Dehydrogenation ntawm butane yog nqa tawm hauv cov kua dej lossis txav txaj ntawm chromium thiab aluminium catalyst. Cov txheej txheem yog nqa tawm ntawm qhov kub thiab txias ntawm 550 txog 575 degrees. Ntawm cov yam ntxwv ntawm cov tshuaj tiv thaiv, peb nco ntsoov qhov txuas ntxiv ntawm cov khoom siv thev naus laus zis.
Technology nta
Butane dehydrogenation feem ntau yog ua los ntawm kev sib cuag adiabatic reactors. Cov tshuaj tiv thaiv yog nqa tawm nyob rau hauv lub xub ntiag ntawm dej vapor, uas txo qis ib feem ntawm lub interacting gaseous tshuaj. Kev them nyiaj rau hauv cov tshuaj tiv thaiv nto apparatuses rau endothermic thermal nyhuv yog nqa tawm los ntawm kev muab cov cua sov los ntawm qhov chaw nrog flue gases.
Simplified version
Dehydrogenation ntawm butane hauv txoj kev yooj yim tshaj plaws suav nrog impregnation ntawm aluminium oxide nrog kev daws ntawm chromic anhydride lossis potassium chromate.
Cov txiaj ntsig catalyst pab txhawb rau cov txheej txheem ceev thiab zoo. Cov txheej txheem tshuaj accelerator no pheej yig nyob rau hauv tus nqi ntau.
Production scheme
Butane dehydrogenation yog ib qho tshuaj tiv thaiv uas tsis muaj qhov tseem ceeb ntawm kev siv cov catalyst. Cov khoomdehydrogenation ntawm cov khoom pib raug coj mus rau qhov chaw muab rho tawm distillation, qhov uas yuav tsum tau olefinic feem yog cais. Dehydrogenation ntawm butane rau butadiene hauv tubular reactor nrog rau kev xaiv cua sov sab nraud tso cai rau cov khoom lag luam zoo.
Qhov tshwj xeeb ntawm cov tshuaj tiv thaiv yog nyob rau hauv nws cov txheeb ze kev nyab xeeb, nrog rau kev siv tsawg tsawg ntawm cov tshuab tsis siv neeg thiab cov khoom siv. Ntawm qhov zoo ntawm cov thev naus laus zis no, ib tus tuaj yeem hais txog qhov yooj yim ntawm cov qauv tsim, nrog rau kev noj tsawg ntawm cov khoom siv pheej yig.
txheej txheem nta
Dehydrogenation ntawm butane yog txheej txheem thim rov qab, thiab pom qhov nce ntawm qhov sib xyaw. Raws li Le Chatelier lub hauv paus ntsiab lus, txhawm rau hloov cov tshuaj sib npaug hauv cov txheej txheem no kom tau txais cov khoom sib cuam tshuam, nws yog ib qho tsim nyog yuav tsum txo qis hauv cov tshuaj tiv thaiv sib tov.
Qhov zoo tshaj plaws yog atmospheric siab ntawm qhov kub txog li 575 degrees, thaum siv cov chromium-aluminium catalyst sib xyaw. Raws li lub accelerator ntawm cov txheej txheem tshuaj yog tso rau saum npoo ntawm cov pa roj carbon monoxide, uas yog tsim thaum lub sij hawm ib sab kev puas tsuaj ntawm cov thawj hydrocarbon, nws cov dej num txo. Txhawm rau rov ua nws cov haujlwm qub, cov catalyst yog rov tsim dua los ntawm tshuab nws nrog huab cua, uas yog tov nrog flue gases.
Flow Conditions
Thaum lub sijhawm dehydrogenation ntawm butane, unsaturated butene yog tsim nyob rau hauv cylindrical reactors. Lub reactor muaj tshwj xeeb gas faib grid, ntsiacyclones uas ntes catalyst plua plav nqa tawm los ntawm cov dej ntws.
Dehydrogenation ntawm butane rau butenes yog lub hauv paus rau kev kho tshiab ntawm cov txheej txheem kev lag luam rau kev tsim cov hydrocarbons unsaturated. Ntxiv nrog rau qhov kev sib cuam tshuam no, cov cuab yeej zoo sib xws yog siv kom tau txais lwm cov kev xaiv rau paraffins. Dehydrogenation ntawm n-butane tau dhau los ua lub hauv paus rau kev tsim cov isobutane, n-butylene, ethylbenzene.
Muaj qee qhov sib txawv ntawm cov txheej txheem thev naus laus zis, piv txwv li, thaum dehydrogenating tag nrho cov hydrocarbons ntawm ib tug xov tooj ntawm paraffins, cov catalysts zoo sib xws yog siv. Kev sib piv ntawm kev tsim cov ethylbenzene thiab olefins tsis yog tsuas yog siv cov txheej txheem accelerator xwb, tab sis kuj siv cov cuab yeej zoo sib xws.
Catalyst siv sijhawm
Dab tsi yog qhov ua rau dehydrogenation ntawm butane? Cov mis ntawm cov catalyst siv rau cov txheej txheem no yog chromium oxide (3). Nws yog precipitated ntawm amphoteric alumina. Txhawm rau kom muaj kev ruaj ntseg thiab kev xaiv ntawm cov txheej txheem accelerator, nws yuav tsum tau ua raws li cov poov tshuaj oxide. Nrog rau kev siv kom raug, lub sijhawm nruab nrab ntawm kev ua haujlwm puv ntawm cov catalyst yog ib xyoos.
Raws li nws siv, maj mam tso cov khoom sib txuas ntawm cov oxides sib xyaw. Lawv yuav tsum raug hlawv kom raws sij hawm siv cov txheej txheem tshuaj tshwj xeeb.
Catalyst lom tshwm sim nrog dej vapor. Nws yog nyob rau ntawm no sib tov ntawm catalysts uas dehydrogenation ntawm butane tshwm sim. Qhov sib npaug ntawm cov tshuaj tiv thaiv yog txiav txim siab hauv tsev kawm ntawv hauv chav kawm ntawm cov organicchemistry.
Thaum qhov kub thiab txias, qhov nrawm ntawm cov txheej txheem tshuaj raug pom. Tab sis tib lub sijhawm, kev xaiv ntawm cov txheej txheem kuj txo qis, thiab ib txheej ntawm coke tso rau ntawm lub catalyst. Tsis tas li ntawd, hauv tsev kawm ntawv theem siab, feem ntau muaj cov haujlwm hauv qab no: sau ib qho kev sib npaug rau cov tshuaj tiv thaiv dehydrogenation ntawm butane, combustion ntawm ethane. Cov txheej txheem no tsis cuam tshuam nrog ib qho teeb meem tshwj xeeb.
Sau qhov sib npaug rau cov tshuaj tiv thaiv dehydrogenation, thiab koj yuav nkag siab tias cov tshuaj tiv thaiv no tshwm sim nyob rau hauv ob qho kev qhia tawm. Rau ib liter ntawm lub ntim ntawm cov tshuaj tiv thaiv accelerator, muaj kwv yees li 1000 litres ntawm butane nyob rau hauv gaseous daim ntawv ib teev, qhov no yog li cas lub dehydrogenation ntawm butane tshwm sim. Cov tshuaj tiv thaiv ntawm combining unsaturated butene nrog hydrogen yog cov txheej txheem rov qab ntawm lub dehydrogenation ntawm ib txwm butane. Cov txiaj ntsig ntawm butylene hauv cov tshuaj tiv thaiv ncaj qha yog nyob nruab nrab ntawm 50 feem pua. Txog 90 kilograms ntawm butylene yog tsim los ntawm 100 kilograms ntawm cov pib alkane tom qab dehydrogenation yog tias cov txheej txheem yog nqa tawm ntawm atmospheric siab thiab kub txog li 60 degrees.
Raw khoom rau kev tsim
Cia peb saib ze dua ntawm dehydrogenation ntawm butane. Cov txheej txheem sib npaug yog ua raws li kev siv cov khoom noj khoom haus (sib xyaw ntawm cov roj) tsim thaum lub sij hawm siv roj refining. Nyob rau hauv thawj theem, cov butane feem yog huv si huv si los ntawm pentenes thiab isobutenes, uas cuam tshuam rau cov kev kawm ntawm lub dehydrogenation cov tshuaj tiv thaiv.
Yuav ua li cas butane dehydrogenate? Qhov sib npaug rau cov txheej txheem no muaj ob peb kauj ruam. Tom qab purification, dehydrogenation ntawm purifiedbutenes rau butadiene 1, 3. Cov concentrate muaj plaub carbon atoms, uas tau txais nyob rau hauv cov ntaub ntawv ntawm catalytic dehydrogenation ntawm n-butane, muaj butene-1, n-butane, thiab butenes-2.
Nws yog qhov teeb meem heev los ua kom zoo tshaj qhov sib cais ntawm qhov sib tov. Los ntawm kev siv cov extractive thiab fractional distillation nrog cov kuab tshuaj, xws li kev sib cais tuaj yeem ua tiav, thiab kev ua haujlwm ntawm qhov kev sib cais no tuaj yeem txhim kho.
Thaum ua tiav cov khoom faib tawm ntawm cov khoom siv nrog lub peev xwm sib cais loj, nws tuaj yeem ua tiav tag nrho cov butane los ntawm butene-1, nrog rau butene-2.
Los ntawm qhov kev xav ntawm kev lag luam, cov txheej txheem ntawm dehydrogenation ntawm butane rau unsaturated hydrocarbons yog suav tias yog ib qho pheej yig ntau lawm. Cov thev naus laus zis no ua rau nws tuaj yeem tau txais cov roj av, nrog rau ntau yam khoom siv tshuaj lom neeg.
Feem ntau, cov txheej txheem no tsuas yog ua nyob rau hauv cov cheeb tsam uas xav tau alkene unsaturated, thiab butane muaj tus nqi qis. Vim qhov txo tus nqi thiab txhim kho cov txheej txheem rau dehydrogenation ntawm butane, Scope ntawm kev siv diolefins thiab monolefins tau nthuav dav.
Cov txheej txheem ntawm butane dehydrogenation yog ua nyob rau hauv ib los yog ob theem, muaj ib tug rov qab ntawm unreacted feedstock rau reactor. Thawj zaug hauv Soviet Union, butane dehydrogenation tau ua nyob rau hauv lub txaj catalyst.
tshuaj lom neeg ntawm butane
Ntxiv rau cov txheej txheem polymerization, butane muaj cov tshuaj tiv thaiv combustion. Ethane, propane, thiab lwm yamMuaj cov neeg sawv cev txaus ntawm saturated hydrocarbons hauv cov nkev, yog li nws yog cov khoom siv raw rau txhua qhov kev hloov pauv, suav nrog kev sib txuas.
Nyob hauv butane, carbon atoms yog nyob rau hauv sp3-hybrid lub xeev, yog li txhua daim ntawv cog lus yog ib leeg, yooj yim. Cov qauv no (tetrahedral puab) txiav txim siab cov tshuaj lom neeg ntawm butane.
Nws tsis muaj peev xwm nkag mus rau hauv cov tshuaj tiv thaiv ntxiv, nws tsuas yog cov txheej txheem ntawm isomerization, hloov pauv, dehydrogenation.
Kev hloov pauv nrog diatomic halogen molecules yog ua raws li cov txheej txheem radical, thiab cov xwm txheej hnyav (ultraviolet irradiation) yog qhov tsim nyog rau kev siv cov tshuaj no. Ntawm tag nrho cov khoom ntawm butane, nws cov combustion, nrog rau kev tso tawm ntawm cov cua sov txaus, yog qhov tseem ceeb ntawm cov tswv yim. Tsis tas li ntawd, cov txheej txheem ntawm dehydrogenation ntawm saturated hydrocarbon yog qhov txaus siab rau kev tsim khoom.
Dehydrogenation specifications
Butane dehydrogenation txheej txheem yog ua nyob rau hauv lub tubular reactor nrog rau sab nraud cua sov ntawm ib tug ruaj catalyst. Nyob rau hauv cov ntaub ntawv no, lub butylene tawm los nce, ntau lawm automation yog yooj yim.
Ntawm qhov zoo ntawm cov txheej txheem no yog qhov tsawg kawg nkaus catalyst noj. Ntawm cov shortcomings, ib tug tseem ceeb noj ntawm alloyed steels, siab peev peev tau sau tseg. Tsis tas li ntawd, catalytic lub cev qhuav dej ntawm butane suav nrog kev siv ntau ntawm cov chav nyob, vim lawv muaj cov khoom lag luam qis.
Ntau lawm muaj cov khoom lag luam qis, yog liraws li ib feem ntawm cov reactors yog tsom rau dehydrogenation, thiab qhov thib ob yog raws li kev tsim dua tshiab. Tsis tas li ntawd, coob tus neeg ua haujlwm hauv kev tsim khoom kuj suav tias yog qhov tsis zoo ntawm cov khoom siv thev naus laus zis no. Nws yuav tsum nco ntsoov tias cov tshuaj tiv thaiv yog endothermic, yog li cov txheej txheem pib ntawm qhov kub siab, nyob rau hauv lub xub ntiag ntawm inert tshuaj.
Tab sis qhov xwm txheej zoo li no muaj kev pheej hmoo ntawm kev raug xwm txheej. Qhov no ua tau yog tias cov ntsaws ruaj ruaj hauv cov cuab yeej tawg. Cov huab cua uas nkag mus rau hauv lub reactor, thaum tov nrog hydrocarbons, tsim ib tug tawg sib tov. Txhawm rau tiv thaiv qhov xwm txheej zoo li no, cov tshuaj sib npaug tau hloov mus rau sab xis los ntawm kev qhia cov dej vapor rau hauv cov tshuaj tiv thaiv sib tov.
ib kauj ruam txheej txheem variant
Piv txwv li, nyob rau hauv cov chav kawm ntawm cov organic chemistry, muaj cov haujlwm hauv qab no: sau ib qho kev sib npaug rau cov tshuaj tiv thaiv ntawm butane dehydrogenation. Txhawm rau tiv nrog cov haujlwm zoo li no, nws yog qhov txaus kom rov nco qab cov khoom siv tshuaj lom neeg ntawm hydrocarbons ntawm chav kawm ntawm saturated hydrocarbons. Cia peb tsom xam cov yam ntxwv ntawm kev tau txais butadiene los ntawm ib theem txheej txheem ntawm butane dehydrogenation.
Lub roj teeb butane dehydrogenation suav nrog ntau lub reactors cais, lawv tus lej nyob ntawm lub sijhawm ua haujlwm, nrog rau qhov ntim ntawm ntu. Yeej, tsib mus rau yim reactors suav nrog hauv roj teeb.
Cov txheej txheem ntawm dehydrogenation thiab rov tsim dua yog 5-9 feeb, lub tshuab tshuab yuav siv sijhawm 5 mus rau 20 feeb.
Vim qhov tseeb tias dehydrogenationbutane yog nqa tawm nyob rau hauv ib tug tsis tu ncua txav txheej, cov txheej txheem yog ruaj khov. Qhov no pab txhawb kev txhim kho kev ua haujlwm ntawm kev tsim khoom, ua kom cov khoom tsim tau ntawm cov reactor.
Cov txheej txheem ntawm ib-theem dehydrogenation ntawm n-butane yog nqa tawm ntawm qhov tsis tshua muaj siab (txog 0.72 MPa), ntawm qhov kub siab tshaj qhov uas siv rau kev tsim khoom ua los ntawm aluminium-chromium catalyst.
Vim tias cov thev naus laus zis cuam tshuam nrog kev siv lub tshuab regenerative reactor, kev siv cov chav tsis suav nrog. Ntxiv nrog rau butadiene, butenes tau tsim nyob rau hauv qhov sib tov, lawv tau rov ua dua rau hauv cov tshuaj tiv thaiv sib tov.
Ib theem yog xam los ntawm qhov piv ntawm butanes hauv cov roj sib cuag rau lawv tus lej hauv cov nqi reactor.
Ntawm qhov zoo ntawm txoj kev no ntawm butane dehydrogenation, peb nco ntsoov cov txheej txheem thev naus laus zis yooj yim ntawm kev tsim khoom, txo qis ntawm kev siv cov khoom siv raw, nrog rau txo tus nqi hluav taws xob rau cov txheej txheem.
Qhov tsis zoo ntawm cov thev naus laus zis no yog sawv cev los ntawm lub sijhawm luv ntawm kev sib cuag ntawm cov khoom ua haujlwm. Sophisticated automation yuav tsum tau kho qhov teeb meem no. Txawm hais tias muaj teeb meem zoo li no, ib-theem butane dehydrogenation yog ib txoj kev zoo tshaj li ob-theem ntau lawm.
Thaum dehydrogenating butane nyob rau hauv ib theem, cov khoom noj yog rhuab mus rau qhov kub ntawm 620 degrees. Cov sib tov yog xa mus rau lub reactor, nws yog nyob rau hauv kev sib cuag nrog cov catalyst.
Txhawm rau tsim qhov tsis tshua muaj tshwm sim hauv cov reactors,Lub tshuab nqus tsev compressors yog siv. Cov roj sib cuag tawm ntawm lub reactor kom txias, ces nws raug xa mus rau kev sib cais. Tom qab lub voj voog dehydrogenation tiav lawm, cov khoom siv raw yog pauv mus rau cov reactors tom ntej, thiab los ntawm cov txheej txheem tshuaj tau dhau los lawm, hydrocarbon vapors raug tshem tawm los ntawm tshuab. Cov khoom raug tshem tawm thiab cov reactors rov qab siv rau butane dehydrogenation.
Zoo kawg
Lub ntsiab dehydrogenation cov tshuaj tiv thaiv ntawm ib txwm butane yog catalytic zus tau tej cov sib tov ntawm hydrogen thiab butenes. Ntxiv nrog rau cov txheej txheem tseem ceeb, tej zaum yuav muaj ntau cov txheej txheem sab nraud uas ua rau muaj kev cuam tshuam loj rau cov saw hlau. Cov khoom tau txais los ntawm kev dehydrogenation yog suav tias yog cov khoom siv tshuaj muaj txiaj ntsig. Nws yog qhov kev thov rau kev tsim khoom uas yog qhov laj thawj tseem ceeb rau kev tshawb nrhiav cov cuab yeej thev naus laus zis tshiab rau kev hloov pauv ntawm hydrocarbons ntawm qhov txwv series rau hauv alkenes.
