摘要:
A process and apparatus for the (co) polymerization of styrene. The process is carried out by employing a liquid polymerization reaction mixture that includes styrene, in a mechanically stirred reactor in the form of a vessel comprising a side wall having the shape of a cylinder of revolution with a vertical axis (A), a bottom head and a top head that are joined to the side wall, the vessel being provided with a mechanical stirring device comprising (i) a central shaft of vertical axis coincident with the axis (A), connected to a drive system comprising a motor for rotating the central shaft, (ii) at least one baffle attached to the vessel, which process is characterized in that the baffle is away from the side wall of the vessel and takes the form of a cylinder of vertical axis and of rhomboidal cross section.
摘要:
A catalyst system suitable for the polymerisation of olefins, said system comprising (a) a transition metal compound or lanthanide metal compound (b) a cocatalyst and (c) at least one porous support material characterised in that the porous support material has been pretreated with a halogen-containing organometallic compound, in particularly with a fluorine-containing organometallic compound. The catalyst system is particularly suitable for the preparation of polymers having broad molecular weight distributions from the polymerisation of olefins in the presence of a single site catalyst.
摘要:
Copolymer of ethylene and an alpha-olefin having (a) a density in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range of 0.01-50 g/10 min, (c) a molecular weight distribution (Mw/Mn) in the range 3.5 to 4.5, and (d) a melt elastic modulus G′(G″=500 Pa) in the range 40 to 150 Pa. The copolymer has a melt index MI2 (2.16 kg, 190° C.) Dow Rheology Index (DRI) and melt elastic modulus G′(G″=500 Pa) satisfying the equations of [DRI/MI2]>0 and [DRI/MI2]
摘要:
Process for introducing a polymerisation catalyst in solid form into a gas-phase fluidised bed using an injection device having an inner tube of internal cross-sectional area of 10-100 mm2 and an outer tube forming an annulus around the inner tube with a cross-sectional area of 1-10 times the internal cross-sectional area of the inner tube. The polymerisation catalyst and a carrier gas are passed through the inner tube into the gas-phase fluidised bed at a carrier gas linear velocity of 4-14 m/s and a carrier gas mass flow rate of 10-35 kg/h. A shielding gas is passed through the outer tube and into the gas-phase fluidised bed at a shielding gas linear velocity of 1-10 times the linear velocity of the carrier gas through the inner tube and at a shielding gas mass flow rate of 100-500 kg/h. No cooled recycle process gas is provided to the injection device.
摘要:
The present invention relates to a process for contacting a hydrocarbon and an oxygen-containing gas with a catalyst bed in a reactor at a space velocity of at least 10,000 h−1, said process being characterised in that a) the reactor has a polygonal internal cross-section at least in the section where the catalyst bed is held, b) the catalyst bed is made up of 2 or more layers of catalyst in the form of tiles of polygonal shape, said tiles have at least 4 sides, c) each layer of catalyst comprises at least 4 tiles which tessellate together to form said layer, and d) the edges where 2 tiles meet in one layer do not align with the edges where 2 tiles meet in an adjacent layer.
摘要:
A complex compound comprising the skeletal unit of Formula A, wherein the ring represented by C(R1)-A1-A2-(A3)x-C(R2)—C— has delocalised unsaturation and is optionally substituted via one or more of A1, A2 and A3 with atoms or groups selected from hydrogen, alkyl, aryl, halogen, or heterocyclic groups containing at least one N, S or O in a carbon ring; A1, A2 and A3 are selected from carbon, nitrogen or oxygen, R1 and R2 are each selected from chlorine, bromine or iodine; x is zero or 1, O is oxygen, E is nitrogen, phosphorus or arsenic, Q represents a divalent bridging group comprising one or more Group 14 atoms; M is a metal selected from Groups 3 to 7; X represents a monovalent atom or group covalently or ionically bonded to M; L is a mono- or bidentate molecule datively bound to M, y satisfies the valency of M and z is from 0 to 5. The complex can be used to polymerise olefins optionally with organo-A1 or -B compounds as activator.
摘要:
This invention relates to a process for the production of lower aliphatic esters by reacting a lower olefin with a saturated lower aliphatic mono-carboxylic acid in the vapor phase in the presence of a heteropolyacid catalyst characterized in that an amount of water in the range from 1-10 mole % based on the total of the olefin, aliphatic monocarboxylic acid and water is added to the reaction mixture during the reaction. The presence of water enhances the yield of the desired ester. The reaction mixture may optionally contain a di-ether to minimize the by-products.The process is particularly suitable for producing ethyl acetate from ethylene and acetic acid in the presence of water.
摘要:
Novel copolymers of ethylene and alpha-olefins are provided having (a) a density in the range 0.900-0.940 g/cm3, (b) a melt index MI2 (2.16 kg, 190° C.) in the range of 0.01-50 g/10 min, (c) a molecular weight distribution (Mw/Mn) in the range 3.5 to 4.5, (d) a melt elastic modulus G′ (G″=500 Pa) in the range 40 to 150 Pa, and (e) a melt index MI2 (2.16 kg, 190° C.), Dow Rheology Index (DRI) and melt elastic modulus G′ (G″=500 Pa) satisfying the equations of [DRI/MI2]>0 and [DRI/MI2]
摘要:
A method for producing rotomoulding polyethylene by fluidized bed gas phase polymerisation of ethylene and the improved rotomoulding polyethylene obtainable by the process.
摘要:
The present invention provides a process for the production of carbon monoxide and hydrogen by partial oxidation of a methane-containing feedstock in the presence of a molecular oxygen-containing gas, wherein said process comprises (a) providing a pre-heated, mixed feedstream comprising said methane-containing feedstock and said molecular oxygen-containing gas, (b) subsequently mixing said pre-heated, mixed feedstream with a diluent, said diluent being pre-heated to a temperature of at least 400° C., to produce a diluent mixed feedstream comprising at least 10% by volume of diluent, and (c) contacting said diluent mixed feedstream with a catalyst suitable for the partial oxidation of the methane, to provide a product stream comprising carbon monoxide and hydrogen.