Abstract: Methods for operating a high pressure olefin polymerization reactor include the steps of introducing an initiator stream containing ethylene and an initiator compound through an initiator nozzle into the reactor, introducing an olefin stream containing ethylene and an optional comonomer through an olefin nozzle into the reactor, and polymerizing ethylene and optionally the comonomer in the presence of the initiator stream in the reactor under high pressure polymerization conditions to produce an ethylene polymer. The amount of ethylene in the initiator stream is from 0.01 to 2 wt. % of the amount of ethylene in the olefin stream. An injection nozzle that can be used in conjunction with the high pressure reactor also is described.

Abstract: A method of operating a polyethylene reactor system includes feeding ethylene, an optional first comonomer, a diluent, and a chromium-based catalyst to a first polymerization reactor. The method further includes contacting ethylene and the comonomer with the catalyst in the first polymerization reactor to form a first product including a first polyethylene. The method further includes feeding the first product from the first polymerization reactor to a second polymerization reactor. The method further includes contacting ethylene and a second optional comonomer with catalyst from the first reactor in the second polymerization reactor to form a second product including the first polyethylene and a second polyethylene. The method further includes controlling one or both of a molecular weight or a breadth of molecular weight distribution of the second product by adjusting a rate of hydrogen fed to one or both of the first polymerization reactor or the second polymerization reactor.

Abstract: Catalysts and catalytic processes for the synthesis of acrylic acid and other ?,?-unsaturated carboxylic acids and their salts, which are carried out in a diluent or in the absence of a diluent. In an aspect, ethylene and CO2 can be contacted with a Group 8-11 transition metal precursor compound or a Group 8-11 transition metal metalalactone compound in the presence of a metal-treated chemically-modified solid oxide (MT-CMSO) or a metal-treated solid oxide (MT-SO), to form a metal acrylate. As the catalytic activity wanes in either the presence or absence of a diluent, pressure cycling—that is, pressurizing the reaction system with CO2 and an olefin such as ethylene for a time period, releasing the pressure, then re-pressurizing with CO2 and ethylene—can rejuvenate the catalyst and restore its declining catalytic activity.

Abstract: Methods of controlling olefin polymerization reactor systems may include a) selecting n input variables, each input variable corresponding to a process condition for an olefin polymerization process; b) identifying m response variables corresponding to a measurable polymer property; c) adjusting one of more of the n input variables using the olefin polymerization reactor system and measuring each of the m response variables as a function of the input variables for olefin polymers; d) analyzing the change in each of the response variables as a function of the input variables to determine coefficients; e) calculating a Response Surface Model (RSM) for each response variable determined in step d); f) applying n selected input variables to the calculated RSM to predict one or more of m target response variables; and g) using the n selected input variables to operate the olefin polymerization reactor system and provide a polyolefin product.

Abstract: A system including a dump tank to receive a reactor product comprising a polymer and hydrocarbons, including liquid hydrocarbons, the dump tank including a vessel with a reactor product inlet, a motive gas inlet, a purge gas inlet, gas outlet(s), and a fluid outlet, the motive gas inlet for introducing a motive gas into the vessel, the purge gas inlet for introducing a purge gas into the vessel, the one or more gas outlets located at a top of the vessel and the fluid outlet located at a bottom of the vessel and fluidly connected with a dump tank fluid outlet line having a dump tank outlet valve to control flow of fluid out of the dump tank via the fluid outlet; and a strainer fluidly connected with the dump tank fluid outlet line to allow passage of liquid hydrocarbons therethrough into a hydrocarbon outlet line.

Abstract: A process is described that includes flowing a carrier fluid through a transfer line, feeding polymer pellets into the transfer line at a feed location, measuring a first pressure value of the carrier fluid at a location in the transfer line upstream of the feed location, measuring a second pressure value of the carrier fluid and polymer pellets at a downstream location in the transfer line which is downstream of the feed location, and determining a mass flow rate of the polymer pellets flowing in the transfer line based on a differential pressure between the first pressure value and the second pressure value.

Abstract: A bimodal polymer composition comprising a lower molecular weight homopolymer and a higher molecular weight copolymer wherein the bimodal polymer composition has a density of from about 0.930 gram per cubic centimeter (g/cc) to about 0.970 g/cc, a ratio of high load melt index:melt index of from about 10 to about 150 and an Environmental Stress Crack Resistance (ESCR) of from about 25 hours to about 300 hours when measured in accordance with ASTM D1693 or ASTM D2561. A chromium-catalyzed polymer composition comprising (i) a lower molecular weight homopolymer and (ii) a higher molecular weight copolymer, wherein the bimodal polymer composition has an Environmental Stress Crack Resistance (ESCR) of from about 25 hours to about 300 hours when measured in accordance with ASTM D1693 or ASTM D2561.

Abstract: Methods for making a supported chromium catalyst are disclosed, and can comprise contacting a silica-coated alumina containing at least 30 wt. % silica with a chromium-containing compound in a liquid, drying, and calcining in an oxidizing atmosphere at a peak temperature of at least 650° C. to form the supported chromium catalyst. The supported chromium catalyst can contain from 0.01 to 20 wt. % chromium, and typically can have a pore volume from 0.5 to 2 mL/g and a BET surface area from 275 to 550 m2/g. The supported chromium catalyst subsequently can be used to polymerize olefins to produce, for example, ethylene-based homopolymers and copolymers having high molecular weights and broad molecular weight distributions.

Abstract: Polymerization processes for producing ethylene-based plastomers and elastomers having densities less than 0.91 g/cm3 utilize a metallocene-based catalyst system containing a chemically-treated solid oxide. These polymerization processes can be conducted in a slurry reactor, a solution reactor, and/or a gas phase reactor. Ethylene polymers produced from the polymerization process can be characterized by a density of less than 0.91 g/cm3, a CY-a parameter of less than 0.2, and a ratio of HLMI/MI of at least 30, or a density less than 0.91 g/cm3, a CY-a parameter from 0.25 to 0.75, and a ratio of Mw/Mn from 2 to 3.

Abstract: Process for producing alpha olefins comprising contacting ethylene, a zirconium based catalyst system comprising, a hydrocarbylmetal compound, a chain transfer agent, and optionally an organic reaction medium. Chain transfer agents which can be utilized include a) hydrogen, b) a compound comprising a hydrogen silicon bond, a compound having a hydrogen sulfur bond, a compound having a hydrogen phosphorus bond, or c) a transition metal compound chain transfer agent.

Abstract: Ethylene-based polymers are characterized by a density from 0.92 to 0.955 g/cm3, a HLMI of less than 35 g/10 min, and a ratio of a number of short chain branches (SCBs) per 1000 total carbon atoms at Mz to a number of SCBs per 1000 total carbon atoms at Mn in a range from 11.5 to 22. These polymers can have a higher molecular weight (HMW) component and a lower molecular weight (LMW) component, in which a ratio of a number of SCBs per 1000 total carbon atoms at Mn of the HMW component to a number of SCBs per 1000 total carbon atoms at Mn of the LMW component is in a range from 10.5 to 22. These ethylene polymers can be produced using a dual catalyst system containing an unbridged metallocene compound with an indenyl group having at least one halogen-substituted hydrocarbyl substituent with at least two halogen atoms, and a single atom bridged metallocene compound with a fluorenyl group and a cyclopentadienyl group.

Abstract: Catalysts and method of preparing the catalysts are disclosed. One of the catalysts includes a zeolite support, a Group VIII metal on the zeolite support, and at least two halides bound to the zeolite support, to the Group VIII metal, or to both, and can have an average crush strength greater than 11.25 lb based on at least two samples of pellets of the catalyst measured in accordance with ASTM D4179.

Abstract: Catalyst compositions containing a metallocene compound, a solid activator, and a co-catalyst, in which the solid activator or the supported metallocene catalyst has a d50 average particle size of 15 to 50 ?m and a particle size distribution of 0.5 to 1.5, can be contacted with an olefin in a loop slurry reactor to produce an olefin polymer. A representative ethylene-based polymer produced using the catalyst composition has excellent dart impact strength and low gels, and can be characterized by a HLMI from 4 to 10 g/10 min, a density from 0.944 to 0.955 g/cm3, a higher molecular weight component with a Mn from 280,000 to 440,000 g/mol, and a lower molecular weight component with a Mw from 30,000 to 45,000 g/mol and a ratio of Mz/Mw ranging from 2.3 to 3.4.

Abstract: Disclosed are ethylene polymer compositions containing a homogeneously-branched first ethylene polymer component and 15-35 wt. % of a homogeneously-branched second ethylene polymer component of higher density than the first ethylene polymer component. The ethylene polymer composition can be characterized by a density from 0.912 to 0.925 g/cm3, a ratio of Mw/Mn from 2 to 5, a melt index less than 2 g/10 min, and a CY-a parameter at 190° C. from 0.35 to 0.7. These polymer compositions have the excellent dart impact strength and optical properties of a metallocene-catalyzed LLDPE, but with improved machine direction tear resistance, and can be used in blown film and other end-use applications. Further, methods for improving film Elmendorf tear strength also are described.

Abstract: A naphtha reforming reactor system comprising a first reactor comprising a first inlet and a first outlet, wherein the first reactor is configured to operate as an adiabatic reactor, and wherein the first reactor comprises a first naphtha reforming catalyst; and a second reactor comprising a second inlet and a second outlet, wherein the second inlet is in fluid communication with the first outlet of the first reactor, wherein the second reactor is configured to operate as an isothermal reactor, and wherein the second reactor comprises a plurality of tubes disposed within a reactor furnace, a heat source configured to heat the interior of the reactor furnace; and a second naphtha reforming catalyst disposed within the plurality of tubes, wherein the first naphtha reforming catalyst and the second naphtha reforming catalyst are the same or different.

Abstract: A bi-modal radial flow reactor comprising a cylindrical outer housing surrounding at least five cylindrical, concentric zones, including at least three annulus vapor zones and at least two catalyst zones. The at least two catalyst zones comprise an outer catalyst zone and an inner catalyst zone. The at least three annulus vapor zones comprise an outer annulus vapor zone, a middle annulus vapor zone, and a central annulus vapor zone, wherein the central annulus vapor zone extends along a centerline of the bi-modal radial flow reactor. The outer catalyst zone is intercalated with the outer annulus vapor zone and the middle annulus vapor zone, and the inner catalyst zone is intercalated with the middle annulus vapor zone and the central annulus vapor zone. A removable head cover can be fixably coupled to a top of the cylindrical outer housing to seal a top of the bi-modal radial flow reactor.

Abstract: Disclosed herein are processes and reaction systems for controlling a temperature of an oligomerization reaction zone using a heat exchange system.

Abstract: A process includes periodically or continuously introducing an olefin monomer and periodically or continuously introducing a catalyst system or catalyst system components into a reaction mixture within a reaction system, oligomerizing the olefin monomer within the reaction mixture to form an oligomer product, and periodically or continuously discharging a reaction system effluent comprising the oligomer product from the reaction system. The reaction system includes a total reaction mixture volume and a heat exchanged portion of the reaction system comprising a heat exchanged reaction mixture volume and a total heat exchanged surface area providing indirect contact between the reaction mixture and a heat exchange medium. A ratio of the total heat exchanged surface area to the total reaction mixture volume within the reaction system is in a range from 0.75 in?1 to 5 in?1, and an oligomer product discharge rate from the reaction system is between 1.0 (lb)(hr?1)(gal?1) to 6.0 (lb)(hr?1)(gal?1).

Abstract: A closed-loop nitrogen transport system including a first transfer line configured for nitrogen pressure conveyance of a polymer fluff from at least one upstream vessel to at least one downstream vessel, a second transfer line configured to return a nitrogen gas stream comprising primarily nitrogen from the at least one downstream vessel to the at least one upstream vessel, a conveyor blower operable to provide flow throughout the closed loop, and a treatment unit operable to remove hydrocarbons from at least a portion of the nitrogen gas stream comprising primarily nitrogen, to provide a purified nitrogen stream.

Abstract: This disclosure relates to the production of chemicals and plastics using pyrolysis oil from the pyrolysis of plastic waste as a co-feedstock along with a petroleum-based, fossil fuel-based, or bio-based feedstock. In an aspect, the polymers and chemicals produced according to this disclosure can be certified under International Sustainability and Carbon Certification (ISCC) provisions as circular polymers and chemicals at any point along complex chemical reaction pathways. The use of a mass balance approach which attributes the pounds of pyrolyzed plastic products derived from pyrolysis oil to any output stream of a given unit has been developed, which permits ISCC certification agency approval.