摘要:
Provided are methods of producing polymers with broadened molecular weight and/or composition distribution in a continuous homogeneous polymerization system utilizing reactor temperature gradients, reactor polymer concentration gradients, monomer concentration gradients, catalyst concentration gradients, and combinations thereof in the polymerization reactor. Such methods are particularly suitable when utilizing metallocene catalysts and other single-site catalysts, which generally produce polymers with narrow molecular weight and composition distribution.
摘要:
A process for feeding ethylene into a polymerization system includes providing a low-pressure ethylene stream, one or more low-pressure C3 to C20 monomer streams, an optional low-pressure inert solvent/diluent stream, and one or more reactors; metering the low-pressure ethylene stream, the one or more low-pressure C3 to C20 monomer streams, and the optional low-pressure inert solvent/diluent stream; blending the metered low-pressure ethylene stream, the metered one or more low-pressure C3 to C20 monomer streams, and the metered low-pressure optional inert solvent/diluent stream to form an ethylene-carrying low-pressure blended liquid feed stream; pressurizing the ethylene-carrying low-pressure blended liquid feed stream to the polymerization system pressure with one or more high-pressure pumps to thrm an ethylene-carrying high-pressure blended reactor feed stream; and feeding the ethylene-carrying high-pressure blended reactor feed stream to the one or more reactors.
摘要:
A monomer recycle process for fluid phase in-line blending of polymers is provided. In one form, the monomer recycle process includes providing a first group (G1) of one or more reactor trains and a second group (G2) of one or more reactor trains and one or more separators fluidly connected to G1 and one separator fluidly connected to G2; polymerizing in each reactor train of G1 and G2 olefin monomers to form homogenous fluid phase polymer-monomer mixtures wherein each of the G1 and G2 reactor trains have at least one common monomer; passing the reactor effluents from the one or more G1 reactor trains through the one or more G1 separators to separate a monomer-rich phase from a polymer-enriched phase; passing the polymer-enriched phase and the reactor effluents from the one or more G2 reactor trains into the G2 separator (separator-blender) to separate another monomer-rich phase from a polymer-rich blend; recycling to one or more G1 reactor trains the separated monomer-rich phase from the one or more G1 separators; and recycling to one or more G2 reactor trains the separated monomer-rich phase from the G2 separator. The polymer-rich blend is conveyed to a downstream finishing stage for further monomer stripping, drying and/or pelletizing to form a polymer product blend.
摘要:
A monomer recycle process for fluid phase in-line blending of polymers is provided. In one form, the monomer recycle process includes providing a first group (G1) of one or more reactor trains and a second group (G2) of one or more reactor trains and one or more separators fluidly connected to G1 and one separator fluidly connected to G2; polymerizing in each reactor train of G1 and G2 olefin monomers to form homogenous fluid phase polymer-monomer mixtures wherein each of the G1 and G2 reactor trains have at least one common monomer; passing the reactor effluents from the one or more G1 reactor trains through the one or more G1 separators to separate a monomer-rich phase from a polymer-enriched phase; passing the polymer-enriched phase and the reactor effluents from the one or more G2 reactor trains into the G2 separator (separator-blender) to separate another monomer-rich phase from a polymer-rich blend; recycling to one or more G1 reactor trains the separated monomer-rich phase from the one or more G1 separators; and recycling to one or more G2 reactor trains the separated monomer-rich phase from the G2 separator. The polymer-rich blend is conveyed to a downstream finishing stage for further monomer stripping, drying and/or pelletizing to form a polymer product blend.
摘要:
Monomer/solvent separation and recycle processes for continuous supercritical, solution and advanced solution polymerization processes for propylene-containing polymers and their blends are provided. The advantageous monomer/solvent separation and recycle process includes heating a polymer-lean recycle stream coming from a gravimetric separator positioned downstream of the reactor to form a heated polymer-lean recycle stream, and subsequently combining the heated polymer-lean recycle stream with the one or more homogenous reactor effluent streams to form a heated reactor effluent mixed stream. The heated reactor effluent mixed stream may then be passed through a pressure let-down valve followed and a gravimetric separator, such as to provide for reduced fouling propensity of the polymer-rich phase and sufficient heating of the polymer-rich phase to be able to pass through the remainder of the processing steps to form a propylene based polymer product without additional heat.
摘要:
Provided are methods of producing polymers with broadened molecular weight and/or composition distribution in a continuous homogeneous polymerization system utilizing reactor temperature gradients, reactor polymer concentration gradients, monomer concentration gradients, catalyst concentration gradients, and combinations thereof in the polymerization reactor. Such methods are particularly suitable when utilizing metallocene catalysts and other single-site catalysts, which generally produce polymers with narrow molecular weight and composition distribution.
摘要:
Monomer/solvent separation and recycle processes for continuous supercritical, solution and advanced solution polymerization processes for propylene-containing polymers and their blends are provided. The advantageous monomer/solvent separation and recycle process includes heating a polymer-lean recycle stream coming from a gravimetric separator positioned downstream of the reactor to form a heated polymer-lean recycle stream, and subsequently combining the heated polymer-lean recycle stream with the one or more homogenous reactor effluent streams to form a heated reactor effluent mixed stream. The heated reactor effluent mixed stream may then be passed through a pressure let-down valve followed and a gravimetric separator, such as to provide for reduced fouling propensity of the polymer-rich phase and sufficient heating of the polymer-rich phase to be able to pass through the remainder of the processing steps to form a propylene based polymer product without additional heat.
摘要:
Provided are methods of producing polymers with broadened molecular weight and/or composition distribution in a continuous homogeneous polymerization system utilizing reactor temperature gradients, reactor polymer concentration gradients, monomer concentration gradients, catalyst concentration gradients, and combinations thereof in the polymerization reactor. Such methods are particularly suitable when utilizing metallocene catalysts and other single-site catalysts, which generally produce polymers with narrow molecular weight and composition distribution.
摘要:
Provided are bulk homogeneous polymerization processes for producing ethylene propylene random copolymers. The process includes contacting in a reactor or in a series of reactors propylene monomer, ethylene comonomer with one or more catalyst systems and optional solvent (present at less than 40 wt %), wherein the reactor train is at a temperature of between 65° C. and 180° C. and at a pressure no lower than 10 MPa below the cloud point pressure of the polymerization system and less than 1500 MPa, and wherein the polymerization system for the reactor train is in its dense fluid state to form a polymer reactor effluent including a homogeneous fluid phase polymer-monomer mixture in the reactor train; and wherein the resultant copolymer product comprises between 10 wt % and 20 wt % randomly distributed ethylene and the concentration of total region defects in the continuous propylene segments of the random EP copolymer is between 40 and 150% greater than in a copolymer of equivalent melt flow rate and wt % ethylene polymerized by a solution polymerization process.
摘要:
Provided are methods of producing polymers with broadened molecular weight and/or composition distribution in a continuous homogeneous polymerization system utilizing reactor temperature gradients, reactor polymer concentration gradients, monomer concentration gradients, catalyst concentration gradients, and combinations thereof in the polymerization reactor. Such methods are particularly suitable when utilizing metallocene catalysts and other single-site catalysts, which generally produce polymers with narrow molecular weight and composition distribution.