Reactor systems, reactor coolant systems, and associated processes for polymerizing polyolefins are described. The reactor systems generally include a reactor pipe and a coolant system, in which the coolant system includes a jacket pipe surrounding at least a portion of the reactor pipe to form an annulus therebetween, at least one spacer coupling the jacket to the reactor pipe, and a coolant which flows through the annulus to remove heat from the reactor pipe. At least one of the external surface of the reactor pipe, the internal surface of the jacket, and at least one spacer, are independently modified, for example by polishing, coating, or reshaping, to reduce the fluid resistance of the coolant flow through the annulus.

The present invention relates to a process for the polymerization of olefin monomers in the presence of a catalyst system, using a tubular pre-polymerization reactor, wherein the tubular pre-polymerization reactor has a length L and the flow of a catalyst system is introduced in the tubular pre-polymerization reactor in the middle (30-70% of L) or the end (70-95% of L) of the tubular pre-polymerization reactor.

Reactor systems, reactor coolant systems, and associated processes for polymerizing polyolefins are described. The reactor systems generally include a reactor pipe and a coolant system, in which the coolant system includes a jacket pipe surrounding at least a portion of the reactor pipe to form an annulus therebetween, at least one spacer coupling the jacket to the reactor pipe, and a coolant which flows through the annulus to remove heat from the reactor pipe. At least one of the external surface of the reactor pipe, the internal surface of the jacket, and at least one spacer, are independently modified, for example by polishing, coating, or reshaping, to reduce the fluid resistance of the coolant flow through the annulus.

A method for minimizing the amount of catalyst inactivating agent that is present in a liquid fraction recovered from a slurry-based polymer production process, the liquid fraction comprising diluent used in the polymer production process, is disclosed. The method includes steps for controlling the pressure over the liquid fraction collected during diluent recovery so as to minimize the concentration of catalyst inactivating agent that is retained in the recovered liquid fraction. Embodiments of apparatus suitable for conducting the disclosed method are also provided.

The present invention discloses an external loop slurry reactor, comprising a gas-liquid integrated distributor, a riser, a degassing zone, a solid-liquid separation circulation unit, and a storage tank. When the reactor works, reactants are injected into the riser through the gas-liquid integrated distributor; the slurry mixes and flows upwards to the degassing zone at the top for gas removal, and a large number of bubbles are removed. The slurry with catalyst particles then enters a downcomer and flows downwards. The slurry flows into a first-stage hydrocyclone and a multi-stage hydrocyclone in sequence for solid-liquid separation. The diameter of the first-stage hydrocyclone is larger than that of the multi-stage hydrocyclone. The separated solid particles flow back into the riser to continue to participate in the reaction.

A system including a dump tank to receive a reactor product comprising a polymer and hydrocarbons, including liquid hydrocarbons, the dump tank including a vessel with a reactor product inlet, a motive gas inlet, a purge gas inlet, gas outlet(s), and a fluid outlet, the motive gas inlet for introducing a motive gas into the vessel, the purge gas inlet for introducing a purge gas into the vessel, the one or more gas outlets located at a top of the vessel and the fluid outlet located at a bottom of the vessel and fluidly connected with a dump tank fluid outlet line having a dump tank outlet valve to control flow of fluid out of the dump tank via the fluid outlet; and a strainer fluidly connected with the dump tank fluid outlet line to allow passage of liquid hydrocarbons therethrough into a hydrocarbon outlet line.

Apparatuses and processes that produce multimodal polyolefins, and in particular, polyethylene resins, are disclosed herein. This is accomplished by using two reactors in series, where one of the reactors is a multi-zone circulating reactor that can circulate polyolefin particles through two polymerization zones optionally having two different flow regimes so that the final multimodal polyolefin has improved product properties and improved product homogeneity.

Provided are methods and/or systems to convert sulfide intermediates to sulfilimines using a series of continuous loop reactors instead of a batch reactor. The advantages of the methods and systems provided include improved total yield, improved heat management, improved phase mixing, and/or improved volume management.

A method of operating a polyethylene reactor system includes feeding ethylene, an optional first comonomer, a diluent, and a chromium-based catalyst to a first polymerization reactor. The method further includes contacting ethylene and the comonomer with the catalyst in the first polymerization reactor to form a first product including a first polyethylene. The method further includes feeding the first product from the first polymerization reactor to a second polymerization reactor. The method further includes contacting ethylene and a second optional comonomer with catalyst from the first reactor in the second polymerization reactor to form a second product including the first polyethylene and a second polyethylene. The method further includes controlling one or both of a molecular weight or a breadth of molecular weight distribution of the second product by adjusting a rate of hydrogen fed to one or both of the first polymerization reactor or the second polymerization reactor.

A reformer assembly for a fuel cell includes a vortex tube receiving heated fuel mixed with steam. A catalyst coats the inner wall of the main tube of the vortex tube and a hydrogen-permeable tube is positioned in the middle of the main tube coaxially with the main tube.