I-molecular sieve yimpahla eneepores (imingxuma encinci kakhulu) yobukhulu obufanayo. Ezi diameters ze-pore zifana nobukhulu kwiimolekyuli ezincinci, kwaye ngoko ke iimolekyuli ezinkulu azikwazi ukungena okanye zibhengezwe, ngelixa iimolekyuli ezincinci zingakwazi. Njengoko umxube weemolekyuli ufuduka kumandlalo omileyo wezinto ezirhabaxa, eziphantse zibe qinileyo ekubhekiselwa kuzo njengesefa (okanye i-matrix), amacandelo obona bunzima buphezulu bemolekyuli (ezingakwaziyo ukudlula kwiipores zemolekyuli) zishiya ibhedi kuqala, zilandelwa ziimolekyuli ezincinci ngokulandelelanayo. Ezinye iisefu zemolekyuli zisetyenziswa kubungakanani-okungabandakanyiyo ichromatography, indlela yokwahlulahlulahlula iimolekyuli ngokusekwe kubungakanani bazo. Ezinye iisefu ze-molecular zisetyenziswa njenge-desiccants (eminye imizekelo ibandakanya i-charcoal esebenzayo kunye ne-silica gel).
Idayamitha yepore yesihluzo semolekyuli ilinganiswa nge-ångströms (Å) okanye i-nanometers (nm). Ngokwe-notation ye-IUPAC, izinto ze-microporous zine-diameter ye-pore engaphantsi kwe-2 nm (20 Å) kunye ne-macroporous materials ine-diameter ye-pore engaphezu kwe-50 nm (500 Å); udidi lwe-mesoporous lulele embindini kunye needayamitha zepore phakathi kwe-2 kunye ne-50 nm (20–500 Å).
Izinto eziphathekayo
I-molecular sieves inokuba yi-microporous, i-mesoporous, okanye i-macroporous material.
Izixhobo zeMicroporous (
● I-Zeolites (iiminerali ze-aluminosilicate, zingadideki kunye 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
● Imixube yeMontmorillonite
● I-Halloysite (endellite): Iifom ezimbini eziqhelekileyo zifunyenwe, xa i-hydrated udongwe lubonisa isithuba se-1 nm ye-leya kwaye xa i-dehydrated (meta-halloysite) i-spacing yi-0.7 nm. I-halloysite yenzeka ngokwendalo njengeesilinda ezincinci ezinomyinge we-30 nm ububanzi nobude obuphakathi kwe-0.5 kunye ne-10 yeemicrometer.
Isixhobo seMesoporous (2–50 nm)
I-silicon dioxide (esetyenziselwa ukwenza ijeli ye-silica): 24 Å (2.4 nm)
Izinto ezinkulu (>50 nm)
I-silika enkulu, 200–1000 Å (20–100 nm)
izicelo[hlela]
Izisefu zemolekyuli zihlala zisetyenziswa kwishishini lepetroleum, ngakumbi ukomisa imijelo yerhasi. Ngokomzekelo, kwishishini legesi yendalo engamanzi (LNG), umthamo wamanzi werhasi kufuneka uncitshiswe ube ngaphantsi kwe-1 ppmv ukuthintela ukuvaleka okubangelwa ngumkhenkce okanye i-methane clathrate.
Kwibhubhoratri, iisefu zemolekyuli zisetyenziselwa ukomisa i-solvent. "Ii-Sieves" zibonakalise ukuba ziphezulu kwiindlela zokomisa eziqhelekileyo, ezihlala zisebenzisa i-desiccants enobudlova.
Ngaphantsi kwegama elithi zeolites, i-molecular sieves isetyenziselwa uluhlu olubanzi lwezicelo ze-catalytic. Zenza i-isomerisation, i-alkylation, kunye ne-epoxidation, kwaye zisetyenziswa kwiinkqubo ezinkulu zemizi-mveliso, kubandakanya i-hydrocracking kunye nokuqhekeka kwe-fluid catalytic.
Zikwasetyenziswa kuhluzo lwezixhobo zomoya kwizixhobo zokuphefumla, umzekelo ezo zisetyenziswa ngabatshutshisi be-scuba kunye nabacimi bomlilo. Kwizicelo ezinjalo, umoya unikezelwa yi-compressor yomoya kwaye idluliselwe kwi-cartridge filter ethi, ngokuxhomekeke kwisicelo, izaliswe nge-molecular sieve kunye / okanye i-carbon activated, ekugqibeleni isetyenziselwa ukuhlawulisa iitanki zokuphefumula zokuphefumula. kunye neemveliso zokukhupha icompressor ezivela kunikezelo lomoya ophefumlayo.
Imvume ye-FDA.
I-US FDA ine-1 ka-Aprili 2012, ivunyiwe i-aluminosilicate ye-sodium yokunxibelelana ngokuthe ngqo kunye nezinto ezidliwayo phantsi kwe-21 CFR 182.2727. Ishishini belingafuni ukuxhasa ngemali uvavanyo olubiza kakhulu olufunekayo ukuze kuphunyezwe urhulumente.
Ukuzalwa ngokutsha
Iindlela zokuhlaziywa kwee-sieves ze-molecular ziquka ukutshintsha koxinzelelo (njengakwi-oxygen concentrators), ukufudumeza kunye nokuhlanjululwa nge-carrier gas (njengaxa isetyenziswe kwi-ethanol dehydration), okanye ukufudumeza phantsi kwe-vacuum ephezulu. Amaqondo obushushu okuhlaziya aqala kwi-175 °C (350 °F) ukuya kuma-315 °C (600 °F) ngokuxhomekeke kuhlobo lwesisefo semolekyuli. Ngokwahlukileyo, ijeli ye-silica inokuvuselelwa ngokuyifudumeza kwi-oven eqhelekileyo ukuya kwi-120 °C (250 °F) iiyure ezimbini. Nangona kunjalo, ezinye iintlobo zejeli ye-silica ziya "pop" xa zibonakaliswe kumanzi aneleyo. Oku kubangelwa kukuqhekeka kwee-silica spheres xa udibana namanzi.
| Umzekelo | Idayamitha yomngxuma (Ångström) | Ubuninzi bobuninzi (g/ml) | Amanzi eAdsorbed (% w/w) | Ukusetyenziswa | |
| 3Å | 3 | 0.60–0.68 | 19–20 | 0.3–0.6 | Ukuphelelwa lithembayeukuqhekeka kwepetroleumigesi kunye ne-alkenes, i-adsorption ekhethiweyo ye-H2O ngaphakathiiglasi egqunyiweyo (IG)kunye nepolyurethane, ukomiswa kweamafutha e-ethanolyokudibanisa nepetroli. |
| 4Å | 4 | 0.60–0.65 | 20–21 | 0.3–0.6 | Ukungeniswa kwamanzi ngaphakathisodium aluminosilicateevunywe yi-FDA (bonangezantsi) isetyenziswe njengesefa yemolekyuli kwizikhongozeli zonyango ukugcina imixholo yomile kwaye njengokoisongezo sokutyaukubaInombolo ye-EE-554 (i-anti-caking agent); Kukhethwa ukuphelelwa ngamanzi emzimbeni okumileyo kwiinkqubo zolwelo ezivaliweyo okanye zerhasi, umz., ekupakishweni kwamachiza, amacandelo ombane kunye neekhemikhali ezinokonakala; ukucocwa kwamanzi kwiinkqubo zoshicilelo kunye neeplastiki kunye nokomisa imijelo ye-hydrocarbon egcweleyo. Iintlobo ze-Adsorbed ziquka i-SO2, i-CO2, i-H2S, i-C2H4, i-C2H6, kunye ne-C3H6. Ngokuqhelekileyo ithathwa njenge-ejenti yokomisa jikelele kwi-polar kunye ne-nonpolar media;[12]ukwahlukana kweigesi yendalokwayeiialkenes, ukungeniswa kwamanzi kwi-non-nitrogen ebuthathakai-polyurethane |
| 5Å-DW | 5 | 0.45–0.50 | 21–22 | 0.3–0.6 | Ukunciphisa kunye nokugalela inqaku lokudakumbauphapho i-kerosenekwayeidizili, kunye nokwahlukana kwe-alkenes |
| 5Å encinci i-oxygen-etyetyiswe | 5 | 0.4–0.8 | ≥23 | Ilungiselelwe ngokukodwa ijenereyitha yeoksijini yezonyango okanye esempilweni[ucaphulo olufunekayo] | |
| 5Å | 5 | 0.60–0.65 | 20–21 | 0.3–0.5 | Ukuhlanjululwa kunye nokuhlanjululwa komoya;ukuphelelwa ngamanzi emzimbenikwayedesulfurizationyegesi yendalo kunyeigesi yepetroleum engamanzi;ioksijinikwayeihydrogenimveliso ngeuxinzelelo swing adsorptioninkqubo |
| 10X | 8 | 0.50–0.60 | 23–24 | 0.3–0.6 | I-sorption ephezulu, esetyenziswa kwi-desiccation, decarburization, desulfurization yegesi kunye nolwelo kunye nokwahlulaihydrocarbon enuka kamnandi |
| 13X | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | I-Desiccation, i-desulfurization kunye nokucocwa kwegesi yepetroleum kunye negesi yendalo |
| 13X-AS | 10 | 0.55–0.65 | 23–24 | 0.3–0.5 | I-Decarburizationkunye ne-desiccation kwishishini lokwahlula umoya, ukwahlukana kwe-nitrogen kwi-oxygen kwi-concentrators ye-oxygen |
| Cu-13X | 10 | 0.50–0.60 | 23–24 | 0.3–0.5 | Ukuswiti(ukususwa kwethiols) yeamafutha eenqwelomoyakunye nokuhambelanaiihydrocarbons ezingamanzi |
Ubunakho beAdsorption
3Å
Ifomula yekhemikhali eqikelelweyo: ((K2O)2⁄3 (Na2O)1⁄3) • Al2O3• 2 SiO2 • 9/2 H2O
I-silica-alumina ratio: SiO2/ Al2O3≈2
Imveliso
3Izisefu zemolekyuli ziveliswa ngokutshintshiselana ngecationipotassiumngenxasodiumkwi-4A iisefu zemolekyuli (Jonga ngezantsi)
Ukusetyenziswa
3Å iisefu zemolekyuli azibhengezi iimolekyuli ezinobubanzi obungaphezulu kwe-3 Å. Iimpawu zezi sieve zemolekyuli zibandakanya isantya esikhawulezayo sokubhengeza, ukukwazi ukuhlaziya rhoqo, ukuxhathisa okulungileyo kokutyumza kunyeukumelana nongcoliseko. Ezi mpawu zinokuphucula kokubili ukusebenza kakuhle kunye nobomi be-sieve. 3Å iisefu zemolekyuli ziyimfuneko ye-desiccant kwimizi-mveliso yepetroleum kunye neekhemikhali zokusulungekisa i-oyile, i-polymerization, kunye neekhemikhali zegesi-ulwelo lobunzulu lokomisa.
3Å iisefu zemolekyuli zisetyenziselwa ukomisa uluhlu lwemathiriyeli, njengei-ethanol, umoya,iifriji,igesi yendalokwayeiihydrocarbons ezingaxutywanga. Ezokugqibela ziquka irhasi yokukrazuka,iacetylene,ethylene,ipropylenekwayebutadiene.
I-3Å i-molecular sieve isetyenziselwa ukususa amanzi kwi-ethanol, enokuthi kamva isetyenziswe ngokuthe ngqo njenge-bio-fuel okanye ngokungathanga ngqo ukuvelisa iimveliso ezahlukeneyo ezifana neekhemikhali, ukutya, amayeza, nokunye. Ekubeni i-distillation eqhelekileyo ayikwazi ukususa onke amanzi (imveliso engafunekiyo evela kwimveliso ye-ethanol) ukusuka kwimijelo yenkqubo ye-ethanol ngenxa yokwenziwa kwe-ethanol.azeotropemalunga neepesenti ze-95.6 zoxinaniso ngobunzima, i-molecular sieve beads isetyenziselwa ukwahlula i-ethanol kunye namanzi kwinqanaba le-molecular ngokubhengeza amanzi kwi-beads kunye nokuvumela i-ethanol ukuba idlule ngokukhululekile. Emva kokuba amaso egcwele amanzi, ubushushu okanye uxinzelelo lunokulawulwa, luvumela amanzi ukuba akhululwe kwi-molecular sieve beads.[15]
I-3Å iisefu ze-molecular zigcinwa kwiqondo lokushisa, kunye nomswakama ohambelanayo ongekho ngaphezu kwe-90%. Zivalwe phantsi koxinzelelo oluncitshisiweyo, zigcinwe kude namanzi, i-acids kunye ne-alkalis.
4Å
Ifomula yemichiza: Na2O•Al2O3•2SiO2•9/2H2O
I-silicon-aluminium ratio: 1:1 (SiO2/ Al2O3≈2)
Imveliso
Imveliso ye-4Å sieve ithe ngqo njengoko ifuna uxinzelelo oluphezulu okanye amaqondo obushushu aphezulu. Ngokuqhelekileyo izisombululo ezinamanzi zesodium silicatekwayesodium aluminatezidityanisiwe kwi-80 °C. Imveliso efakwe kwi-solvent efakwe kwi-solvent "ivulwe" ngo "kubhaka" kwi-400 °C 4A iisefu zisebenza njenge-precursor ye-3A kunye ne-5A ye-seve ngokusebenzisa.ukutshintshiselana ngecationyesodiumngenxaipotassium(for 3A) okanyecalcium(ye5A)
Ukusetyenziswa
Ukomisa izinyibilikisi
4Å iisefu zemolekyuli zisetyenziswa kakhulu ukomisa izinyibilikisi zaselabhoratri. Ziyakwazi ukufunxa amanzi kunye nezinye iimolekyuli ezinobubanzi obubalulekileyo obungaphantsi kwe-4 Å ezifana ne-NH3, H2S, SO2, CO2, C2H5OH, C2H6, kunye ne-C2H4. Zisetyenziswa ngokubanzi ukomisa, ukucocwa kunye nokucocwa kolwelo kunye neegesi (ezifana nokulungiswa kwe-argon).
izongezo zepolyester[hlela]
Ezi zisefu zemolekyuli zisetyenziselwa ukuncedisa izicoci njengoko zinokuvelisa amanzi akhutshwa yimineralizedcalciumutshintsho lwe-ion, susa kwaye uthintele ukubekwa kokungcola. Zisetyenziswa ngokubanzi ukubuyiselaphosphorus. I-4Å molecular sieve idlala indima enkulu ekuthatheni indawo yesodium tripolyphosphate njengesincedisi sesicoci ukuze kuncitshiswe impembelelo yokusingqongileyo yesicoci. Inokusetyenziswa kwakhona njenge-aisephaiarhente yokwenza kwaye ngaphakathiintlama yamazinyo.
Unyango lwenkunkuma eyingozi
4Å iisefu zemolekyuli zinokucoca ilindle leentlobo ze-cationic ezifanaammoniumion, Pb2+, Cu2+, Zn2+ kunye neCd2+. Ngenxa yokukhethwa okuphezulu kwe-NH4 + baye basetyenziswa ngempumelelo kwintsimi yokulwai-eutrophicationkunye nezinye iziphumo kwimijelo yamanzi ngenxa yee-ion ze-ammonium ezigqithisileyo. I-4Å iisefu zemolekyuli ziye zasetyenziselwa ukususa ii-ion zentsimbi enzima ekhoyo emanzini ngenxa yemisebenzi yoshishino.
Ezinye iinjongo
Iishishini metallurgical: i-arhente yokwahlula, ukwahlukana, ukutsalwa kwe-brine potassium,irubidium,cesium, njl.
Ushishino lwepetrochemical,i-catalyst,desiccant, i-adsorbent
Ezolimo:isilungisi somhlaba
Iyeza: layisha isiliverezeolitei-antibacterial agent.
5Å
Ifomula yemichiza: 0.7CaO•0.30Na2O•Al2O3•2.0SiO2 •4.5H2O
I-silica-alumina ratio: SiO2/ Al2O3≈2
Imveliso
5Izisefu zemolekyuli ziveliswa ngokutshintshiselana ngecationcalciumngenxasodiumkwi-4A iisefu zemolekyuli (Jonga ngasentla)
Ukusetyenziswa
Ntlanu-ångström(5Å) iisefu zemolekyuli zihlala zisetyenziswa kwii-petroleumishishini, ngakumbi ukucocwa kwemijelo yerhasi kunye nelebhu yekhemistri yokwahlulaiikhompawundikunye nokumisa izixhobo zokuqalisa zokusabela. Ziqulethe imingxunya emincinci yobukhulu obuchanekileyo kunye nobukhulu obufanayo, kwaye zisetyenziswa ikakhulu njenge-adsorbent yeegesi kunye nolwelo.
I-five-ångström i-molecular sieves isetyenziselwa ukomisaigesi yendalo, kunye nokwenzadesulfurizationkwayei-decarbonationyerhasi. Zisenokusetyenziswa ukwahlula imixube yeoksijini, initrogen kunye nehydrogen, kunye ne-oyile-wax i-n-hydrocarbons ukusuka kwi-branched kunye ne-polycyclic hydrocarbons.
Five-ångström iisefu zemolekyuli zigcinwa kwiqondo lobushushu begumbi, ngeUbuntu bezizalwanengaphantsi kwe-90% kwimigqomo yekhadibhodi okanye ukupakishwa kweebhokisi. I-molecular sieves ayifanele ibonakaliswe ngokuthe ngqo emoyeni kunye namanzi, i-acids kunye ne-alkali kufuneka igwenywe.
I-Morphology ye-molecular sieves
Iisefu zemolekyuli zifumaneka ngokwemilo eyahlukeneyo kunye nobukhulu. Kodwa amaso angqukuva ane-advanteji ngaphezu kwezinye iimilo njengoko enikezela ngokuhla koxinzelelo olusezantsi, ayakwazi ukumelana noxinzelelo njengoko engenazo iincam ezibukhali, kwaye anamandla alungileyo, oko kukuthi amandla okutyumza afunekayo kwindawo nganye yeyunithi aphezulu. Ezinye iisefu zemolekyuli ezinamaso zinika umthamo ophantsi wobushushu ngoko ke zisezantsi iimfuneko zamandla ngexesha lohlaziyo.
Olunye uncedo lokusebenzisa iisefu zeemolekyuli ezinamaso luxinaniso lwesambuku ludla ngokuba phezulu kunenye imilo, kungoko kwimfuno ye-adsorption efanayo ye-molecular sieve umthamo ofunekayo ungaphantsi. Ngaloo ndlela ngelixa usenza i-de-bottlenecking, umntu unokusebenzisa iisefu ze-molecular beaded, ukulayisha ngaphezulu kwe-adsorbent kwivolumu efanayo, kwaye uphephe naluphi na ukuguqulwa kweenqanawa.
Ixesha lokuposa: Jul-18-2023
