Methods of reducing heat exchanger fouling rate or of producing polyolefins may include providing a first gas stream comprising a gas and entrained fine polyolefin particles to a gas outlet line; removing a portion of the entrained fine polyolefin particles from the gas outlet line to form a bypass stream; and providing the bypass stream to a bypass line comprising a bypass line inlet and a bypass line outlet. The bypass line inlet and outlet are located upstream and downstream of a first heat exchanger. The methods may further include providing at least a portion of the first gas stream to the first heat exchanger; and combining the bypass stream and a second gas stream at the bypass line outlet to form a combined gas stream comprising one or more olefins or paraffins. A temperature of the combined gas stream is below the dew point of the combined gas stream.

Methods of reducing heat exchanger fouling rate or of producing polyolefins may include providing a first gas stream comprising a gas and entrained fine polyolefin particles to a gas outlet line; removing a portion of the entrained fine polyolefin particles from the gas outlet line to form a bypass stream; and providing the bypass stream to a bypass line comprising a bypass line inlet and a bypass line outlet. The bypass line inlet and outlet are located upstream and downstream of a first heat exchanger. The methods may further include providing at least a portion of the first gas stream to the first heat exchanger; and combining the bypass stream and a second gas stream at the bypass line outlet to form a combined gas stream comprising one or more olefins or paraffins. A temperature of the combined gas stream is below the dew point of the combined gas stream.

Ethylene, alpha olefins, and other olefinically unsaturated monomers may be polymerized under fluidized bed polymerization reaction conditions in the presence of a Ziegler-Natta catalyst. A recycle stream featuring an induced condensing agent (ICA) comprising isobutane may increase catalyst productivity while maintaining quality of the polymer product, particularly when the recycle stream is delivered to a reactor containing the fluidized bed under conditions suitable to form a condensed or super-condensed mode in the recycle stream. The recycle stream may comprise unreacted olefinic monomers, and isobutane or a mixture of isobutane and isopentane.

Ethylene, alpha olefins, and other olefinically unsaturated monomers may be polymerized under fluidized bed polymerization reaction conditions in the presence of a Ziegler-Natta catalyst. A recycle stream featuring an induced condensing agent (ICA) comprising isobutane may increase catalyst productivity while maintaining quality of the polymer product, particularly when the recycle stream is delivered to a reactor containing the fluidized bed under conditions suitable to form a condensed or super-condensed mode in the recycle stream. The recycle stream may comprise unreacted olefinic monomers, and isobutane or a mixture of isobutane and isopentane.

A method for producing a polymer from a first component and a second component using a reactor (50) offers technical advantages, wherein reaction heat produced in the reactor (50) is discharged via a boiling cooler (40) by supplying gaseous vapors produced in the reactor (50) to the boiling cooler (40). A product flow containing condensed vapors is returned to the reactor (50) from the boiling cooler (40) via a separation vessel (60), and an aqueous phase is separated from the product flow in the separation vessel (60). A system is provided for producing a polymer from a first component and a second component, comprising a reactor (50) and a boiling cooler (40) for discharging reaction heat produced in the reactor (50). A separation vessel (60) is arranged between the boiling cooler (40) and the reactor (50) such that a product flow containing condensed vapors is returned to the reactor (50) from the boiling cooler (40) via the separation vessel (60).

A method for producing a polymer from a first component and a second component using a reactor (50) offers technical advantages, wherein reaction heat produced in the reactor (50) is discharged via a boiling cooler (40) by supplying gaseous vapors produced in the reactor (50) to the boiling cooler (40). A product flow containing condensed vapors is returned to the reactor (50) from the boiling cooler (40) via a separation vessel (60), and an aqueous phase is separated from the product flow in the separation vessel (60). A system is provided for producing a polymer from a first component and a second component, comprising a reactor (50) and a boiling cooler (40) for discharging reaction heat produced in the reactor (50). A separation vessel (60) is arranged between the boiling cooler (40) and the reactor (50) such that a product flow containing condensed vapors is returned to the reactor (50) from the boiling cooler (40) via the separation vessel (60).

A polymerization process includes contacting an olefin or a mixture of the olefin and one or more copolymerizable comonomers under polymerization conditions with a catalyst composition and forming a polymer with a total ash content of less than 15 ppm. The catalyst composition includes one or more polymerization catalysts; and a mixed external electron donor comprising a selectivity control agent comprising at least one silicon-containing compound containing at least one C1-C10 alkoxy group bonded to a silicon atom.

A polymerization process includes contacting an olefin or a mixture of the olefin and one or more copolymerizable comonomers under polymerization conditions with a catalyst composition and forming a polymer with a total ash content of less than 15 ppm. The catalyst composition includes one or more polymerization catalysts; and a mixed external electron donor comprising a selectivity control agent comprising at least one silicon-containing compound containing at least one C1-C10 alkoxy group bonded to a silicon atom.

A process for producing an ethylene copolymer, the process including: (a) contacting ethylene with at least one polar comonomer in the presence of at least one modifier and at least one free radical initiator in a tubular reactor under polymerization conditions including a pressure of from 225 to 270 MPa; (b) injecting the at least one free radical initiator into the reactor at a plurality of reaction zones spaced along the length of the reactor, wherein each reaction zone comprises an inlet and an outlet; (c) maintaining the temperature at the inlet of each reaction zone at 150° C. or less, and the temperature at the outlet of each reaction zone is at least 177° C.; (d) controlling the modifier flow at a rate of from 0.02 to 0.986 wt % of the copolymer; and (e) recovering the ethylene copolymer from the tubular reactor, is provided.

A process for producing an ethylene copolymer, the process including: (a) contacting ethylene with at least one polar comonomer in the presence of at least one modifier and at least one free radical initiator in a tubular reactor under polymerization conditions including a pressure of from 225 to 270 MPa; (b) injecting the at least one free radical initiator into the reactor at a plurality of reaction zones spaced along the length of the reactor, wherein each reaction zone comprises an inlet and an outlet; (c) maintaining the temperature at the inlet of each reaction zone at 150° C. or less, and the temperature at the outlet of each reaction zone is at least 177° C.; (d) controlling the modifier flow at a rate of from 0.02 to 0.986 wt % of the copolymer; and (e) recovering the ethylene copolymer from the tubular reactor, is provided.