ne-dealumination kanye nokwelashwa nge-hydrothermal.
Njengoba ama-FCC catalysts enza imijikelezo ephindaphindiwe yokusabela nokukhiqizwa kabusha, kufanele amelane namazinga okushisa aphezulu kanye{0}}nezindawo ezinothile. Ngakho-ke, i-USY ikhombisa ukuzinza okuphezulu kwe-hydrothermal, ukumelana okuqinile nokuvalwa komusi, ukuqina kohlaka oluphezulu, namandla amahle kakhulu okuqhekeza ama-molecule amakhulu.
REY/RE-I-USY Molecular Sieve: Ibhalansi Umsebenzi, i-Coke Nokuzinza
I-Earth modified Y zeolite engavamile{0}ibambe inani elibalulekile lemboni kuma-catalysts e-FCC. Izinto ezingavamile-zomhlaba ezihilelekile zihlanganisa u-La, Ce, kanye no-Nd. Ukushintshisana{4}}kwe-earth ion okungajwayelekile kungathuthukisa ukuzinza kwe-thermal, ukuzinza kwe-hydrothermal, i-asidi, umsebenzi, nokukhetha kwe-coke kwamasefa Y-wohlobo lwe-zeolite molecular.
Ngakho-ke, i-I-REY (Okuvamile-Umhlaba Y)futhiRE-USY (Okuvamile-I-Earth Ultra-I-Stable Y)ama-molecular sieve ngokuvamile asetshenziswa ku-petroleum FCC, ukuthuthukisa umsebenzi nokuzinza, kanye nokwenza ibhalansi phakathi komsebenzi we-catalytic, isivuno se-coke, kanye nokukhetha kukaphethiloli/udizili.
I-Beta Molecular Sieve: Ithuthukisa Ukuguqulwa Okuqondile Kwe-Hydrocarbons
I-Beta ayisona isisefo esiyinhloko se-molecular kuma-catalysts avamile e-FCC, ngokungafani ne-USY. Kodwa kunalokho, kuyisici esengeziwe sokwakheka okuqondile noma izisefo ze-molecular zeolite eziguquliwe.
I-Beta molecular sieveiphethe i-BEA topology futhi ihlanganisa-isistimu yezimbotshana ezinkulu ezinobukhulu obuthathu. I-asidi yayo eqinile namashaneli amakhulu ambotshana avumela ukusetshenziswa kwayo ezinhlelweni ze-FCC zokuqhekeka kwe-hydrocarbon, i-isomerization, ne-hydrocracking{3}}ukusabela okuhlobene ne-hydrocracking, kanye nokuthuthukisa ukukhethwa kwe-distillate okumaphakathi nokuthuthukisa ukuguqulwa kwama-hydrocarbon athile.
I-ZSM-5 Molecular Sieve: Ithuthukisa Ukwakhiwa Kwe-Olefins Ekhanyayo
Indima yeI-ZSM-5 isisefo se-molecularezinqubweni ze-FCC ihlukile, isebenza njengesengezo se-FCC catalyst. Nakuba u-Y-uhlobo lwe-zeolite ngokuyinhloko lunesibopho sokuqhekeka{2}}ama-molecule kawoyela amakhulu asindayo, i-ZSM{4}}5 igxile ekuguquleni okwengeziwe kwama-hydrocarbons ohlobo lukaphethiloli futhi ikhuthaze ukukhiqizwa kwama-olefin alula.
I-ZSM-i-zeolite engu-5 ihlanganisa uhlaka lwe-MFI olunesakhiwo esincane futhi ibonisa izici ezivelele zokukhetha umumo. Ukufaka i-ZSM-5 ezinhlelweni ze-FCC ngokuvamile kwandisa isivuno se-propylene, i-ethylene, i-LPG, nama-olefin alula, kunciphisa uphethiloli noma kushintsha ukwakheka kwe-olefin kaphethiloli. Futhi inhlanganisela ye-USY kanye ne-ZSM-5 ye-molecular sieve iyisistimu ye-catalyst ye-FCC ejwayelekile kakhulu.
I-ZSM-11 Isisefo Se-Molecular: Ilawula Noma Ukuqhekeka Ngokukhetha Komumo
I-ZSM-11 isisefo se-molecularingeye-MEL topology, isakhiwo esifana kakhulu nesakhiwo se-MFI se-ZSM-5. Umsebenzi wayo ezinqubweni ze-FCC ezifana nokuqhekeka okukhetha ukuma kanye nokulawulwa kwe-olefin, futhi kuyafana nalokho kwe-ZSM-5 yesisefo samangqamuzana.
Kumkhuba we-FCC wezimboni, i-ZSM-11 i-molecular sieve ingasetshenziselwa ukuqhekeka kwe-hydrocarbon, i-aromatization, ne-isomerization, noma isetshenziswe njengesengezo se-FCC catalyst. Kodwa-ke, ngokohlelo lwe-FCC yesikali sezimboni, isisefo semolekyuli se-ZSM-11 sibaluleke kakhulu kune-ZSM-5.
I-Sinmat Chemicaligxile ekuhlinzekeni ama-zeolite ama-molecular sieve ama-FCC catalysts, okuhlanganisa-izisefo zohlobo lwe-molecular (NaY, HY, USY, REY, RE{{1}USY, DAY), isisefo se-Beta molecular, ZSM-5 molecular sieve, kanye ne-ZSM-11 molecular sieve. Ukuze uthole imininingwane eyengeziwe, sicela ubheke emakhasini olwazi lomkhiqizo.
