Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
  • G01N30/02—Column chromatography
  • G01N30/26—Conditioning of the fluid carrier; Flow patterns
  • G01N30/28—Control of physical parameters of the fluid carrier
  • G01N30/34—Control of physical parameters of the fluid carrier of fluid composition, e.g. gradient
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
  • G01N30/00—Investigating or analysing materials by separation into components using adsorption, absorption or similar phenomena or using ion-exchange, e.g. chromatography or field flow fractionation
  • G01N30/02—Column chromatography
  • G01N2030/022—Column chromatography characterised by the kind of separation mechanism
  • G01N2030/025—Gas chromatography
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10S—TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10S526/00—Synthetic resins or natural rubbers -- part of the class 520 series
  • Y10S526/901—Monomer polymerized in vapor state in presence of transition metal containing catalyst
• • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
  • Y10—TECHNICAL SUBJECTS COVERED BY FORMER USPC
  • Y10T—TECHNICAL SUBJECTS COVERED BY FORMER US CLASSIFICATION
  • Y10T436/00—Chemistry: analytical and immunological testing
  • Y10T436/21—Hydrocarbon
  • Y10T436/214—Acyclic [e.g., methane, octane, isoparaffin, etc.]
  • Y10T436/216—Unsaturated [e.g., ethylene, diene, etc.]

Definitions

• the present invention relates to an improvement in the method of analysis by on-line gas chromatography of an essentially gaseous phase originating from an industrial olefin polymerization workshop.
• the present invention relates to a method of in-line gas chromatographic analysis of an essentially gaseous phase originating from an industrial olefin polymerization workshop, the said chromatographic analysis being carried out by means of carrier gases essentially comprising hydrogen and / or nitrogen, characterized in that the oxygen and water content of the hydrogen and nitrogen is less than 5 ppm by weight, preferably less than 1 ppm by weight.
• the polymerization of olefins is preferably carried out in the gas phase, preferably by means of a fluidized bed reactor.
• the Applicant has found that the reliability thus obtained according to the present invention was also accompanied by better control of the polymerization of olefins in the gas phase in an industrial fluidized bed reactor, and in particular that this made it possible to prevent and advantageously avoid the risks of agglomeration (crusts, leaves, etc.) well known to those skilled in the art.
• the oxygen and water content of hydrogen and nitrogen is less than 5 ppm by weight, preferably less than 1 ppm by weight.
• the oxygen content of the hydrogen is less than 0.7 ppm by weight, more preferably less than 0.3 ppm by weight.
• the water content of the hydrogen is less than 0.5 ppm by weight, more preferably less than 0.1 ppm by weight.
• the oxygen content of the nitrogen is less than 0.5 ppm by weight, more preferably less than 0.1 ppm by weight.
• the water content of the nitrogen is less than 0.5 ppm by weight, more preferably less than 0.05 ppm by weight.
• the respective CO and CO 2 content of the hydrogen is less than 5 ppm by weight, preferably less than 1 ppm by weight, preferably less than 0.7 ppm by weight, more preferably less than 0.3 ppm weight.
• the respective CO and CO 2 content of the nitrogen is less than 5 ppm by weight, preferably less than 1 ppm by weight, preferably less than 0.5 ppm by weight, more preferably less than 0.1 ppm weight.
• the impurities present in the carrier gases can be measured by any suitable method. By way of example, mention will be made of that using analyzers comprising probes based on aluminum oxide.
• This improved chromatographic analysis is particularly important because its increased reliability and efficiency now allow it, when used directly in industrial workshops, to instantly consider corrective operating measures in the event of deviation from the analysis values obtained.
• the present invention also relates to a process for the continuous production of polymer in an industrial workshop comprising an olefin polymerization reactor in the presence of a catalytic polymerization system, process during which at least one operating parameter of the workshop by means of an analysis by online chromatography of a phase essentially gas from the said industrial workshop, the said chromatographic analysis being carried out by means of carrier gases essentially comprising hydrogen and / or nitrogen, characterized in that the oxygen and water content of the hydrogen and l nitrogen is less than 5 ppm by weight, preferably less than 1 ppm by weight.
• the polymerization of olefins is preferably carried out in the gas phase, preferably by means of a fluidized bed reactor.
• the catalytic system comprises an organoaluminium compound, preferably an alkylaluminium compound such as triethylaluminium or triisobutylaluminium.
• SBR butadiene polymer copolymerized with styrene
• ABS acrylonitrile, butadiene and styrene polymer
• nitrile butadiene polymer copolymerized with acrylonitrile
• butyl isobutylene polymer copolymerized with isoprene
• EPDM etylene polymer copolymerized with propylene and a diene such as hexadiene, dicyclopentadiene or ethylidene norborene
• copolymer of ethylene and vinyltrimethoxy silane copolymer of ethylene and of one or more compounds chosen from Pacrylonitrile, esters of maleic acid, vinyl acetate, esters of acrylic and methacrylic acid and their counterparts.
• polymers which are preferably polyolefins, in particular copolymers of ethylene and / or propylene and / or butene.
• the preferred alpha-olefins which are used in combination with ethylene and / or propylene and / or butene are those having 4 to 8 carbon atoms.
• the invention applies to the production of polyethylene, for example linear low density polyethylene (LLDPE) based for example on copolymers of ethylene with 1-butene, 4-methylpentene or hexene, or high density polyethylene (HDPE) based for example on ethylene homopolymers or ethylene copolymers with low proportions of higher alpha olefins, for example 1-butene, 1-pentene, hexene or 4-methyl-1-pentene.
• LLDPE linear low density polyethylene
• HDPE high density polyethylene
• the present invention relates to the production of polyethylene powder continuously in an industrial workshop comprising a gas phase polymerization reactor of the vertical fluidized bed reactor type.
• this polymerization is carried out at an absolute pressure between 0.5 and 6 MPa and at a temperature between 60 ° C and 130 ° C.
• the polymerization temperature is preferably between 75 and 100 ° C. and for HDPE it is generally between 80 and 110 ° C. depending on the activity of the catalyst used and the properties desired. polymer.
• the continuous polymerization is carried out in a vertical fluidized bed reactor in accordance with what is described in (patent applications) EP-0 855 411. FR No. 2,207,145 or FRNo. 2335526.
• the present invention therefore applies to workshops of industrial size, namely, by way of example, to fluidized bed polymerization reactors whose annual polymer production is at least one hundred thousand tonnes, preferably at least two hundred thousand tonnes.
• this polymerization is carried out in the presence of a catalytic system of the Ziegler-Natta type which generally consists of a solid catalyst essentially comprising a compound of a transition metal and a cocatalyst comprising an organic compound of a metal (by example, an organometallic compound, for example an alkylaluminum compound).
• a catalytic system of the Ziegler-Natta type which generally consists of a solid catalyst essentially comprising a compound of a transition metal and a cocatalyst comprising an organic compound of a metal (by example, an organometallic compound, for example an alkylaluminum compound).
• High activity catalytic systems of this type generally include a solid catalyst which consists essentially of transition metal, magnesium and halogen atoms.
• metallocene type catalysts as well as complex iron catalysts. and / or cobalt, for example those described in WO98 / 27124 or in the application filed under the number WOGB98 / 2638. It is also possible to use catalysts based on chromium oxide supported on a refractory oxide. The catalysts can be used directly or in the form of prepolymers prepared beforehand during a prepolymerization step.

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• General Health & Medical Sciences (AREA)
• Health & Medical Sciences (AREA)
• Life Sciences & Earth Sciences (AREA)
• Chemical & Material Sciences (AREA)
• Analytical Chemistry (AREA)
• Biochemistry (AREA)
• Physics & Mathematics (AREA)
• General Physics & Mathematics (AREA)
• Immunology (AREA)
• Pathology (AREA)
• Polymerisation Methods In General (AREA)
• Transition And Organic Metals Composition Catalysts For Addition Polymerization (AREA)
• Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

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• 2001
  • 2001-11-30 EP EP01990632A patent/EP1340070A1/de not_active Withdrawn
  • 2001-11-30 US US10/433,893 patent/US6904785B1/en not_active Expired - Fee Related
  • 2001-11-30 WO PCT/IB2001/002789 patent/WO2002046738A2/fr not_active Application Discontinuation
  • 2001-11-30 AU AU2002230017A patent/AU2002230017A1/en not_active Abandoned

Non-Patent Citations (1)

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