Isihlungi sama-molecule siyinto enezimbobo (imigodi emincane kakhulu) enobukhulu obufanayo. Lawa ma-pore diameter afana ngobukhulu nama-molecule amancane, ngakho-ke ama-molecule amakhulu awakwazi ukungena noma ukumuncwa, kuyilapho ama-molecule amancane engakwazi. Njengoba ingxube yama-molecule idlula embhedeni omile wento enezimbobo, e-semi-solid ebizwa ngokuthi isihlungi (noma i-matrix), izingxenye zesisindo esiphezulu sama-molecule (ezingakwazi ukudlula ema-pores ama-molecule) ziphuma embhedeni kuqala, zilandelwe ama-molecule amancane ngokulandelana. Amanye ama-molecule sieves asetshenziswa ku-chromatography yokukhipha usayizi, inqubo yokuhlukanisa ehlela ama-molecule ngokusekelwe kusayizi wawo. Amanye ama-molecule sieves asetshenziswa njenge-desiccant (ezinye izibonelo zifaka phakathi i-activated charcoal kanye ne-silica gel).
Ububanzi bembobo yesihlungi sama-molecule bulinganiswa ngama-ångströms (Å) noma ama-nanometers (nm). Ngokusho kwe-IUPAC notation, izinto ezinamabhamuza amancane zine-diameter yembobo engaphansi kuka-2 nm (20 Å) kanti izinto ezinamabhamuza amancane zine-diameter yembobo engaphezu kuka-50 nm (500 Å); ngakho-ke isigaba se-mesoporous sisephakathi nendawo lapho ububanzi bembobo buphakathi kuka-2 no-50 nm (20–500 Å).
Izinto zokwakha
Izisefo zama-molecule zingaba izinto ezinezimbobo ezincane, ezi-mesoporous, noma ezinezimbobo ezinkulu.
Izinto ezinezimbobo ezincane (
●Ama-Zeolite (amaminerali e-aluminosilicate, akufanele adidaniswe ne-aluminium silicate)
●I-Zeolite LTA: 3–4 Å
●Ingilazi enezimbobo: 10 Å (1 nm), nangaphezulu
●Ikhabhoni esebenzayo: 0–20 Å (0–2 nm), nangaphezulu
●Ubumba
●Izingxube ze-Montmorillonite
●Indawo yokulala (i-endellite): Kutholakala izinhlobo ezimbili ezivamile, uma imanziswa ubumba luveza isikhala esingu-1 nm sezingqimba kanti uma luphelelwa amanzi (i-meta-halloysite) isikhala siba ngu-0.7 nm. I-Halloysite ngokwemvelo ivela njengamasilinda amancane aphakathi kuka-30 nm ububanzi nobude obuphakathi kuka-0.5 no-10 micrometres.
Izinto ezi-Mesoporous (2–50 nm)
I-silicon dioxide (esetshenziselwa ukwenza ijeli ye-silica): 24 Å (2.4 nm)
Izinto ezinama-macroporous (>50 nm)
I-silica enezimbobo ezinkulu, 200–1000 Å (20–100 nm)
Izinhlelo zokusebenza[hlela]
Izisefo zama-molecule zivame ukusetshenziswa embonini kaphethiloli, ikakhulukazi ekomiseni imifudlana yegesi. Isibonelo, embonini yegesi yemvelo ewuketshezi (LNG), okuqukethwe kwamanzi kwegesi kudinga ukuncishiswa kube ngaphansi kwe-1 ppmv ukuvimbela ukuvinjelwa okubangelwa yiqhwa noma i-methane clathrate.
Elabhorethri, kusetshenziselwa izisefo zama-molecule ukomisa isinyibilikisi. "Izisefo" zibonakalise ukuthi zingcono kunezindlela zendabuko zokomisa, ezivame ukusebenzisa ama-desiccant anolaka.
Ngaphansi kwegama elithi zeolites, izihlungi zama-molecular zisetshenziselwa izinhlelo zokusebenza eziningi zokulungisa izinto. Zivuselela i-isomerization, i-alkylation, kanye ne-epoxidation, futhi zisetshenziswa ezinqubweni ezinkulu zezimboni, okuhlanganisa ukuqhuma kwe-hydrocracking kanye nokuqhekeka kwe-fluid catalytic.
Zisetshenziswa futhi ekuhlungeni izinsiza zomoya zemishini yokuphefumula, isibonelo lezo ezisetshenziswa ngababhukudi be-scuba kanye nabacishi bomlilo. Ezinhlelweni ezinjalo, umoya unikezwa yi-air compressor futhi udluliswa ngesihlungi se-cartridge, kuye ngokuthi sisetshenziswa kanjani, esigcwaliswe ngesihlungi sama-molecule kanye/noma i-activated carbon, ekugcineni sisetshenziselwa ukushaja amathangi omoya okuphefumula. Ukuhlunga okunjalo kungasusa izinhlayiya kanye nemikhiqizo yokukhipha umoya we-compressor ekuhlinzekweni komoya ophefumulayo.
Ukuvunyelwa yi-FDA.
I-US FDA kusukela ngomhlaka-1 Ephreli 2012, ivumile i-sodium aluminosilicate yokuxhumana ngqo nezinto ezisetshenziswayo ngaphansi kwe-21 CFR 182.2727. Ngaphambi kwalokhu kuvunyelwa, i-European Union yayisebenzise izisefo zama-molecule ezinemithi futhi ukuhlolwa okuzimele kwaphakamisa ukuthi izisefo zama-molecule zihlangabezana nazo zonke izidingo zikahulumeni kodwa imboni yayingafuni ukuxhasa ukuhlolwa okubizayo okwakudingeka ukuze kuvunyelwe uhulumeni.
Ukuvuselelwa kabusha
Izindlela zokuvuselela ama-molecule sieves zifaka phakathi ukushintsha kwengcindezi (njengakuma-oxygen concentrators), ukushisa nokuhlanza ngegesi ethwala (njengalapho kusetshenziswa ekuphelelweni yi-ethanol), noma ukushisa ngaphansi kwe-vacuum ephezulu. Amazinga okushisa okuvuselela aqala ku-175 °C (350 °F) kuya ku-315 °C (600 °F) kuye ngohlobo lwesisefo sama-molecule. Ngokuphambene nalokho, i-silica gel ingavuselelwa ngokuyifudumeza kuhhavini ojwayelekile kuya ku-120 °C (250 °F) amahora amabili. Kodwa-ke, ezinye izinhlobo ze-silica gel "zizoqhuma" uma zichayeke emanzini anele. Lokhu kubangelwa ukuphuka kwama-silica sphere lapho ithinta amanzi.
| Imodeli | Ububanzi bembobo (I-Ångström) | Ubuningi be-Bulk (g/ml) | Amanzi afakwe emanzini (% w/w) | Ukuwa noma ukuguguleka, W(% w/w) | Ukusetshenziswa |
| 3Å | 3 | 0.60–0.68 | 19–20 | 0.3–0.6 | Ukuncibilikisakweukuqhekeka kwephethiloliigesi kanye nama-alkenes, ukumuncwa okukhethiwe kwe-H2O kuingilazi evalekile (IG)kanye ne-polyurethane, ukomiswa kwe-uphethiloli we-ethanolukuxuba nophethiloli. |
| 4Å | 4 | 0.60–0.65 | 20–21 | 0.3–0.6 | Ukumuncwa kwamanzi kui-sodium aluminosilicateokuvunyelwe yi-FDA (bhekangezansi) isetshenziswa njengesihlungi sama-molecule ezitsheni zezokwelapha ukugcina okuqukethwe komile futhiisithasiselo sokudlaukubaInombolo ye-EI-E-554 (i-anti-caking agent); Ikhethwa kakhulu ekuphelelweni kwamanzi emzimbeni okuqinile ezinhlelweni ezivaliwe zoketshezi noma zegesi, isib. ekupakishweni kwemithi, izingxenye zikagesi kanye namakhemikhali abolayo; ukucosha amanzi ezinhlelweni zokunyathelisa kanye nezamapulasitiki kanye nokumisa imifudlana ye-hydrocarbon egcwele. Izinhlobo ezimuncwayo zifaka phakathi i-SO2, i-CO2, i-H2S, i-C2H4, i-C2H6, kanye ne-C3H6. Ngokuvamile kubhekwa njenge-ejenti yokomisa ebanzi ezindaweni eziphansi nezingaphansi kwephansi;[12]ukuhlukaniswaigesi yemvelofuthiama-alkenesukumuncwa kwamanzi ezindaweni ezingazweli i-nitrogeni-polyurethane |
| 5Å-DW | 5 | 0.45–0.50 | 21–22 | 0.3–0.6 | Ukunciphisa amafutha kanye nokunciphisa iphuzu lokuthululaizindiza uphethilolifuthiudizili, kanye nokuhlukaniswa kwama-alkenes |
| 5Å okucebile nge-oxygen encane | 5 | 0.4–0.8 | ≥23 | Yenzelwe ngokukhethekile i-oksijini yezokwelapha noma enempilo [kudingeka ingcaphuno] | |
| 5Å | 5 | 0.60–0.65 | 20–21 | 0.3–0.5 | Ukuhlanza umoya nokuwukhipha;ukuphelelwa amanzi emzimbenifuthiukuhlanzwa kwe-sulfurizationyegesi yemvelo kanyeigesi kaphethiloli ewuketshezi;umoya-mpilofuthii-hydrogenukukhiqizwa ngu-ukumuncwa kwengcindezi yokushintshashintshainqubo |
| 10X | 8 | 0.50–0.60 | 23–24 | 0.3–0.6 | Ukumunca kahle kakhulu, okusetshenziswa ekukhipheni igesi, ekususeni i-carb, ekususeni i-sulfurization yegesi kanye noketshezi kanye nokuhlukaniswa kwayoi-hydrocarbon enuka kamnandi |
| 13X | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | Ukuhlanza, ukususa isibabule kanye nokuhlanzwa kwegesi kaphethiloli kanye negesi yemvelo |
| 13X-AS | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | Ukususwa kwe-carburizationkanye nokuncibilika embonini yokuhlukanisa umoya, ukuhlukaniswa kwe-nitrogen nomoya-mpilo kuma-concentrator e-oxygen |
| I-Cu-13X | 10 | 0.50–0.60 | 23–24 | 0.3–0.5 | Ukunambitheka okumnandi(ukususwa kweama-thiol) kauphethiloli wezindizakanye nokuhambisanayoama-hydrocarbon aketshezi |
Amandla okumunca
3Å
Ifomula yamakhemikhali elinganiselwa: ((K2O)2⁄3 (Na2O)1⁄3) • Al2O3• 2 SiO2 • 9/2 H2O
Isilinganiso se-Silica-alumina: SiO2/ Al2O3≈2
Ukukhiqizwa
3 Izisefo zama-molecule zikhiqizwa ngokushintshaniswa kwe-cationi-potassiumngobai-sodiumkuma-molecule seeves angu-4A (Bheka ngezansi)
Ukusetshenziswa
Izisefo zama-molecule ze-3Å azimunci ama-molecule anama-diameter amakhulu kune-3Å. Izici zalezi zisefo zama-molecule zifaka phakathi isivinini sokumunca okusheshayo, ikhono lokuvuselela njalo, ukumelana okuhle kokuchoboza kanyeukumelana nokungcolaLezi zici zingathuthukisa kokubili ukusebenza kahle kanye nesikhathi sokuphila kwesihlungo. Izihlungo zama-molecule angu-3Å ziyi-desiccant edingekayo ezimbonini zikaphethiloli namakhemikhali ukuze kuhlungwe uwoyela, kupholimethwe, kanye nokomiswa kokujula kwegesi noketshezi ngamakhemikhali.
Izisefo zama-molecule angu-3Å zisetshenziselwa ukomisa uhla lwezinto, njengei-ethanol, umoya,iziqandisi,igesi yemvelofuthiama-hydrocarbon angagcwalisiweLokhu kokugcina kufaka phakathi igesi eqhekekayo,i-acetylene,i-ethylene,i-propylenefuthii-butadiene.
Isihlungi sama-molecule esingu-3Å sisetshenziselwa ukususa amanzi ku-ethanol, angasetshenziswa kamuva ngqo njengophethiloli we-bio noma ngokungaqondile ukukhiqiza imikhiqizo ehlukahlukene efana namakhemikhali, ukudla, imithi, nokuningi. Njengoba ukuhluzwa okuvamile kungakwazi ukususa wonke amanzi (umkhiqizo ongathandeki ovela ekukhiqizweni kwe-ethanol) emifudlaneni yenqubo ye-ethanol ngenxa yokwakheka kwe-i-azeotropecishe ngamaphesenti angama-95.6 ngokwesisindo, ama-molecular sieve beads asetshenziselwa ukuhlukanisa i-ethanol namanzi ezingeni lama-molecule ngokumunca amanzi abe ama-beads nokuvumela i-ethanol ukuthi idlule ngokukhululeka. Uma ama-beads esegcwele amanzi, izinga lokushisa noma ingcindezi ingashintshwa, okuvumela amanzi ukuthi akhishwe kuma-molecular sieve beads.[15]
Izisefo zama-molecule angu-3Å zigcinwa ekushiseni kwegumbi, zinomswakama olinganiselwe ongekho ngaphezu kuka-90%. Zivalwa ngaphansi kwengcindezi encishisiwe, zigcinwa kude namanzi, ama-asidi nama-alkali.
4Å
Ifomula yamakhemikhali: Na2O•Al2O3•2SiO2•9/2H2O
Isilinganiso se-silicon-aluminium: 1:1 (SiO2/ Al2O3≈2)
Ukukhiqizwa
Ukukhiqizwa kwesihlungi se-4Å kulula kakhulu njengoba kungadingi ukucindezela okuphezulu noma amazinga okushisa aphezulu kakhulu. Ngokuvamile izixazululo zamanzi ze-i-sodium silicatefuthii-sodium aluminatezihlanganiswa ku-80 °C. Umkhiqizo ofakwe isinyibilikisi "uyasebenza" ngokuthi "ubhake" ku-400 °C. Izisefo ze-4A zisebenza njengesandulela sezisefo ze-3A kanye ne-5A ngokusebenzisaukushintshaniswa kwe-cationkwei-sodiumngobai-potassium(ye-3A) nomai-calcium(nge-5A)
Ukusetshenziswa
Izithambisi zokomisa
Izisefo zama-molecule ze-4Å zisetshenziswa kabanzi ukomisa izinyibilikisi zelebhu. Zingamunca amanzi namanye ama-molecule anobubanzi obubalulekile obungaphansi kuka-4Å njenge-NH3, H2S, SO2, CO2, C2H5OH, C2H6, kanye ne-C2H4. Zisetshenziswa kabanzi ekomiseni, ekucwengisiseni nasekuhlanzeni uketshezi namagesi (njengokulungiselela i-argon).
Izithasiselo ze-polyester[hlela]
Lezi zisefo zama-molecule zisetshenziselwa ukusiza insipho njengoba zingakhiqiza amanzi angenawo amaminerali ngokusebenzisai-calciumukushintshaniswa kwama-ion, ukususa nokuvimbela ukungcola. Zisetshenziswa kabanzi ukufaka esikhundleni sazoi-phosphorusIsihlungi sama-molecule angu-4Å sidlala indima enkulu ekuthatheni indawo ye-sodium tripolyphosphate njengesivikelo sokuhlanza ukuze kuncishiswe umthelela wensipho endaweni ezungezile. Singasetshenziswa futhi njenge-insiphoi-ejenti yokwakha kanyeumuthi wamazinyo.
Ukwelashwa kwemfucuza eyingozi
Izisefo zama-molecule angu-4Å zingahlanza indle yezinhlobo ze-cationic ezifanai-ammoniumama-ion, i-Pb2+, i-Cu2+, i-Zn2+ kanye ne-Cd2+. Ngenxa yokukhetha okuphezulu kwe-NH4+ asetshenziswe ngempumelelo enkundleni ukulwai-eutrophicationkanye neminye imiphumela emigwaqweni yamanzi ngenxa yama-ion amaningi e-ammonium. Izisefo zama-molecule angu-4Å nazo zisetshenziswe ukususa ama-ion ensimbi esindayo akhona emanzini ngenxa yemisebenzi yezimboni.
Ezinye izinjongo
Iimboni yezinsimbi: i-ejenti yokuhlukanisa, ukuhlukanisa, ukukhipha i-potassium ene-brine,i-rubidium,i-cesium, njll.
Imboni ye-Petrochemical,i-catalyst,i-desiccant, isithambisi
Ezolimo:isilungisi somhlabathi
Umuthi: isiliva somthwaloi-zeolitei-ejenti yokulwa namagciwane.
5Å
Ifomula yamakhemikhali: 0.7CaO•0.30Na2O•Al2O3•2.0SiO2 •4.5H2O
Isilinganiso se-Silica-alumina: SiO2/ Al2O3≈2
Ukukhiqizwa
5 Izisefo zama-molecule zikhiqizwa ngokushintshaniswa kwe-cationi-calciumngobai-sodiumkuma-molecule seeves angu-4A (Bheka ngenhla)
Ukusetshenziswa
Ezinhlanu-ångström(5Å) izisefo zama-molecule zivame ukusetshenziswa ku-uphethiloliimboni, ikakhulukazi ukuhlanzwa kwemifudlana yegesi kanye naselabhorethri yamakhemikhali yokuhlukanisaama-compoundskanye nezinto zokuqala zokusabela okomisa. Ziqukethe izikhala ezincane ezinobukhulu obuqondile nobufanayo, futhi zisetshenziswa kakhulu njengesithasiselo samagesi noketshezi.
Izisefo zama-molecule ezinhlanu ze-ångström zisetshenziselwa ukomisaigesi yemvelo, kanye nokwenzaukuhlanzwa kwe-sulfurizationfuthiukususwa kwekhabhoniyegesi. Zingasetshenziswa futhi ukuhlukanisa izingxube ze-oxygen, i-nitrogen ne-hydrogen, kanye nama-n-hydrocarbons kawoyela-wax kuma-hydrocarbons ahlanganisiwe kanye nama-polycyclic.
Izisefo zama-molecule ezinhlanu ze-ångström zigcinwa ekushiseni kwegumbi, kanyeumswakama olinganiselwengaphansi kuka-90% emiphongolweni yamakhadibhodi noma ekupakishweni kwamakhadibhodi. Ama-molecule sieves akufanele avele ngqo emoyeni nasemanzini, ama-asidi nama-alkali kufanele kugwenywe.
Ukwakheka kwezisefo zama-molecule
Izisefo zama-molecule ziyatholakala ngezimo nobukhulu obuhlukahlukene. Kodwa ubuhlalu obuyindilinga bunenzuzo kunezinye izimo njengoba bunikeza ukwehla kwengcindezi okuphansi, buyamelana nokuwa njengoba bungenazo izingqimba ezibukhali, futhi bunamandla amahle, okungukuthi amandla okuchoboza adingekayo endaweni ngayinye ephakeme. Ezinye izisefo zama-molecule ezinama-beaded zinikeza amandla okushisa aphansi ngakho-ke izidingo zamandla ziphansi ngesikhathi sokuvuselelwa.
Enye inzuzo yokusebenzisa izisefo zama-molecule ezinobuhlalu ukuthi ubuningi be-bulk buvame ukuba phezulu kunezinye izimo, ngakho-ke ukuze uthole isidingo esifanayo sokumuncwa, ivolumu yesisefo sama-molecule iyadingeka incane. Ngakho-ke ngenkathi wenza i-de-bottlenecking, umuntu angasebenzisa izisefo zama-molecule ezinobuhlalu, alayishe i-adsorbent eningi ngobuningi obufanayo, futhi agweme noma yikuphi ukuguqulwa kwemikhumbi.
Isikhathi sokuthunyelwe: Julayi-18-2023
