Ukuqonda Ukulinganiswa Kobuningi Boketshezi Kuma-Reactor E-Polymerization
Uketshezi olunembile lokulinganisa ubuningi lubalulekile ekulawulweni kwenqubo yamakhemikhali kuma-reactor e-polyethylene polymerization. Ezinqubweni ze-polyethylene polymerization, ubuningi busebenza njengesibonakaliso esiqondile sokusabalala kwe-polymer, ubukristali, kanye nokusatshalaliswa kwesisindo sama-molecule, okubonisa izakhiwo ezibalulekile zezinto ezifana nokuqina, ukumelana nomthelela, kanye nokucutshungulwa. Isibonelo, i-polyethylene ephansi (LDPE) idinga ukulawulwa okuqinile kokuhlanganiswa kwe-long-chain, kuyilapho i-polyethylene ephezulu (HDPE) ibonakala ngokuhlanganiswa okuncane; kokubili kuncike ekuqondeni kokufundwa kobuningi boketshezi ukuze kuqondiswe izimo zokusabela kokusebenza okuqondiwe.
Ngesikhathi sokusabela kwe-polyethylene polymerization, ukulinganisa ubuningi boketshezi ngesikhathi sangempela kuvumela abaqhubi bezinqubo ukuthi balungise izinga lokushisa, ingcindezi, kanye namazinga okuphakelwa kwe-monomer, balondoloze izimo zokusabela ezifanele kanye nekhwalithi yomkhiqizo ehambisanayo. Ubuningi buyipharamitha ehamba phambili yokuhlukanisa amabanga e-polyethylene (LDPE, HDPE, LLDPE) kanye nokuqinisekisa ukufana kweqembu kuyo yonke inqubo yokukhiqiza i-polyethylene. Ukulandelela ubuningi okuthembekile ngamamitha obuningi angaphakathi njengalawo akhiqizwe yi-Lonnmeter akusekeli nje kuphela ukuqinisekiswa kwekhwalithi kodwa futhi kunciphisa ukuguquguquka komkhiqizo futhi kuthuthukise isivuno.
Umdwebo Wokukhiqiza i-Polyethylene Yezimboni
*
Izisekelo ze-Polyethylene Polymerization Reactors
Imiklamo Eyinhloko Ye-Reactor Yokukhiqizwa Kwe-Polyethylene
Ama-reaktha emibhede e-Fluidized (ama-FBR) abalulekile enqubweni ye-polyethylene polymerization, ikakhulukazi ekukhiqizweni kwe-LLDPE ne-HDPE ngesigaba segesi. Lawa ma-reactor amisa izinhlayiya ze-polymer ekukhuphukeni kwegesi, okwenza umbhede oguquguqukayo onokusatshalaliswa kwezinhlayiya ezifanayo. Ukuphathwa kokushisa okuphumelelayo kuyinzuzo evelele; ukusebenzisana okuqhubekayo phakathi kwezinto eziqinile negesi kukhuthaza ukususwa okusheshayo kokushisa kokusabela, kunciphisa ingozi yezindawo ezishisayo kanye ne-polymerization ebalekayo. Kodwa-ke, kuvela izinselele zokulawula, ikakhulukazi ukuguquguquka kwezinga lokushisa okufushane okuhlobene nokulinganisa kwe-catalyst noma ukuhlukahluka kwamazinga okuphakelwa kwe-coolant. Izinhlelo zokulawula ze-PID ezithuthukisiwe zisetshenziswa ukucindezela lokhu kuguquguquka nokugcina ukuzinza kokusebenza, kusekela ikhwalithi ye-polymer eqhubekayo kanye nokusebenza okuphephile kwe-reactor. Amamodeli e-Population Balance (PBM) ahlanganiswe ne-Computational Fluid Dynamics (CFD) anikeza indlela eyinkimbinkimbi yokulingisa nokwenza ngcono i-particle dynamics kanye ne-hydrodynamics, okwenza kube lula ukwandisa nokulungisa izimfanelo zomkhiqizo.
Ama-reactor anengcindezi ephezulu ayinsika yokwenziwa kwe-LDPE, asebenza ngezingcindezi ezivame ukwedlula amabha angu-2000. Ukwenziwa kwe-polymerization okukhulu kulezi zimo kudinga ukulawulwa okukhulu kokuxuba nesikhathi sokuhlala. Ukuxuba okuphumelelayo kuvimbela ukwakheka kwezindawo ezishisayo zendawo ezingalimaza ukuhambisana nokuphepha komkhiqizo. Isikhathi sokuhlala sinquma ubude beketanga le-polymer—izikhathi ezimfushane zikhetha izinsimbi eziphansi zama-molecule, kuyilapho ukuhlala isikhathi eside kusekela izinsimbi eziphakeme zama-molecule. Izifundo ezisebenzisa i-orthogonal collocation kanye nezindlela ze-finite element zembula ukuthi amazinga okuphakelwa kwabaqalisi kanye namazinga okushisa ejakethi kubalulekile ekwandiseni ukuguqulwa kwe-ethylene nokuqinisekisa ukuthi imigomo yenkomba yokugeleza kokuncibilika iyahlangatshezwa. Ukuxuba okubi kungaholela ekusabalalisweni kwesisindo sama-molecule okungajwayelekile kanye nokwanda kokungcola, okusongela kokubili ukuphepha kanye nokufana komkhiqizo.
Ama-Multizone Circulating Reactors (ama-MZCR) aveza indlela yokulawula ukusabela kwe-polyethylene polymerization. Lawa aklama ukwakheka kwe-polymerization ezindaweni eziningana ezixhumene ngokugeleza okulungisekayo, izinga lokushisa, kanye nokwethulwa kwe-ethylene. Izindlela zokupholisa zangaphakathi—ikakhulukazi ngaphakathi kwezingxenye ezikhuphukayo—zinciphisa kakhulu ukuguquguquka kwezinga lokushisa, zithuthukisa ukufana kwezinga lokushisa kusukela ekushintsheni okufika ku-8°C kuya cishe ku-4°C. Le ndawo ehlelwe kahle yenza amazinga okuguqulwa kwe-ethylene athuthuke ngaphezu kuka-7%, futhi isekela ukulawulwa okuqinile kokusatshalaliswa kwesisindo sama-molecule. Izakhiwo zezinhlayiya zihambisana kakhulu ngenxa yokuhlanganiswa kwejubane legesi kanye nokujikeleza okuqinile phakathi kwezindawo. Ama-MZCR ahlinzeka futhi ngamapulatifomu angandiswa, asize ekushintsheni kusuka ekukhiqizweni kwelebhu kuya ekuhlolweni kanye nasezimbonini ngenkathi kugcinwa inqubo kanye nokuvumelana komkhiqizo.
Umthelela Wezinguquko Zenqubo
Izinga lokushisa liyipharamitha ephakathi ethinta amazinga okusabela kwe-polyethylene polymerization, isisindo sama-molecule, kanye ne-crystallinity. Amazinga okushisa aphezulu andisa ukudluliselwa kweketanga kanye nemvamisa yokuphela, okuholela ekunciphiseni isisindo sama-molecule esimaphakathi. Amazinga okushisa aphansi akhuthaza ukwakheka kwamaketanga amade e-polymer kodwa anganciphisa amazinga okuguqulwa. Ukulinganisa kwe-Catalyst kuthonya umsebenzi kanye ne-polymer chain nucleation. Ukugxila okuphezulu kwe-catalyst kusheshisa i-polymerization kodwa kunganciphisa noma kwandise ukusatshalaliswa kwesisindo sama-molecule, kuye ngokuthi i-catalyst chemistry kanye nomklamo we-reactor. Ukulinganisa okwenziwe kahle kuqinisekisa izakhiwo ze-polymer ezifiselekayo ngaphandle kokufakwa ngokweqile noma amaphutha esakhiwo.
Ukuxuba ngaphakathi kwe-reactor ye-polymerization kuhambisana ngqo nokufana komkhiqizo. Ukuxuba okungeyona ekahle kuletha ukwehluka kwendawo ekugxilweni okukhulu kanye nokushisa, okubangela ukusatshalaliswa kwesisindo sama-molecule okubanzi noma okune-multimodal. Izifundo ze-CFD ziqinisekisa ukuthi amaphethini okujikeleza alungiselelwe kanye nebhalansi yesikhathi sokuhlala kungacindezela ukweqisa kwe-kinetic okungafuneki, kuveze i-polyethylene enokucubungula okulungiselelwe kanye nokusebenza komshini. Ezinhlelweni ze-MZCR, ukuhlukanisa amapharamitha endawo kulawula ukuxubana kanye nokushisa, kuthuthukise ukuguqulwa kwe-ethylene ye-single-pass kanye nokunciphisa izinto ezingaphandle kwe-spec.
Ukuxhumana phakathi komklamo we-polymerization reactor kanye nezici zomkhiqizo kuqondile futhi kuyalinganiswa. Ama-FBR akhiqiza amamaki e-polyethylene afanelekela ifilimu kanye nokubumba okujikelezayo, azuza kuma-indices amancane okuncibilika kanye nokulawulwa kwesisindo sama-molecule okuqinile. Ama-reactor aphezulu e-LDPE aletha izakhiwo zeketanga ezihlukile ezithandwa ukusetshenziswa kwe-extrusion kanye nokupakisha. Imiklamo ye-Multizone inikeza ukuguquguquka ekuqondiseni amaphrofayili esisindo sama-molecule ayinkimbinkimbi, esekela amamaki akhethekile. Amasu okulinganisa uketshezi oluthuthukisiwe, kufaka phakathi amamitha wobuningi obungaphakathi kwe-Lonnmeter, asekela ukulawulwa kwekhwalithi kwesikhathi sangempela ngokunika amandla ukuqapha okunembile kobuningi benqubo kanye nokuhlushwa kwe-polymer, okubalulekile ekuqinisekiseni ukuhambisana kwemininingwane kuyo yonke inqubo yokukhiqiza i-polyethylene.
Amasu Okulinganisa Ubuningi Boketshezi Ezindaweni Ze-Reactor
Izimiso Ezisekela Ukulinganiswa Kobuningi
Ubuningi buchazwa njengobuningi ngeyunithi ngayinye yevolumu yento. Kumongo we-reactors ye-polyethylene polymerization, ukulinganiswa kobuningi besikhathi sangempela kubalulekile, njengoba kuhlobene ngqo ne-polymer crystallinity kanye nezakhiwo zemishini, okuthinta kokubili ukulawulwa kwenqubo kanye nekhwalithi yomkhiqizo. Isibonelo, ukuqapha ubuningi kuvumela onjiniyela ukuthi babone izinguquko ku-polymerization kinetics, okungabonisa izinguquko ekusebenzeni kwe-catalyst noma amazinga okuphakelwa kwe-monomer.
Kokubili izici zomzimba nezamakhemikhali zithonya ubuningi ezindaweni ze-reactor. Ukwanda kwezinga lokushisa kubangela ukwanda kanye nobuningi obuphansi boketshezi, kanti ukucindezela okuphezulu kuvame ukucindezela uketshezi futhi kukhuphule ubuningi balo. Ku-reactors ye-polymerization, izinguquko zokwakheka (njengokuhlushwa kwe-monomer, amagesi ancibilikisiwe, izithasiselo, noma imikhiqizo elandelanayo) zenza kube nzima ukulinganisa, okwenza kube nesidingo sokucabangela zonke iziguquguquko zenqubo ekuqapheni okunembile kobuningi. Ukuze uthole ukusabela okungafani, njenge-slurry noma i-suspension polymerization, ukulayisha kwezinhlayiya, i-agglomeration, kanye nokwakheka kwama-bubble kungathinta kakhulu ukufundwa kobuningi okubonakalayo.
Izindlela Ezisunguliwe Zokulinganisa Ubuningi Boketshezi
Izindlela zokulinganisa ngqo zifaka phakathi ama-hydrometer, amamitha okuxinana kwedijithali, kanye nezinzwa zamashubhu adlidlizayo. Ama-hydrometer anikeza ukusebenza okulula ngesandla kodwa awanawo ukunemba kanye nokuzenzakalela okudingekayo ezinqubweni ze-polymerization yokucindezela okuphezulu. Amamitha okuxinana kwedijithali ahlinzeka ngokunemba okuthuthukisiwe futhi angahlanganisa isinxephezelo sokushisa, okwenza afaneleke ekulinganisweni kwelabhorethri kanye nokulawula okuvamile. Amamitha okuxinana kweshubhu adlidlizayo, okuwumthombo oyinhloko ovela eLonnmeter, asebenza ngokulinganisa izinguquko zemvamisa ye-oscillation njengoba uketshezi lugcwalisa ishubhu eklanywe kahle. Lezi zinguquko zihlobene ngqo nokuxinana koketshezi, ngamamodeli okulinganisa abangela ukuncika kokucindezela kanye nokushisa.
Izindlela ezithuthukisiwe nezingaqondile ziyathandwa ekusebenzeni okuqhubekayo, okuzenzakalelayo kwe-reactor. Izinzwa ze-Ultrasonic zisebenzisa amaza omsindo avame kakhulu, okuvumela ukulinganisa ubuningi ngesikhathi sangempela okungaphazamisi ngisho nasemazingeni okushisa aphezulu kanye nokucindezela, futhi zimelana nokungcola ezindaweni zamakhemikhali. Izinzwa ezisekelwe e-nuclear zisebenzisa izimiso zokumunca imisebe, ezifanelekela imifudlana yenqubo engacacile kanye nokufakwa kwe-reactor yokushisa okuphezulu, ikakhulukazi lapho kukhona khona amasimu e-gamma noma e-neutron. Izinzwa ze-microwave zilinganisa ukushintsha kwempahla ye-dielectric ehlobene nobuningi boketshezi, okubalulekile emifudlaneni ethile ecebile nge-solvent noma ye-multiphase.
Izinhlelo zokulinganisa eziku-inthanethi nezingaphakathi ezindaweni eziyinselele kumele zibhekane nokweqisa kwenqubo—njengezihibe ze-slurry ezinengcindezi ephezulu noma ama-reactor esigaba segesi enqubweni yokukhiqiza i-polyethylene. Ama-densimeter e-vibrating tube anikeza amavolumu amancane esampula kanye nokusebenza okuqinile kuwo wonke amazinga okushisa nokucindezela. Ngokuphambene nalokho, izinzwa ze-ultrasonic nezenuzi ziphumelela kakhulu ekumelaneni nokuhlaselwa ngamakhemikhali, ukungcola, kanye nemisebe, ngenkathi zigcina ukuthembeka kwesiginali. Izinzwa zesikhathi sangempela ezifakwe ngqo ngaphakathi kwezihibe ze-reactor zivumela ukulungiswa kwenqubo enamandla ukuze kugcinwe izinhloso zobuningi ezifanele, kunciphisa umkhiqizo ongekho ku-spec futhi kunciphisa ukuthembela ekuhlaziyweni kwelebhu okwenziwa ngezikhathi ezithile.
Ukubhekana Nobunzima Bemidiya Yenqubo
Imidiya ye-reactor eyinkimbinkimbi efana nama-slurry ahlukene, ama-emulsion, noma ukumiswa kokusabela kuveza ubunzima obukhulu ekulinganisweni kobuningi boketshezi. Ukuhlushwa kwezinto eziqinile, amabhamuza egesi, kanye namaconsi e-emulsion kungaphazamisa ukufundwa ngokushintsha ukudluliselwa kwesisindo okusebenzayo kanye ne-hydrodynamics. Imiklamo ye-probe kumele ivumelane nokulungiswa kwezinhlayiya kanye nemiphumela yokuqoqana kwendawo, okudinga ukuphathwa kokugeleza koketshezi ukuze kuncishiswe izinto zokulinganisa ubuningi. Isibonelo, kuma-reactor e-polyethylene polymerization asebenzisa ukusebenza kwesigaba se-slurry, ukusatshalaliswa kosayizi wezinhlayiya kanye namagesi angenayo angeziwe anselela ukuhambisana kokulinganisa ubuningi.
Isinxephezelo esinembile sokushintshashintsha kwezinga lokushisa, ingcindezi, kanye nokwakheka kubalulekile. Izindlela eziningi zokulinganisa ubuningi boketshezi zihlanganisa izinzwa zokushisa kanye nokucindezela, zisebenzisa amathebula okulungisa okwenziwa nge-empirical noma ama-algorithms ekhompyutha azenzakalelayo okulungiswa kwesikhathi sangempela sokuphakelayo. Amamitha e-vibrating tube e-Lonnmeter asebenzisa amamodeli okulinganisa ukuze aqedele imithelela yemvelo ekunyakazeni kwenzwa. Kuma-multicomponent media, ukufundwa kobuningi kungalungiswa kusetshenziswa izingxube zokubhekisela noma izindlela zokulinganisa ezihambisana nokwakheka kwenqubo okulindelekile. Isinxephezelo sokuhlukaniswa kwesigaba—njenge-emulsions yamafutha-amanzi noma ukumiswa kwe-polymer—kungadinga ama-probe engeziwe noma i-sensor fusion ukuze kuhlukaniswe izinhlayiya, igesi, kanye neminikelo yoketshezi.
Ukuhlanganiswa Kwedatha Yobuningi Boketshezi Yokwenza Inqubo Ye-Reactor Isebenze Kahle
Ukubaluleka Kwedatha Yesikhathi Sangempela Kumasu Okulawula Okubonakalayo Ngokusebenzisa I-Polmerization
Ukuqapha okuqhubekayo kobuningi bengxube yokusabela kubalulekile enqubweni yokwenza i-polyethylene polymerization. Ukulinganisa ubuningi obuqhubekayo kuvumela ukusebenza okuphephile kwe-reactor ngokuvumela ukutholakala okusheshayo kokuphambuka okungabangela ukuguquka kwezinga lokushisa okuyingozi noma kubangele ukukhiqizwa kwe-polymer engacacisiwe. Ukugcina ubuningi boketshezi obuzinzile kuqinisekisa ukuthi i-polyethylene ephumayo inesisindo sama-molecule esifanayo kanye nezici zemishini, ezibalulekile kokubili ezimakethe zezimpahla kanye nemikhiqizo ekhethekile.
Amasu okulawula e-PID (Proportional-Integral-Derivative) asebenzisa impendulo yobuningi besikhathi sangempela ukuze alungise ngokuguquguqukayo amapharamitha e-reactor. Lapho izinzwa—njengamamitha obuningi angaphakathi kwe-inline avela eLonnmeter—zinikeza idatha yoketshezi yokulinganisa ubuningi obuqhubekayo, uhlelo lokulawula lulungisa amazinga okuphakelwa kwe-ethylene, imithamo ye-catalyst, kanye nama-setpoints okushisa ngokushesha. Lokhu kuguqulwa, okuqhutshwa impendulo yobuningi, kuvimbela ukuphazamiseka futhi kuzinzise i-reactor ye-polymerization, okuholela ekuthembekeni okuphezulu kwenqubo kanye nokuphepha kokusebenza.
Ukuhlaziywa kokuzwela kwembula ukuthi izinto eziguquguqukayo ezifana nokugeleza kwe-monomer kanye ne-catalyst, kanye nokushisa kokusabela, kuthinta ngqo ukuzinza kwe-reactor ye-polymerization. Izinguquko ezincane kumazinga okuphakelayo noma ukugxila kwe-catalyst kungasakazeka, okuholela ekushintsheni kobuningi okungathi, uma kungahlolwanga, kubangele izindawo ezishisayo noma ukuguqulwa okungaphansi kokufanele. Ukusetshenziswa kwedatha yesikhathi sangempela kuvumela abalawuli be-PID ukuthi balungise kusengaphambili izindawo ezibucayi, balondoloze ubuqotho benqubo. Isibonelo, ukulawulwa kwe-PID okuguquguqukayo, okuthembele kumasignali obuningi abukhoma, kungamelana ngokunembile nezinguquko ezisheshayo zokwakheka kwe-feedstock, kugweme ukusabela okubalekayo futhi kugcinwe izakhiwo ze-polyethylene ezihambisanayo.
Ukuxhumanisa Idatha Yobuningi Nekhwalithi Yomkhiqizo Nokusebenza Kahle Kwenqubo
Ukulinganisa ubuningi boketshezi ngesikhathi sangempela kunikeza ukuqonda okusebenzayo mayelana nokuguquguquka kwangaphakathi kwe-reactor ye-polymerization kanye nekhwalithi yokugcina yomkhiqizo. Izitayela zobuningi zivumela ukutholakala kokuguquguquka okuhlobene nokuxubana okungekuhle, ukulahlekelwa ngokunemba kwezinga lokushisa, noma ukwehla komsebenzi we-catalyst. Lokhu kuguquguquka kungabonisa izindawo ezishisayo ezisendaweni - izindawo zokusabela ngokweqile - okungaholela ezicini ze-polymer ezingathandeki kanye nengozi eyengeziwe yokungcola.
Ngokuhlanganisa idatha yokulinganisa uketshezi ekusebenzeni kwe-reactor, opharetha bangalungisa njalo amazinga okuphakelwa kokudla, ukunikezwa kwe-catalyst, kanye nezimo zokushisa ukuze balwe nokuphambuka kobuningi. Ukuguqulwa okusekelwe ekuqineni okuthandwayo kunciphisa ukungcola, ngoba kuvimbela izimo ezikhuthaza ukwakheka kwe-polymer noma ama-oligomer awonakele ezindongeni ze-reactor. Ukulawulwa kobuningi okuthuthukisiwe kuhumusha izinqubo zokukhipha ukumuncwa ezisebenza kahle ngaphakathi kwe-reactor, kusekela amasu angcono okumuncwa kwegesi kanye nokukhipha ukumuncwa kokukhiqizwa kwe-polyethylene.
Ukuboniswa kwedatha—njengamashadi ethrendi yobuningi—kubalulekile ekuxhumaniseni izinguquko zobuningi ezibonwe nokulungiswa kwenqubo engezansi. Cabanga ngesibonelo esilandelayo seshadi lobuningi besikhathi sangempela ku-reactor ye-loop:
Njengoba kuboniswe, ukutholakala kokwehla kobuningi ngesikhathi esifanele kuqala ukwanda okusheshayo komthamo we-catalyst kanye nokwehla okuncane kwezinga lokushisa, okuqinisa ngempumelelo umphumela wenqubo. Umphumela uba ukungcola okuncishisiwe, amazinga okuguqulwa kwe-monomer athuthukisiwe, kanye nokuvumelana okuphezulu emiphumeleni yokusabela kwe-polyethylene polymerization.
Ngamafuphi, ukuqapha okuqhubekayo, okuqondile kobuningi boketshezi—okufezwe ngamasu okulinganisa ubuningi boketshezi njengalawo aklanywe yiLonnmeter—kuqinisa indima yawo ekwakhiweni nasekusebenzeni kwe-polymer reactor ethuthukisiwe, okuthinta ngqo inqubo yokukhiqiza i-polyethylene ngokusekela kokubili ukuthuthukiswa kwekhwalithi yomkhiqizo kanye nokuthuthukiswa kokusebenza kahle kwenqubo.
Izinqubo Zokumunca Ekukhiqizweni Kwe-Polyethylene
Ukumuncwa kanye nokuguquguquka kokukhipha amanzi kuyisisekelo senqubo yokupholisa i-polyethylene, kulawula ukunyakaza kanye nokuguqulwa kwamagesi e-monomer njengoba esebenzisana nezindawo ze-catalyst ngaphakathi kwe-reactor ye-polymerization. Ngesikhathi sokusabela kwe-polyethylene polymerization, ama-molecule e-monomer amuncwa phezu kwe-catalyst. Lokhu kuthathwa kuncike kokubili ezimpahleni zama-molecule ze-monomer—njengobuningi, i-polarity, kanye nokuguquguquka—kanye nendawo yamakhemikhali ngaphakathi kwe-reactor. Ukususwa kwamanzi, ngokuphambene nalokho, inqubo lapho la ma-molecule afakwe khona amanzi ehlukana futhi abuyele esigabeni esikhulu. Izinga kanye nokusebenza kahle kwalezi zinqubo kuthinta ngqo ukutholakala kwe-monomer, ukukhula kwe-polymer, kanye nokukhiqiza kwe-reactor iyonke.
Amandla okususa imfucuza alinganisa isithiyo okumele i-molecule ye-monomer inqobe ukuze ishiye ubuso be-catalyst. Izifundo zokulinganisa ziveza ukuthi la mandla ancike kakhulu ekwakhekeni kwama-molecule e-monomer kunohlobo oluthile lobuso, okuvumela amamodeli ajwayelekile okubikezela kuzo zonke izinhlelo ezahlukene ze-reactor. Isikhathi sokuphila sokususa imfucuza, noma isikhathi esimaphakathi i-molecule ehlala imuncwe, sithinta kakhulu izinga lokushisa ngaphakathi kwe-reactor. Amazinga okushisa aphansi andisa isikhathi sokuphila, okungenzeka ukuthi anciphise amazinga okusabela, kuyilapho amazinga okushisa aphezulu ekhuthaza ukushintshashintsha okusheshayo, okuthinta ukuminyana komkhiqizo we-polyethylene.
Ukuthathwa kwe-monomer kanye nokusebenzisana kwe-catalyst akubuswa kuphela yi-kinetics ye-oda lokuqala. Ucwaningo lwamuva lubonisa ukuthi ukuziphatha kokudonswa kwe-coverage okuncike ekumbozweni kungenzeka, lapho ukusebenzisana kwe-adsorbate-adsorbate kuqhuba i-kinetics engeyona eqondile, ikakhulukazi ezindaweni eziphakeme zokumbozwa. Isibonelo, njengoba ubuso be-catalyst bugcwala, ukudonswa kokuqala kuqhubeka kancane nangokuqondile kuze kube yilapho ukumbozwa kobuso kwehla ngaphansi komkhawulo obalulekile, lapho ukudonswa okusheshayo kushesha khona. Lokhu kuguquguquka kumele kucatshangelwe ekwakhiweni nasekusebenzeni kwe-polymer reactor, njengoba kuthinta kokubili ukusebenza kahle kokusetshenziswa kwe-monomer kanye nokuvumelana kokukhishwa kwe-polymer.
Ukuhlanganisa idatha yokumunca kanye nokukhipha amanzi nezindlela zokulinganisa uketshezi ngesikhathi sangempela kubalulekile ekugcineni inqubo yokukhiqizwa kwe-polyethylene ezinzile. Amamitha angaphakathi akhiqizwe yi-Lonnmeter anikeza impendulo eqhubekayo ngobuningi besigaba soketshezi, okubonisa ukushintsha okucashile kokuhlushwa kwe-monomer kanye namazinga okukhula kwe-polymer. Njengoba ukumunca kuletha ama-monomer endaweni yokusabela—futhi ukumunca kususa ama-molecule asetshenzisiwe noma adlulele—noma yikuphi ukungalingani noma ukushintshashintsha kwe-kinetic kuzobonakala ngqo ekufundweni kobuningi, okuvumela ukulungiswa okusheshayo kokusebenza. Isibonelo, uma ukumunca kushesha ngokungalindelekile, ukwehla kobuningi obulinganisiwe kungabonisa ukusetshenziswa okunganele kwama-monomer noma ukungasebenzi kahle kwe-catalyst, okuqondisa opharetha ukuthi bashintshe amazinga okuphakelayo noma amaphrofayili okushisa.
Isithombe 1 ngezansi sibonisa ubudlelwano phakathi kokumuncwa kwe-monomer kanye namazinga okumuncwa, ukumbozwa kwendawo, kanye nokuminyana koketshezi okubangelwa yi-reactor ejwayelekile ye-polyethylene polymerization, ngokusekelwe ezimweni ezilingisiwe:
| Ubuningi (g/cm³) | Ukumbozwa kwe-Monomer (%) | Izinga Lokumunca | Izinga Lokumunca |
|------------------|- ...|--------------------|
| 0.85 | 90 | Okuphezulu | Okuphansi |
| 0.91 | 62 | Okumaphakathi | Okumaphakathi |
| 0.94 | 35 | Okuphansi | Okuphezulu |
Ukuqonda lezi zindlela zokulinganisa uketshezi kanye nokuhlanganisa izindlela eziqondile zokulinganisa ubuningi boketshezi, njengalezo ezitholakala eLonnmeter, kwenza kube lula ukulawula inqubo yokwenza i-polyethylene polymerization. Lokhu kuqinisekisa ukuhambisana komkhiqizo okuhle kakhulu, isivuno esiphezulu, kanye nokusetshenziswa kahle kwe-catalyst kulo lonke ukukhiqizwa okuqhubekayo.
Izindlela Ezinhle Kakhulu Zokulinganisa Ubuningi Obunembile Enqubweni Yokwenza I-Polyethylene Polymerization
Ukulinganiswa kokuqina okuqinile kubalulekile ekulawuleni okunembile kokusabela kwe-polyethylene polymerization. Ukuze kulinganiswe ukuqina koketshezi olungaphakathi kule ndawo.
Amasu Okuthatha Amasampula: Ukukhishwa Okumele Koketshezi Noma Ukulinganisa Ukugeleza Okuqhubekayo
Ukulinganisa okunembile kobuningi boketshezi kuma-reactor e-polymerization kuncike ekwakhiweni okuphumelelayo kokuthatha amasampula. Izindlela zokukhipha ezimele zisebenzisa ama-nozzles e-isokinetic ukugwema ukuphazamiseka kwesampula, ngezingxenye zesistimu ezifana nama-valve okuzihlukanisa kanye nama-cooler esampula agcina ubuqotho besampula ngesikhathi sokudluliselwa. Ingozi eyinhloko yokukhipha ukulahlekelwa yizingxenyana eziguquguqukayo noma izinguquko ekwakhiweni kwe-polymer uma isampula ingacinywanga noma ipholiswe ngokushesha. Ukulinganisa okuqhubekayo kobuningi be-flow-through kusetshenziswa izinzwa ze-Lonnmeter eziku-inline kunikeza idatha yesikhathi sangempela ebalulekile enkambisweni yokukhiqiza i-polyethylene; noma kunjalo, le ndlela idinga ukuphathwa kwezinkinga ezifana nokungcola, ukuhlukaniswa kwesigaba, noma amabhamuza angase anciphise ukunemba. Imiklamo yokukhipha uketshezi oluqhubekayo ifaka ukuphinda kusetshenziswe i-solvent ukuze kugcinwe izimo ezizinzile, ngokusetha kwezigaba eziningi kanye nokulinganisa okuzenzakalelayo kwesampula kanye nesikhathi sokuphendula. Ukukhetha phakathi kwezindlela ezihlukile neziqhubekayo kuncike esikalini senqubo kanye nezidingo zokuphendula okuguquguqukayo, ngempendulo yesikhathi sangempela eqhubekayo evame ukukhethwa ekulawulweni kwe-reactor ye-polymer.
Iphutha Lokunciphisa Ukulinganisa: Imiphumela Yama-Gradients Okushisa, Ukuhlukaniswa Kwesigaba, kanye Nemidiya Ephezulu Ye-Viscosity
Iphutha lokulinganisa ekuzweleni ubuningi livela ikakhulukazi kuma-gradients okushisa, ukuhlukaniswa kwesigaba, kanye ne-viscosity ephezulu. Ama-gradients okushisa ngaphakathi kwe-reactor, ikakhulukazi esikalini, abangela ukwehluka kwendawo ekuxineni koketshezi, okwenza kube nzima ukuphendula kwenzwa. Ukuhlukaniswa kwesigaba phakathi kwezizinda ezicebile nge-polymer kanye ne-solvent-rich kuholela ekuhlukeni kobuningi—izinzwa eziseduze kwezixhumi zingase zilethe idatha engalungile noma engameleli. I-viscosity ephezulu, evamile kwimidiya ye-polymerizing, ivimbela ukulingana kokushisa kanye nokwakheka, okwandisa ukubambezeleka kanye nephutha ekuphenduleni kwezinzwa. Ukuze kuncishiswe le miphumela, ukwakheka kwe-reactor kumele kubeke phambili ukuxubana okufanayo kanye nokubekwa kwezinzwa okunesu, kuqinisekiswe ukuthi izinzwa zivikelekile noma zihlukaniswe nezixhumi zesigaba sendawo. Izifundo ze-empirical zigcizelela ukuxhumana phakathi kwama-gradients okushisa abekwe kanye nokusebenza kwezinzwa, ukuthola ukwanda kwamaphutha ezindaweni zokusabela ezibonisa ukuxubana okubi noma izinguquko zesigaba esisheshayo. Ukumodela okubikezelayo kusetshenziswa izindlela ezihlanganisiwe ze-Cahn-Hilliard, ukudluliselwa kokushisa kwe-Fourier, kanye nezindlela zokulinganisela inani labantu kunikeza izinhlaka zokubikezela nokulungisa ukungalingani, ngaleyo ndlela kuthuthukisa ukuthembeka kokulinganiswa kobuningi boketshezi olungaphakathi.
Ukuqinisekiswa nge-Population Balance kanye ne-CFD Modeling Approaches
Ukuqinisekiswa kokulinganiswa kobuningi boketshezi kuma-reactor e-polyethylene polymerization kwenziwa ngokuxhumanisa idatha yesikhathi sangempela ebonwe nezibikezelo ezisekelwe kumodeli. Amamodeli ebhalansi yabantu (ama-PBM) alandelela ukukhula nokusatshalaliswa kwezinhlayiya ze-polymer, ebala ukwehluka komsebenzi we-catalyst, isisindo sama-molecule, kanye namazinga okuphakelayo. I-Computational fluid dynamics (i-CFD) ilingisa amaphrofayili e-reactor hydrodynamics, ukuxuba, kanye nokushisa, okwazisa izimo zenzwa ezilindelekile. Ukuhlanganisa ama-PBM ne-CFD kunikeza izibikezelo ezinesinqumo esiphezulu zokusatshalaliswa kwesigaba kanye nezinguquko zobuningi kulo lonke i-reactor. Lawa mamodeli aqinisekiswa ngokufanisa umkhiqizo wawo nokufundwa kwangempela kwenzwa—ikakhulukazi ngaphansi kwezimo zesikhashana noma ezingezinhle. Izifundo zibonisa ukuthi uhlaka lwe-CFD-PBM lungaphinda ukwehluka kobuningi obulinganisiwe, lusekele ukuthembeka kokulinganisa kanye nokwenza ngcono ukwakheka kwe-reactor. Ukuhlaziywa kokuzwela, ukuqhathanisa impendulo yemodeli nokushintsha kwamapharamitha okusebenza njengesilinganiso sokushisa noma sokuxuba, kuthuthukisa ukunemba kanye nekhono lokuxilonga. Ngenkathi isivumelwano semodeli siqinile ngaphansi kwezimo eziningi, ukuhluzwa okuqhubekayo kuyadingeka ukuze kube ne-viscosity noma ukungafani okukhulu, lapho ukulinganisa okuqondile kuhlala kuyinselele. Amashadi okulinganisa iphutha lobuningi uma kuqhathaniswa nokwehla kwezinga lokushisa, ubunzima bokuhlukaniswa kwesigaba, kanye ne-viscosity ahlinzeka ngezinkombandlela ezibonakalayo zokwenza okuhle kokusebenza kanye nokuqinisekiswa kwemodeli okuqhubekayo.
Ukucatshangelwa Kokulawula Okuthuthukisiwe Kuma-Reactor E-Polymerization
Ukuhlanganisa ukumodela kwe-Computational Fluid Dynamics (CFD) nedatha yokuhlola kubalulekile ekuthuthukisweni kokulawula kuma-reactor e-polymerization, ikakhulukazi enqubweni ye-polyethylene polymerization. I-CFD ivumela ukulingiswa okuningiliziwe kokugeleza koketshezi, ukuxuba, ukusatshalaliswa kwezinga lokushisa, kanye nokusebenza kahle kokuxuba ngaphakathi kwe-reactor ye-polymerization. Lezi zibikezelo ziqinisekiswa yizifundo zokuhlola, ngokuvamile ngama-reactor emodeli asebenzisa imikhumbi esobala kanye nezilinganiso ezisekelwe ku-tracer zokusatshalaliswa kwesikhathi sokuhlala. Uma amaphrofayili okulinganisa kanye nobuningi bokuhlola ehambisana, kuqinisekisa ukumodela okunembile kwezimo zenqubo yangempela, njengokusatshalaliswa kwe-reactant efanayo kanye nokuphathwa kokushisa ngesikhathi sokusabela kwe-polyethylene polymerization. Ukuqapha inqubo esekelwe ekuxineni kunikeza impendulo eqondile kokubili ukunemba kwemodeli kanye nokulawulwa kokusebenza kwansuku zonke, okuvumela ukutholakala kwezindawo ezifile noma ukuxubana okunganele ngaphambi kokuba kuthinte ikhwalithi noma ukuphepha komkhiqizo.
Ukuqinisekiswa kwe-CFD ngama-benchmark okuhlola kubalulekile ekunciphiseni ubungozi. Ukuxubana kabi kuma-reactor e-polymerization anamandla aphezulu kungabangela ukushisa ngokweqile kwendawo (izindawo ezishisayo), okungase kubangele ukubola kwe-initiator okungalawulwa, ikakhulukazi uma kusetshenziswa ama-peroxide. Izindawo ezishisayo zivame ukuphunyuka ekutholakaleni kweprobe yokushisa ejwayelekile kodwa zibonakala ngezinguquko ezisheshayo ekuminyaneni kwendawo. Idatha yoketshezi yokulinganisa ubuningi besikhathi sangempela, njengoba ikhiqizwa izinzwa eziqondile njengalezo ezivela eLonnmeter, inikeza ukuqonda okuhlanganisiwe kokungafani kokugeleza kanye nezindawo zokuguqulwa kuyo yonke i-reactor. Ukuqapha ubuningi boketshezi ezindaweni ezibalulekile kuvumela opharetha ukuthi bathole ukuhamba kwe-exothermic, baqale izenzo zokulawula ngaphambi kokuba kwenzeke isenzakalo sokushisa esibalekayo. Ukuvimbela izimo ezinjalo ezibalekayo kuqinisekisa ukuphepha futhi kuqinisekisa ukusetshenziswa kwe-peroxide okusebenzayo, kanye nokunciphisa umkhiqizo ongekho ku-spec ngenxa yokwanda kwezinga le-polymerization.
Esinye isici esithonywe kakhulu ukuqapha ubuningi ukulawula ukusatshalaliswa kwesisindo sama-molecular (MWD). Ukuguquguquka kwe-MWD kuthinta kokubili izici zomshini kanye nokucutshungulwa kwe-polyethylene. Idatha yobuningi be-granular, yesikhathi sangempela ivumela ukuqagela okungaqondile, kodwa okusheshayo kwezitayela ze-MWD. Amasu okulawula asekelwe kumodeli, athembele kumanani oketshezi wokulinganisa ubuningi be-inthanethi, alungisa amazinga okuphakelayo okuqala kanye namaphrofayili okupholisa ngokuguquguqukayo ekuphenduleni ukushintsha kobuningi, ukunciphisa ukuguquguquka kwe-MWD ye-batch-to-batch kanye nokuqinisekisa izakhiwo eziqondile ze-polyethylene. Izifundo zokulingisa kanye nezifundo eziqinisekisa ukuthi ukugcina ukuqina okuzinzile kuvimbela ukuziphatha okungafuneki kwe-nucleation noma i-crystallization, kusekela ukukhiqizwa kwamabanga e-polyethylene amathathu anezimpawu eziqondiwe.
Ukuze kuthuthukiswe ukusebenza kahle kokuguqulwa, ukwakheka nokusebenza kwe-reactor kufanele kusebenzise ukuxubana okulungiselelwe kanye nokupholisa kwangaphakathi, okusekelwa yizilinganiso zobuningi eziqhubekayo. Kuma-reactor e-autoclave ajikelezayo anezindawo eziningi zanamuhla, ukwakheka okuqhutshwa yi-CFD okusekelwa idatha yobuningi be-in-situ kuqondisa ukubekwa kwama-baffle angaphakathi kanye nama-coil okupholisa akhuphukayo. Lezi zinyathelo ziqinisekisa ukuba yi-single phase, kunciphisa amathuba okushisa, futhi kuthuthukise ukuguqulwa. Isibonelo, ukwethula ukupholisa kwangaphakathi okusekelwa yi-density mapping kuholele ekukhuleni okubikiwe okungu-7% kokuguqulwa kwe-ethylene ngesikhathi senqubo yokukhiqiza i-polyethylene, ngamaphrofayili okushisa afanayo kakhulu. Ukulungiswa kwe-topology okusekelwe kubuningi nakho kwazisa i-manifold geometry kanye nokuhlelwa kwe-flow-channel, okuholela ekusetshenzisweni ngcono kwe-reactant kanye nokufana komkhiqizo okuphezulu.
Empeleni, ukulinganisa ubuningi boketshezi kuma-reactor e-polymerization akulona nje ithuluzi lokuqinisekisa inqubo, kodwa futhi kubalulekile ekuphenduleni ngesikhathi sangempela kanye nokuphathwa kwengozi. Izinzwa ezithuthukisiwe eziku-inthanethi, njengezinto ezidlidlizayo kanye nezinhlobo zokucindezela okuhlukile ezivela ku-Lonnmeter, zivumela ukulandelela ubuningi okuqinile nokunembile ngaphansi kokucindezela okuphezulu kanye nokushisa, okufanelekela indawo ye-polyethylene polymerization. Ukuhlanganiswa kwazo ezinhlelweni zokulawula inqubo ezenzakalelayo kusekela ukulawulwa okuqinile kwe-kinetics yenqubo yokumunca, kunciphisa ukuphambuka kwesisindo sama-molecule, futhi kuqinisekisa ukuphepha kwe-reactor.
Ukusetshenziswa okuphumelelayo kwe-CFD sekukonke, okuqinisekiswe ngedatha yokulinganisa ubuningi bokuhlola nesikhathi sangempela, kusekela izindlela zesimanje ekwakhiweni nasekusebenzeni kwe-polymer reactor. Ukusebenzisa lawa masu kuvumela opharetha ukuthi bandise isivuno, banciphise ubungozi, futhi balawule ngokuqinile izimfanelo zekhwalithi ezibalulekile zokusabela kwe-polyethylene polymerization.
Imibuzo Evame Ukubuzwa
Ulinganisa kanjani ubuningi boketshezi ngesikhathi senqubo yokwenza i-polyethylene polymerization?
Ubuningi boketshezi enqubweni ye-polyethylene polymerization bulinganiswa kusetshenziswa izinzwa ezingaphakathi njenge-vibrating-tube densitometers noma amadivayisi e-ultrasonic. Lokhu kuncike ekushintsheni kwemvamisa ye-resonance, impedance, noma ukushintsha kwesigaba njengoba uketshezi luxhumana nobuso benzwa. Izinzwa ze-Ultrasonic, ikakhulukazi, zinikeza ukuhlaziywa okusheshayo, kwesikhathi sangempela futhi zisebenza kahle ngaphansi kwezimo ezinzima zokucindezela okuphezulu kanye nokushisa okujwayelekile kuma-reactor e-polymerization. Ukulandelela kwesikhathi sangempela kuvumela ukutholakala kwezinguquko zobuningi ezisheshayo, okubalulekile ekusekeleni ukulawulwa kwenqubo okuzenzakalelayo kanye nokugcina ikhwalithi yomkhiqizo kulo lonke ukusabela. Intuthuko yakamuva kuma-transducer e-ultrasonic e-piezoelectric micromachined kuvumela i-miniaturization, ukunemba okuphezulu, kanye nokuhlanganiswa okuqinile nokusethwa kwezimboni kokuqapha okuqhubekayo kobuningi.
Iyiphi indima edlalwa ukulinganisa ubuningi boketshezi ku-reactor ye-polymerization?
Ukulinganisa okunembile kobuningi boketshezi kubalulekile ekusebenzeni kwe-reactor ye-polymerization. Kuvumela opharetha ukuthi baqaphe amazinga e-reactant, bathole ukuhlukaniswa kwesigaba, futhi baphendule ngokuguquguqukayo ekushintsheni kwezinguquko zenqubo. Isibonelo, ukufundwa kobuningi kuvumela ukulungiswa okusheshayo kumthamo we-catalyst, amazinga okuxuba, noma amaphrofayili okushisa—amapharamitha athinta ngqo i-kinetics kanye nokukhetha kokusabela kwe-polyethylene polymerization. Ikhono lokubona izinguquko zobuningi ngesikhathi sangempela lisiza ukugcina ukusatshalaliswa kwesisindo sama-molecule okufiselekayo, amazinga okuguqulwa kokusabela, kanye nekhwalithi ye-polymer ehambisanayo.
Iyini inqubo yokususa ukumuncwa futhi ixhumana kanjani nokulinganiswa kobuningi?
Inqubo yokumunca ama-reactor kuma-polymerization reactor ibhekisela kuma-monomer ancibilika, noma akhishwa, endaweni yokusabela. Lapho ama-monomer noma amagesi emuncwa, ubuningi boketshezi buyashintsha, bubonise ukwanda kokuhlushwa kwe-solute; lapho kwenzeka ukumunca, ubuningi buyehla njengoba izingxenye ziphuma esigabeni soketshezi. Ukuqapha lokhu kuguquguquka kobuningi kubalulekile ekutholeni izehlakalo zokuthathwa noma ukukhululwa futhi kunikeza ukuqonda ngenqubekela phambili ye-polymerization, isimo sokulingana kwesigaba, kanye nokuqina ngaphakathi kwe-reactor. Ukulandelela okunamandla kobuningi ekuphenduleni ukumunca kanye nokumunca kwenza kube ngcono ukumodela kokudluliselwa kwesisindo kanye nokukhulisa okuphumelelayo kwama-reactor ezimboni.
Kungani ukulinganisa ubuningi kubalulekile enkambisweni yokwenza i-polyethylene polymerization?
Ukulinganiswa kobuningi kubalulekile ukuqinisekisa ukulawulwa kwenqubo okuhle kakhulu ku-polyethylene polymerization. Kunikeza impendulo esheshayo ngokwakheka kwangaphakathi kwe-reactor, okuvumela ukulungiswa kahle kokusetshenziswa kwe-catalyst, izilinganiso zengxube, kanye nezimo zokushisa. Lezi zinto azithinti nje kuphela isisindo sama-molecule kanye namazinga okuguqulwa kodwa futhi zivikela kuma-polymer batches angacacisiwe. Ukulinganiswa okuqondile kobuningi kusekela ukusebenza okuphephile, kukhulisa ukusebenza kahle kwezinsizakusebenza, futhi kuthuthukisa ukuphathwa kwamandla, kuthuthukise ukufana komkhiqizo wokugcina kuyo yonke imijikelezo yokukhiqiza.
Uhlobo lwe-reactor luyithinta kanjani indlela yokulinganisa uketshezi olunobuningi?
Umklamo kanye nokusebenza kwama-reactor e-polyethylene polymerization—njenge-fluidized bed reactors (FBRs) kanye nama-high-pressure tubular reactors (HPTRs)—kunquma amasu okulinganisa ubuningi asetshenziswayo. Ama-FBR aletha izinselele njengokusatshalaliswa kwezinhlayiya ezingafani kanye nokugeleza kwegesi okuqinile kwezigaba eziningi, okudinga izinzwa ezixazululwe ngokwendawo ezikwazi ukulandelela ukushintsha kobuningi okusheshayo. Amathuluzi okulingisa (njenge-CFD kanye ne-DEM) kanye namamitha okuqina aqinile alungiselelwe izimo zezigaba eziningi abalulekile ekuqapheni okunembile. Ama-HPTR, ngokuphambene, adinga izinzwa ezincane, ezingamelani nokucindezeleka, kanye neziphendula ngokushesha ukuze zisebenze ngaphansi kwezimo eziguquguqukayo, ezinokucindezeleka okuphezulu. Ukukhethwa nokubekwa kwezinzwa okufanele kuqinisekisa ukukhiqizwa kwedatha okuthembekile, ukugcina ukuzinza kwenqubo kanye nokusekela ukwanda okuphumelelayo kuzo zombili izinhlobo ze-reactor.
Isikhathi sokuthunyelwe: Disemba 16-2025
