Isihluzo semolekyuli sisixhobo esineembobo (imingxunya emincinci kakhulu) enobukhulu obufanayo. Ezi dayamitha zembobo zifana ngobukhulu neemolekyuli ezincinci, ngoko ke iimolekyuli ezinkulu azinakungena okanye zifunxwe, ngelixa iimolekyuli ezincinci zisenokwenza njalo. Njengoko umxube weemolekyuli uhamba ngebhedi emileyo yento eneembobo, e-semi-solid ebizwa ngokuba yi-sieve (okanye i-matrix), izinto ezinobunzima obukhulu beemolekyuli (ezingenakukwazi ukudlula kwiimbobo zemolekyuli) ziphuma kuqala ebhedini, zilandelwe ziimolekyuli ezincinci ngokulandelelanayo. Ezinye ii-sieve zemolekyuli zisetyenziswa kwi-chromatography yokukhupha ubungakanani, indlela yokwahlulahlula ehlela iimolekyuli ngokusekelwe kubukhulu bazo. Ezinye ii-sieve zemolekyuli zisetyenziswa njenge-desiccants (eminye imizekelo ibandakanya i-activated charcoal kunye ne-silica gel).
Ububanzi bembobo yesihluzo semolekyuli bulinganiswa nge-ångströms (Å) okanye ii-nanometers (nm). Ngokwe-IUPAC notation, izinto ezinamachibi amancinci zinobubanzi bembobo obungaphantsi kwe-2 nm (20 Å) kwaye izinto ezinamachibi amancinci zinobubanzi bembobo obungaphezulu kwe-50 nm (500 Å); ngoko ke udidi lwe-mesoporous luphakathi kunye nobubanzi bembobo obuphakathi kwe-2 kunye ne-50 nm (20–500 Å).
Izixhobo
Iisefu zemolekyuli zinokuba zizinto ezinemingxuma emincinci, ezithambileyo, okanye ezinemingxuma emincinci.
Izinto ezinemibhobho emincinci (
●IiZeolite (iiminerali zealuminosilicate, akufuneki zidideke ne-aluminium silicate)
●I-Zeolite LTA: 3–4 Å
●Iglasi enemingxuma: 10 Å (1 nm), nangaphezulu
●Ikhabhoni esebenzayo: 0–20 Å (0–2 nm), nangaphezulu
●Udongwe
●Iingxubevange zeMontmorillonite
●Indawo yokuHlanganisa (i-endellite): Kufunyanwa iintlobo ezimbini eziqhelekileyo, xa imanziswa udongwe lubonisa isithuba se-1 nm kwiileya kwaye xa imanziswa (i-meta-halloysite) isithuba se-0.7 nm. I-Halloysite ngokwemvelo ifumaneka njengeesilinda ezincinci ezinobubanzi obuyi-30 nm kunye nobude obuphakathi kwe-0.5 kunye ne-10 micrometers.
Izinto ezijongeka ngathi zincinci (2–50 nm)
I-silicon dioxide (esetyenziselwa ukwenza ijeli ye-silica): 24 Å (2.4 nm)
Izinto ezinamacala amakhulu (>50 nm)
I-Macroporous silica, 200–1000 Å (20–100 nm)
Izicelo[hlela]
Ii-molecular seeves zihlala zisetyenziswa kwishishini le-petroleum, ingakumbi kwimisinga yegesi eyomileyo. Umzekelo, kwishishini legesi yendalo engamanzi (LNG), umxholo wamanzi wegesi kufuneka uncitshiswe ube ngaphantsi kwe-1 ppmv ukuthintela ukuvaleka okubangelwa ngumkhenkce okanye i-methane clathrate.
Kwilabhoratri, kusetyenziswa izihluzo zemolekyuli ukomisa isinyibilikisi. "Izihluzo" zibonakalise ukuba zingcono kuneendlela zemveli zokomisa, ezidla ngokusebenzisa izihluzo ezibukhali.
Phantsi kwegama elithi zeolites, ii-molecular seeves zisetyenziselwa uluhlu olubanzi lwezicelo ze-catalytic. Zi-catalyze i-isomerisation, i-alkylation, kunye ne-epoxidation, kwaye zisetyenziswa kwiinkqubo ezinkulu zoshishino, kubandakanya i-hydrocracking kunye ne-fluid catalytic cracking.
Zikwasetyenziswa ekuhluzeni izixhobo zomoya kwizixhobo zokuphefumla, umzekelo ezo zisetyenziswa ngabadubuli be-scuba kunye nabacimi-mlilo. Kwizicelo ezinjalo, umoya unikezelwa yi-air compressor kwaye udlula kwi-cartridge filter, exhomekeke kwisicelo, izaliswe yi-molecular seeve kunye/okanye i-activated carbon, ekugqibeleni isetyenziselwa ukutshaja iitanki zomoya zokuphefumla. Olu hlobo lokuhluza lunokususa ii-particles kunye neemveliso zokukhupha umoya we-compressor kwi-air supply.
Imvume ye-FDA.
I-FDA yase-US ukusukela nge-1 ka-Epreli 2012, ivumile i-sodium aluminosilicate yokunxibelelana ngokuthe ngqo nezinto ezisetyenziswayo phantsi kwe-21 CFR 182.2727. Ngaphambi kolu vumo, iManyano yaseYurophu yayisebenzise izihluzo zemolekyuli kunye namayeza kwaye uvavanyo oluzimeleyo lubonise ukuba izihluzo zemolekyuli ziyahlangabezana nazo zonke iimfuno zikarhulumente kodwa eli shishini belingafuni ukuxhasa uvavanyo olubizayo olufunekayo ukuze kuvunywe ngurhulumente.
Ukuhlaziywa kwakhona
Iindlela zokuhlaziya ii-molecular seeves ziquka ukutshintsha koxinzelelo (njengakwi-oxygen concentrators), ukufudumeza kunye nokucoca ngegesi ethwala (njengaxa kusetyenziswa kwi-ethanol dehydration), okanye ukufudumeza phantsi kwe-vacuum ephezulu. Amaqondo obushushu okuhlaziya aqala kwi-175 °C (350 °F) ukuya kwi-315 °C (600 °F) kuxhomekeke kuhlobo lwe-molecular seeve. Ngokwahlukileyo koko, i-silica gel inokuhlaziywa ngokuyifudumeza kwi-oven eqhelekileyo ukuya kwi-120 °C (250 °F) iiyure ezimbini. Nangona kunjalo, ezinye iintlobo ze-silica gel ziya "kuvela" xa zifakwe emanzini aneleyo. Oku kubangelwa kukwaphuka kwe-silica spheres xa idibana namanzi.
| Imodeli | Ububanzi bembobo (Ångström) | Ubuninzi bobuninzi (g/ml) | Amanzi afunxwayo (% w/w) | Ukusetyenziswa | |
| 3Å | 3 | 0.60–0.68 | 19–20 | 0.3–0.6 | Ukutyumzayeukuqhekeka kwepetroliyamigesi kunye nee-alkenes, ukufunxwa okukhethekileyo kwe-H2O kwiiglasi egqunyiweyo (IG)kunye ne-polyurethane, ukomiswa kweipetroli ye-ethanolyokuxuba nepetroli. |
| 4Å | 4 | 0.60–0.65 | 20–21 | 0.3–0.6 | Ukufunxwa kwamanzii-sodium aluminosilicateevunyiweyo yi-FDA (jongangezantsi) isetyenziswa njengesihluzo semolekyuli kwizikhongozeli zonyango ukugcina umxholo womile kwayeisongezo sokutyaukubaInombolo ye-EI-E-554 (iarhente yokulwa nokubopha); Ikhethwa kakhulu xa kusetyenziswa ulwelo olunganyangekiyo kwiinkqubo ezivaliweyo zolwelo okanye zegesi, umz., xa kufakwa amayeza, izinto zombane kunye neekhemikhali ezibolayo; ukucocwa kwamanzi kwiinkqubo zokuprinta nezeplastiki kunye nokumisa imilambo ye-hydrocarbon eyomileyo. Iintlobo ezifunxwayo ziquka i-SO2, i-CO2, i-H2S, i-C2H4, i-C2H6, kunye ne-C3H6. Ngokuqhelekileyo ithathwa njengearhente yokomisa eqhelekileyo kwiindawo eziphantsi komhlaba kunye nezingaphandle komhlaba;[12]ukwahlulwa kweigesi yendalokwayeii-alkenesukufunxwa kwamanzi kwiindawo ezingachaphazeleki yinitrogeni-polyurethane |
| 5Å-DW | 5 | 0.45–0.50 | 21–22 | 0.3–0.6 | Ukunciphisa amafutha kunye nokuthotywa kwe-pour pointiinqwelomoya i-kerosenekwayeidizilikunye nokwahlukana kwe-alkenes |
| 5Å i-oxygen encinci etyebisiweyo | 5 | 0.4–0.8 | ≥23 | Yenzelwe ngokukodwa umatshini wokuvelisa ioksijini kwezonyango okanye okunempilo[isicatshulwa siyafuneka] | |
| 5Å | 5 | 0.60–0.65 | 20–21 | 0.3–0.5 | Ukucoca umoya nokuwucoca;ukuphelelwa ngamanzi emzimbenikwayeukususwa kwesalfurizationyegesi yendalo kunyeigesi yepetroliyam elulwelo;ioksijinikwayei-hydrogenimveliso nguukufunxwa koxinzelelo lwe-swinginkqubo |
| 10X | 8 | 0.50–0.60 | 23–24 | 0.3–0.6 | Ukufunxa okusebenzayo kakhulu, okusetyenziswa ekukhupheni ityuwa, ekususeni ityuwa kwi-carbon dioxide, ekususeni i-sulfurization yegesi kunye nolwelo kunye nokwahlulahlula i-carbon dioxidei-hydrocarbon enuka kamnandi |
| 13X | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | Ukucocwa, ukucocwa kwegesi yepetroliyam kunye negesi yendalo |
| 13X-AS | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | Ukususwa kwekhabhohayidreyithikunye nokunyibilika komoya kushishino lokwahlukanisa umoya, ukwahlulwa kwe-nitrogen kwi-oxygen kwi-oxygen concentrators |
| I-Cu-13X | 10 | 0.50–0.60 | 23–24 | 0.3–0.5 | Ukwandisa incasa(ukususwa kweama-thiol) kaipetroli yeenqwelo-moyakunye nehambelanayoiihydrocarbon ezingamanzi |
Amandla okufunxa
3Å
Ifomula yeekhemikhali eqikelelweyo: ((K2O)2⁄3 (Na2O)1⁄3) • Al2O3• 2 SiO2 • 9/2 H2O
Umlinganiselo we-silica-alumina: SiO2/ Al2O3≈2
Imveliso
3A ii-molecular seeves ziveliswa ngokutshintshiselana kwe-cationi-potassiumngenxai-sodiumkwiisivi ze-molecular ze-4A (Jonga ngezantsi)
Ukusetyenziswa
Ii-3Å molecular seeves azifunxi iimolekyuli ezinobubanzi obungaphezulu kwe-3 Å. Iimpawu zezi zi-molecular seeves ziquka isantya sokufunxa ngokukhawuleza, amandla okuhlaziya rhoqo, ukumelana nokutyumza okuhle kunyeukumelana nongcolisekoEzi mpawu zinokuphucula ukusebenza kakuhle kunye nobomi besihluzo. Ii-3Å molecular seeves zezona zinto zifunekayo kwimizi-mveliso yepetroleum kunye neekhemikhali zokucoca ioyile, i-polymerization, kunye nokomisa ubunzulu begesi kunye nolwelo lweekhemikhali.
Izihluzo ze-molecular ze-3Å zisetyenziselwa ukomisa uluhlu lwezinto ezahlukeneyo, ezinjei-ethanol, umoya,iifriji,igesi yendalokwayeiihydrocarbons ezingagcwaliyoEzi zilandelayo ziquka igesi eqhekekayo,iasetilini,i-ethylene,ipropylenekwayei-butadiene.
Isihluzo se-molecular se-3Å sisetyenziselwa ukususa amanzi kwi-ethanol, anokuthi kamva asetyenziswe ngqo njenge-bio-fuel okanye ngokungathanga ngqo ukuvelisa iimveliso ezahlukeneyo ezifana neekhemikhali, ukutya, amayeza, nokunye. Ekubeni i-distillation eqhelekileyo ayinakususa onke amanzi (imveliso engafunekiyo evela kwimveliso ye-ethanol) kwimijelo yenkqubo ye-ethanol ngenxa yokwenziwa kwe-ethanoli-azeotropemalunga ne-95.6% yoxinzelelo ngokobunzima, ii-molecular see beads zisetyenziselwa ukwahlula i-ethanol kunye namanzi kwinqanaba le-molecular ngokufunxa amanzi kwii-beads nokuvumela i-ethanol ukuba idlule ngokukhululekileyo. Nje ukuba ii-beads zizele ngamanzi, ubushushu okanye uxinzelelo lunokuguqulwa, okuvumela amanzi ukuba akhululwe kwii-molecular see beads.[15]
Izihluzo ze-molecular ze-3Å zigcinwa kubushushu begumbi, kunye nokufuma okuhambelanayo okungekho ngaphezulu kwe-90%. Zivalwa phantsi koxinzelelo oluphantsi, zigcinwe kude namanzi, ii-asidi kunye ne-alkalis.
4Å
Ifomula yekhemikhali: Na2O•Al2O3•2SiO2•9/2H2O
Umlinganiselo weSilicon-aluminium: 1:1 (SiO2/ Al2O3≈2)
Imveliso
Ukuveliswa kwesihluzo se-4Å kulula kakhulu kuba akudingi xinzelelo luphezulu okanye amaqondo obushushu aphezulu. Ngokwesiqhelo izisombululo zamanzi zei-sodium silicatekwayei-sodium aluminatezidibene kwi-80 °C. Imveliso efakwe isinyibilikisi "iyasebenza" "ngokubhaka" kwi-400 °C. Izihluzo ze-4A zisebenza njengesandulela sezihluzo ze-3A kunye ne-5A ngokusebenzisautshintshiselwano lwe-cationyei-sodiumngenxai-potassium(kwi-3A) okanyeikhalsiyam(kwi-5A)
Ukusetyenziswa
Izinyibilikisi zokomisa
Ii-4Å molecular seeves zisetyenziswa kakhulu ukomisa izinyibilikisi zelebhu. Zinokufunxa amanzi kunye nezinye iimolekyuli ezinobubanzi obungaphantsi kwe-4 Å ezifana ne-NH3, H2S, SO2, CO2, C2H5OH, C2H6, kunye ne-C2H4. Zisetyenziswa kakhulu ekomiseni, ekucoceni nasekucoceni ulwelo kunye neegesi (ezifana nokulungiselela i-argon).
Izongezo ze-polyester [hlela]
Ezi zihluzo zemolekyuli zisetyenziselwa ukunceda iisepha njengoko zinokuvelisa amanzi angenazimbiwa ngokusebenzisaikhalsiyamukutshintshiselana kwee-ion, ukususa nokuthintela ukugcwala kokungcola. Zisetyenziswa kakhulu ukutshintshai-phosphorusIsihluzo se-molecular se-4Å sidlala indima enkulu ekuthatheni indawo ye-sodium tripolyphosphate njengesixhobo sokuncedisa isepha ukuze kuncitshiswe impembelelo yesepha kwindalo esingqongileyo. Singasetyenziswa njengesixhobo sokukhuselaisephaiarhente yokwenza izinto kwayeintlama yamazinyo.
Unyango lwenkunkuma eyingozi
Izihluzo ze-molecular ze-4Å zinokucoca indle yeentlobo ze-cationic ezifanai-ammoniumii-ion, i-Pb2+, i-Cu2+, i-Zn2+ kunye ne-Cd2+. Ngenxa yokukhetha okuphezulu kwe-NH4+ zisetyenziswe ngempumelelo ebaleni ukulwai-eutrophicationkunye nezinye iziphumo ezikwiindlela zamanzi ngenxa yee-ion ze-ammonium ezininzi. Ii-4Å molecular seeves nazo zisetyenzisiwe ukususa ii-ion zesinyithi ezinzima ezikhoyo emanzini ngenxa yemisebenzi yemizi-mveliso.
Ezinye iinjongo
Iimboni yesinyithi: iarhente yokwahlula, ukwahlula, ukukhupha i-potassium enetyuwa,i-rubidium,i-cesium, njl. njl.
Ishishini lePetrochemical,isikhuthazi,isicoci sedesikhanti, isithambisi
Ezolimo:isicoci somhlaba
Amayeza: umthwalo wesiliverei-zeoliteiarhente yokulwa neentsholongwane.
5Å
Ifomula yekhemikhali: 0.7CaO•0.30Na2O•Al2O3•2.0SiO2 •4.5H2O
Umlinganiselo we-silica-alumina: SiO2/ Al2O3≈2
Imveliso
5Izihluzo zemolekyuli ziveliswa ngokutshintshiselana kwe-cationikhalsiyamngenxai-sodiumkwiisivi ze-molecular ze-4A (Jonga ngasentla)
Ukusetyenziswa
Ntlanu-ångström(5Å) izihluzo zemolekyuli zihlala zisetyenziswaipetroliyamishishini, ingakumbi ukucocwa kwemithombo yegesi nakwilebhu yekhemistri yokwahlulahlulaiikhompawundikunye nezinto zokuqala zokusabela okomisayo. Ziqulathe iimbobo ezincinci ezinobukhulu obuchanekileyo nobufanayo, kwaye zisetyenziswa kakhulu njengesithambisi seegesi kunye nolwelo.
Izisefo zeemolekyuli ze-ångström ezintlanu zisetyenziselwa ukomisaigesi yendalo, kunye nokwenzaukususwa kwesalfurizationkwayeukususwa kwekhabhoniZingasetyenziselwa ukwahlula imixube yeoksijini, initrogen kunye nehydrogen, kunye neoyile-wax n-hydrocarbons kwi-branched kunye ne-polycyclic hydrocarbons.
Izihluzo zeemolekyuli ze-ångström ezintlanu zigcinwa kubushushu begumbi, kunyeUbuntu bezizalwanengaphantsi kwe-90% kwiibhareli zekhadibhodi okanye kwiipakethe zekhadibhodi. Ii-molecular seeves akufuneki zibekwe ngqo emoyeni nasemanzini, ii-asidi kunye ne-alkalis kufuneka ziphetshwe.
Imbonakalo yezihluzo zemolekyuli
Iisefu zeemolekyuli ziyafumaneka ngemilo nobukhulu obahlukeneyo. Kodwa iibead ezingqukuva ziluncedo kunezinye iimilo kuba zinika uxinzelelo oluphantsi, azikwazi ukuhla ngenxa yokuba azinamiphetho ebukhali, kwaye zinamandla amahle, oko kukuthi, amandla okutyumza afunekayo kwindawo nganye angaphezulu. Ezinye iisefu zeemolekyuli ezineebead zinika amandla obushushu aphantsi ngoko ke iimfuno zamandla ziphantsi ngexesha lokuvuselelwa.
Enye inzuzo yokusebenzisa ii-seeves ze-molecular ezineentsimbi kukuba ubuninzi be-bulk buhlala buphezulu kunezinye iimo, ngoko ke kwimfuneko efanayo ye-adsorption, umthamo we-molecular see ofunekayo ungaphantsi. Ngoko ke, ngelixa ususa i-bottlenecking, umntu angasebenzisa ii-seeves ze-molecular ezineentsimbi, afake i-adsorbent eninzi ngomthamo ofanayo, kwaye aphephe naluphi na utshintsho kwi-vessel.
Ixesha lokuposa: Julayi-18-2023
