Abstract: The present invention relates to a process to monitor unwanted formation of a polymer having internal mechanical strain wherein acoustic emission generated by said polymer formation is detected by one or more acoustic sensors attached to a piece of equipment. In a preferred embodiment the device to carry-out the process comprises: a resonant piezo-electric transducer attached to a piece of equipment, optionally a conditioner unit, connected to the previous transducer, said conditioner unit comprising means for filtering and an operational preamplifier, optionally a unit, connected to said conditioner unit, in which there is at least one adjustable threshold level (unless the conditioner unit comprises said adjustable threshold level), optionally a pulse counter connected to the conditioner unit comprising at least one adjustable threshold level. The invention is particularly useful for monitoring the unwanted popcorn polymers made from butadiene or isoprene.

Abstract: A process is provided for recovering polymer solids from a polymerisation reactor effluent. The process comprises extracting the polymerisation effluent from a polymerisation reactor; passing the effluent, or a part thereof, to a flash vessel for flashing liquid in the effluent to vapour, and removing said vapour from said flash vessel; passing the polymer solids from the flash vessel to a transfer apparatus which comprises a transfer vessel; passing the polymer solids from the transfer vessel to a purging means for removing residual liquid from the polymer solids; wherein the polymer solids are passed from the flash vessel to the purging means in a continuous flow such that a quantity of polymer solids is maintained in the transfer vessel. An apparatus for performing the process is also provided.

Abstract: The present invention discloses the use of a chromium-based catalyst system in two serially connected loop reactors for copolymerising ethylene and a comonomer, at reduced productivity, the final polyethylene having a reduced amount of gel.

Abstract: The present invention discloses a slurry loop reactor having at least two loops (1, 2) and comprising a by-pass line (11) connecting two points (12, 13) of the same loop reactor by an alternate route having a different transit time than that of the main route, said by-pass line also collecting the growing polymer of a first loop reactor (1) and sending said growing polymer to an entry point (13) in a second reactor (2).

Abstract: Methods for polymerization of an olefin monomer and polymers formed therefrom are described herein.

Abstract: The present invention relates to a process for the selective production of olefins from light hydrocarbons comprising: a) fractionating a butane fraction in a de-isobutanizer to obtain an enriched iso-butane fraction and an enriched normal-butane fraction, b) cracking said normal-butane fraction and optionally an ethane fraction, optionally a propane fraction, in a non-catalytic cracking zone to produce an olefin rich stream, preferably the ethane fraction, if any, the propane fraction, if any, and normal-butane fractions are cracked in separate non-catalytic cracking zones, c) treating said olefin rich stream in a separating section comprising: removing hydrogen and methane, recovering an ethylene stream, recovering an ethane stream and recycling said stream to the cracking zone, recovering a propylene stream, recovering a propane stream, optionally recycling said stream to the cracking zone, recovering a C4 stream, removing the heavies, d) selectively hydrogenating the dienes and alkynes in the C4 strea

Abstract: This invention relates to the fluorinated dialkoxy-diimine metal complexes and their use in catalyst system for the polymerisation or oligomerisation of ethylene and alpha-olefins.

Abstract: Provided is a method for the production of an olefin polymer, which method comprises polymerizing an olefin monomer in the presence of a metallocene catalyst, which catalyst comprises one or more alkyl moieties having a terminal olefin group, and is selected from a catalyst of formula (I): R? (CpRq)XMQp wherein Cp is a substituted or unsubstituted cyclopentadienyl or fluorenyl ring; R? is a structural bridge between Cp and X imparting stereorigidity to the component; each R is the same or different and is selected from a hydrocarbyl group having from 1-20 carbon atoms, a halogen, an alkoxy group, an alkoxyalkyl group, an alkylamino group or an alkylsilylo group; q is an integer from 0-8; X is a heteroatom from group VA or group VIA; M is a metal atom from group 11113, IVB, VB or VIB in any of its theoretical oxidation states; and each Q is a hydrocarbon having from 1-20 carbon atoms or is a halogen; p is an integer which is the oxidation state of M minus 2; wherein the alkyl moiety having a terminal olefin gr

Abstract: The present invention relates to a polymerization process for producing olefin polymers in a loop reactor comprising the steps on introducing into the loop reactor one or more olefin reactants, polymerization catalysts and diluents, and while circulating said reactants, catalysts and diluents, polymerizing said one or more olefin reactants to produce a polymer slurry comprising essentially liquid diluent and solid olefin polymer particles, said process further comprising one or more cycles of: (a) allowing said polymer slurry to settle in one or more setting legs connected to said reactor, and (b) discharging from a setting leg a predetermined volume of polymer slurry substantially equal to the volume of polymer slurry settled in said settling leg since its previous discharge.

Abstract: The present invention relates to a process for reducing residuals content in a vinyl aromatic polymer, said residuals comprising essentially unpolymerized vinyl aromatic monomer, wherein the vinyl aromatic polymer in the molten state is brought in contact with a solid in powder capable to catalyze the alkylation of said residual vinyl aromatic monomer on the vinyl aromatic polymer. Advantage of the present invention is a sharp reduction of the unpolymerized vinyl aromatic monomer in the vinyl aromatic polymer without generating a new residual and without inducing a colored vinyl aromatic polymer. The present invention also relates to said vinyl aromatic polymer having a low residuals content.

Abstract: A process for producing polylactide-urethane copolymers, which comprises the step of contacting a polylactide having terminal hydroxyl groups, produced by contacting at least one lactide monomer with a diol or diamine, with a diisocyanate compound optionally in the presence of a second diol or diamine in the presence of a catalytic system under polymerisation conditions characterised in that the polylactide and the polylactide-urethane copolymers are produced by reactive extrusion.

Abstract: The present invention relates to a process for the production of polypropylene fibers and polypropylene spunbond nonwoven comprising a degradation step, wherein the melt flow of the polypropylene is increased, and a fiber or filament extrusion step. The present invention also relates to the fibers and nonwoven produced with said process and to composites and laminates comprising said fibers and nonwoven.

Abstract: The present invention relates to a polymerization process for producing olefin polymers in a loop reactor comprising two or more settling legs, comprising the steps of: —introducing into the loop reactor one or more olefin reactants, polymerization catalysts and diluents, and while circulating said reactants, catalysts and diluents; —polymerizing said one or more olefin reactants to produce a polymer slurry comprising essentially liquid diluent and solid olefin polymer particles; said process further comprising one or more cycles of: (a) allowing said polymer slurry to settle into said setting legs, and (b) sequentially discharging said settled polymer slurry from said two or more settling legs out of the reactor, whereby the aggregate time of discharge of all the legs is more than 50%, preferentially more than 80% and most preferably more than 95% of the time interval between two triggerings of the same settling leg.

Abstract: The present invention discloses an olefin polymerisation process carried out in the presence of a Ziegler-Natta catalyst in two liquid full loop reactors connected in series wherein different molecular weight fractions are produced to form a polyolefin, said process being characterized in that the Ziegler-Natta catalyst has a particle size distribution d50 of less than 20 ?m and greater that 5 ?m.

Abstract: A process for converting a hydrocarbon feedstock to provide an effluent containing light olefins, the process comprising passing a hydrocarbon feedstock, the feedstock containing at least 25 wt % C5+ paraffins, through a reactor containing a crystalline silicate catalyst to produce an effluent including propylene.

Abstract: The present invention provides a process for preparing a supported chromium-based catalyst for the production of polyethylene comprising the steps of a) providing a silica-based support having a specific surface area of at least 250 m2/g and of less than 400 m2/g and comprising a chromium compound deposited thereon, the ratio of the specific surface area of the support to chromium content being at least 50000 m2/g Cr; b) dehydrating the product of step a); and c) titanating the product of step b) in an atmosphere of dry and inert gas containing at least one vaporised titanium compound of the general formula selected from RnTi(OR?)m and (RO)nTi(OR?)m, wherein R and R? are the same or different hydrocarbyl groups containing from 1 to 12 carbon atoms, and wherein n is 0 to 3, m is 1 to 4 and m+n equals 4, to form a titanated chromium-based catalyst having a ratio of specific surface area of the support to titanium content of the titanated catalyst ranging from 5000 to 20000 m2/g Ti.

Abstract: The present invention discloses catalyst components based on ferricinium ligands, their method of preparation and their use in the polymerisation of olefins.

Abstract: The present invention relates to the field of single site catalyst systems based on pyrrol-iminophenol, pyrrol-iminoalcohol or pyrrol-iminoamine complexes and suitable for oligomerising or homo- or co-polymerising ethylene and alpha-olefins.

Abstract: This invention relates to an improved method for improving the tacticity of Ziegler-Natta catalyst systems and for controlling the behaviour of the active stereospecific sites.

Abstract: The present invention discloses a metallocene catalyst system for producing polyolefins comprising: A. a hafnocene-based catalyst component suitable for producing the high molecular weight fraction of the polyolefin; B. one or more metallocene or post-metallocene components different from the component A and suitable for producing the low molecular weight fraction of the polyolefin; C. an activating agent having a low or no coordinating capability.