Sieve ea molek'hule ke thepa e nang le li-pores (likoti tse nyenyane haholo) tsa boholo bo lekanang. Li-diameter tsena tsa pore li tšoana ka boholo le limolek'hule tse nyenyane, kahoo limolek'hule tse kholo li ke ke tsa kena kapa tsa phatlalatsoa, ha limolek'hule tse nyenyane li ka khona. Ha motsoako oa limolek'hule o ntse o falla ka har'a bethe e emeng ea ntho e nang le porous, semi-solid eo ho thoeng ke sefe (kapa matrix), likarolo tsa boima bo phahameng ka ho fetisisa ba limolek'hule (tse sa khoneng ho feta ka har'a likoti tsa molek'hule) li tloha betheng pele, e lateloa ke limolek’hule tse nyenyane tse latellanang. Li-sieve tse ling tsa limolek'hule li sebelisoa ho size-exclusion chromatography, mokhoa oa karohano o hlophisang limolek'hule ho latela boholo ba tsona. Li-sieve tse ling tsa molek'hule li sebelisoa e le li-desiccants (mehlala e meng e kenyelletsa mashala a kentsoeng le silica gel).
Bophara ba pore ea sieve ea molek'hule bo lekanngoa ka ångströms (Å) kapa nanometers (nm). Ho ea ka lintlha tsa IUPAC, lisebelisoa tsa microporous li na le li-diameter tsa pore tse ka tlase ho 2 nm (20 Å) le lisebelisoa tsa macroporous li na le bophara ba pore ho feta 50 nm (500 Å); sehlopha sa mesoporous ka hona se bohareng le bophara ba pore pakeng tsa 2 le 50 nm (20–500 Å).
Lisebelisoa
Li-sieve tsa limolek'hule li ka ba lintho tse nyenyane haholo, tsa mesoporous, kapa tse macroporous.
Lintho tse nyenyane tse nyenyane (
● Zeolite (aluminosilicate minerals, e sa lokelang ho ferekanngoa le aluminium silicate)
●Zeolite LTA: 3–4 Å
● Khalase e nang le masoba: 10 Å (1 nm), ho ea holimo
●Khabone e sebetsang: 0–20 Å (0–2 nm), le holimo
●Matsopa
● Li-intermixes tsa Montmorillonite
● Halloysite (endellite): Mefuta e 'meli e tloaelehileng e fumanoa, ha letsopa le tšeloa metsi le bontša sebaka sa 1 nm sa lihlopha le ha se feletsoe ke metsi (meta-halloysite) sebaka ke 0.7 nm. Halloysite ka tlhaho e hlaha e le lisilindara tse nyane tse bophara ba 30 nm ka bolelele bo pakeng tsa 0.5 le 10 micrometres.
Mesoporous material (2–50 nm)
Silicon dioxide (e sebelisetsoang ho etsa gel ea silika): 24 Å (2.4 nm)
Macroporous material (>50 nm)
Macroporous silica, 200–1000 Å (20–100 nm)
Lisebelisoa[edit]
Hangata li-sieve tsa molek'hule li sebelisoa indastering ea petroleum, haholo-holo bakeng sa ho omisa melapo ea khase. Ka mohlala, indastering ea khase ea tlhaho ea metsi (LNG), metsi a khase a hloka ho fokotsoa hore a be ka tlase ho 1 ppmv ho thibela litšitiso tse bakoang ke leqhoa kapa methane clathrate.
Ka laboratoring, li-sieve tsa limolek'hule li sebelisetsoa ho omisa solvent. "Li-sieve" li ipakile li phahametse mekhoa e tloaelehileng ea ho omisa, e atisang ho sebelisa li-desiccants tse mabifi.
Tlas'a lentsoe li-zeolites, li-sieve tsa molek'hule li sebelisoa bakeng sa mefuta e mengata ea li-catalytic applications. Li kenya letsoho ho isomerisation, alkylation, le epoxidation, 'me li sebelisoa lits'ebetsong tse kholo tsa indasteri, ho kenyeletsoa hydrocracking le mokelikeli oa catalytic cracking.
Li boetse li sebelisoa ho sefa lisebelisoa tsa moea bakeng sa lisebelisoa tsa ho phefumoloha, mohlala, tse sebelisoang ke li-scuba divers le bo-ralitima-mollo. Lits'ebetsong tse joalo, moea o fanoa ke compressor ea moea 'me o fetisoa ka mochini oa cartridge oo, ho itšetlehile ka kopo, o tlatsitsoeng ka sieve ea molek'hule le / kapa carbon activated, qetellong e sebelisetsoa ho lefisa litanka tsa moea tse phefumolohang.Filtration e joalo e ka tlosa likaroloana. le lihlahisoa tsa ho ntša konpresser ho tsoa phepelong ea moea o phefumolohang.
Tumello ea FDA.
US FDA e na le ho tloha ka la 1 April, 2012, e amohetse aluminosilicate ea sodium bakeng sa ho kopana ka ho toba le lintho tse ka sebelisoang tlas'a 21 CFR 182.2727.Pele ho tumello ena European Union e ne e sebelisitse li-sieve tsa limolek'hule tse nang le meriana le tlhahlobo e ikemetseng e ile ea fana ka maikutlo a hore li-molecular sieves li finyella litlhoko tsohle tsa mmuso empa indasteri e ne e sa ikemisetsa ho lefella tlhahlobo e theko e boima e hlokahalang bakeng sa tumello ea mmuso.
Tsosoloso
Mekhoa ea ho nchafatsa li-sieve tsa limolek'hule e kenyelletsa phetoho ea khatello (joalo ka li-concentrators tsa oksijene), ho futhumatsa le ho hloekisoa ka khase e tsamaisang (joalo ka ha e sebelisoa ho felloa ke metsi ethanol), kapa ho futhumatsa tlas'a vacuum e phahameng. Lithempereichara tsa tsosoloso li tloha ho 175 °C (350 °F) ho ea ho 315 °C (600 °F) ho itšetlehile ka mofuta oa sieve ea molek'hule. Ka lehlakoreng le leng, gel ea silica e ka nchafatsoa ka ho e futhumatsa ka ontong e tloaelehileng ho 120 ° C (250 ° F) ka lihora tse peli. Leha ho le joalo, mefuta e meng ea gel ea silica e tla "pop" ha e pepesehetse metsi a lekaneng. Sena se bakoa ke ho robeha ha silika ha ho kopana le metsi.
| Mohlala | Pore bophara (Ångström) | Boima ba bongata (g/ml) | Metsi a adsorbed (% w/w) | Tšebeliso | |
| 3Å | 3 | 0.60–0.68 | 19–20 | 0.3–0.6 | Desiccationeaho petsoha ha peterolekhase le alkenes, adsorption e khethehileng ea H2O inkhalase e sirelelitsoeng (IG)le polyurethane, ho omisa eamafura a ethanolbakeng sa ho kopanya le peterole. |
| 4Å | 4 | 0.60–0,65 | 20–21 | 0.3–0.6 | Ho kenngoa ha metsi ka har'asodium aluminosilicatee amohetsoeng ke FDA (bonaka tlase) e sebelisoang e le sieve ea limolek'hule ka lijaneng tsa bongaka ho boloka likahare li omme le joalo katlatsetso ya dijoho ba leNomoro ea EE-554 (moemeli oa anti-caking); E ratoang bakeng sa dehydration e tsitsitseng tsamaisong ea metsi kapa ea khase e koetsoeng, mohlala, ka har'a ho paka lithethefatsi, likarolo tsa motlakase le lik'hemik'hale tse senyehang; ho hloekisoa ha metsi lits'ebetsong tsa khatiso le tsa polasetiki le ho omisa melapo ea hydrocarbon e tletseng metsi. Mefuta ea Adsorbed e kenyelletsa SO2, CO2, H2S, C2H4, C2H6, le C3H6. Ka kakaretso e nkuoa e le sesebelisoa sa ho omisa bokahohleng mecheng ea polar le ea nonpolar;[12]karohano eakhase ea tlhaholealkenes, ho kenella ha metsi sebakeng se se nang naetrojenepolyurethane |
| 5Å-DW | 5 | 0.45–0,50 | 21–22 | 0.3–0.6 | Ho theola le ho tšela ntlha khatello ea maikutlo easefofane parafinelediesel, le karohano ea alkenes |
| 5Å e nyenyane e nang le oksijene | 5 | 0.4–0.8 | ≥23 | E etselitsoe jenereithara ea oksijene ea bongaka kapa e phetseng hantle[qotso e hlokahalang] | |
| 5Å | 5 | 0.60–0,65 | 20–21 | 0.3–0.5 | Desiccation le tlhoekiso ea moea;ho felloa ke metsiledesulfurizationea khase ea tlhaho lekhase e metsi ea peterole;oksijenelehaedrojenetlhahiso kakhatello ea khatello ea maikutlotshebetso |
| 10X | 8 | 0.50–0,60 | 23–24 | 0.3–0.6 | sorption e sebetsang hantle haholo, e sebelisetsoang ho hlakisa, ho tlosa mokelikeli, desulfurization ea khase le lino le ho arolahydrocarbon e nkhang hamonate |
| 13X | 10 | 0.55–0,65 | 23–24 | 0.3–0.5 | Desiccation, desulfurization le tlhoekiso ea khase ea peterole le khase ea tlhaho |
| 13X-AS | 10 | 0.55–0,65 | 23–24 | 0.3–0.5 | Decarburizationle desiccation indastering ea karohano ea moea, karohano ea naetrojene ho oksijene ho li-concentrators tsa oksijene |
| Cu-13X | 10 | 0.50–0,60 | 23–24 | 0.3–0.5 | Monate(ho tlosoa hathiols) eamafura a sefofanele tse tsamaisanangli-hydrocarbon tse metsi |
Matla a Adsorption
3Å
Kakaretso ea foromo ea lik'hemik'hale: ((K2O)2⁄3 (Na2O)1⁄3) • Al2O3• 2 SiO2 • 9/2 H2O
Silika-alumina karo-karolelano: SiO2/ Al2O3≈2
Tlhahiso
3A sieve ea molek'hule e hlahisoa ke phapanyetsano ea cation eapotasiamobakeng sasodiumka har'a sieve ea 4A ea molek'hule (Sheba ka tlase)
Tšebeliso
3Å li-sieve tsa molek'hule ha li khahlise limolek'hule tseo bophara ba tsona bo leng kholo ho feta 3 Å. Litšobotsi tsa li-sieve tsena tsa limolek'hule li kenyelletsa lebelo la adsorption e potlakileng, bokhoni ba ho nchafatsa khafetsa, khanyetso e ntle ea ho senya lekhanyetso ea tšilafalo. Likarolo tsena li ka ntlafatsa ts'ebetso le bophelo bohle ba sieve. 3Å li-sieve tsa molek'hule ke li-desiccant tse hlokahalang indastering ea peterole le ea lik'hemik'hale bakeng sa ho hloekisa oli, polymerization, le ho omisa botebo ba khase ea khase.
3Å li-sieve tsa molek'hule li sebelisoa ho omisa mefuta e mengata ea lisebelisoa, joalo kaethanol, moea,lihatsetsi,khase ea tlhaholeli-hydrocarbon tse sa tsoakoang. Ea ho qetela e kenyelletsa khase e phunyehang,acetylene,ethylene,propylenelebutadiene.
3Å sieve ea molek'hule e sebelisoa ho ntša metsi ho ethanol, eo hamorao e ka sebelisoang ka kotloloho e le biofuel kapa ka tsela e sa tobang ho hlahisa lihlahisoa tse fapaneng joalo ka lik'hemik'hale, lijo, meriana le tse ling. Kaha distillation e tloaelehileng e ke ke ea tlosa metsi ohle (sehlahisoa se sa rateheng se tsoang tlhahisong ea ethanol) ho tsoa melapong ea ts'ebetso ea ethanol ka lebaka la ho thehaazeotropehoo e ka bang karolo ea 95.6 lekholong ea mahloriso ka boima ba 'mele, lifaha tsa sieve ea molek'hule li sebelisetsoa ho arola ethanol le metsi ka tekanyo ea molek'hule ka ho kenya metsi ka har'a lifaha le ho lumella ethanol hore e fete ka bolokolohi. Hang ha lifaha li tletse metsi, mocheso kapa khatello li ka sebelisoa, ho lumella metsi hore a lokolloe lifaha tsa sieve ea molecular.[15]
3Å li-sieve tsa molek'hule li bolokiloe mocheso oa kamore, ka mongobo o sa feteng 90%. Li tiisitsoe tlas'a khatello e fokotsehileng, li bolokiloe hole le metsi, li-acids le alkalis.
4Å
Foromo ea lik'hemik'hale: Na2O•Al2O3•2SiO2•9/2H2O
Silicon-aluminium karo-karolelano: 1:1 (SiO2/ Al2O3≈2)
Tlhahiso
Tlhahiso ea 4Å sieve e batla e otlolohile kaha ha e hloke likhatello tse phahameng kapa mocheso o phahameng haholo. Ka tloaelo aqueous tharollo easodium silicatelesodium aluminateli kopantsoe ka mocheso oa 80 ° C. Sehlahisoa se kentsoeng ka solvent se "ketsoa" ka "ho baka" ka 400 °C 4A sieves e sebetsa e le selelekela sa 3A le 5A sieves ka hare.phapanyetsano ea cationeasodiumbakeng sapotasiamo(bakeng sa 3A) kapacalcium(bakeng sa 5A)
Tšebeliso
Ho omisa solvents
4Å li-sieve tsa molek'hule li sebelisoa haholo ho omisa metsoako ea laboratori. Li ka monya metsi le limolek'hule tse ling tse nang le bophara ba bohlokoa bo ka tlase ho 4 Å tse kang NH3, H2S, SO2, CO2, C2H5OH, C2H6, le C2H4. Li sebelisoa haholo ho omisa, ho hloekisa le ho hloekisa metsi le likhase (tse kang ho lokisetsa argon).
Lisebelisoa tsa polyester[edita]
Lisefa tsena tsa limolek'hule li sebelisoa ho thusa lisebelisoa tsa ho hloekisa kaha li ka hlahisa metsi a nang le demineralized kacalciumion phapanyetsano, tlosa le ho thibela deposition ea litšila. Li sebelisoa haholo ho nka sebakaphosphorus. Sefe ea molek'hule ea 4Å e bapala karolo e kholo ho nkela sodium tripolyphosphate sebaka e le sehlatsoa se thusang molemong oa ho fokotsa tšusumetso ea tikoloho ea sesepa. E ka boela ea sebelisoa e le asesepaho etsa moemeli le hosesepa sa meno.
Phekolo ea litšila e kotsi
4Å sieve molek'hule ka hloekisa likhoerekhoere mefuta cationic tse kangammoniumions, Pb2+, Cu2+, Zn2+ le Cd2+. Ka lebaka la khetho e phahameng ea NH4 + li 'nile tsa sebelisoa ka katleho tšimong ho loantšaEutrophicationle litlamorao tse ling litseleng tsa metsi ka lebaka la li-ion tsa ammonium tse feteletseng. 4Å li-sieve tsa molek'hule le tsona li sebelisitsoe ho tlosa li-ion tse boima tse teng metsing ka lebaka la mesebetsi ea indasteri.
Merero e meng
Theindasteri ea metallurgic: ho arola moemeli, karohano, ho ntšoa ha potasiamo ea brine,rubidium,cesium, joalo-joalo.
Indasteri ea peterole,catalyst,desiccant, adsorbent
Temo:mobu oa mobu
Meriana: boima ba sileverazeolitemoemeli oa antibacterial.
5Å
Foromo ea lik'hemik'hale: 0.7CaO•0.30Na2O•Al2O3•2.0SiO2 •4.5H2O
Silika-alumina karo-karolelano: SiO2/ Al2O3≈2
Tlhahiso
5Lisefa tsa molek'hule li hlahisoa ke phapanyetsano ea cation eacalciumbakeng sasodiumka har'a sieve ea 4A molecular (Sheba ka holimo)
Tšebeliso
Hlano-ångström(5Å) li-sieve tsa molek'hule li sebelisoa hangata hopetroleumindasteri, haholo-holo bakeng sa tlhoekiso ea melapo ea khase le ka laboratoring ea k'hemistri bakeng sa ho arolametsoakole lisebelisoa tsa ho qala tsa ho omisa. Li na le li-pores tse nyane tsa boholo bo nepahetseng le bo ts'oanang, 'me li sebelisoa haholo e le sehlaseli sa likhase le maro.
Li-sieve tse hlano-ångström tsa molek'hule li sebelisetsoa ho omellakhase ea tlhaho, mmoho le ho etsadesulfurizationledecarbonationea khase. Li ka boela tsa sebelisoa ho arola metsoako ea oksijene, nitrogen le hydrogen, le oli-wax n-hydrocarbons ho tloha ho branched le polycyclic hydrocarbons.
Li-sieve tsa limolek'hule tse hlano-ångström li bolokiloe mocheso oa kamore, ka amongobo o lekanyelitsoengka tlase ho 90% ka libarele tsa khateboto kapa liphutheloana tsa mabokose. Li-sieve tsa molek'hule ha lia lokela ho pepeseha ka ho toba moeeng le metsi, li-acids le alkali li lokela ho qojoa.
Morphology ea li-sieves tsa molek'hule
Li-sieve tsa molek'hule li fumaneha ka sebopeho le boholo bo fapaneng. Empa lifaha tse chitja li na le molemo ho feta libopeho tse ling kaha li fana ka ho theoha ha khatello e tlase, ha li khone ho ts'oana kaha ha li na mapheo a bohale, 'me li na le matla a matle, ke hore, matla a ho senya a hlokahalang sebakeng se seng le se seng a phahame. Li-sieve tse ling tsa limolek'hule tse entsoeng ka lifaha li fana ka mocheso o tlase, kahoo litlhoko tsa matla li theola nakong ea nchafatso.
Monyetla o mong oa ho sebelisa sieve ea limolek'hule tse entsoeng ka lifaha ke boholo ba boima ba 'mele hangata bo phahame ho feta sebopeho se seng, kahoo bakeng sa tlhokahalo e tšoanang ea adsorption, molumo oa molek'hule o hlokahalang o fokotseha. Kahoo ha a ntse a etsa de-bottlenecking, motho a ka sebelisa li-sieve tsa molek'hule tse entsoeng ka lifaha, a jarisa adsorbent e eketsehileng ka molumo o tšoanang, 'me a qobe liphetoho leha e le life tsa sekepe.
Nako ea poso: Jul-18-2023
