Isihlungi se-molecular sieve esinezimbotshana (izimbobo ezincane kakhulu) zobukhulu obufanayo. Lawa ma-diameter ama-pore afana ngosayizi nama-molecule amancane, ngakho-ke ama-molecule amakhulu awakwazi ukungena noma ukukhangiswa, kuyilapho ama-molecule amancane engakwazi. Njengoba ingxube yamangqamuzana ifuduka embhedeni omile wezinto ezimbotshana ezimbotshana, ingxenye eqinile ebizwa ngokuthi isisefo (noma i-matrix), izingxenye zesisindo sengqamuzana eliphakeme kakhulu (ezingakwazi ukudlulela ezimbotsheni zamangqamuzana) zishiya umbhede kuqala, kulandelwa ama-molecule amancane ngokulandelana. Amanye ama-molecular sieve asetshenziswa ku-size-exclusion chromatography, indlela yokuhlukanisa ehlunga ama-molecule ngokusekelwe kusayizi wawo. Amanye ama-sieve ama-molecular asetshenziswa njengama-desiccants (ezinye izibonelo zihlanganisa amalahle acushiwe kanye nejeli ye-silica).
Ububanzi bembotshana yesisefo semolekyuli bulinganiswa ngo-ångströms (Å) noma ama-nanometers (nm). Ngokusho kwe-IUPAC notation, izinto ezisetshenziswayo ezincane zinezimbotshana ezidayamitha ezingaphansi kuka-2 nm (20 Å) futhi izinto ezimacroporous zinezimbotshana ezinobubanzi obungaphezu kuka-50 nm (500 Å); Ngakho-ke isigaba se-mesoporous siphakathi nendawo enobubanzi bembotshana obuphakathi kuka-2 no-50 nm (20–500 Å).
Izinto zokwakha
Izisefo zamangqamuzana zingaba yi-microporous, i-mesoporous, noma i-macroporous material.
I-Microporous material (
● Ama-Zeolite (amaminerali e-aluminosilicate, akufanele adidaniswe ne-aluminium silicate)
●I-Zeolite LTA: 3–4 Å
●Ingilazi enembobo: 10 Å (1 nm), naphezulu
● Ikhabhoni esebenzayo: 0–20 Å (0–2 nm), naphezulu
●Ubumba
●Ama-intermix e-Montmorillonite
● I-Halloysite (i-endellite): Izinhlobo ezimbili ezivamile ziyatholakala, lapho ubumba lufakwe amanzi amaningi lubonisa isikhala esingu-1 nm sezendlalelo futhi lapho kuphelelwa amanzi (i-meta-halloysite) isikhala singu-0.7 nm. I-halloysite ngokwemvelo yenzeka njengamasilinda amancane anesilinganiso esingu-30 nm ububanzi nobude obuphakathi kuka-0.5 no-10 wamamicrometer.
Impahla ye-Mesoporous (2–50 nm)
I-silicon dioxide (esetshenziselwa ukwenza ijeli ye-silica): 24 Å (2.4 nm)
Impahla ye-Macroporous (>50 nm)
I-Macroporous silica, 200–1000 Å (20–100 nm)
Izinhlelo zokusebenza[hlela]
Izisefo zamamolekyuli zivame ukusetshenziswa embonini ye-petroleum, ikakhulukazi ukomisa imifudlana yegesi. Isibonelo, embonini yegesi yemvelo ewuketshezi (LNG), umthamo wamanzi wegesi udinga ukwehliswa ube ngaphansi kuka-1 ppmv ukuze kuvinjelwe ukuvinjwa okubangelwa iqhwa noma i-methane clathrate.
Elabhorethri, ama-sieve ama-molecular asetshenziselwa ukomisa i-solvent. "Ama-Sieves" afakazele ukuthi angcono kunezinqubo zokomisa zendabuko, ezivame ukusebenzisa ama-desiccants anolaka.
Ngaphansi kwegama elithi ama-zeolites, izisefo zamamolekyuli zisetshenziselwa uhla olubanzi lwezinhlelo zokusebenza ze-catalytic. Zenza i-isomerisation, i-alkylation, ne-epoxidation, futhi zisetshenziswa ezinqubweni ezinkulu zezimboni, okuhlanganisa i-hydrocracking kanye nokuqhekeka kwe-fluid catalytic.
Zibuye zisetshenziswe ekuhlungeni izinto zomoya ezisetshenziswa ukuphefumula, isibonelo lezo ezisetshenziswa abatshuzi be-scuba nabacimi bomlilo. Kulezi zinhlelo zokusebenza, umoya uhlinzekwa nge-compressor yomoya futhi udluliswa ngesihlungi se-cartridge okuthi, kuye ngokuthi isicelo, sigcwaliswe ngesisefo se-molecular kanye/noma i-activated carbon, ekugcineni sisetshenziselwa ukushaja amathangi omoya okuphefumulayo.Ukuhlunga okunjalo kungasusa izinhlayiya kanye nemikhiqizo ye-compressor exhaust evela ekuhlinzekeni komoya ophefumulayo.
Ukugunyazwa kwe-FDA.
I-FDA yase-US kusukela ngo-April 1, 2012, igunyaze i-aluminosilicate ye-sodium ukuze ixhumane ngokuqondile nezinto ezidliwayo ngaphansi kwe-21 CFR 182.2727.Ngaphambi kwalokhu kugunyazwa i-European Union yayisebenzise izisefo zamangqamuzana anemithi kanye nokuhlola okuzimele kwaphakamisa ukuthi izisefo zamangqamuzana zihlangabezana nazo zonke izidingo zikahulumeni kodwa imboni ibikade ingazimisele ukuxhasa ngezimali ukuhlolwa okumba eqolo okudingekayo ukuze kugunyazwe uhulumeni.
Ukuvuselelwa
Izindlela zokuvuselela izisefo zamangqamuzana zihlanganisa ukushintsha kwengcindezi (njengakuma-concentrators komoya-mpilo), ukushisisa nokuhlanzwa ngegesi yenkampani yenethiwekhi (njengalapho kusetshenziswa ekuphelelweni kwamanzi kwe-ethanol), noma ukushisisa ngaphansi kwe-vacuum ephezulu. Amazinga okushisa okuvuselela asukela ku-175 °C (350 °F) kuya ku-315 °C (600 °F) kuye ngohlobo lwesisefo samangqamuzana. Ngokuphambene, ijeli ye-silica ingavuselelwa ngokuyishisisa kuhhavini ojwayelekile iye ku-120 °C (250 °F) amahora amabili. Kodwa-ke, ezinye izinhlobo zejeli ye-silica "zizovela" lapho zivezwe emanzini anele. Lokhu kubangelwa ukuphuka kwama-silica sphere lapho uthintana namanzi.
Imodeli | Imbobo encane (Ångström) | Ukuminyana kwenqwaba (g/ml) | Amanzi e-Adsorbed (% w/w) | Ukulimala noma ukuhuzuka, W(% w/w) | Ukusetshenziswa |
3Å | 3 | 0.60–0.68 | 19-20 | 0.3–0.6 | I-Desiccationkweukuqhekeka kwe-petroleumigesi nama-alkenes, i-adsorption ekhethiwe ye-H2O iningilazi evalekile (IG)kanye ne-polyurethane, ukomiswa kwei-ethanol fuelyokuhlanganisa nophethiloli. |
4Å | 4 | 0.60–0.65 | 20–21 | 0.3–0.6 | I-Adsorption yamanzi ngaphakathisodium aluminosilicateokugunyazwe yi-FDA (bonangezansi) esetshenziswa njengesisefo samangqamuzana ezitsheni zokwelapha ukugcina okuqukethwe komile futhi njengobaisithasiselo sokudlaukubaInombolo ye-EI-E-554 (i-anti-caking agent); Okuncanyelwayo ukuphelelwa amanzi emzimbeni okumile kumasistimu oketshezi noma igesi avaliwe, isb, emaphaketheni ezidakamizwa, izakhi zikagesi namakhemikhali abolayo; Ukukhipha amanzi ezinhlelweni zokuphrinta nezamapulasitiki nokomisa imifudlana ye-hydrocarbon egcwele. Izinhlobo ze-Adsorbed zifaka i-SO2, CO2, H2S, C2H4, C2H6, ne-C3H6. Ngokuvamile kubhekwa njenge-ejenti yokomisa yendawo yonke emithonjeni ye-polar ne-nonpolar;[12]ukuhlukana kweigesi yemvelofuthiama-alkenes, ukufakwa kwamanzi ku-non-nitrogen sensitivei-polyurethane |
5Å-DW | 5 | 0.45–0.50 | 21–22 | 0.3–0.6 | Degreasing futhi uthele iphuzu ukucindezelekaezondiza uphalafinifuthiudizili, kanye nokuhlukana kwe-alkenes |
5Å encane enomoya-mpilo | 5 | 0.4–0.8 | ≥23 | Idizayinelwe ngokukhethekile ijeneretha ye-oxygen yezokwelapha noma enempilo[ingcaphuno edingekayo] | |
5Å | 5 | 0.60–0.65 | 20–21 | 0.3–0.5 | Ukuhlanza nokuhlanzwa komoya;ukuphelelwa amanzi emzimbenifuthii-desulfurizationwegesi yemvelo kanyei-liquid petroleum gas;umoya-mpilofuthii-hydrogenukukhiqizwa nguingcindezi swing adsorptioninqubo |
10X | 8 | 0.50–0.60 | 23–24 | 0.3–0.6 | I-sorption esebenza kahle kakhulu, esetshenziswa ekuhlukaniseni, ekukhipheni i-carburization, ekuqedeni igesi noketshezi kanye nokuhlukaniswai-hydrocarbon enamakha |
13X | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | I-Desiccation, i-desulfurization kanye nokuhlanzwa kwegesi ye-petroleum negesi yemvelo |
13X-AS | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | I-Decarburizationkanye ne-desiccation embonini yokuhlukanisa umoya, ukuhlukaniswa kwe-nitrogen ku-oksijini kuma-concentrators oksijini |
Ku-13X | 10 | 0.50–0.60 | 23–24 | 0.3–0.5 | Okumnandi(ukususwa kwethiol) kweamafutha endizanokuhambisanaama-hydrocarbon e-liquid |
Amakhono e-Adsorption
3Å
Ifomula yamakhemikhali elinganiselwe: ((K2O)2⁄3 (Na2O)1⁄3) • Al2O3• 2 SiO2 • 9/2 H2O
Isilinganiso se-silica-alumina: SiO2/ Al2O3≈2
Ukukhiqiza
3Izisefo ze-molecular zikhiqizwa ngokushintshaniswa kwe-cation ofi-potassiumokwei-sodiumku-4A izisefo ze-molecular (Bheka ngezansi)
Ukusetshenziswa
3Å Izisefo zamamolekyuli azikhangisi ama-molecule amadiamitha awo makhulu kuno-3 Å. Izici zalezi zisefo zamangqamuzana zihlanganisa isivinini sokukhangisa esisheshayo, ikhono lokuvuselela njalo, ukumelana okuhle kokuchotshozwa kanyeukumelana nokungcola. Lezi zici zingathuthukisa kokubili ukusebenza kahle kanye nempilo yonke yesisefo. 3Å Izisefo zamamolekyuli ziyi-desiccant edingekayo ezimbonini ze-petroleum namakhemikhali zokucwenga uwoyela, i-polymerization, nokomisa ukujula koketshezi lwegesi yegesi.
3Å Izisefo zamamolekyuli zisetshenziselwa ukomisa uhla lwezinto, njengei-ethanol, umoya,amafriji,igesi yemvelofuthii-unsaturated hydrocarbons. Lokhu okulandelayo kuhlanganisa igesi eqhekekayo,i-acetylene,i-ethylene,ipropylenefuthibutadiene.
3Å isisefo semolekyuli sisetshenziselwa ukususa amanzi ku-ethanol, kamuva angasetshenziswa ngokuqondile njengesibaso sezinto eziphilayo noma ngokungaqondile ukukhiqiza imikhiqizo eyahlukene njengamakhemikhali, ukudla, imithi, nokunye. Njengoba ukucwiliswa okujwayelekile kungakwazi ukususa wonke amanzi (umkhiqizo ongathandeki ovela ekukhiqizweni kwe-ethanol) emifudlaneni yenqubo ye-ethanol ngenxa yokwakheka kwe-ethanol.azeotropecishe kumaphesenti angama-95.6 okugxilwa ngesisindo, ubuhlalu be-molecular sieve busetshenziselwa ukuhlukanisa i-ethanol namanzi ezingeni lamangqamuzana ngokukhangisa amanzi ebuhlaluni nokuvumela i-ethanol ukuba idlule ngokukhululeka. Uma ubuhlalu sebugcwele amanzi, izinga lokushisa noma ukucindezela kungashintshwa, okuvumela amanzi ukuba akhululwe ebuhlalu besisefu se-molecular.[15]
3Å Izisefo zamangqamuzana zigcinwa ekamelweni lokushisa, nomswakama isihlobo hhayi ngaphezu 90%. Zivalwa ngaphansi kwengcindezi encishisiwe, zigcinwe kude namanzi, ama-asidi nama-alkali.
4Å
Ifomula yamakhemikhali: Na2O•Al2O3•2SiO2•9/2H2O
Isilinganiso se-silicon-aluminium: 1:1 (SiO2/ Al2O3≈2)
Ukukhiqiza
Ukukhiqizwa kwe-4Å sieve kuqondile njengoba kungadingi ukucindezela okukhulu noma amazinga okushisa aphezulu. Izixazululo ezijwayelekile ezinamanzi wei-sodium silicatefuthii-sodium aluminatekuhlanganiswa ku-80 °C. Umkhiqizo ofakwe kwi-solvent "ucushwa" "ngokubhaka" ku-400 °C 4A izisefo zisebenza njengesandulela ku-3A kanye ne-5A sieve ngokusebenzisa.ukushintshana kocingokwei-sodiumokwei-potassium(ye-3A) nomai-calcium(okwe-5A)
Ukusetshenziswa
Ukomisa ama-solvents
4Å Izisefo zamamolekyuli zisetshenziswa kakhulu ukomisa izincibilikisi zaselabhorethri. Angakwazi ukumunca amanzi namanye ama-molecule anobubanzi obubalulekile obungaphansi kuka-4 Å njenge-NH3, H2S, SO2, CO2, C2H5OH, C2H6, ne-C2H4. Zisetshenziswa kabanzi ekomisweni, ekucwengisweni nasekuhlanzweni koketshezi namagesi (njengokulungiswa kwe-argon).
Izengezo ze-polyester ejenti[hlela]
Lezi zisefo zamangqamuzana zisetshenziselwa ukusiza izinto zokuhlanza njengoba zingakhiqiza amanzi akhishwe amamineralii-calciumukushintshaniswa kwe-ion, susa futhi uvimbele ukufakwa kokungcola. Zisetshenziswa kabanzi ukufaka esikhundlenii-phosphorus. I-4Å molecular sieve idlala indima enkulu ukufaka esikhundleni se-sodium tripolyphosphate njengesisetshenziswa sokuhlanza ukuze kwehliswe umthelela wemvelo wokuhlanza. Ingasetshenziswa futhi njenge-ainsiphoukwakha i-ejenti futhi kuumuthi wokuxubha.
Ukwelashwa kwemfucuza eyingozi
4Å Izisefo zamangqamuzana zingahlanza indle yezinhlobo ze-cationic ezifanaammoniumions, Pb2+, Cu2+, Zn2+ kanye ne-Cd2+. Ngenxa yokukhetha okuphezulu kwe-NH4+ asetshenziswe ngempumelelo enkundleni ukuze alwei-eutrophicationkanye neminye imiphumela emizileni yamanzi ngenxa yama-ammonium ion amaningi. 4Å Izisefo zamamolekyuli nazo zisetshenziselwe ukususa ama-ion ensimbi esindayo akhona emanzini ngenxa yemisebenzi yezimboni.
Ezinye izinjongo
Iimboni ye-metallurgical: i-ejenti ehlukanisayo, ukuhlukaniswa, ukukhishwa kwe-brine potassium,i-rubidium,cesium, njll.
Imboni ye-Petrochemical,i-catalyst,i-desiccant, i-adsorbent
Ezolimo:inhlabathi conditioner
Umuthi: layisha isilivazeolitei-ejenti ye-antibacterial.
5Å
Ifomula yekhemikhali: 0.7CaO•0.30Na2O•Al2O3•2.0SiO2 •4.5H2O
Isilinganiso se-silica-alumina: SiO2/ Al2O3≈2
Ukukhiqiza
5Izisefo zamamolekyuli zikhiqizwa ngokushintshaniswa kwe-cation ofi-calciumokwei-sodiumku-4A izisefo ze-molecular (Bheka ngenhla)
Ukusetshenziswa
Ezinhlanu-ångström(5Å) izisefo zamangqamuzana zivame ukusetshenziswa kuuwoyelaimboni, ikakhulukazi yokuhlanza imifudlana yegesi kanye nelebhu yekhemistri ukuze ihlukaniseizinhlanganiselakanye nokumisa izinto zokuqala zokusabela. Aqukethe izimbotshana ezincane ezinosayizi oqondile nofanayo, futhi asetshenziswa kakhulu njenge-adsorbent yamagesi noketshezi.
Amasefa ama-molecular amahlanu-ångström asetshenziselwa ukomisaigesi yemvelo, kanye nokwenzai-desulfurizationfuthii-decarbonationkwegesi. Angasetshenziswa futhi ukuhlukanisa izingxube zomoya-mpilo, i-nitrogen ne-hydrogen, kanye nama-n-hydrocarbon kawoyela-wax kuma-branched nama-polycyclic hydrocarbons.
Izisefo ze-molecular ezinhlanu-ångström zigcinwa ekamelweni lokushisa, nge-umswakama ohlobenengaphansi kwama-90% emiphongolweni yekhadibhodi noma emaphaketheni ebhokisi. Izisefo zamangqamuzana akufanele zivezwe ngokuqondile emoyeni nasemanzini, ama-asidi nama-alkali kufanele agwenywe.
I-Morphology ye-sieves ye-molecular
Izisefo ze-molecular zitholakala ngezindlela ezihlukahlukene nobukhulu obuhlukahlukene. Kodwa ubuhlalu obuyindilinga bunenzuzo ngaphezu kwezinye izimo njengoba bunikeza ukwehla kokucindezela okuphansi, abukwazi ukumelana nokugoba njengoba bengenakho imiphetho ebukhali, futhi bunamandla amahle, okungukuthi amandla okuchoboza adingekayo endaweni ngayinye aphakeme. Ezinye izisefo zamangqamuzana ezinobuhlalu zinikeza umthamo ophansi wokushisa ngaleyo ndlela zinciphise izidingo zamandla ngesikhathi sokukhiqiza kabusha.
Enye inzuzo yokusebenzisa izisefo zamamolekyuli ezinobuhlalu ukuminyana kwenqwaba kuvamise ukuba phezulu kunomunye umumo, ngakho-ke isidingo se-adsorption efanayo ivolumu yesisefo se-molecular edingekayo incane. Ngakho-ke ngenkathi enza i-de-bottlenecking, umuntu angase asebenzise izisefo zamangqamuzana ezinobuhlalu, alayishe i-adsorbent eyengeziwe ngevolumu efanayo, futhi agweme noma yikuphi ukuguqulwa komkhumbi.
Isikhathi sokuthumela: Jul-18-2023