Dab tsi yog Cov Txheej Txheem Ntau Lawm ntawm Polyethylene

Kev tsim cov txheej txheem ntawm polyethylene tuaj yeem muab faib ua:

• Txoj kev kub siab, txoj kev kub siab yog siv los tsim cov polyethylene tsawg.
• Nruab nrab siab
• Txoj kev tsis tshua muaj siab. Raws li txoj kev tsis tshua muaj kev txhawj xeeb, muaj cov txheej txheem slurry, txoj kev daws teeb meem thiab cov txheej txheem roj.

Txoj kev kub siab yog siv los tsim cov polyethylene tsawg ntom ntom. Txoj kev no tau tsim thaum ntxov. Cov polyethylene tsim los ntawm txoj kev no suav txog li 2/3 ntawm tag nrho cov khoom tsim tawm ntawm polyethylene, tab sis nrog kev txhim kho ntawm cov cuab yeej siv thiab cov catalysts, nws txoj kev loj hlob tau zoo heev tom qab txoj kev tsis tshua muaj siab.

Raws li txoj kev tsis tshua muaj kev txhawj xeeb, muaj cov txheej txheem slurry, txoj kev daws teeb meem thiab cov txheej txheem roj. Txoj kev slurry slurry feem ntau yog siv los tsim cov qauv siab polyethylene, tab sis kuj paub cov qauv kev daws teeb meem, tab sis kuj hu ua domear tsawg dua polyethylene. yas yas. Ntau yam txheej txheem uas tsis tshua muaj siab tab tom txhim kho sai.

Txoj Kev Siab Siab

Ib txoj hauv kev ntawm polymerizing ethylene rau hauv polyethylene tsawg ntom siv oxygen lossis peroxide ua tus pib. Ethylene nkag mus rau hauv lub reactor tom qab ob compression, thiab yog polymerized rau hauv polyethylene nyob rau hauv lub siab ntawm 100-300 MPa, kub ntawm 200-300 ° C thiab qhov kev txiav txim ntawm ib tug pib. Cov polyethylene nyob rau hauv daim ntawv ntawm cov yas yog extruded thiab pelletized tom qab ntxiv cov yas additives.

Cov polymerization reactors siv yog tubular reactors (nrog rau lub raj ntev txog 2000 m) thiab tank reactors. Qhov kev hloov pauv ib zaug ntawm cov txheej txheem tubular yog 20% ​​rau 34%, thiab txhua xyoo muaj peev xwm ntawm ib kab yog 100 kt. Qhov kev hloov pauv ib zaug ntawm cov txheej txheem kettle yog 20% ​​mus rau 25%, thiab ib-kab txhua xyoo muaj peev xwm yog 180 kt.

Txoj Kev Tsis Txaus Siab

Qhov no yog lwm cov txheej txheem ntawm polyethylene, nws muaj peb hom: slurry method, solution method thiab gas phase method. Tsuas yog rau txoj kev daws teeb meem, lub siab polymerization yog qis dua 2 MPa. Cov noobral Cov kauj ruam suav nrog kev npaj catalyst, ethylene polymerization, polymer sib cais thiab granulation.

①Slurry txoj kev:

Lub resulting polyethylene yog insoluble nyob rau hauv cov kuab tshuaj thiab nyob rau hauv daim ntawv ntawm ib tug slurry. Slurry polymerization tej yam kev mob yog me me thiab yooj yim rau kev khiav lag luam. Alkyl txhuas feem ntau yog siv los ua tus activator, thiab hydrogen yog siv los ua tus tswj qhov hnyav molecular, thiab lub tank reactor feem ntau siv. Lub polymer slurry los ntawm lub tank polymerization yog dhau los ntawm lub tank flash, cov roj-kua cais mus rau lub tshuab ziab khaub ncaws, thiab tom qab ntawd granulated. Cov txheej txheem ntau lawm kuj suav nrog cov kauj ruam xws li hnyav rov qab thiab hnyav refining. Txawv polymerization kettles tuaj yeem ua ke hauv series lossis hauv paralll kom tau txais cov khoom nrog sib txawv molecular hnyav distributions.

② Kev daws teeb meem:

Lub polymerization yog nqa tawm nyob rau hauv ib tug hnyav, tab sis ob qho tib si ethylene thiab polyethylene yog yaj nyob rau hauv cov kuab tshuaj, thiab cov tshuaj tiv thaiv system yog ib homogeneous tov. Cov tshuaj tiv thaiv kub (≥140 ℃) thiab siab (4 ~ 5MPa) siab. Nws yog tus cwj pwm los ntawm lub sij hawm luv luv polymerization, kev siv zog ntau lawm, thiab tuaj yeem tsim cov polyethylene nrog qhov siab, nruab nrab thiab qis, thiab tuaj yeem tswj cov khoom zoo ntawm cov khoom; Txawm li cas los xij, cov polymer tau los ntawm txoj kev daws teeb meem muaj qhov hnyav molecular, nqaim molecular hnyav faib, thiab cov khoom siv. Cov ntsiab lus tsawg.

③ Gas theem txoj kev:

Ethylene yog polymerized nyob rau hauv lub xeev gaseous, noobrally siv lub txaj fluidized reactor. Muaj ob hom catalysts: chromium series thiab titanium series, uas yog quantitatively ntxiv rau hauv txaj los ntawm lub tank cia, thiab high-ceev ethylene ncig yog siv los tswj lub fluidization ntawm lub txaj thiab tshem tawm cov tshav kub ntawm polymerization. Lub resulting polyethylene yog tawm ntawm lub hauv qab ntawm lub reactor. Lub siab ntawm lub reactor yog li 2 MPa, thiab qhov kub ntawm 85-100 ° C.

Cov txheej txheem roj-theem yog txoj hauv kev tseem ceeb tshaj plaws rau kev tsim cov linear low-density polyethylene. Cov txheej txheem roj-theem tshem tawm cov txheej txheem ntawm cov kuab tshuaj rov qab thiab polymer kom qhuav, thiab txuag 15% ntawm kev nqis peev thiab 10% ntawm cov nqi khiav lag luam piv nrog cov kev daws teeb meem. Nws yog 30% ntawm kev nqis peev ntawm cov txheej txheem kev kub ntxhov ib txwm muaj thiab 1/6 ntawm tus nqi khiav haujlwm. Yog li nws tau tsim kho sai heev. Txawm li cas los xij, cov txheej txheem roj theem yuav tsum tau txhim kho ntxiv ntawm cov khoom zoo thiab ntau yam.

Txoj Kev Siab Nruab Nrab

Siv cov chromium-based catalyst txhawb nqa ntawm silica gel, nyob rau hauv ib lub voj reactor, ethylene yog polymerized nyob rau hauv nruab nrab siab los tsim high-density polyethylene.

Dab tsi yog Cov Txheej Txheem Ntau Lawm ntawm Polyethylene