Iyini Inqubo Yokukhiqiza Ye-Polyethylene

Inqubo yokukhiqiza i-polyethylene ingahlukaniswa:

• Indlela yokucindezela okuphezulu, indlela yokucindezela okuphezulu isetshenziselwa ukukhiqiza i-polyethylene ephansi.
• Ukucindezela okulingene
• Indlela yokucindezela okuphansi. Ngokuqondene nendlela yokucindezela okuphansi, kukhona indlela ye-slurry, indlela yesisombululo kanye nendlela yesigaba segesi.

Indlela yokucindezela okuphezulu isetshenziselwa ukukhiqiza i-polyethylene ephansi. Le ndlela yasungulwa kusenesikhathi. I-polyethylene ekhiqizwa yile ndlela ilandisa mayelana ne-2/3 yomkhiqizo ophelele we-polyethylene, kodwa ngokuthuthukiswa kobuchwepheshe bokukhiqiza kanye nama-catalysts, izinga lokukhula kwayo liye lalandela kakhulu indlela yokucindezela okuphansi.

Ngokuqondene nendlela yokucindezela okuphansi, kukhona indlela ye-slurry, indlela yesisombululo kanye nendlela yesigaba segesi. Indlela ye-slurry isetshenziselwa ikakhulukazi ukukhiqiza i-polyethylene ephezulu, kuyilapho indlela yesisombululo kanye nendlela yesigaba segesi ayikwazi nje ukukhiqiza i-polyethylene ephakeme kakhulu, kodwa futhi ikhiqize i-polyethylene ephakathi nendawo ephansi ngokungeza ama-comonomers, eyaziwa nangokuthi i-polyethylene ephansi ye-linear. i-vinyl. Izinqubo ezihlukahlukene zokucindezela okuphansi zikhula ngokushesha.

Indlela Yokucindezela Okuphezulu

Indlela yokwenza i-ethylene ibe yi-polymerizing i-polyethylene enezinga eliphansi usebenzisa i-oxygen noma i-peroxide njengesiqalisi. I-ethylene ingena ku-reactor ngemva kokucindezelwa kwesibili, futhi i-polymerized ibe i-polyethylene ngaphansi kwengcindezi ye-100-300 MPa, izinga lokushisa lika-200-300 ° C kanye nesenzo se-initiator. I-polyethylene ngendlela yepulasitiki ikhishwa futhi ifakwe i-pelletized ngemva kokwengeza izithasiselo zepulasitiki.

Ama-polymerization reactor asetshenziswayo ama-tubular reactor (anobude beshubhu obufika ku-2000 m) kanye nama-reactors ethangi. Izinga lokuguqulwa kwephasi elilodwa lenqubo ye-tubular yi-20% kuya ku-34%, futhi umthamo wonyaka wokukhiqiza womugqa owodwa yi-100 kt. Izinga lokuguqulwa kwephasi elilodwa lenqubo yendlela yeketela lingu-20% kuya ku-25%, kanti umthamo wokukhiqiza wonyaka owodwa womugqa owodwa ngu-180 kt.

Indlela Yokucindezela Okuphansi

Lena enye inqubo yokukhiqiza ye-polyethylene , inezinhlobo ezintathu : indlela ye-slurry, indlela yesisombululo kanye nendlela yesigaba segesi. Ngaphandle kwendlela yesisombululo, ingcindezi ye-polymerization ingaphansi kwe-2 MPa. Isakhi sofuzoral izinyathelo zihlanganisa ukulungiswa kwe-catalyst, i-ethylene polymerization, ukuhlukaniswa kwe-polymer kanye ne-granulation.

①Indlela ye-slurry:

I-polyethylene eyavela yayingancibiliki ku-solvent futhi yayisesimweni se-slurry. Izimo ze-slurry polymerization zithambile futhi kulula ukusebenza. I-alkyl aluminium ivame ukusetshenziswa njenge-activator, futhi i-hydrogen isetshenziswa njengesilawuli sesisindo samangqamuzana, futhi i-reactor tank ivame ukusetshenziswa. I-polymer slurry esuka ethangini le-polymerization idluliswa ku-flash tank, isihlukanisi segesi esiwuketshezi siye esomisweni esiyimpuphu, bese sigaywa. Inqubo yokukhiqiza iphinde ihlanganise nezinyathelo ezifana nokubuyiswa kwe-solvent kanye nokucwengwa kwe-solvent. Amaketela e-polymerization ahlukene angahlanganiswa ngochungechunge noma ku-parallel ukuthola imikhiqizo enesisindo esihlukene samangqamuzana.

②Indlela yesixazululo:

I-polymerization yenziwa ku-solvent, kodwa kokubili i-ethylene ne-polyethylene kuncibilika ku-solvent, futhi uhlelo lokusabela luyisixazululo esilinganayo. Izinga lokushisa lokusabela (≥140℃) nokucindezela (4～5MPa) kuphezulu. Ibonakala ngesikhathi esifushane se-polymerization, umfutho ophezulu wokukhiqiza, futhi ingakhiqiza i-polyethylene nge-high, medium and low densities, futhi ingalawula kangcono izakhiwo zomkhiqizo; Nokho, i-polymer etholwe ngendlela yesisombululo inesisindo esiphansi samangqamuzana, ukusatshalaliswa kwesisindo samangqamuzana amancane, kanye nezinto eziqinile. Okuqukethwe kuphansi.

③Indlela yesigaba segesi:

I-Ethylene i-polymerized esimweni segesi, isakhi sofuzoralsebenzisa i-reactor yombhede enamanzi. Kunezinhlobo ezimbili zama-catalysts: uchungechunge lwe-chromium kanye nochungechunge lwe-titanium, ezingezwe ngobuningi embhedeni kusukela ethangini lokugcina, futhi ukujikeleza kwe-ethylene ngesivinini esiphezulu kusetshenziselwa ukugcina uketshezi kombhede nokuqeda ukushisa kwe-polymerization. I-polyethylene ewumphumela ikhishwa ngaphansi kwe-reactor. Ukucindezela kwe-reactor cishe ku-2 MPa, futhi izinga lokushisa lingu-85-100 °C.

Indlela ye-gas-phase iyindlela ebaluleke kakhulu yokukhiqiza i-linear low density polyethylene. Indlela yesigaba segesi iqeda inqubo yokubuyiswa kwe-solvent kanye nokomisa kwe-polymer, futhi ilondoloza u-15% wokutshalwa kwezimali kanye ne-10% yezindleko zokusebenza uma kuqhathaniswa nendlela yesixazululo. Kungu-30% wokutshalwa kwezimali kwendlela evamile yokucindezela okuphezulu kanye ne-1/6 yemali yokusebenza. Ngakho iye yathuthuka ngokushesha. Kodwa-ke, indlela yesigaba segesi idinga ukuthuthukiswa ngokwengeziwe ngokwezinga lomkhiqizo nokuhlukahluka.

Indlela Yokucindezela Okumaphakathi

Kusetshenziswa i-chromium-based catalyst esekelwe kujeli ye-silica, ku-loop reactor, i-ethylene yenziwa i-polymerized ngaphansi kwengcindezi ephakathi ukuze ikhiqize i-polyethylene ephezulu.

Iyini Inqubo Yokukhiqiza Ye-Polyethylene