The present invention provides a method for preparing a polybutene oligomer including a step of oligomerizing a polymerization solution including a halogenated hydrocarbon solvent, a nonpolar hydrocarbon solvent and an isobutene monomer in the presence of an organometal catalyst.

A method of operating a dump tank of a polymer production process by transferring all or a portion of a content of a polymerization reactor into the dump tank, wherein the reactor contents comprise solid polymer, and liquid and gaseous non-product components, and removing at least a portion of the liquid and gaseous non-product components from the dump tank by: reducing a pressure of the dump tank, subjecting the solid polymer to a first cleaning stage comprising heating the solid polymer by introducing a first heated treatment gas into the dump tank, and subjecting the solid polymer to a second cleaning stage comprising purging the solid polymer by introducing a second heated treatment gas into the dump tank.

The present invention deals with a process for polymerising olefins in a solution and withdrawing a stream of the solution from the polymerisation reactor and passing it to a sequence of heating steps. The heated solution is passed to a separation step, which is conducted at a pressure of no more than 15 bar and in which separation step a liquid phase comprising the polymer and a vapour phase coexist. A vapour stream and a concentrated solution stream comprising the polymer are withdrawn from the separation step. At least a part of the vapour stream is passed to the first polymerisation reactor, to the second polymerisation reactor or to both.

The present invention relates to a super absorbent polymer which maintains excellent absorption performance and retains physical properties even after being physically damaged by an external force. The super absorbent polymer comprises: a base polymer powder including a first cross-linked polymer of a water-soluble ethylenically unsaturated monomer having at least partially neutralized acidic groups; and a surface cross-linked layer formed on the base polymer powder and including a second cross-linked polymer in which the first cross-linked polymer is further cross-linked via an alkylene carbonate having 2 to 5 carbon atoms, wherein the super absorbent polymer satisfies predetermined physical properties.

The present invention discloses methods for removing volatile components from an ethylene polymer effluent stream from a polymerization reactor, and related polyethylene recovery and volatile removal systems. In these methods and systems, the polymer solids temperature is increased significantly prior to introduction of the polymer solids into a purge column for the final stripping of volatile components from the polymer solids.

A reactor comprising a first portion having a generally cylindrical housing, an inlet at one end of said first portion housing, the opposed end of said first portion housing being the outlet of said first portion, where said first portion includes a rotatable shaft positioned axially within said housing and including at least two shearing paddles extending radially from said rotatable shaft and a second portion having a generally frustoconical housing having a first end larger than a second end, said first end constituting an inlet to said second portion and coextensive with said opposed end of said first portion housing, and an outlet at said second end, where said second portion includes a rotatable shaft positioned axially within said housing and including at least one generally helical flight extending radially from said rotatable shaft.

A process for reducing the amount of residual monomer in aqueous polymerization emulsion by using a sequential polymerization steps, The first step consists in adding an emulsion, of vinyl ester of alkyl of C1 to C18 carboxylic acids, to water containing a radical initiator, the second step consists in adding further an emulsion of alkyl acrylate and/or methacrylate, and the third step consists in c) adding to polymeric emulsion, resulting of the steps a) and b), pure liquid acrylate or methacrylate with alkyl chain of C.sub.1 to C.sub.12.

A method for preparing a dried powder is provided. The facility includes a first drying chamber having a heating element and a second drying chamber. A mixture of powder and diluent is introduced into the first drying chamber. A pre-dried powder is transferred from the first drying chamber into the second drying chamber. A dried powder, including a recirculated amount of powder and a discharge amount of powder, is formed in the second drying chamber. The recirculated amount of the dried powder is transferred by a conveyor device from the second drying chamber into the first drying chamber. The discharge amount of the dried powder is discharged from the second drying chamber.

The present invention is concerned with a screening assembly comprising a separating device connected to a conduit for an effluent stream comprising a polymer and a mixture of hydrocarbons, wherein the separating device is configured to separate the effluent stream into a polymer-rich stream and a polymer-lean vapor stream, wherein the first separation device comprises an inlet, a first outlet for withdrawing a polymer-rich stream, and a second outlet for withdrawing a polymer-lean vapor stream, a screening device connected to the separating device via a conduit for the polymer-lean vapor stream, wherein the screening device comprises a first inlet connected to the conduit for the polymer-lean vapor stream, a first outlet for withdrawing a cleaned vapor stream, a second outlet for withdrawing a polymer-comprising condensed vapor stream, and at least one second inlet for introducing a condensed vapor stream.

The present invention discloses methods for removing volatile components from an ethylene polymer effluent stream from a polymerization reactor, and related polyethylene recovery and volatile removal systems. In these methods and systems, the polymer solids temperature is increased significantly prior to introduction of the polymer solids into a purge column for the final stripping of volatile components from the polymer solids.