Apparatus for undertaking a chemical reaction includes an elongate housing and a receptacle. The elongate housing may include a cooling means, and end fittings, which may include ports where fluids may be introduced and/or removed. In use of the apparatus, a chemical reaction product is formed within the receptacle. Subsequently the receptacle containing the chemical reaction product is withdrawn from the elongate housing.

A production method of an addition condensation product includes a step at which an aromatic compound, a carbonyl compound, and a catalyst are mixed in a reaction solvent, and an addition condensation reaction of the aromatic compound and the carbonyl compound is conducted in the temperature range of 60 to 97° C., both inclusive, to obtain the addition condensation product of the aromatic compound and the carbonyl compound. At the step to obtain the addition condensation product, 1 mole of the aromatic compound is mixed with 0.1 to 0.999 mole, both inclusive, of the carbonyl compound as the mole ratio. A ratio of the aromatic compound dimer to the aromatic compound multimer is in the range of 1:75 to 1:1,000.

An olefin polymerisation method and arrangement comprising polymerising at least one olefin in gas phase in a fluidised bed in the presence of an olefin polymerisation catalyst in a polymerisation reactor having a vertical body; a generally conical downwards tapering bottom zone; a generally cylindrical middle zone, above and connected to said bottom zone; and a generally conical upwards tapering top zone above and connected to said middle zone wherein (i) fluidisation gas is introduced to the bottom zone of the reactor from where it passes upwards through the reactor; (ii) the fluidisation gas is withdrawn from the top zone of the reactor; (iii) a fluidised bed is formed within the reactor where the growing polymer particles are suspended in the upwards rising gas stream; and wherein the polymerisation reactor has an operating temperature set point and which reactor comprises at least one temperature measurement sensor, wherein a temperature difference (DT) between the temperature measurement sensor (Tm), and the operating temperature set point (Ts) of the reactor is equal to or less than 10° C.

An olefin polymerisation method and arrangement comprising polymerising at least one olefin in gas phase in a fluidised bed in the presence of an olefin polymerisation catalyst in a polymerisation reactor having a vertical body; a generally conical downwards tapering bottom zone; a generally cylindrical middle zone, above and connected to said bottom zone; and a generally conical upwards tapering top zone above and connected to said middle zone wherein (i) fluidisation gas is introduced to the bottom zone of the reactor from where it passes upwards through the reactor; (ii) the fluidisation gas is withdrawn from the top zone of the reactor; (iii) a fluidised bed is formed within the reactor where the growing polymer particles are suspended in the upwards rising gas stream; and wherein the polymerisation reactor has an operating temperature set point and which reactor comprises at least one temperature measurement sensor, wherein a temperature difference (DT) between the temperature measurement sensor (Tm), and the operating temperature set point (Ts) of the reactor is equal to or less than 10° C.

A process for producing polyethylene polymers including contacting ethylene and at least one C.sub.3 to C.sub.8 alpha-olefin comonomer with a polymerization catalyst on a particulate support in a fluidized bed polymerization reactor under conditions effective to polymerize at least part of the ethylene and comonomer and produce the polyethylene polymers, wherein the support has a d.sub.10 particle size as measured by laser diffraction of at least 18 microns, is provided.

A method for controlling the start up conditions in a gas phase polymerization process is provided. An inventory can be calculated for each monomer, comonomer, and hydrogen sufficient to produce a polyethylene polymer having desired properties, such as, a certain melt index and/or density.

A method for controlling the start up conditions in a gas phase polymerization process is provided. An inventory can be calculated for each monomer, comonomer, and hydrogen sufficient to produce a polyethylene polymer having desired properties, such as, a certain melt index and/or density.

The present invention relates to a process for the continuous production of a polyolefin, preferably polypropylene, in a horizontal stirred bed polymerization reactor by contacting one or more olefins, preferably propylene, with a catalyst system while stirring, said catalyst system comprising: * a procatalyst comprising i) titanium; ii) a magnesium-containing support, preferably a magnesium chloride-containing support, and iii) an internal electron donor; * optionally an external electron donor; and * a co-catalyst, being a alkyl aluminum catalyst having formula AlX.sub.nR.sub.3-n, wherein each X is independently a halide or a hydride and wherein n is 0, 1 or 2, preferably 0, and wherein R is an C1-C12 alkyl group, preferably ethyl, wherein the molar ratio of aluminum (Al) from the co-catalyst to titanium (Ti) from the procatalyst (Al/Ti) is at least 75. The present invention also relates to polyolefin prepared using said process and a shaped article comprising said polyolefin. The present invention moreover relates to the use of a titanium to aluminum ratio during the Ziegler-Natta polymerization of olefins in a horizontal stirred bed reactor to reduce the energy (power) consumption in view of a situation wherein the titanium to aluminum ratio is lower.

The present invention relates to a process for the continuous production of a polyolefin, preferably polypropylene, in a horizontal stirred bed polymerization reactor by contacting one or more olefins, preferably propylene, with a catalyst system while stirring, said catalyst system comprising: * a procatalyst comprising i) titanium; ii) a magnesium-containing support, preferably a magnesium chloride-containing support, and iii) an internal electron donor; * optionally an external electron donor; and * a co-catalyst, being a alkyl aluminum catalyst having formula AlX.sub.nR.sub.3-n, wherein each X is independently a halide or a hydride and wherein n is 0, 1 or 2, preferably 0, and wherein R is an C1-C12 alkyl group, preferably ethyl, wherein the molar ratio of aluminum (Al) from the co-catalyst to titanium (Ti) from the procatalyst (Al/Ti) is at least 75. The present invention also relates to polyolefin prepared using said process and a shaped article comprising said polyolefin. The present invention moreover relates to the use of a titanium to aluminum ratio during the Ziegler-Natta polymerization of olefins in a horizontal stirred bed reactor to reduce the energy (power) consumption in view of a situation wherein the titanium to aluminum ratio is lower.

According to one or more embodiments disclosed herein, the amount of one or more contaminants in an initial ultra high molecular weight polyethylene composition may be reduced by a method including contacting the initial ultra high molecular weight polyethylene composition with an acid to form a processed ultra high molecular weight polyethylene composition. The initial ultra high molecular weight polyethylene composition may include at least 0.02 wt. % of one or more contaminants. The contacting of the acid with the initial ultra high molecular weight polyethylene composition may be for a time, at a pressure, and at a temperature sufficient to reduce the amount of the one or more contaminants in the initial ultra high molecular weight polyethylene.