The present invention relates to a process for removing hydrocarbons comprising the steps of: (A) passing a stream of a solution into a separator wherein a liquid phase comprising polymer and a vapour phase coexist; (B) withdrawing a vapour stream and a concentrated solution stream from the separator; (C) passing at least a part of the vapour stream into a first fractionator; (D) withdrawing a first overhead stream and a first bottom stream from the first fractionator; (E) passing the first bottom stream to a second fractionator; (F) withdrawing a second overhead stream and a second bottom stream from the second fractionator; characterised in that at least a part of the second overhead stream is withdrawn as a purge stream.

A process for producing a polymer composition comprising the steps (A) to (M) as recited herein, involving the polymerization, in a polymerization reactor of a first polymer, a first stream thereof being passed into a first separator wherein a first liquid phase comprising the polymer and a first vapor phase coexist; withdrawing a first vapor stream and a first concentrated solution stream comprising the polymer from the first separator, passing at least a part of the first vapor stream to a first fractionator; withdrawing a first overhead stream and a first bottom stream from the first fractionator; recovering at least a part of the first overhead stream as a first recycle stream and passing it to the polymerization reactor; passing the first concentrated solution stream from the first separator to a second separator, wherein a second liquid phase comprising the polymer and a second vapor phase coexist; passing at least a part of the second vapor stream to a second fractionator; withdrawing a second overhead stream and a second bottom stream from the second fractionator; recovering at least a part of the second overhead stream as a second recycle stream and passing it to the polymerization reactor; wherein the mass flow rate of the first recycle stream is at least 80% of the mass flow rate of the first vapor stream and the mass flow rate of the second recycle stream is at least 70% of the mass flow rate of the second 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.

The invention relates to a method for producing thermoplastic molding materials based on acrylonitrile-butadiene-styrene copolymers (ABS) having improved surface properties, in particular improved resistance of the surface quality to storage in a warm, humid environment, and having a reduced content of residual monomers. The invention further relates to the use of a fluid bed dryer and/or a flash dryer in the production of thermoplastic ABS molding materials in order to improve the surface quality. The invention further relates to the use of a fluid bed dryer and/or a flash dryer in the production of thermoplastic ABS molding materials having a reduced content of residual monomers. The invention further relates to ABS molding materials that can be produced by means of the method according to the invention and to molded parts (e.g., molded bodies, films, and coatings) that can be produced from the thermoplastic molding materials according to the invention.

Methods for separating gaseous components, such as unreacted hydrocarbon monomer and/or solvent, from polyolefin solids are provided. The methods include flowing a first stream including polyolefin solids and gaseous unreacted hydrocarbon monomer and/or solvent through a portion of a gas-solid separation vessel having a volume sufficient so that polyolefin solids present in the first stream have an increased residence time within the gas-solid separation vessel to separate gaseous unreacted hydrocarbon monomer and/or solvent from the polyolefin solids to produce a second stream including polyolefin solids substantially free of gaseous unreacted hydrocarbon monomer and/or solvent and a third stream including the gaseous unreacted hydrocarbon monomer and/or solvent. Systems for carrying out such methods are also provided.

Methods for separating gaseous components, such as unreacted hydrocarbon monomer and/or solvent, from polyolefin solids are provided. The methods include contacting a first stream including polyolefin solids and gaseous unreacted hydrocarbon monomer and/or solvent with a first purge gas in a gas-solid separation vessel to separate the gaseous unreacted hydrocarbon monomer and/or solvent from the polyolefin solids to produce a second stream including polyolefin solids substantially free of gaseous unreacted hydrocarbon monomer and/or solvent and a third stream including the gaseous unreacted hydrocarbon monomer and/or solvent. The first purge gas includes hydrocarbon monomer and/or solvent and has a temperature of at least about 70 C. when entering the gas-solid separation vessel. Systems for carrying out such methods are also provided.

A polymer synthesis system has a polymerization reactor and a deliquifying-quench extruder downstream of and in fluid communication with the polymerization reactor. The polymerization reactor has an inlet and an outlet with a rotatable shaft positioned axially within the reactor. The deliquifying-quench extruder has an inlet and an outlet, with a shaft assembly positioned axially within the extruder. The shaft assembly includes multiple helical flight configurations and multiple processing zones defined by the multiple flight configurations. The processing zones include an extraction-compaction zone, a sealing zone downstream of the extraction-compaction zone, a vent-cooling zone downstream of the sealing zone, a quenching zone downstream of the vent-cooling zone, and a conveying zone downstream of the quenching zone.

This invention relates to a process for forming polymer including: polymerizing a monomer dissolved in a solvent in the presence of a catalyst system under conditions to obtain a first effluent stream including a solution of the polymer and the solvent; heating the first effluent stream in at least one spiral heat exchanger to produce a second effluent stream, where the first effluent stream flows through the spiral heat exchanger in a cross-flow direction relative to spirals of the spiral heat exchanger and performing a separation on the second effluent stream to produce: a third effluent stream including polymer substantially free of the solvent; and a recycle stream including the solvent and unreacted monomer. Processes for devolatilizing a polymer stream are also provided herein.

A mobile vacuum distillation unit for extracting, condensing, and collecting volatile organic compound vapor emissions from one or more polymer-containing articles includes a shell that defines an enclosed interior space and is mounted to a transportable support platform, a vacuum distillation vessel, a condenser, a condensate storage tank, and a vacuum pump system in fluid communication with a vacuum distillation chamber of the vacuum distillation vessel. The vacuum distillation chamber that includes the one or more polymer-containing articles from which the VOC vapor emissions are extracted may be heated by an exhaust gas heat exchanger if the transportable support platform is connected to and hauled by a tractor unit powered by a diesel engine. A method of using the mobile vacuum distillation unit to extract VOC vapor emissions from one or more polymer-containing article during transportation of the one or more polymer-containing articles between geographically separate destinations is also disclosed.

Provided in one implementation is a method that includes introducing a volume of raw material into a chamber of a cavitation machine. The raw material can include a mixture comprising a powder and a solvent. The powder can have a first average particle size in the raw material. The method includes applying a hydrodynamic cavitation process to the raw material to produce a product material. The powder can have a second average particle size, smaller than the first average particle size, in the product material. The method includes causing the product material to exit the cavitation chamber and drying the product material to remove the solvent. Apparatus employed to apply the method are also provided.