Abstract: Method for switching between steady-state and non-steady-state operations of a process for the production of a polymer by polymerization of a monomer in the presence of a comonomer and/or hydrogen. The process includes (a1) at non-steady-state controlling the process based on the ratio of comonomer to monomer in the reactor, and (b1) at steady-state controlling the process based on the flow ratio of comonomer to monomer to the reactor, and/or (a2) at non-steady-state controlling the process based on the ratio of hydrogen to monomer in the reactor, and (b2) at steady-state controlling the process based on the flow ratio of hydrogen to monomer to the reactor.

Abstract: Polymerization process for the polymerization of monomer in a polymerization system having at least one component attached thereto which component is flushed with a flush medium which enters the polymerization system. Initially, the component is flushed with a first flush medium, and subsequently the component is flushed with a second flush medium.

Abstract: A catalytic composition useful for the conversion of an olefin selected from the group consisting of propylene, isobutylene or mixtures thereof, to acrylonitrile, methacrylonitrile, and mixtures thereof. The catalytic composition comprises a complex of metal oxides comprising rubidium, bismuth, cerium, molybdenum, iron and other promoters, with a desirable composition.

Abstract: Petrochemical complex containing an olefin monomer polymerization plant having at least one polymerization reactor and an optional degassing section. The polymerization reactor contains process hydrocarbons consisting of the monomer, the optional comonomer(s) and optionally at least one inert hydrocarbon diluent, together with aluminum containing compound(s). The polymerization plant includes liquid purge stream(s) which contain aluminum containing compounds and optionally polymer fines, together with accumulated hydrocarbons which are different from the process hydrocarbons and which are hydrocarbons containing at least 4 carbon atoms. The petrochemical complex also contains a multipurpose hydrocarbon treatment unit which separates the liquid purge stream(s) into one stream having substantially all of the aluminum containing compounds and optional polymer fines, and one stream containing the accumulated hydrocarbons.

Abstract: Polymerization unit for producing polymer powder having at least one polymerization reactor for the polymerization of light (co)monomer(s) having less than 7 carbon atoms, and heavy comonomer(s) having at least 7 carbon atoms, and a degassing section including two (and optionally a third) cylindrical degassing vessels in series. Light (co)monomer(s) are degassed in the first degassing vessel (V1) and recovered, and heavy comonomers are degassed in the second degassing vessel (V2) and recovered. The active polymer powder is optionally polished and/or optionally deactivated in the optional third degassing vessel (V3). The cross-sectional area (S2) of the second degassing vessel is greater than 1.5 times the cross-sectional area (S1) of the first degassing vessel [S2>1.5×S1], and vessels V1 and V2 are equipped with a vent recovery unit (VR) for respectively recovering the light (co-)monomer(s) (VR1) and the heavy comonomer(s) (VR2) from the gases exiting the vessels.

Abstract: Injection molded article made from a composition containing 81-88 wt % of a propylene homopolymer (A) having a melt flow rate of between 1 and 2 g/10 min, 12-19 wt % of a propylene-ethylene copolymer (B) containing 45-65 wt % of ethylene, and 50-10000 ppm by weight of a nucleating agent. The total ethylene content of the composition is 6-10 wt %, and the melt flow rate (MFR) of the composition is 0.7-2 g/10 min.

Abstract: Silica supported catalyst composition useful in olefin polymerization, having a SiO2 content not more than 70 weight %, a transition metal (M) content between 2.5 and 9.1 weight %, a magnesium content between 0.5 and 3.3 weight %, an aluminium content between 0.3 and 5 weight % and a chlorine content between 5 and 30 weight %. The silica support has, prior to addition of catalytically active ingredients, a residual surface hydroxyl content between 0.6 and 2 mmole/g of silica, and the molar ratio of transition metal (M) to magnesium is between 0.3 and 2.5.

Abstract: Process for the polymerization of olefins in a polymerization reactor system including (i) a gas phase reactor having a gas outlet and one or more withdrawal lines for withdrawal of a polymer-containing stream, (ii) a recycle loop for recycling gas exiting the reactor through the gas outlet back to the reactor, (iii) a polymer separation system for separating reactants from the polymer product in the withdrawn polymer-containing stream, and (iv) a recycle system for recycling reactants removed from the reactor in the withdrawn polymer-containing stream back to the reactor. A scavenger is introduced directly into one or more of the recycle loop, the polymer separation system and the recycle system.

Abstract: Process for polymerizing olefins in a polymerization reactor system including at least first and second introduction points by which the same reaction component may be introduced directly at different locations on the reactor system. At a first time, the reaction component is introduced through at least the first introduction point, such that a proportion X of the reaction component which is introduced through the first and second introduction points is introduced through the first introduction point. At a second, later, time the same reaction component is introduced through at least the second introduction point and such that a proportion Y of the reaction component which is introduced through the first and second introduction points is introduced through the first introduction point. Y is less than X, and at least one of the first and second introduction points is located on the reactor system at a location not on the reactor.

Abstract: A promoted VPO catalyst for the oxidation of n-butane to maleic anhydride wherein the catalyst comprises the mixed oxides of vanadium and phosphorus, niobium and at least one of antimony and bismuth, wherein the catalyst may be produced in a process comprising impregnating a VPO catalyst with a metal source compound of niobium and a metal source compound of at least one of antimony and bismuth, to form a metal impregnated VPO catalyst, and then drying the metal impregnated VPO catalyst to form the promoted VPO catalyst.

Abstract: An apparatus comprises a first controller configured to control at least the flow rate of a polymerization inhibitor or acrylonitrile product to a first location where the two are mixed. The apparatus comprises a first on-line analyzer configured to measure polymerization inhibitor concentration in the acrylonitrile product at a second location, the second location downstream of the first location. The first on-line analyzer is configured to provide information relating to the measured inhibitor concentration at the second location to the first controller, the first controller configured to process the information from the first on-line analyzer and to adjust at least a first operating parameter of a first addition device if the measured inhibitor concentration at the second location is outside a first predetermined condition. A second controller and a second on-line analyzer are provided to provide similar control of water addition to acrylonitrile product.

Abstract: Process for the polymerization or copolymerization of olefins by bringing the olefins into contact with a catalyst under polymerization or copolymerization conditions in a reactor containing a charge powder. The process includes, prior to introducing the catalyst into the reactor, introducing a scavenger into the reactor which reacts with catalyst poison present. The scavenger is added to the reactor until the charge powder contains a remaining amount of scavenger of between 0.1 and 2.5 moles per ton of charge powder.

Abstract: Process for operating a hot particle rotary valve having a rotor and a casing. The process includes subjecting the hot particle rotary valve to an internal temperature increase treatment in which the inside of the rotary valve is heated during the start-up of the particle rotary valve.

Abstract: A catalytic composition useful for the conversion of an olefin selected from the group consisting of propylene, isobutylene or mixtures thereof, to acrylonitrile, methacrylonitrile, and mixtures thereof. The catalytic composition comprises a complex of metal oxides comprising bismuth, molybdenum, iron, cerium, and at least one of samarium, praseodymium and neodymium.

Abstract: Method of producing ethylene and, optionally, propylene by subjecting a feedstock to steam cracking to produce a first olefin containing stream; heating an ethanol containing stream with heat from a steam cracker; passing the heated ethanol containing stream over a dehydration catalyst at a temperature between 200 C to 500 C preferably 250 C to 450 C to produce a second olefin containing stream; and combining the first and second olefin containing streams to give an initial product stream containing ethylene and optionally propylene. The initial product stream is subjected to purification including at least i) water content reduction ii) hydrogen content reduction iii) reduction of content of molecules containing 4 or more carbon atoms and iv) ethane content reduction.

Abstract: Polymerization process, in particular for the polymerization of monomer selected from ethylene and propylene in a reaction system containing at least three reactors operated in series. The process includes (a) polymerizing monomer in a first reactor having a volume of at least 50 m3 to produce a first polymer, (b) passing the first polymer to a second reactor and polymerizing monomer in the second reactor to produce a second polymer containing the first polymer and polymer produced in the second reactor, and (c) passing the second polymer to a third reactor and polymerizing monomer in the third reactor to produce a third polymer containing the second polymer and polymer produced in the third reactor. The polymerizations are performed such that between 0.01 and 5 w % of the total mass of the third polymer is polymer produced in the second reactor.

Abstract: Process for enhancing the separation of monomer components from light components other than monomer by providing a first stream containing monomer and light components other than monomer and passing the first stream to a first separator at a first pressure to separate a gaseous second stream containing at least some of the light components other than monomer and provide a liquid third stream containing monomer. A portion of the third stream and a fourth stream containing monomer and light components other than monomer is passed to a second separator at a second pressure which is lower than the first pressure to separate a gaseous fifth stream containing at least some of the light components other than monomer from the fourth stream and provide a liquid sixth stream containing monomer.

Abstract: Process for polymerizing monomer in a reactor by withdrawing an effluent from the reactor which is a slurry of polymer solids in a liquid medium and contacting a first stream containing vapor derived from the effluent withdrawn from the reactor with a feed stream to the reactor. The first stream which has the majority of the vaporized components of the liquid medium in the effluent withdrawn from the reactor is brought into contact with the feedstream to the reactor at a pressure of 0.5 MPa or above and/or the first stream is separated from the polymer withdrawn from the reactor at a pressure of 0.5 MPa or above.

Abstract: Catalytic compositions are provided that are effective for providing increased acrylonitrile product without a significant decrease in hydrogen cyanide and/or acetonitrile production and provide an overall increase in production of acrylonitrile, hydrogen cyanide and acetonitrile. The catalytic compositions include a complex of metal oxides and include at least about 15% m-phase plus t-phase by weight and have a weight ratio of m-phase to m-phase plus t-phase of 0.45 or greater.

Abstract: Method for controlling a process for the production of a polymer by polymerization of a monomer and a comonomer. The process includes maintaining a substantially constant effective flow ratio (EFR), the effective flow ratio being defined as EFR=(Qcomo?Lcomo)/(Qmono?Lmono), Qcomo and Qmono being, respectively, flow rates of comonomer and monomer to the reactor, Lcomo and Lmono being, respectively, losses of comonomer and monomer.