Njira ya cumene imayang'anira kupanga kwa phenol-acetone padziko lonse lapansi, koma machitidwe ake ovuta komanso njira zoyeretsera zimafuna kuwunika kolondola nthawi yeniyeni. Kuyeza kuchuluka kwa madzi m'mizere sikungatheke pano: kumatsata nthawi yomweyo kapangidwe ka madzi m'mitsinje kudutsa kupatukana kosafunikira, kuyeretsa acetone, ndi magawo oyeretsera a phenol, zomwe zimathandiza kuzindikira mwachangu kusintha kwa zodetsa kapena zolakwika za njira. Deta iyi imatsogolera mwachindunji kusintha kwa magawo oyeretsera, kuonetsetsa kuti kuyera kwa chinthucho kumakwaniritsa miyezo yamafakitale, ndikuchepetsa zoopsa zachitetezo monga kuwotcha nsanja kapena kuwonongeka kwa hydroperoxide kosakhazikika - kudzaza mpata womwe sampuli yopanda ntchito, yokhala ndi kuchedwa kwake ndi zoopsa zake zoyenda, sizingathe kuthana nawo.
Chidule cha Njira ya Cumene Yopangira Phenol ndi Acetone
Njira yopangira cumene, yomwe imadziwika kuti Hock process, ndiyo njira yayikulu yopangira phenol ndi acetone kuchokera ku benzene ndi propylene. Ili ndi magawo atatu akuluakulu: alkylation ya benzene kuti ipange cumene, okosijeni ya cumene kukhala cumene hydroperoxide, ndi acid-catalyzed hydroperoxide iyi kuti ipange phenol ndi acetone.
Poyamba, benzene imakumana ndi propylene pansi pa acidity—nthawi zambiri imagwiritsa ntchito ma catalyst amakono a zeolite—kuti ipange cumene. Kusankha n'kofunika kwambiri pagawoli; magawo a njira monga kutentha ndi ma ratios a benzene-to-propylene amalamulidwa mwamphamvu kuti achepetse polyalkylation yosafunikira. Kusankha kwakukulu kwa ma catalyst amakono kumachepetsa zinyalala ndikuchepetsa kuwononga chilengedwe, chinthu chofunikira kwambiri chomwe chimaganiziridwa masiku ano.
Chomera cha Cumene
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Kusungunuka kwa cumene kumachitika ndi mpweya, zomwe zimapangitsa kuti cumene hydroperoxide ipangidwe kudzera mu radical chain reaction. Izi ndizofunikira kwambiri pa ntchitoyi koma zimayambitsa zoopsa zazikulu. Cumene hydroperoxide imatha kuwonongeka ndi kutentha pang'ono, motero imafuna chitetezo champhamvu m'malo osungiramo zinthu ndi momwe zimachitikira.
Kenako hydroperoxide imadutsa mu cleavage yothandizidwa ndi asidi—nthawi zambiri yothandizidwa ndi sulfuric acid—zomwe zimapangitsa kuti phenol ndi acetone zipangidwe nthawi imodzi mu chiŵerengero chokhazikika cha 1:1 molar. Chiŵerengerochi chimafotokoza mgwirizano wachuma wa njirayi, chifukwa kusinthasintha kwa kufunikira kapena mtengo wamsika wa chinthu chimodzi kumakhudza kupulumuka kwa china. Phenol ndi acetone zimapangidwa pamodzi m'matani mamiliyoni ambiri pachaka, ndipo njira ya cumene imakhala pafupifupi 95% ya kupanga phenol padziko lonse lapansi kuyambira mu 2023. Zopangidwa kuchokera pamenepo, monga alpha-methylstyrene, zimabwezeretsedwanso mu dongosolo, zomwe zimapangitsa kuti zinthu zizigwira ntchito bwino.
Kusankhidwa kwa cumene hydroperoxide ngati gawo lofunika kwambiri la kapangidwe kake ka zinthu ndi zomangamanga. Kuwola kwake kolamulidwa ndikofunikira kwambiri pakupanga zipatso zambiri komanso kudalirika kwa njira. Ma catalyst owononga hydroperoxide ndi kapangidwe kabwino ka reactor zakulitsa kuchuluka kwa kusintha kwa zinthu pamene zikuletsa zotsatira zoyipa. Kugwira ntchito kwa mizati yosungunuka yopanda kanthu ndi mayunitsi oyeretsera acetone kumaperekanso chitsanzo chabwino cha njira zoyeretsera mafakitale zomwe zimaphatikizidwa pansi pa mzere woyamba wa reaction. Kulekanitsa kumeneku kumayendetsedwa ndi kapangidwe kake kolimba ka mizati yosungunuka ndi njira zogwirira ntchito zothandizira njira zoyeretsera ketone zomwe zimakwaniritsa malamulo a mtundu wa mankhwala.
Njira ya cumene ili ndi zovuta zingapo zogwirira ntchito komanso chitetezo zomwe zimasiyana ndi zomwe zimachitika. Zina mwa izi ndi kuyang'anira bwino momwe zinthu zimachitikira, kupewa kuchulukana kwa hydroperoxide, komanso kuletsa mpweya woipa kapena woopsa mkati mwa malo ofunikira zachilengedwe. Kukhazikitsa mafakitale kumafuna ma reactor apadera, kuyang'anira kwapamwamba, ndi machitidwe adzidzidzi chifukwa cha kuopsa kwa cumene hydroperoxide komanso kuyaka kwambiri kwa mitsinje ya njira. Ngakhale ndi mapangidwe amakono a njira zoyendetsera ntchito, mbiri ya zoopsa imafuna kuyang'anira kosalekeza, kuphunzitsa ogwiritsa ntchito, komanso kusanthula bwino chitetezo cha njira.
Ngakhale kuti kafukufuku akuchitika pa njira zina zopangira phenol, kuthekera kwa njira ya cumene kupanga phenol ndi acetone yoyera kwambiri ndi njira zoyeretsera ndi kubwezeretsa zinthu kumateteza udindo wake ngati muyezo wa makampani. Kugwirizana kwake ndi msika, chemistry, ndi process engineering kumaumba msika wapadziko lonse wa phenol ndi acetone mpaka lero.
Njira ndi Kulamulira Kuwonongeka kwa Cumene Hydroperoxide
Kuwonongeka kwa Kutentha ndi Njira
Cumene hydroperoxide (CHP) ndi yofunika kwambiri pakupanga phenol-acetone. Kuwonongeka kwake kumathandizira kusintha kwa cumene kukhala phenol ndi acetone, mankhwala awiri omwe amafunidwa kwambiri m'mafakitale. Njira yowola imayamba ndi kugawanika kwa homolytic kwa O-O bond mu CHP, ndikupanga ma cumyloxy radicals. Ma radical awa amadutsa mwachangu β-scission, ndikupanga acetone ndi phenol, zomwe zimafunidwa mu njira ya cumene.
Ma reaction kinetics ndi ovuta ndipo amasiyana ndi khalidwe losavuta la first order. Differential scanning calorimetry (DSC) ndi ma integral kinetic models (Flynn-Wall-Ozawa ndi Kissinger-Akahira-Sunose) amavumbula mphamvu yapakati yoyambitsa ya ~122 kJ/mol, yokhala ndi reaction order pafupi ndi 0.5, kusonyeza njira yosakanikirana. Njirayi imaphatikizapo ma chain reaction okhudzana ndi cumyl peroxy ndi cumyloxy radicals, zomwe zimatha kuchitapo kanthu kwambiri popanga zinthu zina monga acetophenone, α-methylstyrene, ndi methane.
Mikhalidwe yogwirira ntchito, kuphatikizapo kutentha, kupanikizika, ndi kuchuluka kwa CHP, zimapangitsa kuti kusankha ndi kukolola kwa acetone ndi phenol kukhale kovuta kwambiri. Kutentha kokwera kumathandizira kuyambitsa kwamphamvu, kuonjezera kuchuluka kwa kusintha koma kungachepetse kusankha mwa kulimbikitsa zotsatira zoyipa. Mosiyana ndi zimenezi, kupanikizika pang'ono ndi kuchuluka kwa CHP koyenera kumalimbikitsa kupanga phenol ndi acetone pamene kumachepetsa kupanga kwa zinthu zina. Kuwonjezeka kwa njira—pogwiritsa ntchito njira yowongolera kutentha—kumakhalabe gawo lofunikira kwambiri pakupanga phenol ndi acetone motetezeka, komanso kopindulitsa kwambiri, ndi kuyang'anira nthawi yeniyeni kudzera mu inline density meters, monga zomwe zimapangidwa ndi Lonnmeter, kupereka mayankho odalirika a njira yonse yopangira cumene.
Zothandizira ndi Kukhazikika kwa Mankhwala
Kuwonongeka kwa catalytic kumapanga magwiridwe antchito komanso chitetezo cha njira ya cumene. Ma catalyst oyambira monga sodium hydroxide (NaOH) amachepetsa kwambiri kutentha kwa kuyamba kwa kuwonongeka ndi mphamvu yoyambitsa ya CHP, zomwe zimapangitsa kuti kusinthaku kuchitike mwachangu komanso kuwonjezera chiopsezo cha kusintha kosatha. Zinthu za asidi, kuphatikiza sulfuric acid (H₂SO₄), zimathandiziranso kuwonongeka, ngakhale ndi njira zosiyanasiyana zamakina, nthawi zambiri zimasintha nthawi yayitali ndikukhudza kusakanikirana kwa mankhwala ndi kuchuluka kwa zinthu zina.
Kusankha chothandizira kumakhudza mwachindunji kuchuluka kwa kusintha, kuchepetsa zinthu zina, komanso chitetezo cha ntchito. Pakupanga phenol ndi acetone, kuchuluka kwa NaOH komwe kumalamulidwa nthawi zambiri kumakondedwa m'mafakitale, chifukwa kumalimbikitsa kuwonongeka kwa CHP ndikuthandizira kusankha bwino zinthu zomwe mukufuna. Komabe, chothandizira chochulukirapo chingapangitse kufalikira kwa unyolo kosalamulirika, zomwe zimawonjezera chiopsezo cha kutentha komwe kungachitike komanso kupanga zinthu zina zoopsa, monga α-methylstyrene ndi acetophenone. Kuyesa kotetezeka komanso kokhazikika kwa chothandizira, pamodzi ndi kusanthula kolondola kwa njira, ndikofunikira kwambiri pakuwonongeka kwa cumene hydroperoxide.
Kuyang'anira Chitetezo Powonongeka
CHP ndi yosakhazikika pa kutentha ndipo imayambitsa zoopsa zazikulu panthawi yogwira ntchito ndi kuwonongeka kwa zinthu. Izi zikuphatikizapo kuthekera kwake koyambitsa kusintha kwadzidzidzi kwa kutentha, kufooka kwa zinthu zoyambitsa kutentha, komanso kukhudzidwa ndi kuipitsidwa ndi malo otentha. Popanda kuyang'aniridwa, kuwonongeka kwa CHP kungayambitse kukwera kwa mphamvu, kuphulika kwa zida, komanso kutulutsa mpweya woopsa.
Kusunga kukhazikika kwa dongosolo kumagwiritsa ntchito njira zingapo zofunika. Zida zowunikira mkati, monga Lonnmeter inline density mita, zimapereka chidziwitso cha nthawi yeniyeni cha ma profiles a concentration ndi momwe kutentha kumayendera, kuonetsetsa kuti zinthu sizikuyenda bwino nthawi yomweyo. Machitidwe otsekedwa amachepetsa kufalikira ndi kuipitsidwa. Kuwongolera mosamala kutentha kwa CHP, kugwiritsa ntchito mpweya wopanda mpweya (monga nayitrogeni), komanso kupewa kuchuluka kwa catalyst kumachepetsa mwayi woti zinthu zichitike. Kuwunika kwa calorimetric (pogwiritsa ntchito adiabatic calorimetry) kumagwiritsidwa ntchito kwambiri poyesa kuyambika kwa kuwonongeka pansi pa zochitika zinazake ndikuwunikira njira zadzidzidzi.
Kapangidwe ka njira kamagwiritsa ntchito njira zolekanitsira ndi kutulutsira mpweya kuti zithetse kukwera kwa mphamvu, pomwe zowongolera kutentha ndi zolumikizirana zimachepetsa kuthekera kwa kutentha kwambiri. Machitidwe owonongeka nthawi zambiri amachitidwa pansi pa kayendedwe koyendetsedwa kosalekeza, mkati mwa ma reactor omwe adapangidwa kuti achotse kutentha mwachangu. Njirazi zimatsimikizira kuti kutentha kwa CHP - kofunikira pakupanga acetone ndi phenol - kumakhalabe kogwira mtima komanso kotetezeka mkati mwa dongosolo lonse la njira ya cumene.
Kukonza Njira mu Njira Yopangira Cumene
Kupititsa patsogolo Zokolola ndi Kugwiritsa Ntchito Mphamvu Mwanzeru
Kuphatikiza kutentha ndi njira yoyambira popanga cumene kuti iwonjezere mphamvu ya kutentha. Mwa kubwezeretsa ndikugwiritsanso ntchito mphamvu ya kutentha kuchokera ku mitsinje yotentha kwambiri, zomera zimatha kutenthetsa chakudya, kuchepetsa kugwiritsa ntchito zinthu zakunja, komanso kuchepetsa ndalama zogwirira ntchito. Njira zolumikizira kutentha zomwe zimakhudza kwambiri nthawi zambiri zimaphatikizapo kupanga ndi kukonza ma network osinthira kutentha (HENs), motsogozedwa ndi kusanthula kwa pinch kuti agwirizane ndi ma curve otentha ndi ozizira kuti azitha kubwezeretsanso kutentha kwambiri. Mwachitsanzo, kulinganiza ntchito za kutentha kwa reboiler ndi condenser mkati mwa magawo oyeretsera ndi kutentha kungathandize kusunga mphamvu zambiri ndikuchepetsa mpweya woipa womwe umapangidwa chifukwa cha kupanga nthunzi. Kafukufuku waposachedwa wa mafakitale wanena kuti zinthu zogwiritsidwa ntchito zachepa mpaka 25%, ndi phindu lachindunji pamtengo wamagetsi komanso kutsatira malamulo azachilengedwe.
Chinthu china chofunikira kwambiri chothandizira kukonza bwino zinthu ndi kubwezeretsanso chakudya. Mu njira ya cumene, kusintha kwathunthu kwa benzene ndi propylene sikumachitika kawirikawiri mu payipi imodzi ya reactor. Mwa kubwezeretsanso benzene ndi cumene zomwe sizinachitike, njirayi imawonjezera kusintha kogwira mtima kwa reactant ndikugwiritsa ntchito zinthu za catalyst bwino kwambiri. Njirayi sikuti imangochepetsa kutayika kwa zinthu zopangira komanso imathandizira kuti zomera zonse zibereke bwino. Kapangidwe kogwira mtima ka recycle loop kamaganizira kuchepetsa kutsika kwa kuthamanga kwa mpweya, kuyang'anira kapangidwe kake nthawi yeniyeni, komanso kulinganiza bwino kayendedwe ka madzi. Kuwongolera bwino kubwezeretsanso zinthu kumathandizanso kuchepetsa chiopsezo cha kuipitsidwa kwa catalyst ndikuwonjezera moyo wa catalyst cycle, kuchepetsa nthawi yopuma komanso ndalama zosinthira catalyst.
Zipangizo zowunikira mphamvu monga Aspen Plus ndi MATLAB zimathandiza kuwunika mwatsatanetsatane gawo lililonse la chomera. Kafukufuku akutsimikizira kuti kutayika kwakukulu kwa mphamvu—ndipo motero kuthekera kokonzanso—kuli m'magawo oyeretsera ndi olekanitsa kutentha kwambiri. Chifukwa chake, kuyang'ana magawo awa motsatira kuchuluka, koyendetsedwa ndi kuyerekezera, kumakhala kofunikira kwambiri pofunafuna kukonza kayendedwe ka mphamvu ndikuchepetsa kusasinthika kwa chomera chonse.
Ntchito ya Reactor ndi Distillation Column
Kukonza kukula ndi kapangidwe ka reactor ndikofunikira kwambiri kuti ndalama zogulira zinthu zigwirizane bwino ndi momwe zimagwirira ntchito. Kuchuluka kwa reactor, nthawi yogona, ndi kukweza kwa catalyst kuyenera kukonzedwa kuti zitsimikizire kuti kusintha kwakukulu kwa single-pass popanda kuyika pachiwopsezo cha kutsika kwambiri kwa kuthamanga kwa mpweya kapena kugwiritsa ntchito mopitirira muyeso kwa zinthu zofunikira. Mwachitsanzo, kuwonjezera kukula kwa reactor kungachepetse kutsika kwa kuthamanga kwa mpweya koma kungayambitse kusakanizika bwino, pomwe ma reactor ataliatali amawongolera kusintha mpaka kufika pochepetsa kubwerera chifukwa cha malire a reaction equilibrium ndi mapangidwe a byproduct.
Pa gawo lotsikira pansi pa distillation, makamaka distillation yopanda kanthu, kusintha kwa reflux ratio, malo odyetsera, mtunda wa thireyi, ndi kupanikizika kwa mzati kumathandiza kulekanitsa kwambiri cumene ndi benzene yosakhudzidwa, polyisopropylbenzene, ndi zinthu zina. Kapangidwe koyenera ka distillation sikuti kamangowonjezera kuchira kwa cumene komanso kumachepetsanso ntchito ya ma reboiler ndi ma condenser, zomwe zimapangitsa kuti mphamvu zichepetsedwe. Kugwiritsa ntchito bwino ma drawer am'mbali kapena mapangidwe ogawanika kungathandize kulekanitsa pakati pa zinthu zotentha monga acetone ndi cumene, kuthandizira kupanga phenol ndi acetone yoyera kwambiri yomwe msika wa phenol ndi acetone umafuna.
Chithunzi cha mphamvu ya distillation column chikuwonetsedwa pansipa, chomwe chikuwonetsa momwe mphamvu imalowera pa reboiler ndi kutuluka pa condenser, ndi ma loops ophatikizana obwezeretsa kutentha omwe amachepetsa kufunikira konse kwa zida zoyambira zotenthetsera ndi kuziziritsa.
Zatsopano mu Kapangidwe ka Reactor
Njira zamakono zowonjezerera mphamvu za ntchito zikukonzanso ukadaulo wa cumene reactor. Kugwiritsa ntchito ma microbubble ndi ma reactor ang'onoang'ono kumawonjezera kukhudzana pakati pa ma reactants, zomwe zimapangitsa kuti pakhale kusamutsa mwachangu komanso kusankha bwino. Ma reactor osazolowereka awa amatha kugwira ntchito nthawi yochepa yokhalamo pomwe akusunga kapena kupitirira zolinga zosinthira, potero amachepetsa mphamvu zomwe zimafunikira pa unit iliyonse ya chinthu chomwe chapangidwa.
Ma reactor a microbubble amapereka mphamvu zambiri pa kutentha kwambiri komanso amachepetsa kupanga zinthu zolemera zomwe zingawononge ma catalyst kapena kupangitsa kuti kulekanitsa kwa madzi kukhale kovuta. Izi zimathandizira chitetezo—mwa kuchepetsa malo otentha ndi kukwera kwa mphamvu—ndipo zimachepetsa kuwonongeka kwa chilengedwe kudzera mu kuchepetsa mpweya woipa, kutentha kwambiri, komanso kugwiritsa ntchito mopitirira muyeso kwa chakudya. Kuphatikiza apo, ma reactor ang'onoang'ono amathandizira mapangidwe a zomera zokhazikika, zomwe zimakula pamtengo wotsika kuti zigwirizane ndi kufunikira kwa msika kwa phenol ndi acetone.
Zatsopanozi zikukhazikitsa njira yatsopano yogwiritsira ntchito bwino ma reactor komanso kukhazikika kwa njira zoyeretsera cumene oxidation ndi hydroperoxide, kukonza kupanga kwa phenol-acetone komanso kukwaniritsa miyezo yolimba yoyeretsa zinthu yomwe ikufunika mu njira zoyeretsera acetone ndi njira zoyeretsera ketone.
Mwa kugwiritsa ntchito njira izi zowongolera njira, opanga amatha kukwaniritsa bwino kwambiri pakati pa kugwiritsa ntchito bwino mphamvu, kugwiritsa ntchito bwino zomera, zolinga zoyera, ndi kukhazikika popanda kusokoneza miyezo yolimba ya chitetezo cha njira ya cumene.
Kukonza Pansi: Kupatukana kwa Phenol ndi Acetone
Kulekanitsa phenol ndi acetone pambuyo pa kuwonongeka kwa cumene hydroperoxide kumafuna njira yotsatizana yoyeretsera ndi kuyeretsa. Kuyang'anira bwino mphamvu ndi kubwezeretsa zinthu kumapanga kapangidwe ka njira ndi machitidwe ogwirira ntchito popanga phenol ndi acetone ambiri.
Kugawikana kwa Zinthu
Gawo la pansi pa madzi limayamba ndi kukonza mpweya wochokera ku reactor yosaphika, yomwe ili ndi phenol, acetone, madzi, α-methylstyrene, cumene, benzene, ndi zinthu zina zazing'ono zomwe zimapangidwa. Mukatuluka mu reactor, chisakanizocho chimachotsedwa ndipo kulekanitsidwa kwa gawo kumachitika ngati pali madzi ambiri.
Cholinga choyamba cholekanitsa ndi kuchotsa acetone. Chifukwa cha kutentha kochepa kwa acetone (56 °C), nthawi zambiri imasungunuka pamwamba kuchokera ku gawo lonse la organic lotentha kwambiri. Izi zimachitika mu distillation column yopanda kanthu, komwe acetone, madzi, ndi zonyansa zopepuka zimapita pamwamba, ndipo phenol yokhala ndi mankhwala olemera imakhalabe ngati chinthu chapansi. Acetone ya pamwamba ikhoza kukhalabe ndi madzi ndi zizindikiro za mbali zina za kuwala, kotero imatha kuuma ndi kuyengedwa pambuyo pake—kudzera mu distillation ya azeotropic kapena extractive ngati pakufunika kuyera kwambiri—ngakhale kuti distillation yachizolowezi imakwanira m'mabizinesi ambiri.
Zotsalira za phenol zimatsukidwanso motsatizana ndi mizati yoyeretsera. Choyamba chimachotsa malekezero owala monga acetone yotsalira, benzene, ndi mpweya wosungunuka. Mzati wotsatira wa phenol umapereka kulekanitsa kwakukulu, kutulutsa phenol yoyera ndikulekanitsa zinthu zina zotentha kwambiri pansi pa mzati. Mu mapangidwe ambiri, zinthu zina zofunika monga α-methylstyrene zimapezedwanso mwa kutengera mbali kapena njira zina zoyeretsera. Mizati iyi imagwiritsidwa ntchito pamavuto owerengedwa ndi nthawi ya kutentha kuti iwonjezere magwiridwe antchito olekanitsa ndikuchepetsa kutayika kwa zinthu.
Kuyeretsedwa kwa Distillation ndi Crude Distillation Column Performance
Mizati yoyeretsera ndi yofunika kwambiri pakuyeretsa acetone ndi phenol. Kapangidwe kake ndi kagwiritsidwe ntchito kake zimakhudza mwachindunji kuyera, kukolola, ndi kugwiritsa ntchito mphamvu mkati mwa njira yopangira cumene.
Pochotsa acetone, gawo loyeretsera mafuta lopanda mafuta liyenera kupereka mphamvu yolekanitsa bwino chifukwa cha kusiyana kwa kutentha pakati pa acetone ndi phenol. Mizati yayitali yokhala ndi mathireyi ogwira ntchito bwino kapena kulongedza bwino kwambiri imagwiritsidwa ntchito. Kuphatikiza mphamvu ndikofunikira; kutentha kuchokera ku nthunzi pamwamba kumatha kutenthetsa chakudya kapena kubwezeretsedwanso m'mabwalo obwezeretsanso, zomwe zimachepetsa kugwiritsa ntchito mphamvu yonse monga momwe zasonyezedwera ndi maphunziro oyeserera njira omwe akuwonetsa kuchepa kwa 15% kwa mphamvu inayake mutatha kukhazikitsa kuphatikiza kutentha m'mafakitale akuluakulu ([Chemical Engineering Progress, 2022]).
Mavuto ogwirira ntchito ndi monga kupangika kwa azeotrope, makamaka pakati pa acetone ndi madzi. Ngakhale izi zitha kupangitsa kuti kulekanitsidwa kwathunthu kukhale kovuta, kusinthasintha kwa ma sikelo amafakitale nthawi zambiri kumalimbikitsa kukonzanso kwachikhalidwe. Kuwongolera kuthamanga ndikofunikira kuti tipewe kutaya kwa nthunzi ya acetone ndikusunga mphamvu zoyendetsera kutentha. Kuwongolera kutentha kolondola pamwamba ndi pansi kumawonetsetsa kuti zinthu zomwe zili mumlengalenga zimakwaniritsidwa popanda kutentha kwambiri.
Kusungunuka kwa Phenol kumakhala ndi zopinga zake. Chifukwa chakuti Phenol imatentha kwambiri komanso chifukwa cha okosijeni, zinthu zamkati mwa mzati ziyenera kulimbana ndi dzimbiri, nthawi zambiri pogwiritsa ntchito ma alloys apadera. Kupanikizika kwa mzati kumakonzedwa kuti kugwirizane ndi mtengo wa mphamvu ndikuchepetsa zoopsa zowola. Zinthu zomwe zimakhudzidwa ndi kutentha kwa polymerization, monga α-methylstyrene, zimachotsedwa mwachangu ndikuzizidwa kuti zichepetse zotsatira zoyipa.
Zipangizo zowongolera njira zamakono komanso zoyezera mkati mwa mzere—monga Lonnmeter inline density ndi viscosity meters—zimagwiritsidwa ntchito nthawi zonse kukonza bwino ntchito ya mzati, kuonetsetsa kuti zolinga za kuyera ndi kulemera kwa mzati zikukwaniritsidwa nthawi zonse.
Kuphatikiza ndi Kuwonongeka kwa Hydroperoxide ndi Kubwezeretsa Zinthu
Kuphatikiza kosalekeza kwa mayunitsi owonongeka, olekanitsa, ndi oyeretsa ndikofunikira kwambiri pa njira ya cumene. Kutuluka kwa madzi m'thupi kumapita mwachindunji ku kulekanitsa kwa madzi. Kusamutsa mwachangu kumachepetsa zotsatira zoyipa kapena polymerization.
Gawo lililonse lolekanitsa limalumikizidwa mwamphamvu ndi lotsatira. Acetone pamwamba imafupikitsidwa mwachangu ndikusonkhanitsidwa kuti isatayike mosavuta. Mitsinje ya phenol ndi zinthu zina zomwe zimapangidwa pamodzi zimalowa mu njira zawo zoyeretsera. Pamene zinthu zina zofunika zimapezekanso, mitsinje yawo yonyamuka imakokedwa pambuyo pofufuza mwatsatanetsatane gawo ndi kapangidwe kake.
Chofunika kwambiri ndi kupewa kuipitsidwa pakati pa malekezero a kuwala (acetone/gawo la madzi) ndi zinthu zodetsa zolemera (cumene yosayanjanitsidwa, ma tar). Izi zimachitika kudzera mu magawo angapo ofanana ndi nthunzi-madzi mkati mwa mipiringidzo ndi kugwiritsa ntchito mitsinje ya reflux. Mapaipi ndi ziwiya zamagazi zimapangidwa kuti zichepetse kutsekeka ndi kufupika kwa mpweya.
Kuchuluka kwa acetone ndi phenol kumaposa 97% m'zomera zokonzedwa bwino, ndipo kutayika kwakukulu kumangokhala chifukwa cha mitsinje yosatha komanso kuwonongeka pang'ono. Madzi otayira omwe amapangidwa panthawi yonseyi, okhala ndi zinthu zachilengedwe zosungunuka, amasungidwa padera ndikutumizidwa ku machitidwe apamwamba ochizira kuti akwaniritse zofunikira zoyang'anira.
Kuphatikiza bwino kumadalira kuyang'anira kosalekeza zinthu zofunika: kuchulukana ndi kukhuthala kwa mawerengedwe kuchokera ku mita yolowera ngati ya ku Lonnmeter kutsimikizira ubwino wa chakudya ndi kuyera kwa zinthu nthawi yeniyeni, zomwe zimathandiza kuwongolera mayankho kuti pakhale zokolola zambiri komanso chitetezo chogwira ntchito.
Kapangidwe kogwira mtima ka njira zopangira phenol-acetone kumadalira njira zolekanitsira zolimba, kusungunuka bwino kwa mphamvu, kuphatikizana kwa zochita ndi kuyeretsa, komanso kuyang'anira mosalekeza mkati, kuthandizira kuchepetsa njira ndi ubwino wa zinthu.
Njira Zapamwamba Zoyeretsera Acetone
Kuyeretsedwa kwa acetone pambuyo pa kupanga phenol-acetone pamodzi kudzera mu njira ya cumene kumapangidwa ndi kufunikira kwa khalidwe la chinthu. Kusankha njira yoyenera yoyeretsera acetone kumadalira zofunikira za kuyera kwa ntchito yomaliza, malire olamulira, ndi mawonekedwe a kuipitsidwa komwe kumachitika panthawi ya kuwonongeka kwa cumene hydroperoxide ndi machitidwe opita patsogolo.
Mfundo Zofunika Kwambiri Pakuyeretsa Acetone
Acetone yosaphwanyidwa yochokera ku cumene oxidation ili ndi madzi ambiri, phenol, α-methylstyrene, cumene, acetophenone, carboxylic acids, aldehydes, ndi zinthu zina zachilengedwe zokhala ndi mpweya. Kuyeretsa pansi pa madzi kumayang'ana zonyansa izi kuti zichotsedwe. Msana umapangidwa motsatizana:
- Mizati yoyambirira imachotsa zinthu zolemera komanso zotentha kwambiri—makamaka phenol, α-methylstyrene, acetophenone, ndi zinthu zopangira phula—potulutsa pansi. Gawo lapakati lili ndi azeotrope ya acetone-water, pomwe malekezero a kuwala (monga cumene yosayatsidwa) amatha kugawidwa pamwamba m'magawo otsatira.
Kusakaniza kwa Azeotropic nthawi zambiri kumakhala kofunikira pakugawaniza zosakaniza zovuta za acetone ndi madzi, pogwiritsa ntchito hydrocarbon entrainer kuti isokoneze kapangidwe ka azeotropic ndikuwonjezera kuyera kwa acetone. Pamene zinyalala zili ndi malo ofanana owira, kusakaniza kochokera kumadzi—ndi ma glycols kapena zosungunulira zopangidwa—kumayikidwa. Apa, chowonjezeracho chimasintha kusinthasintha kwa zinthu, zomwe zimathandiza kulekanitsa bwino zinthu zachilengedwe zokhudzana nazo ndikuwonjezera kuchuluka kwa acetone.
Kupatula kusungunuka kwa madzi, njira zotsukira madzi zimachotsa phenol yotsalira ndi mankhwala a polar. Ma resins opangidwa ndi mpweya, silica gel, ndi ion-exchange resins amagwira ntchito bwino pakati pa magawo a mzati kapena pambuyo pake. Pamene pali acidic organics, njirayi ingaphatikizepo kuchepetsedwa ndi caustic soda kutsatiridwa ndi kutsukidwa ndi madzi kuti achotse mchere ndi ma acids musanatsukidwe komaliza.
Acetone yoyera kwambiri (≥99.5 wt% pazofunikira zambiri zamafakitale kapena za labotale) nthawi zambiri imadutsa mu gawo lomaliza la "kupukuta" kuphatikiza kusefa bwino ndi kulowetsedwa kwapamwamba kuti zitsimikizire kuti zofunikira za madzi (<0.3 wt%), phenol (<10 ppm), heavy aromatics (<100 ppm), ndi total non-volatiles (<20 ppm) zakwaniritsidwa. Izi ndizofunikira kwambiri pa acetone yamagetsi kapena yamankhwala.
Kukonza ndi Kuthetsa Mavuto mu Distillation
Kugwira ntchito bwino kwa njira yothira acetone kumadalira kapangidwe kabwino ka mizati yothira ndi ntchito yolongosoka. Mizati yogawa magawo imakulitsidwa ndikugwiritsidwa ntchito kuti ipititse patsogolo kusamutsa kwamphamvu kwa misa ndi kulekanitsa bwino. Njira zingapo zimathandizira kuyera ndi kukolola:
- Mizati yayitali yokhala ndi mathireyi ambiri kapena kulongedza bwino kwambiri kumatsimikizira kulekanitsidwa kwakukulu, makamaka komwe kuwira kwa acetone-madzi kapena acetone-cumene kuli pafupi.
- Kuphatikiza kutentha pakati pa ma reboilers ndi ma condenser (monga, kudzera mu nthunzi yobwezeretsanso kapena ma heat exchangers) kumachepetsa kugwiritsa ntchito mphamvu ndikukhazikitsa kutentha, zomwe zimathandiza kuti pakhale kusiyana kosalekeza.
- Kukonza bwino chiŵerengero cha reflux ndi kuchuluka kwa mankhwala ochotsera, motsogozedwa ndi kuyang'anira kuchuluka ndi kapangidwe kake (ndi zida monga Lonnmeter inline density mita), zimathandiza kusintha mwachangu komanso kulunjika bwino kwa mankhwala, kuonetsetsa kuti gulu lililonse likukwaniritsa miyezo yoyera bwino.
Mavuto omwe amapezeka kawirikawiri otulutsa madzi ndi monga kusefukira kwa madzi m'mizere, thovu, ndi kusonkhanitsa zinyalala:
Kusefukira kwa madzi m'mizere kumachitika ngati kuchuluka kwa madzi m'mizere kuli kokwera kwambiri—madzi amakwera mmwamba osati pansi, zomwe zimachepetsa kwambiri magwiridwe antchito a kulekanitsa. Kuthetsa izi kumafuna kuchepetsa kutuluka kwa madzi m'mizere kapena kusintha ma reflux ratios. Thovu limachokera ku kuthamanga kwa nthunzi kapena kupezeka kwa zinthu zomwe zimagwira ntchito pamwamba (monga tars kapena phenol traces). Zoletsa thovu, kusanthula mosamala mizere, ndi kuyika kwa mitsinje ya njira kungachepetse thovu lopitirira.
Kuchulukana kwa zotsalira, zomwe nthawi zambiri zimawoneka m'mathireyi otsika kwambiri kapena mu reboiler ya distillation unit, kumachokera ku zinthu za oligomerization kapena phula. Kuchotsa zinthu pansi nthawi ndi nthawi, kuyeretsa nthawi zonse, komanso kusunga mawonekedwe a kutentha mkati mwa malire kumachepetsa kupangika kwa phula ndikuwonetsetsa kuti mzati umakhala nthawi yayitali.
Polekanitsa azeotropes kapena kusamalira zinyalala zomwe zimawira kwambiri, mathireyi achikhalidwe amatha kusinthidwa ndi zinthu zonyamula bwino kwambiri. Ma profiles a kutentha ndi kuthamanga kwa mpweya m'mbali mwake amasungidwa mkati mwa mawindo olimba. Zida zodziyimira zokha—monga muyeso wopitilira wa inline density—zimathandiza ogwiritsa ntchito kuzindikira mwachangu zinthu zomwe sizili bwino ndikuyankha nthawi yeniyeni, zomwe zimawonjezera magwiridwe antchito komanso phindu.
Tchati chosavuta chofotokozera kusungunuka kwa acetone m'magawo ambiri ndi kuyeretsa kwa phenol ndi acetone (kujambula kwanu kutengera machitidwe wamba)
Zotsatira zophatikizana za njira zamakono zoyeretsera acetone izi zimatsimikizira kuti zinthu zina zochokera ku cumene zikugwiritsidwa ntchito bwino, kutsatira miyezo ya msika wa acetone ndi phenol modalirika, komanso kuchepetsa kuwonongeka kwa chilengedwe.
Zotsatira za Kukonza Mafakitale ndi Kukhazikika
Mu njira yopangira cumene, kulumikiza bwino kapangidwe ka njira, catalysis, ndi kusankha kulekanitsa ndi kugwiritsa ntchito bwino zinthu ndikofunikira. Kapangidwe ka njira kophatikizana kamawongolera uinjiniya wa reaction, ukadaulo wolekanitsa, ndi kubwezeretsa mphamvu kuti pakhale zokolola zambiri ndikuchepetsa zinyalala pagawo lililonse la phenol-acetone co-production. Mwa kugwiritsa ntchito njira zamakono zoyendetsera, monga ma catalyst olimba a asidi (kuphatikiza zeolites ndi heteropolyacids), ogwiritsa ntchito amapeza kusankha kwakukulu pakuwonongeka kwa cumene hydroperoxide, zomwe zimachepetsa mapangidwe azinthu monga α-methylstyrene ndi acetophenone. Kukweza kwa kusankha kumeneku sikungowonjezera zokolola za njira komanso kumathandizira kukhazikika kudzera mu mitsinje yocheperako ya zinyalala.
Posankha ma catalyst owonongeka ndi hydroperoxide, kukulitsa kwa njira kumachita gawo lofunika kwambiri. Mwachitsanzo, njira zosakanikirana zosinthira, zomwe zimaphatikiza mawonekedwe a catalysis yofanana komanso yosiyana, zikuyamba kugwira ntchito chifukwa cha kusinthasintha kwawo kogwira ntchito komanso nthawi yayitali ya catalyst. Komabe, kapangidwe ka catalyst kuyenera kuyanjanitsa ntchito yayikulu komanso kukhazikika motsutsana ndi mavuto monga kuphika ndi poizoni chifukwa cha zinyalala, kuonetsetsa kuti catalyst ikusintha pang'ono komanso kuchuluka kwa zinthu zachilengedwe kuchokera ku catalyst yomwe yagwiritsidwa ntchito. Zatsopano zomwe zikuchitika mu catalyst zimakhudza mwachindunji kugwiritsa ntchito bwino kwa zinthu, kuchepetsa kutayika kwa zinthu zopangira ndikuchepetsa kufunikira kwa zinthu zofunikira.
Kuphatikiza kapangidwe ka njira, makamaka panthawi yoyeretsa acetone ndi njira yoyeretsera acetone, kumakhalabe kofunikira kwambiri pakukonza mafakitale. Kukhazikitsa mapangidwe apamwamba a mizati yoyeretsera—monga kugawa mizati ya makoma—ndi kulekanitsa kogwiritsa ntchito nembanemba kosunga mphamvu kumathandizira ntchito zotsika mtengo komanso zokhazikika. Kugawa mizati ya makoma, mwachitsanzo, kumachepetsa ntchito ya mizati yoyeretsera yopanda mafuta, zomwe zimapangitsa kuti mphamvu zokwana 25% zisungidwe bwino kuposa njira zachikhalidwe zokhala ndi mizati yambiri, komanso kumasula malo enieni a chomera. Kuphatikiza apo, njira zamakono zolumikizira kutentha, motsogozedwa ndi njira monga kusanthula kwa pinch, zawonetsa kuchepetsa kugwiritsa ntchito nthunzi kopitilira 20%, monga momwe zasonyezedwera pakukonzanso malo opangira phenol ndi acetone. Njira izi zimachepetsa kutulutsa mpweya woipa komanso kuchepetsa kudalira magwero a nthunzi ochokera ku mafuta oyambira.
Kuphatikiza madzi ndi kutentha kumawonjezeranso mphamvu ya zinthu mu njira yothira madzi mu cumene ndi njira zotsatizana. Machitidwe ogwiritsiranso ntchito a Cascade ndi malo ozimitsira madzi omwe ali ndi cholinga chabwino amatha kuchepetsa kutulutsa madzi otayira ndi 40%, kuthana ndi kuchuluka kwa madzi otayira komanso kuipitsidwa kwake. Izi ndizofunikira kwambiri pakutsata malamulo omwe akusintha m'misika yayikulu ya phenol ndi acetone, komwe zoletsa kutulutsa madzi otayira ndi mpweya wa carbon zikukulirakulira.
Kuganizira za malamulo ndi zachilengedwe kumakhudzidwa kwambiri pakupanga phenol-acetone pogwiritsa ntchito njira ya cumene. Kuwongolera kokhwima pa zinthu zoopsa monga cumene hydroperoxide—kumafuna kuwongolera molondola njira ndi kuyang'anira chitetezo nthawi yeniyeni panthawi yogwira ntchito zoopsa kwambiri. Malamulo azachilengedwe, makamaka m'madera aku North America ndi ku Europe, amawonjezera zofunikira pakukonza zinyalala, kuwongolera utsi, ndi kubwezeretsanso zosungunulira/kutentha. Njira zotsatirira malamulo zimayikidwa mu kapangidwe ka njira yoyambirira, nthawi zambiri zimaphatikizapo ziwerengero zamphamvu za njira ndi kusanthula kwa moyo zomwe zimapangitsa mwachindunji kapangidwe ka zomera ndi kusankha ukadaulo.
Kuyang'anira nthawi yeniyeni ndi kukonza bwino njira ndizofunikira kwambiri kuti zinthu zizigwira ntchito bwino komanso kuchepetsa kutayika kwa njira zomwe sizingapeweke. Mwachitsanzo, mita ya inline density ndi ma viscosity mita ochokera ku Lonnmeter zimathandiza kuti zinthu zisamayende bwino komanso zisamayende bwino nthawi zonse. Mwa kutsatira mosamala kuchuluka kwa zinthu zomwe zapangidwa ndi zinthu zina, ogwiritsa ntchito amatha kusintha zinthu zofunika kwambiri monga kuchuluka kwa reflux, ma cut points mu distillation, ndi catalyst dosing, motero amachepetsa kugwiritsa ntchito mphamvu ndikuchepetsa kuchuluka kwa zinthu zomwe sizili bwino kapena zinyalala.
Kugwiritsa ntchito njira zoyeretsera mafakitale, mothandizidwa ndi deta ya masensa nthawi yeniyeni, kumathandiziranso kuthetsa mavuto ndi kutseka mayankho poyang'anizana ndi zovuta. Ndi kuchepa kwa kusinthasintha kwa kampeni komanso kuchulukitsa kubwerezabwereza kwa batch, ogwira ntchito amazindikira kusunga ndalama mwachindunji, kuchepa kwa zinthu zopangira, komanso kuphwanya malamulo azachilengedwe. Zotsatira zake, kukonza njira zenizeni nthawi yeniyeni, komwe kumathandizidwa ndi ukadaulo wolondola woyezera mkati, kumakhalabe kofunikira kwambiri pakupanga phenol ndi acetone zopikisana, zogwirizana, komanso zokhazikika.
Mafunso Ofunsidwa Kawirikawiri (Mafunso Ofunsidwa Kawirikawiri)
Kodi njira ya cumene ndi yotani ndipo n’chifukwa chiyani ndi yofunika kwambiri popanga phenol-acetone pamodzi?
Njira ya cumene, yomwe imadziwikanso kuti njira ya Hock, ndi njira ya mafakitale yopangira phenol ndi acetone pamodzi mu sequence imodzi yolumikizidwa. Imayamba ndi alkylation, pomwe benzene imakumana ndi propylene kuti ipange cumene pogwiritsa ntchito ma catalysts olimba a asidi monga zeolites kapena phosphoric acid. Kenako cumene imasungunuka ndi mpweya kuti ipange cumene hydroperoxide. Izi zimadutsa pakati pa acid-catalyzed cleavage, zomwe zimapangitsa phenol ndi acetone kukhala ndi chiŵerengero cholondola cha 1:1 molar. Njirayi ndi yofunika chifukwa imalamulira kupanga phenol ndi acetone padziko lonse lapansi, zomwe zimapereka phindu lalikulu komanso kuphatikiza zinthu. Pafupifupi 95% ya phenol yapadziko lonse imapangidwa kudzera mu njirayi kuyambira 2023, zomwe zimagogomezera kufunika kwake kwa mafakitale ndi zachuma.
Kodi kuwonongeka kwa cumene hydroperoxide kumakhudza bwanji chitetezo ndi zokolola za njira?
Kuwonongeka kwa cumene hydroperoxide kumakhala kotentha kwambiri, komwe kumatulutsa kutentha kwakukulu. Ngati sikusamalidwa mosamala, kungayambitse kutentha koopsa, kuphulika, kapena moto—zomwe zimapangitsa kuti pakhale kufunikira kwakukulu pakupanga njira ndi kayendetsedwe ka ntchito. Kusankha mosamala ma catalyst a hydroperoxide decomposition ndi kuwongolera bwino momwe zinthu zimachitikira ndikofunikira kwambiri kuti ntchito ikhale yotetezeka. Kuyang'anira kutentha ndi kuchuluka kwa momwe zinthu zimachitikira kumatsimikizira kuti phindu la phenol ndi acetone limakhalabe lokwanira pamene likuchepetsa kupanga zinthu zina ndi zoopsa zachitetezo. Njira zabwino kwambiri zogwirira ntchito m'makampani zimaphatikizapo kuyang'anira kosalekeza makina, kuzimitsa mwadzidzidzi, komanso kapangidwe kamphamvu ka reactor kuti athetse kutentha koopsa komanso kupewa kukwera kwa mphamvu.
Kodi gawo lanji la distillation column limagwira ntchito pakupanga cumene?
Mzati wothira mafuta wosaphika ndi ntchito yofunika kwambiri pambuyo poti hydroperoxide yagawanika. Umalekanitsa phenol, acetone, cumene yosakhudzidwa, ndi zinthu zina zazing'ono. Kugwira ntchito bwino kwa mzati wothira mafuta wosaphika kumathandizira kubwezeretsa zinthu, kuchepetsa kugwiritsa ntchito mphamvu, komanso kupanga mitsinje yomwe imalowa mwachindunji mu njira zoyeretsera pambuyo pake. Kapangidwe ndi kagwiritsidwe ntchito ka mzati wothira mafuta kuyenera kuwerengera malo otentha a zinthu zosiyanasiyana, zomwe zimafuna kulondola kwa kutentha ndi kuwongolera kuthamanga kwa mpweya. Kulephera kwa kuthira mafuta kumatha kubweretsa kutayika kwa zinthu, kuipitsidwa, kapena ndalama zambiri zogwiritsidwa ntchito.
Chifukwa chiyani kuyeretsedwa kwa acetone ndikofunikira popanga phenol-acetone?
Acetone yomwe imapezeka kuchokera ku njira ya cumene ili ndi zinthu zosiyanasiyana zosafunika: zinthu zomwe zimayambitsidwa ndi zinthu zina (monga methyl isobutyl ketone, isopropanol), madzi, ndi ma organic acid omwe amapangidwa panthawi ya okosijeni ndi kugawanika kwa zinthu. Kuyeretsa kolimba kumafunika kuti acetone ikwaniritse miyezo yokhwima ya mafakitale yogwiritsidwa ntchito m'mafakitale, zosungunulira, ndi mapulasitiki. Njira zoyeretsera, monga kugawa magawo pogwiritsa ntchito mipiringidzo yothira, zimachotsa zonyansazi. Acetone yoyera imapezanso mtengo wokwera pamsika, zomwe zimalimbitsa chifukwa cha zachuma choyeretsera bwino.
Kodi kuphatikiza njira ndi zatsopano za reactor zingawongolere bwanji chuma ndi chilengedwe cha njira ya cumene?
Kuphatikiza njira kumathandizira mwayi wobwezeretsa kutentha, kubwezeretsanso zinthu zomwe sizinachitike, komanso kukonza magwiridwe antchito a mayunitsi kuti achepetse kugwiritsa ntchito mphamvu. Mwachitsanzo, kuphatikiza kutumiza kutentha kwa reaction kapena kuphatikiza njira zoyeretsera zinthu kungachepetse ndalama zamafuta ndi ntchito. Kugwiritsa ntchito njira zamakono monga ma microbubble reactors kwawonetsa kuti kumathandizira kusamutsa zinthu zambiri, kukulitsa mphamvu ya okosijeni, komanso kuchepetsa kupanga zinyalala. Zatsopanozi pamodzi zimachepetsa kuwonongeka kwa chilengedwe pochepetsa mpweya woipa komanso kupanga madzi otayira, komanso kuchepetsa ndalama zonse zokonzera, zomwe zimapangitsa kuti kupanga pamodzi kwa phenol-acetone kukhale kokhazikika komanso kolimba pazachuma.
Nthawi yotumizira: Disembala-19-2025
