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 method for determining polymer concentration can include synthesizing a polymer in a reactor under a set of parameters, wherein the reactor comprises a solution mixture having a refractive index, and wherein the solution mixture comprises a solvent, a polymer, and optionally a monomer, wherein the solution mixture has a polymer concentration; measuring the refractive index of the solution mixture; comparing the refractive index of the solution mixture with a calibration curve; and identifying the polymer concentration in the solution mixture. A system for determining polymer concentration can include a reactor containing a solution mixture comprising a solvent, a polymer, and optionally a monomer; a flash vessel fluidly coupled to the reactor to receive the solution mixture from the reactor; and a first refractometer fluidly coupled to the reactor, placed between the reactor and the flash vessel, and configured to measure a refractive index of the solution mixture.

Disclosed are systems and processes for distributing reactor coolant flow to the cooling jackets of a loop slurry reactor, where the reactor coolant is used to control the temperature of the loop slurry reactor in olefin polymerization. Also disclosed are systems and processes for controlling the temperature of the reactor coolant that is used for cooling olefin polymerization reactors, which can be used in combination with traditional coolant distribution regimes and in combination with the coolant distribution systems and processes that are disclosed herein.

Methods for determining the catalytic activity of an activated chemically-treated solid oxide using a color measurement technique are described, and these methods are integrated into transition metal-based catalyst preparation processes and systems, as well as into olefin polymerization processes and related polymerization reactor systems.

A method for monitoring and controlling the polymerization in a polymerization vessel by using a camera viewing unit to (a) detect features of the polymer particles, or the particles' environment, (b) compare the features to pre-defined acceptable values of these features or the environment, and (c) if a variation from the pre-defined values is detected, act on process parameters to reduce or eliminate the variation.

Provided are integrated processes for the conversion of beta propiolactone to acrylic acid. Systems for the production of acrylic acid are also provided.

A process of polymerizing olefins comprising combining propylene with a polymerization catalyst, hydrogen, and at least one external electron donor, such as at least one amino-silane donor, to form polypropylene in a first polymerization medium under solution or slurry conditions at or below the bubble point; removing hydrogen from the first polymerization medium and providing a first olefin/polyolefin separation step to form a second polymerization medium; transferring the second polymerization medium to a gas phase reactor and further combining with ethylene; obtaining a propylene-based impact copolymer. The propylene-based impact copolymer desirably has a melt flow rate of at least 60 g/10 min and is useful in automotive components.

The invention relates to a process for the preparation of a composition comprising polylactide and lactide by ring-opening polymerization of lactide, said process comprising the steps of: (a) providing lactide and polymerization catalyst to a reactor, (b) melt polymerizing said lactide to a degree of polymerization of at most 96.0%, to form a composition comprising polylactide and lactide, and (c) removing said composition from the reactor, wherein the whole process is performed at pressures of at least 1 bar, and wherein the composition removed from the reactor is never subjected to a pressure below 1 bar and wherein the composition is not subjected to one of more devolatilization steps.

A liquid process assembly, the assembly including a length of pipework, and a reversible pump for selectively reciprocally moving liquid through the pipework.