PROCESS FOR PREPARING AN OLEFIN POLYMER, VESSEL, AND METHOD FOR CONTROLLING AN OLEFIN POLYMERIZATION PROCESS

Abstract

A process for preparing an olefin polymer, vessel, and method for controlling an olefin polymerization process. A process for preparing an olefin polymer in a polymerization apparatus in the presence of a solid particulate polymerization catalyst and an organometallic compound, comprising withdrawing a gas stream from the polymerization apparatus, passing the gas stream through a bed of particulate solid having on its surface chemical groups that are reactive with the organometallic compound, and feeding a sample of the gas stream into an analyzer.

Description

/ 31 PROCESS FOR PREPARING AN OLEFIN POLYMER, VESSEL, AND METHOD FOR CONTROLLING AN OLEFIN POLYMERIZATION PROCESS Field of invention

[001] The present disclosure provides processes for preparing an olefin polymer. In particular, the present disclosure provides processes for preparing an olefin polymer in which a gaseous sample is taken from a polymerization apparatus comprising a polymerization reactor or a combination of polymerization reactors and fed to an analyzer. Background of the invention

[002] Polyolefins are widely used commercial polymers. Suitable processes for producing polyolefins include suspension and gas-phase polymerization processes in the presence of a solid polymerization catalyst and an organometallic compound as a cocatalyst and / or as a scavenger. Suspension polymerization is often carried out in stirred tank reactors or cyclic reactors. Suitable reactors for conducting gas-phase polymerizations are, for example, fluidized bed reactors, stirred gas-phase reactors, or multi-zone circulating reactors with two distinct interconnected gas-phase polymerization zones. The polymerization of olefins in a series of a fluidized bed reactor and a multi-zone circulating reactor is, for example, disclosed in documents No. EP 3524343 A1, No. WO 2018 / 115236 A1 and No. WO 2016 / 150997 A1.

[003] To control the polymerization reaction, it is necessary to have information about the composition of the reaction mixture inside the polymerization reactor or inside each of the polymerization reactors if a combination of polymerization reactors is used. This is usually done by taking a gas sample from the polymerization reactor or from the Petition 870230100510, dated 11 / 14 / 2023, page 12 / 49 / 31, describes a combination of polymerization reactors, or a piece of equipment from a polymerization apparatus in which a gas phase is present, and analyzing the composition of the gas sample, for example by a gas chromatograph. Document No. US 4,469,853 discloses a process for preparing polyolefins that have predetermined properties by detecting parameters that determine those properties by gas chromatography, generating signals corresponding to the detected parameters, comparing those signals with predetermined values, and controlling the parameters. Document No. US 2012 / 0283395 A1 discloses a gas-phase polymerization reactor system and a cyclic fluid paste polymerization reactor system, wherein each reactor system includes measuring systems that can be employed to control and / or monitor the reaction conditions within the reactors.The document reveals that analyzers for determining the composition of gaseous samples can be chromatographic analyzers such as gas chromatographs, mass spectrometers, or Raman probes.

[004] To improve the quality of gas analysis and extend the service life of analytical equipment, the gas sample is often passed through a filter before being fed into the analyzer. Document No. US 3,556,730, for example, reveals that such filters can be a chamber filled with glass fibers or filters employing paper elements. However, the analysis of gas compositions of samples taken from olefin polymerization reactors frequently yields unreliable results that necessitate recalibration of the analyzer and cleaning of the sample dosing equipment.

[005] There is, consequently, a need to provide improved processes for preparing an olefin polymer that allows for the reliable determination of the composition of reaction mixtures within polymerization reactors and that have reduced maintenance costs. Petition 870230100510, dated 11 / 14 / 2023, page 13 / 49 / 31 for the reviewers. Summary of the invention

[006] The present disclosure provides a process for preparing an olefin polymer comprising feeding a solid particulate polymerization catalyst, an organometallic compound and an olefin or a combination of an olefin and one or more other olefins into a polymerization apparatus comprising a polymerization reactor or a combination of polymerization reactors, homopolymerizing the olefin or copolymerizing the olefin and one or more other olefins at temperatures of 20 °C to 200 °C and pressures of 0.1 MPa to 20 MPa in the presence of the polymerization catalyst and the organometallic compound, drawing a gas stream from the polymerization apparatus, passing the gas stream through a bed of particulate solid having on its surface chemical groups that are reactive with the organometallic compound, and feeding a sample of the gas stream into an analyzer for analyzing the gas sample.

[007] In some embodiments, the analyzer is a gas chromatograph.

[008] In some embodiments, the organometallic compound is an aluminum alkyl.

[009] In some embodiments, the particulate solid is an oxide or a mixed oxide of the elements calcium, aluminum, silicon, magnesium or titanium or the particulate solid is ZrO2 or B2O3.

[0010] In some embodiments, the chemical groups on the surface of the particulate solid that are reactive with the organometallic compound are OH groups, adsorbed water, or expanded Si-O-Si bridges. Petition 870230100510, dated 11 / 14 / 2023, p. 14 / 49 / 31

[0011] In some embodiments, the particulate solid is a silica gel equipped with a moisture indicator.

[0012] In some embodiments, the gas stream withdrawn from the polymerization apparatus is a continuous gas stream that is withdrawn from the polymerization apparatus at a flow rate of 1 Nl / h / ha 500 Nl / h.

[0013] In some embodiments, the gas stream sample is supplied to the analyzer at intervals.

[0014] In some embodiments, two or more gas streams are withdrawn from the polymerization apparatus at different positions, and samples of some or all of the two or more gas streams are subsequently fed to an analyzer for sample analysis, or some or all of the two or more gas streams have a dedicated analyzer to which only samples of one of the gas streams withdrawn from the polymerization apparatus are supplied.

[0015] In some embodiments, the particulate solid bed is contained in a vessel with a volume of 50 cm3 to 10000 cm3.

[0016] In some embodiments, the particulate solid bed is contained in a vessel comprising a pipe having a diameter of 6 mm to 100 mm, an inlet for introducing a gas stream into the pipe and an outlet for removing a gas stream from the pipe, and wherein the distance between the inlet and the outlet is 0.2 m to 10 m.

[0017] In some embodiments, the vessel further comprises a first valve at one end of the pipe for introducing the particulate solid bed into the pipe and a second valve at the other end of the pipe for removing the particulate solid bed from the pipe and / or the inlet and outlet of the pipe are fitted with screens having a mesh size of 35 µm to 2 mm to retain the particulate solid bed within the pipe.

[0018] In some modalities, the results obtained by the analysis Petition 870230100510, dated 11 / 14 / 2023, p. 15 / 49 / 31: Gas samples are fed as measurement signals to a controller to control the process for preparing the olefin polymer.

[0019] The present disclosure further provides a vessel comprising a pipe having a diameter of 6 mm to 100 mm, an inlet for introducing a stream of gas into the pipe, an outlet for removing a stream of gas from the pipe, and a first valve at one end of the pipe for introducing a bed of particulate solid into the pipe and a second valve at the other end of the pipe for removing the bed of particulate solid from the pipe, wherein the inlet and outlet of the pipe are fitted with screens with a mesh size of 35 µm to 2 mm, and the distance between the inlet and outlet is 0.2 m to 10 m.

[0020] The present disclosure further provides a method for controlling an olefin polymerization process, comprising homopolymerizing an olefin or copolymerizing an olefin and one or more other olefins at temperatures from 20 °C to 200 °C and pressures from 0.1 MPa to 20 MPa in the presence of a solid particulate polymerization catalyst and an organometallic compound in a polymerization apparatus comprising a reactor or a combination of polymerization reactors, the method comprising, - to remove a gas stream from the polymerization apparatus; - passing the gas stream through a bed of particulate solid that has chemical groups on its surface that are reactive with the organometallic compound; - Feeding a sample of the gas stream into an analyzer to analyze the gas sample; - Analyze the sample and obtain information about the conditions inside the polymerization apparatus; and - Adapt the polymerization conditions within the polymerization apparatus based on the information obtained from the sample analysis. Petition 870230100510, dated 11 / 14 / 2023, page 16 / 49 / 31 for predefined values. Brief description of the drawings

[0021] Figure 1 schematically shows a configuration of a polymerization apparatus comprising a series of polymerization reactors in which the process of the present disclosure can be carried out.

[0022] Figure 2 schematically shows a vessel for containing a bed of particulate solid according to the present disclosure. Detailed description of the invention

[0023] The present disclosure provides a process for preparing an olefin polymer. Olefins for preparing the olefin polymer are especially 1-olefins, that is, hydrocarbons having terminal double bonds, without being restricted to this. Preference is given to nonpolar olefinic compounds. Particularly preferred 1-olefins are linear or branched C2-C12-1-alkenes, in particular, linear C2-C10-1-alkenes such as ethylene, propylene, 1-butene, 1-pentane, 1-hexene, 1-heptane, 1-octene, 1-decene or branched C2-C10-1-alkenes such as 4-methyl-1-pentene, conjugated and non-conjugated dienes such as 1,3-butadiene, 1,4-hexadiene or 1,7-octadiene. It is also possible to polymerize mixtures of various 1-olefins. Suitable olefins also include those in which the double bond is part of a cyclic structure that may have one or more ring systems.Examples include cyclopentene, norbornene, tetracyclododecene, or methylnorbornene, or dienes such as 5-ethylidene-2-norbornene, norbornadiene, or ethylnorbornadiene. It is also possible to polymerize mixtures of two or more olefins, for example, mixtures of two, three, or four olefins.

[0024] The olefin polymer can be obtained by homopolymerization of an olefin or by copolymerization of an olefin and one or more other olefins. The olefin polymer can be obtained in particular by homopolymerization or copolymerization of ethylene or propylene, and Petition 870230100510, dated 11 / 14 / 2023, page 17 / 49 / 31, especially by homopolymerization or copolymerization of ethylene. Preferred comonomers in propylene polymerization have up to 60% by weight of ethylene, 1-butene and / or 1-hexene, preferably from 0.5% by weight to 35% by weight of ethylene, 1-butene and / or 1-hexene. As comonomers in ethylene polymerization, preference is given to the use of up to 20% by weight, more preferably from 0.01% by weight to 15% by weight, and especially from 0.05% by weight to 12% by weight of C3-Cs-1-alkenes, in particular 1-butene, 1-pentene, 1-hexene and / or 1-octene. Particular preference is given to polymerizations in which ethylene is copolymerized with 0.1% by weight to 12% by weight of 1-hexene and / or 1-butene.

[0025] In the present disclosure process, the homopolymerization of an olefin or the copolymerization of an olefin and one or more other olefins is carried out at temperatures in the range of 20 °C to 200 °C, preferably 30 °C to 150 °C and particularly preferably 40 °C to 130 °C, and pressures of 0.1 MPa to 20 MPa and particularly preferably 0.3 MPa to 5 MPa in the presence of a solid particulate polymerization catalyst and an organometallic compound, which are fed, together with the olefin or the combination of an olefin and one or more other olefins, into a polymerization apparatus comprising a polymerization reactor or a combination of polymerization reactors.

[0026] The polymerization catalyst can be any usual solid particulate polymerization catalyst that can be used in the polymerization of olefins in combination with an organometallic compound as a cocatalyst.This means that polymerization can be carried out using Ziegler or Ziegler-Natta catalysts, using chromium oxide-based Phillips catalysts, or using single-site catalysts. For the purposes of the present disclosure, single-site catalysts are catalysts based on chemically uniform transition metal coordination compounds. Furthermore, it is also possible to use... Petition 870230100510, dated 11 / 14 / 2023, page 18 / 49 / 31 mixtures of two or more of these catalysts for the polymerization of olefins. Such mixed catalysts are often referred to as hybrid catalysts. The preparation and use of these catalysts for olefin polymerization are generally known.

[0027] Preferred catalysts are of the Ziegler or ZieglerNatta type, preferably comprising a titanium or vanadium compound, a magnesium compound and, optionally, an electron-donating compound and / or a particulate inorganic oxide as a support material. As titanium compounds, trivalent or tetravalent titanium halides or alkoxides are generally used, and titanium alkoxy-halogen compounds or mixtures of various titanium compounds are also possible. Preference is given to the use of titanium compounds comprising chlorine as a halogen. In the production of the solid component, at least one magnesium compound is preferably used additionally.Suitable compounds of this type are magnesium compounds containing halogens, such as magnesium halides, and in particular chlorides or bromides, and magnesium compounds from which magnesium halides can be obtained in a conventional manner, for example, by reaction with halogenating agents. As magnesium compounds for the production of particulate solids, preference is given to the use of, in addition to magnesium dichloride or magnesium dibromide, di(C1-C10-alkyl)magnesium compounds. Suitable electron-donating compounds for preparing Ziegler or Ziegler-Natta type catalysts are, for example, alcohols, glycols, esters, ketones, amines, amides, nitriles, alkoxysilanes, and aliphatic ethers. These electron-donating compounds can be used alone or in mixtures with other electron-donating compounds. Preferred electron donor compounds are selected from the group consisting of amides, esters, and alkoxysilanes.

[0028] Preferred catalysts are also catalysts for Petition 870230100510, dated 11 / 14 / 2023, page 19 / 49 / 31 Phillips-type chromium, which are preferably prepared by applying a chromium compound to an inorganic support and subsequently activating the resulting catalyst precursor at temperatures in the range of 350 to 1000 °C, resulting in chromium present in valences lower than six which are converted to the hexavalent state. In addition to chromium, other elements such as magnesium, calcium, boron, aluminum, phosphorus, titanium, vanadium, zirconium or zinc can also be used. Particular preference is given to the use of titanium, zirconium or zinc. Combinations of the aforementioned elements are also possible. The catalyst precursor can be doped with fluoride before or during activation. Examples of catalyst supports for Phillips-type catalysts include aluminum oxide, silicon dioxide (e.g., in the form of silica gel), titanium dioxide, zirconium dioxide or their oxides or mixed cogels, or aluminum phosphate.Other suitable support materials can be obtained by modifying the surface area of ​​the pores, for example, using compounds of boron, aluminum, silicon, or phosphorus. Silica gel is preferred. Spherical or granular silica gels are preferred, the former also being spray-dried. The activated chromium catalysts can subsequently be pre-polymerized or pre-reduced. Pre-reduction is normally carried out using cobalt or hydrogen at 250 °C to 500 °C, preferably 300 °C to 400 °C, in an activator.

[0029] Preferred catalysts for the process of the present disclosure are also supported single-site catalysts. Particularly suitable are those comprising bulky organic ligands linked by sigma or pi, for example, catalysts based on mono-Cp complexes, catalysts based on bis-Cp complexes, which are commonly referred to as metallocene catalysts, or catalysts based on late-transition metal complexes, in particular ferrobisimine complexes. Additional preferred catalysts are mixtures of two or more Petition 870230100510, dated 11 / 14 / 2023, page 20 / 49 / 31 single-site catalysts or mixtures of different types of catalysts comprising at least one single-site catalyst. Suitable materials as support for the Phillips-type chromium catalyst are also useful as support for single-site catalysts.

[0030] The solid particulate polymerization catalysts employed in the present disclosure process are used in combination with an organometallic compound. Preferred organometallic compounds are organometallic compounds of metals from Groups 1, 2, 12, 13 or 14 of the Periodic Table of Elements, in particular, organometallic compounds of metals from Group 13 and especially organoaluminum compounds. Preferred organometallic compounds are, for example, organometallic alkyls, organometallic alkoxides or organometallic halides.

[0031] Organometallic compounds serve, on the one hand, as cocatalysts for solid particulate polymerization catalysts and, on the other hand, are scavengers that react with polar compounds that can be introduced into the polymerization reactor and that can act as catalytic poisons.

[0032] Preferred organometallic compounds comprise lithium alkyls, magnesium or zinc alkyls, magnesium alkyl halides, aluminum alkyls, silicon alkyls, silicon alkoxides and silicon alkyl halides. More preferably, organometallic compounds comprise aluminum alkyls and magnesium alkyls. Even more preferably, organometallic compounds comprise aluminum alkyls, most preferably trialkylaluminum compounds or compounds of this type in which an alkyl group is replaced by a halogen atom, for example by chlorine or bromine. Examples of such aluminum alkyls are trimethylaluminum, triethylaluminum, triisobutylaluminum, trinhexylaluminum or diethylaluminum chloride, or mixtures thereof.

[0033] The process of this disclosure can be carried out using Petition 870230100510, dated 11 / 14 / 2023, page 21 / 49 / 31 of all industrially known low-pressure polymerization methods in a polymerization apparatus comprising a polymerization reactor or a combination of polymerization reactors. These polymerization reactors may be, for example, stirred tank reactors or cyclic reactors, or the polymerization reactors may be fluidized bed reactors, gas-phase stirred reactors or multi-zone circulation reactors with two distinct interconnected gas-phase polymerization zones. Polymerization may be carried out in batches or, preferably, continuously in one or more stages, for example in one, two, three or four stages. Solution processes, suspension processes and gas-phase processes are all possible. Processes of this type are generally known to those skilled in the art.Among the polymerization methods mentioned, gas-phase polymerization is preferred, particularly in gas-phase fluidized bed reactors or multi-zone circulating reactors, and suspension polymerization, particularly in cyclic reactors or stirred tank reactors.

[0034] In a preferred embodiment of the present disclosure, the polymerization process is a suspension polymerization in a suspension medium, preferably in an inert hydrocarbon, such as isobutane or mixtures of hydrocarbons, or even in the monomers themselves. The suspension polymerization temperatures are generally in the range of 20 to 115 °C, and the pressure is in the range of 0.1 to 10 MPa. The solids content of the suspension is generally in the range of 10 to 80% by weight. Polymerization can be carried out in batches, for example, in autoclaves with stirring, and continuously, for example, in tubular reactors, preferably in cyclic reactors. In particular, it can be carried out by the Phillips PF process as described in documents No. US 3,242,150 and US 3,248,179.

[0035] Suitable suspension media are all media generally known for use in suspension reactors. The suspension medium must be Petition 870230100510, dated 11 / 14 / 2023, page 22 / 49 / 31 inert and liquid or supercritical under reaction conditions and must have a boiling point significantly different from the monomers and comonomers used to enable the recovery of these starting materials from the product mixture by distillation. The usual suspension media are saturated hydrocarbons with 4 to 12 carbon atoms, for example isobutane, butane, propane, isopentane, pentane and hexane, or a mixture thereof, also known as diesel oil.

[0036] In a preferred suspension polymerization process, polymerization occurs in a series of two, or preferably three or four stirred vessels. The molecular weight of the polymer fraction prepared in each reactor is preferably fixed by adding hydrogen to the reaction mixture. The polymerization process is preferably carried out with the highest hydrogen concentration and the lowest comonomer concentration, based on the amount of monomer, established in the first reactor. In subsequent reactors, the hydrogen concentration is gradually reduced and the comonomer concentration is altered, in each case again based on the amount of monomer. Ethylene or propylene is preferably used as the monomer, and a 1-olefin with 4 to 10 carbon atoms is preferably used as the comonomer.

[0037] Another preferred suspension polymerization process is suspension polymerization in loop reactors, in which the polymerization mixture is continuously pumped through a cyclic reactor tube. As a result of the pumped circulation, continuous mixing of the reaction mixture is achieved, and the introduced catalyst and fed monomers are distributed throughout the reaction mixture. Furthermore, the pumped circulation prevents sedimentation of the suspended polymer. Removal of reaction heat via the reactor wall is also promoted by the pumped circulation. In general, these reactors essentially consist of a cyclic reactor tube with one or more ascending legs and one or more connecting legs. Petition 870230100510, dated 11 / 14 / 2023, page 23 / 49 / 31 descending tubes that are enclosed by cooling jackets for the removal of reaction heat, and also horizontal tube sections that connect the vertical legs. The impeller pump, catalyst supply facilities, monomer supply facilities, and also the discharge facility, usually the settling legs, are generally installed in the lower tube section. However, the reactor may also have more than two vertical tube sections, so that a sinuous arrangement is obtained.

[0038] Preferably, suspension polymerization is carried out in the loop reactor at an ethylene concentration of at least 5 mol percent, preferably 10 mol percent, based on the suspension medium. In this context, the suspension medium does not mean the supplied suspension medium, such as isobutane alone, but rather the mixture of this supplied suspension medium with the monomers dissolved therein. The ethylene concentration can be easily determined by gas chromatography analysis of the suspension medium.

[0039] In a particularly preferred embodiment of the present disclosure, the polymerization process is carried out as gas-phase polymerization, that is, by a process in which solid polymers are obtained from a gaseous phase of the monomer or monomers. Such gas-phase polymerizations are generally carried out at pressures of 0.1 MPa to 20 MPa, preferably 0.5 MPa to 10 MPa and in particular 1.0 MPa to 5 MPa and polymerization temperatures of 40 °C to 150 °C and preferably 65 °C to 125 °C.

[0040] Suitable gas-phase polymerization reactors are horizontally or vertically stirred reactors, fluidized bed gas-phase reactors or multi-zone circulating reactors, and preferably fluidized bed gas-phase reactors or multi-zone circulating reactors. Petition 870230100510, dated 11 / 14 / 2023, page 24 / 49 / 31

[0041] Fluidized bed polymerization reactors are reactors in which polymerization occurs in a bed of polymer particles that is maintained in a fluidized state by supplying gas at the lower end of the reactor, usually below a gas distribution grid that dispenses the gas flow and removes the gas again at its upper end. The reactor gas is then returned to the lower end of the reactor via a recycle line equipped with a compressor and a heat exchanger. The circulated reactor gas is usually a mixture of olefins to be polymerized, inert gases such as nitrogen and / or lower alkanes such as ethane, propane, butane, pentane or hexane, and optionally a molecular weight regulator such as hydrogen. The use of nitrogen or propane as the inert gas is preferred, if appropriate, in combination with other lower alkanes.The reactor gas velocity must be high enough, firstly to fluidize the mixed bed of finely divided polymer present in the tube that serves as the polymerization zone, and secondly to effectively remove the heat of polymerization. Polymerization can also be carried out in a condensed or supercondensed mode, in which part of the circulating reaction gas is cooled below the dew point and returned to the reactor separately as a liquid and a gas phase, or together as a two-phase mixture to make additional use of the enthalpy of vaporization to cool the reaction gas.

[0042] Multi-zone circulation reactors are gas-phase reactors in which two polymerization zones are linked to each other and the polymer is passed alternately several times through these two zones. Such reactors are, for example, described in documents no. WO 97 / 04015 A1 and WO 00 / 02929 A1 and have two interconnected polymerization zones, a riser, in which the growing polymer particles flow upwards under rapid fluidization or transport conditions, and a downpipe, in Petition 870230100510, dated 11 / 14 / 2023, page 25 / 49 / 31, in which the growing polymer particles flow in a densified manner under the action of gravity. The polymer particles leaving the riser enter the downpipe, and the polymer particles leaving the downpipe are reintroduced into the riser, thus establishing a polymer circulation between the two polymerization zones, and the polymer is passed alternately a plurality of times through these two zones. Furthermore, it is also possible to operate the two polymerization zones of a multi-zone circulation reactor with different polymerization conditions by establishing different polymerization conditions in its riser and downpipe. For this, the gas mixture exiting the riser and carrying the polymer particles can be partially or totally prevented from entering the downpipe.This can, for example, be achieved by supplying a barrier fluid in the form of a gas and / or a liquid mixture in the downpipe, preferably at the top of the downpipe. The barrier fluid must have a suitable composition, different from the gas mixture present in the riser. The amount of barrier fluid added can be adjusted to generate an upward gas flow countercurrent to the flow of polymer particles, mainly at the top of the particles, acting as a barrier to the gas mixture entrained between the particles from the riser. In this way, it is possible to obtain zones of different gas composition in a multi-zone circulation reactor. Additionally, it is also possible to introduce compensating monomers, comonomers, molecular weight regulators such as hydrogen, and / or inert fluids at any point in the downpipe, preferably below the barrier supply point.In this way, it is also easily possible to create variable concentrations of monomer, comonomer, and hydrogen along the downpipe, resulting in further differentiation of the polymerization conditions.

[0043] Gas-phase polymerization processes according to Petition 870230100510, dated 11 / 14 / 2023, page 26 / 49 / 31, the present disclosure is preferably carried out in the presence of a C3C5 alkane as a polymerization diluent and more preferably in the presence of propane, especially in the case of homopolymerization or copolymerization of ethylene.

[0044] Different or identical polymerization processes can also, if desired, be connected in series and thus form a polymerization cascade. A parallel arrangement of reactors using two or more different or identical processes is also possible.

[0045] In a particularly preferred embodiment of the present disclosure, the polymerization of olefins is carried out in a reactor cascade of two or more gas-phase reactors. More preferably, the polymerization of olefins is carried out in a reactor cascade comprising a fluidized bed reactor and a multi-zone circulation reactor. Preferably, the fluidized bed reactor is arranged upstream of the multi-zone circulation reactor. Such gas-phase reactor series may also comprise additional polymerization reactors. These additional reactors may be any type of low-pressure polymerization reactors, such as gas-phase reactors or suspension reactors, and may also include a prepolymerization stage.

[0046] In the process of the present disclosure, a gas stream is withdrawn from the polymerization apparatus comprising a polymerization reactor or a combination of polymerization reactors. If the polymerization is a gas-phase polymerization, the gas stream can be withdrawn from any position within the polymerization apparatus. Preferably, the gas stream is withdrawn from a position within the polymerization apparatus where the reaction gas is present. This means that, if the polymerization is a gas-phase polymerization, the gas stream can be withdrawn directly from the reactor or, for example, in polymerizations in a Petition 870230100510, dated 11 / 14 / 2023, page 27 / 49 / 31. In a fluidized bed reactor or a multi-zone circulation reactor, the gas stream can be withdrawn from the gas recycling line. If the polymerization is a suspension polymerization conducted in a polymerization reactor not completely filled with suspension, the gas stream is preferably withdrawn from a vapor section within the polymerization reactor above the suspension level in the reactor. It is also possible, especially if the polymerization is carried out in a completely filled polymerization reactor such as a cyclic reactor, to withdraw the gas stream not directly from a polymerization reactor, but from a piece of equipment in the polymerization apparatus in which a gas phase is present. Such a piece of equipment may be, for example, a vaporization vessel installed downstream of a polymerization reactor or equipment connected to a vaporization vessel.

[0047] Figure 1 schematically shows an installation of a polymerization apparatus comprising a series of polymerization reactors comprising a fluidized bed reactor and a multi-zone circulation reactor in which the process of the present disclosure can be carried out.

[0048] The first gas-phase reactor, the fluidized bed reactor (1), comprises a fluidized bed (2) of polyolefin particles, a gas distribution grid (3) and a velocity reduction zone (4). The velocity reduction zone (4) generally has an increased diameter compared to the diameter of the fluidized bed portion of the reactor. The polyolefin bed is maintained in a fluidized state by an upward flow of gas fed through the gas distribution grid (3) located at the bottom of the reactor (1). The gas stream of the reaction gas mixture leaving the top of the velocity reduction zone (4) via the recycle line (5) is compressed by a compressor (6), transferred to a heat exchanger (7) where it is cooled and then recycled at the bottom of the reactor. Petition 870230100510, dated 11 / 14 / 2023, page 28 / 49 / 31 of fluidized bed (1) at a point below the gas distribution grid (3) at position (8). The recycle gas may, if appropriate, be cooled to below the condensation point of one or more of the recycle gas components in the heat exchanger so as to operate the reactor with condensate, i.e., in condensation mode. The recycle gas may comprise, in addition to unreacted monomers, inert condensable gases such as alkanes, as well as inert non-condensable gases such as nitrogen. Composition monomers, hydrogen, and optional inert gases or process additives may be fed into the reactor (1) at various positions, for example, via line (9) upstream of compressor (6). In general, the catalyst is fed into the reactor (1) through a line (10) which is preferably placed in the lower part of the fluidized bed (2).

[0049] The polyolefin particles obtained in the fluidized bed reactor (1) are discharged discontinuously through line (11) and fed into a solid / gas separator (12), so as to prevent the gas mixture from the fluidized bed reactor (1) from entering the second gas phase reactor. The gas leaving the solid / gas separator (12) leaves the reactor through line (13) as exhaust gas while the separated polyolefin particles are fed through line (14) to the second gas phase reactor.

[0050] To analyze the composition of the reaction gas inside the fluidized bed reactor (1), a gas stream is taken from the recycle line (5) at a position between the compressor (6) and the heat exchanger (7) through the sampling line (15).

[0051] The second gas-phase reactor is a multi-zone circulating reactor (21) comprising a riser (22) and a downpipe (23) that are repeatedly passed through the polyolefin particles. Inside the riser (22), the polyolefin particles flow upwards under conditions of Petition 870230100510, dated 11 / 14 / 2023, page 29 / 49 / 31 rapid fluidization along the direction of the arrow (24). Inside the downpipe (23), the polyolefin particles flow down under the action of gravity along the direction of the arrow (25). The riser (22) and the downpipe (23) are appropriately interconnected by the interconnecting bends (26) and (27).

[0052] After flowing through the riser (22), the polyolefin particles and the reaction gas mixture leave the riser (22) and are transported to a solid / gas separation zone (28). This solid / gas separation can be carried out using conventional separation means, such as, for example, a centrifugal separator like a cyclone. From the separation zone (28) the polyolefin particles enter the downpipe (23).

[0053] The reaction gas mixture leaving the separation zone (28) is recycled in the riser (22) by means of a recycling line (29), equipped with a compressor (30) and a heat exchanger (31). Between the compressor (30) and the heat exchanger (31), the recycling line (29) splits and the gas mixture is divided into two separate streams: line (32) carries a portion of the recycling gas to the interconnecting bend (27), while line (33) carries another portion of the recycling gas to the bottom of the riser (22), so as to establish conditions for rapid fluidization therein.

[0054] Polyolefin particles from the first gas phase reactor via line (14) enter the multi-zone circulating reactor (21) at the interconnecting bend (27) at position (34). Polyolefin particles obtained in the multi-zone circulating reactor (21) are continuously discharged from the bottom of the downpipe (23) via discharge line (35).

[0055] A portion of the gas mixture leaving the separation zone (28) exits the recycling line (29) after passing through the compressor (30) and is sent via line (36) to the heat exchanger (37), where it is cooled to a temperature at which the monomers and optional inert gas are partially condensed. A separation vessel (38) is placed downstream. Petition 870230100510, dated 11 / 14 / 2023, page 30 / 49 / 31 of the heat exchanger (37). The separated liquid is withdrawn from the separation vessel (38) by means of line (39) and fed into the downpipe (23) through lines (40), (41), (42) and (43) by means of a pump (44), the feed stream introduced by means of line (40) being provided to generate the barrier to prevent the reaction gas mixture from the riser pipe (22) from entering the downpipe (23). Composition monomers, composition comonomers and, optionally, inert gases and / or process additives may be introduced via lines (45), (46) and (47) into lines (41), (42) and (43) and then fed into the downpipe (23) at monomer feed points (48), (49) and (50). Composition monomers, composition comonomers and, optionally, inert gases and / or process additives may be further introduced into the recycling line (29) via line (51).The gas mixture obtained as gas phase in the separation vessel (38) is recirculated in the recycling line (29) through line (52).

[0056] The bottom of the downpipe (23) is fitted with a control valve (53) which has an adjustable opening to adjust the flow of polyolefin particles from the downpipe (23) through the interconnecting bend (27) in the riser (22). Above the control valve (53), quantities of a recycling gas mixture from the recycling line (29) through lines (32) and (54) are introduced into the downpipe (23) to facilitate the flow of polyolefin particles through the control valve (53).

[0057] To analyze the composition of the reaction gas inside the riser (22) and downpipe (23), gas streams are taken from the recycle line (29) at a position between the compressor (30) and the heat exchanger (31) through the sampling line (55) and from the downpipe (23) through the sampling line (56).

[0058] In the process of the present disclosure, the gas stream withdrawn from the polymerization apparatus is fed to an analyzer. The analyzer Petition 870230100510, dated 11 / 14 / 2023, page 31 / 49 21 / 31 can be a gas chromatograph, a Raman probe, an IR detector, a mass spectrometer, or a thermal conductivity detector. The analyzer is preferably a gas chromatograph.

[0059] Before being introduced into the analyzer, the gas stream is passed through a bed of particulate solid that has chemical groups on its surface that are reactive with the organometallic compound.

[0060] In preferred embodiments of the present disclosure, the particulate solid having chemical groups on its surface that are reactive with the organometallic compound is a porous material such as talc, a silicate sheet or an inorganic oxide.

[0061] Suitable inorganic oxides as particulate solids can be found among the oxides of the elements in groups 2, 3, 4, 5, 13, 14, 15 and 16 of the Periodic Table of Elements. Preference is given to oxides or mixed oxides of the elements calcium, aluminum, silicon, magnesium or titanium. Other inorganic oxides that can be used alone or in combination with the aforementioned oxides are, for example, ZrO2 or B2O3. Preferred oxides are silicon dioxide, particularly in the form of silica gel or a pyrogenic silica, aluminum oxide or mixed oxides of silicon and aluminum. A preferred mixed oxide is, for example, calcined hydrotalcite. Preference is also given to the use of silica of the formula SiO2·a Al2O3, where a is from 0 to 2, preferably from 0 to 0.5.The particles of particulate solids can be in granular form, or the particles are in spray-dried form, in which the particulate solid particles are composed of much smaller primary particles, which have, for example, an average particle diameter of 5 nm to 5 μm.

[0062] The particulate solid having chemical groups on its surface that are reactive with the organometallic compound is preferably constructed of particles having an average particle diameter in the range of 50 µm to 10 mm, more preferably from 200 µm to 5 mm. The solid Petition 870230100510, dated 11 / 14 / 2023, p. 32 / 49 / 31 particulate matter preferably has a specific surface area in the range of 200 m2 / g to 1000 m2 / g, more preferably 500 m2 / g to 800 m2 / g determined by gas adsorption according to the BET method as specified in ISO 9277:2010.

[0063] The chemical groups on the surface of the particulate solid that are reactive with the organometallic compound are preferably OH groups, adsorbed water or, in particular for calcined solids, expanded Si-OSi bridges.

[0064] Upon reacting with the organometallic compound, the reactive chemical groups on the surface of the particulate solid are consumed. Consequently, the zone within the particulate solid bed in which a reaction of the organometallic compound with the reactive surface groups occurs moves through the particulate solid bed. Preferably, the particulate solid bed is replaced by a new particulate solid bed that has chemical groups on its surface that are reactive with the organometallic compound before all the reactive groups on the surface of the particulate solid bed that is passed through the gas stream removed from the polymerization apparatus have reacted with the organometallic compound.

[0065] In preferred embodiments of the present disclosure, the particulate solid having chemical groups on its surface that are reactive with the organometallic compound is a silica gel equipped with a humidity indicator. By passing the gas stream from the polymerization apparatus through a bed of silica gel particles equipped with a humidity indicator, the organometallic compound can react with the usually colored humidity indicator and change the color of the silica gel particles. This allows for easy monitoring of the consumption of the reactive surface groups by reaction with the organometallic compound.

[0066] In preferred embodiments of the present disclosure, the gas stream withdrawn from the polymerization apparatus is a gas stream Petition 870230100510, dated 11 / 14 / 2023, p. 33 / 49 / 31 continuous flow that is removed from the polymerization apparatus at a flow rate of 1 Nl / ha 5000 Nl / h, preferably 1 Nl / ha 500 Nl / h, more preferably 5 Nl / ha 350 Nl / h, and in particular 10 Nl / ha 250 Nl / h. The unit “Nl” should be understood as a standard liter, which is the quantity of a gas with a volume of one liter under standard conditions of 101,325 Pa (= 1.01325 bar) and 0 °C.

[0067] In preferred embodiments of the present disclosure, the gas stream sample is supplied to the analyzer at intervals.

[0068] In preferred embodiments of the present disclosure, two or more, for example two, three, four or five gas streams are withdrawn from the polymerization apparatus at different positions, and samples of some or all of the two or more gas streams are subsequently fed to an analyzer to analyze the sample, or some or all of the two or more gas streams have a dedicated analyzer to which only samples of one of the gas streams withdrawn from the polymerization apparatus are provided.

[0069] To analyze a material composition in a polymerization apparatus according to the present disclosure, a gas stream is withdrawn from the polymerization apparatus. The gas stream is preferably transported to a sampling circuit located near or preferably within the analyzer, such as a gas chromatograph. The sampling circuit provides a defined volume of a gas sample which is then transferred, for example, by an inert carrier gas, to the analysis unit. The analyzer is normally calibrated so that the sum of all measured components is 100%. However, it has been found that when withdrawing the gas stream from a polymerization apparatus in which olefin polymerization is performed in the presence of a polymerization catalyst and an organometallic compound, this calibrated value is not stable and the measured sum of all components continuously decreases. It was Petition 870230100510, dated 11 / 14 / 2023, pp. 34 / 49 / 31, found that due to fine solid particles accumulating within the sample circuit, the sample circuit volume slowly decreases, so the volume dosed in the analyzer decreases and the analysis values ​​are distorted. The more the measured sum of the components deviates from 100%, the less accurate the measurement becomes. It was also found that recalibrating the analyzer allows the measured sum of the components to return to 100%; however, after each recalibration, the period until an intolerable deviation is reached becomes increasingly shorter. After five to ten recalibrations of the analyzer, cleaning the sample circuit and sampling valve is inevitable. During this cleaning, the analyzer can no longer be used.Since running polymerization in the polymerization apparatus without control can result in polymer products that no longer meet a specified property profile or can cause serious process incidents, such uncontrolled operation of the polymerization apparatus is commonly avoided. Consequently, it may be necessary to suspend polymerization in the polymerization apparatus during cleaning, resulting in production loss, or a spare analyzer must be present, requiring additional effort.

[0070] Passing the gas stream from the polymerization apparatus through a particulate solid bed with chemical groups on its surface that are reactive with the organometallic compound prevents the accumulation of fine solid particles within the analyzer's sampling device, and the measured sum of all components remains stable. By passing the gas stream through a particulate solid bed with chemical groups on its surface that are reactive with the organometallic compound, the concentration of the organometallic compound in the gas stream exiting the particulate solid bed is preferably less than 99%, more preferably less than 99.5%, even more preferably less than 99.8%, and in particular less than 99.9% of the compound's concentration. Petition 870230100510, dated 11 / 14 / 2023, page 35 / 49 / 31 organometallic in the gas stream removed from the polymerization apparatus.

[0071] The particulate solid bed having chemical groups on its surface that are reactive with the organometallic compound is preferably contained in a vessel having a volume of 50 cm3 to 10,000 cm3, preferably 100 cm3 to 5,000 cm3, and most preferably 200 cm3 to 2,500 cm3.

[0072] Figure 2 schematically shows a vessel for containing a bed of particulate solid according to the present disclosure.

[0073] The vessel comprises a vertical tube (101) having flanges (102) and (103) at the top and bottom. Attached to the flange (102) is a first short tube element (104) comprising a ball valve (105) for filling the tube (101) with the particulate solid bed having chemical groups on the surface that are reactive with the organometallic compound, such as silica. Attached to the flange (103) is a second short tube element (106) comprising a ball valve (107) for emptying the tube (101).

[0074] The vertical tube (101) is fitted with a short horizontal tube (108) terminating with a flange (109) near the upper end of the tube (101) and is fitted with a short horizontal tube (110) terminating with a flange (111) near the lower end of the tube (101). A thinner tube (112) for feeding a gas stream into the tube (101) is attached to the flange (111); and a thinner tube (113) is attached to the flange (109) for removing the gas stream from the tube (101) after passing through the tube (101). To retain the particulate solid bed within the tube (101), the connection between the flange (111) and the tube (112) and the connection between the flange (109) and the tube (113) are fitted with screens (114) and (115) made of steel.

[0075] In preferred embodiments of the present disclosure, the particulate solid bed is contained in a vessel comprising a pipe having a diameter of 6 mm to 100 mm, preferably 10 mm to 80 mm and, in Petition 870230100510, dated 11 / 14 / 2023, p. 36 / 49 / 31 particular, from 15 mm to 50 mm, which has an inlet to introduce a gas stream into the pipe and an outlet to remove a gas stream from the pipe, wherein the distance between the inlet and the outlet is 0.2 m × 10 m, preferably 0.3 m × 5 m, and in particular 0.4 m × 2 m.

[0076] The vessel further preferably comprises a first valve at one end of the pipe for introducing the particulate solid bed into the pipe and a second valve at the other end of the pipe for removing the particulate solid bed from the pipe. In preferred embodiments, the inlet and outlet of the pipe are preferably fitted with screens having a mesh size of 35 µm to 2 mm, preferably 50 µm to 1.5 mm and, in particular, 100 µm to 1 mm to retain the particulate solid bed inside the pipe. In especially preferred embodiments, the vessel comprises a first and a second valve at the ends of the pipe and the inlet and outlet of the pipe are fitted with screens.

[0077] In one embodiment, the present disclosure consequently also provides a vessel comprising a pipe having a diameter of 6 mm to 100 mm, preferably 10 mm to 80 mm, and in particular 15 mm to 50 mm, an inlet for introducing a gas stream into the pipe, an outlet for removing a gas stream from the pipe and a first valve at one end of the pipe for introducing a bed of particulate solid into the pipe and a second valve at the other end of the pipe for removing the bed of particulate solid from the pipe, wherein the inlet and outlet of the pipe are provided with screens having a mesh size of 35 µm to 2 mm, preferably 50 µm to 1.5 mm, and in particular 100 µm to 1 mm and the distance between the inlet and outlet is 0.2 m to 10 m, preferably 0.3 m to 5 m, and in particular 0.4 m to 2 m.

[0078] In preferred embodiments of the polymerization process of the present disclosure, the results obtained from the analysis of the gas samples are fed as measurement signals to a controller to control the Petition 870230100510, dated 11 / 14 / 2023, page 37 / 49 / 31 olefin polymer preparation process.

[0079] In one embodiment, the present disclosure also provides a method for controlling an olefin polymerization process, characterized in that it comprises homopolymerizing an olefin or copolymerizing an olefin and one or more other olefins at temperatures of 20 to 200 °C and pressures of 0.1 MPa to 20 MPa in the presence of a solid particulate polymerization catalyst and an organometallic compound in a polymerization apparatus comprising a polymerization reactor or a combination of polymerization reactors, wherein the method comprises, - withdrawing a gaseous stream from the polymerization apparatus; - passing the gas stream through a bed of particulate solid that has chemical groups on its surface that are reactive with the organometallic compound; - Feeding a sample of the gas stream into an analyzer to analyze the gas sample; - Analyze the sample and obtain information about the conditions inside the polymerization apparatus; and - Adapt, based on the information obtained from the sample analysis, the polymerization conditions within the polymerization apparatus to predefined values.

[0080] The present disclosure, therefore, also provides a process for preparing an olefin polymer comprising such a method for controlling the polymerization process of olefins.

[0081] The results obtained from the analysis of gas stream samples provide information about the conditions inside the polymerization apparatus. This data can be used, on the one hand, to define the polymerization conditions for certain grades or conditions and, on the other hand, to adapt the measured polymerization conditions to predefined values. Such adaptations can be performed manually by a Petition 870230100510, dated 11 / 14 / 2023, page 38 / 49 / 31 operator or automated. In preferred embodiments of the present disclosure, the results obtained by analyzing samples of the gas stream are fed as measurement signals to a controller to control the olefin polymerization process. Examples Comparative example A

[0082] In a series of fluidized bed reactors and multi-zone circulating reactors (MZCRs) having two interconnected reaction zones as shown in Figure 1, various grades of ethylene 1-hexene copolymer having a 1-hexene content in the range of 0 wt% to 4 wt% were produced with an average output of 100 kg / h at temperatures in the range of 60 °C to 110 °C and pressures of 1 MPa to 10 MPa. The catalytic system to carry out the polymerizations was a Ziegler-Natta catalytic system comprising a solid catalyst prepared by supporting TiCl4 in a MgCl2 carrier. Tri-isobutylaluminum was employed as a cocatalyst and fed into the polymerizations at feed rates in the range of 25 g / ha to 50 g / h.

[0083] Polymerizations were controlled by measuring the gas compositions in the fluidized bed reactor (1) and in the riser (22) and downpipe (23) of the multi-zone circulating reactor (21) by withdrawing the reaction gas through sampling lines (15), (55) and (56) and transferring the gases to a MAXUM Edition II gas chromatograph (Siemens AG, Nuremberg, Germany; not shown in Figure 1). The gas chromatograph was fed alternately with reaction gas through lines (15), (55) and (56). After selecting the polymerization zone to determine the reaction gas composition and therefore the appropriate sampling line, the reaction gas was continuously withdrawn through one of the sampling lines (15), (55) and (56), passed first through a 15 µm particle inline filter (Swagelok Company, Solon, Ohio, USA) to Petition 870230100510, dated 11 / 14 / 2023, page 39 / 49 / 31 to protect the gas chromatograph from fine particles and subsequently through a pressure reducer that reduced the pressure to 0.17 MPa (abs). The reaction gas flow rates, measured after the pressure reducer at 0.17 MPa, were 30 Nl / h for all selected sampling lines (15), (55) and (56). In the spatial proximity of the gas chromatograph, a side stream with a flow rate of 5 Nl / h was branched and fed to a sample valve comprising an injection circuit, while the remainder of the reaction gas was withdrawn through lines (15), (55) and (56) and transported to the outlet gas.The operation of the sampling lines (15), (55) and (56) with a reaction gas flow rate higher than the flow rate of the gas actually fed into the sampling valve was selected to reduce the dead time between the withdrawal of a gas from the polymerization apparatus and finally introducing this gas into the gas chromatograph.

[0084] To perform the measurement, the position of the sampling valve was changed and the injection circuit, which had previously been passed through the reaction gas to be analyzed, was integrated into a carrier gas line and the contents of the injection circuit were then transferred to the gas chromatograph by the carrier gas. To perform a subsequent GC chromatogram, the sampling valve was placed back in a position where the injection circuit was again passed through the reaction gas to be analyzed. Washing of the injection circuit with reaction gas continued for at least 1 minute before the injection circuit was again integrated into the carrier gas stream. On average, the gas chromatograph operated at a recording rate of 20 gas chromatographs per hour.

[0085] It was observed that the sum of all measured components regularly decreased, eventually requiring cleaning of the injection circuit and sample valve. After this cleaning operation, the gas chromatograph was calibrated so that the sum of all measured components was 100%. This value was not stable; the sum of all the Petition 870230100510, dated 11 / 14 / 2023, page 40 / 49 / 31 measured components decreased continuously. After two weeks, the sum of all measured components was below 80%, drastically decreasing the accuracy of the GC measurement. By recalibrating the gas chromatograph, the sum of all measured components could be reset to 100%, and the gas chromatograph could be used with sufficient accuracy for another 10 days until the still continuous decrease in the sum of all measured components fell below 80% again, requiring further recalibration. One week later, the sum of all measured components was again below 80%.To avoid further reduction in the time period with acceptable GC measurement accuracy, polymerization was stopped, the gas chromatograph was disassembled, and the injection circuit and sample valve were cleaned. Subsequently, polymerization was resumed, resulting, on average, in a two-day interruption of polymerization. Example 1

[0086] The polymerization sequence performed in Comparative Example A was continued, on average, under the same conditions, but a vessel containing a silica bed as shown in Figure 2 was installed in the sampling line between the pressure reducer and the position where the flow to the gas chromatograph sample valve was branched. The vessel comprised a tube (101) having an internal diameter of 25 mm and a length of 850 mm from flange (102) to flange (103). The vessel was filled with silica equipped with a moisture indicator (Orange Silica Gel, 2-5 mm, with indicator, beads, Carl Roth GmbH + Co. KG, Karlsruhe, Germany). Screens (114) and (115) were selected to be 20 mesh screens (mesh size 850 μm).

[0087] Polymerizations were carried out over 4 weeks, but the sum of all measured components remained above 99% throughout the period. After 4 weeks, polymerization was stopped and the Petition 870230100510, dated 11 / 14 / 2023, page 41 / 49 / 31 vessel (101) was emptied. About a quarter of the silica changed color from orange to dark brown. Example 2

[0088] Example 1 was repeated with fresh silica. Polymerizations were carried out over 3 months. The sum of all measured components decreased to 95%, still allowing for highly precise polymerization control. After that, the silica bed was removed from the vessel (101). A smaller portion of the silica had not yet changed from orange to dark brown. Example 3

[0089] Example 2 was repeated, but a different silica equipped with a moisture indicator was used (Orange Silica Gel, granular, 0.2-1 mm, Sigma-Aldrich, Merck KGaA, Darmstadt, Germany) and the screens (114) and (115) were 100 mesh screens (mesh size 150 μm).

[0090] The sum of all measured components decreased to 96%, still allowing control of the polymerization with high precision. Emptying the vessel (101) after 3 months showed that most of the silica had turned dark brown, but a smaller portion was still orange.

[0091] Examples 1 to 3 demonstrate that by installing a particulate solid bed that has chemical groups on its surface that are reactive with organometallic compounds, it is possible to operate a gas chromatograph in an olefin polymerization plant in the presence of an alkyl aluminum cocatalyst with high precision without the need to repeatedly clean the gas chromatograph dosing equipment and / or recalibrate the gas chromatograph. Petition 870230100510, dated 11 / 14 / 2023, pp. 42 / 49

Claims

1 / 4 CLAIMS 1. Process for preparing an olefin polymer, comprising: feeding a solid particulate polymerization catalyst, an organometallic compound and an olefin or a combination of an olefin and one or more other olefins into a polymerization apparatus comprising a polymerization reactor (1, 21) or a combination of polymerization reactors (1, 21), homopolymerizing the olefin or copolymerizing the olefin and one or more other olefins at temperatures of 20 °C to 200 °C and pressures of 0.1 MPa to 20 MPa in the presence of the polymerization catalyst and the organometallic compound, withdrawing a gas stream from the polymerization apparatus, characterized in that said process further comprises the steps of: passing the gas stream through a bed of particulate solid having on its surface chemical groups that are reactive with the organometallic compound,and feed a sample of the gas stream into an analyzer to analyze the gas sample, wherein the organometallic compound is an aluminum alkyl and the chemical groups on the surface of the particulate solid that are reactive with the organometallic compound are OH groups, adsorbed water or expanded Si-O-Si bridges, and wherein the results obtained by analyzing the gas samples are fed as measurement signals to a controller to control the process for preparing the olefin polymer.

2. Process according to claim 1, characterized in that the analyzer is a gas chromatograph.

3. Process according to any of the claims in Petition 870260057121, dated 12 / 06 / 2026, page 11 / 18 2 / 4 above, characterized in that the particulate solid is an oxide or a mixed oxide of the elements calcium, aluminum, silicon, magnesium or titanium, or the particulate solid is ZrO2 or B2O3.

4. A process according to any of the preceding claims, characterized in that the particulate solid is a silica gel equipped with a moisture indicator.

5. Process according to any of the preceding claims, characterized in that the gas stream withdrawn from the polymerization apparatus is a continuous gas stream that is withdrawn from the polymerization apparatus at a flow rate of 1 Nl / ha 5000 Nl / h.

6. Process according to any of the preceding claims, characterized in that the gas stream withdrawn from the polymerization apparatus is a continuous gas stream that is withdrawn from the polymerization apparatus at a flow rate of 1 Nl / ha 500 Nl / h.

7. A process according to any of the preceding claims, characterized in that the sample of the gas stream is supplied to the analyzer at intervals.

8. A process according to any of the preceding claims, characterized in that two or more gas streams are withdrawn from the polymerization apparatus at different positions, and samples of some or all of the two or more gas streams are subsequently fed to an analyzer for sample analysis, or some or all of the two or more gas streams have a dedicated analyzer to which only samples of one of the gas streams withdrawn from the polymerization apparatus are provided.

9. A process according to any of the preceding claims, characterized in that the bed of particulate solid is contained in a vessel with a volume of 50 cm3 to 10000 cm3.

10. Process according to claim 9, characterized in Petition 870260057121, dated 12 / 06 / 2026, p. 12 / 18 3 / 4 by the fact that the particulate solid bed is contained in a vessel comprising a pipe (101) having a diameter of 6 mm to 100 mm, an inlet (112) for introducing a gas stream into the pipe (101) and an outlet (113) for removing a gas stream from the pipe (101), and wherein the distance between the inlet (112) and the outlet (113) is 0.2 m to 10 m.

11. Process according to claim 9 or 10, characterized in that the vessel further comprises a first valve (105) at one end of the pipe (101) for introducing the particulate solid bed into the pipe (101) and a second valve (107) at the other end of the pipe for removing the particulate solid bed from the pipe (101), and / or the inlet (112) and outlet (113) of the pipe (101) are provided with screens (114, 115) having a mesh size of 35 µm to 2 mm for retaining the particulate solid bed inside the pipe (101).

12. Vessel, as defined in claim 9, characterized in that it comprises a pipe (101) having a diameter of 6 mm to 100 mm, an inlet (112) for introducing a gas stream into the pipe (101), an outlet (113) for removing a gas stream from the pipe (101) and a first valve (105) at one end of the pipe (101) for introducing a bed of particulate solid into the pipe (101) and a second valve (107) at the other end of the pipe (101) for removing the bed of particulate solid from the pipe (101), wherein the inlet (112) and the outlet (113) of the pipe (101) are provided with screens (114, 115) with a mesh size of 35 µm to 2 mm and the distance between the inlet (112) and the outlet (113) is 0.2 m to 10 m.

13. Method for controlling an olefin polymerization process as defined in claim 1, characterized in that it comprises homopolymerizing an olefin or copolymerizing an olefin and one or more other olefins at temperatures of 20 to 200 °C and pressures of 0.1 MPa to 20 MPa in the presence of a solid particulate polymerization catalyst and an organometallic compound in a polymerization apparatus that Petition 870260057121, dated 12 / 06 / 2026, p.13 / 18 4 / 4 comprises a polymerization reactor (1, 21) or a combination of polymerization reactors (1, 21), wherein the method comprises: - withdrawing a gas stream from the polymerization apparatus; - passing the gas stream through a bed of particulate solid having on its surface chemical groups that are reactive with the organometallic compound, wherein the organometallic compound is an aluminum alkyl and the chemical groups on the surface of the particulate solid that are reactive with the organometallic compound are OH groups, adsorbed water or expanded Si-O-Si bridges; - feeding a sample of the gas stream into an analyzer to analyze the gas sample; - analyzing the sample and obtaining information about the conditions inside the polymerization apparatus; and - adapting, based on the information obtained from the sample analysis, the polymerization conditions inside the polymerization apparatus to predefined values. Petition 870260057121, dated 12 / 06 / 2026, pp. 14 / 18.

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