US4588790A — Method for fluidized bed polymerization

Claim 1

Independent Claim 133 words

In a continuous gas fluidized bed process for the production of polymer by continuously passing a gaseous stream comprising monomer through a fluidized bed in a reaction zone in the presence of catalyst under reactive conditions, withdrawing from said reaction zone polymer product and a stream comprising unreacted gases and solid particles, cooling said stream and recycling said cooled stream to said reaction zone together with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product, the improvement comprising cooling at least a part of said recycle stream to condense a portion thereof and form a liquid-containing mixture wherein the weight ratio of liquid to solid particles is not less than about two to one, and introducing said mixture into said reaction zone wherein the liquid in said mixture is vaporized.

Claim 2

Dependent Claim 133 words

In a continuous gas fluidized bed process for the production of polymer by continuously passing a gaseous stream comprising monomer through a fluidized bed in a reaction zone in the presence of catalyst under reactive conditions, withdrawing from said reaction zone polymer product and a stream comprising unreacted gases and solid particles, cooling said stream and recycling said cooled stream to said reaction zone together with sufficient additional monomer to replace monomer polymerized and withdrawn as polymer product, the improvement comprising cooling at least a part of said recycle stream to condense a portion thereof and form a liquid-containing mixture wherein the weight ratio of liquid to solid particles is not less than about two to one, and introducing said mixture into said reaction zone wherein the liquid in said mixture is vaporized.

Claim 3

Dependent Claim 22 words

An improved process according to claim 1 wherein said recycle stream comprising unreacted gases and solid particles is compressed prior to cooling.

Claim 4

Dependent Claim 24 words

An improved process according to claim 1 wherein means are provided to maintain said liquid entrained in said mixture until said liquid is vaporized.

Claim 5

Dependent Claim 25 words

An improved process according to claim 1 wherein an inert condensible fluid is present in said mixture to raise the dew point of said mixture.

Claim 6

Dependent Claim 16 words

An improved process according to claim 4 wherein said inert condensible fluid is a saturated hydrocarbon.

Claim 7

Dependent Claim 29 words

An improved process according to claim 1 wherein said liquid in said mixture comprises from 2 to about 20 percent by weight of the total weight of said mixture.

Claim 8

Dependent Claim 29 words

An improved process according to claim 6 wherein said liquid in said mixture comprises from 2 to about 12 percent by weight of the total weight of said mixture.

Claim 9

Dependent Claim 80 words

An improved process according to claim 1 wherein said mixture is divided into at least two separate streams at least one of which is introduced into the reactor at a point below the reaction zone and one or more of said separate streams is optionally introduced directly into said reaction zone, provided that the velocity of all gases introduced below said reaction zone is at least sufficient to support said fluidized bed and to maintain it in a fluidized condition.

Claim 10

Dependent Claim 56 words

An improved process according to claim 1 wherein the gas stream flowing upwardly through the fluidized bed is generally uniform in composition and moving in a manner through said fluidized bed such that the entire fluidized bed is maintained in a gas fluidized condition and with essentially no dead spaces through which gases do not pass.

Claim 11

Dependent Claim 23 words

An improved process according to claim 1 wherein said additional monomer is introduced into said reactor in liquid form below the reaction zone.

Claim 12

Dependent Claim 27 words

An improved process according to claim 1 wherein said additional monomer is introduced into said recycle stream prior to entry of said recycle stream into said reactor.

Claim 13

Dependent Claim 31 words

An improved process according to claim 1 wherein gas distributor means is provided immediately below the fluidized bed and above the region where said recycle stream is introduced into said reactor.

Claim 14

Dependent Claim 23 words

An improved process according to claim 1 wherein the internal pressure within said reactor is from about 250 psig to about 500 psig.

Claim 15

Dependent Claim 41 words

An improved process according to claim 1 wherein said monomer is an alpha olefin monomer having from two to four carbon atoms alone or in admixture with one or more other alpha olefin monomers having from two to eight carbon atoms.

Claim 16

Dependent Claim 31 words

An improved process according to claim 14 wherein said monomer is ethylene alone or in admixture with one or more other alpha olefin monomers having from two to eight carbon atoms.

Claim 17

Dependent Claim 31 words

An improved process according to claim 14 wherein said monomer is propylene alone or in admixture with one or more other alpha olefin monomers having from two to eight carbon atoms.

Claim 18

Dependent Claim 14 words

An improved process in accordance with claim 1 wherein said monomer is vinyl chloride.

Claim 19

Independent Claim 88 words

A method for controlling the temperature of the reaction zone during the production of polymer from monomer in a gas fluidized bed by an exothermic polymerization reaction comprising continuously introducing a monomer-containing stream comprising a gas phase and a liquid phase into the bottom of said bed where said liquid phase is vaporized, said liquid phase comprising from 2 to about 20 weight percent of said stream and the weight ratio of liquid to any solid particles in said stream is not less than about two to one.

Claim 20

Independent Claim 88 words

A method for controlling the temperature of the reaction zone during the production of polymer from monomer in a gas fluidized bed by an exothermic polymerization reaction comprising continuously introducing a monomer-containing stream comprising a gas phase and a liquid phase into the bottom of said bed where said liquid phase is vaporized, said liquid phase comprising from 2 to about 20 weight percent of said stream and the weight ratio of liquid to any solid particles in said stream is not less than about two to one.

Claim 21

Dependent Claim 34 words

A method according to claim 18 wherein a supplemental liquid is introduced into the reaction zone at one or more levels above the region of lower temperature at the bottom of said fluidized bed.

Claim 22

Dependent Claim 166 words

A process for producing polymer from monomer by an exothermic polymerization reaction in a reaction zone containing a bed of gas fluidized growing polymer particles which comprises: (1) continuously passing a gaseous stream comprising monomer through said reaction zone with an upward velocity sufficient to maintain said particles in a suspended and gas fluidized condition; (2) introducing a polymerization catalyst into said reaction zone; (3) withdrawing polymer product from said reaction zone; (4) continuously withdrawing a stream comprising unreacted gases from said reaction zone, compressing and cooling said stream to a temperature below the dew point of said stream to form a mixture comprising a gas phase and a liquid phase, said liquid phase comprising from 2 to about 20 weight percent of said stream and wherein the weight ratio of liquid to any solid particles in said stream is not less than about two to one; and (5) continuously introducing said mixture into the bottom of said reaction zone wherein said liquid phase is vaporized.

Claim 23

Dependent Claim 166 words

A process for producing polymer from monomer by an exothermic polymerization reaction in a reaction zone containing a bed of gas fluidized growing polymer particles which comprises: (1) continuously passing a gaseous stream comprising monomer through said reaction zone with an upward velocity sufficient to maintain said particles in a suspended and gas fluidized condition; (2) introducing a polymerization catalyst into said reaction zone; (3) withdrawing polymer product from said reaction zone; (4) continuously withdrawing a stream comprising unreacted gases from said reaction zone, compressing and cooling said stream to a temperature below the dew point of said stream to form a mixture comprising a gas phase and a liquid phase, said liquid phase comprising from 2 to about 20 weight percent of said stream and wherein the weight ratio of liquid to any solid particles in said stream is not less than about two to one; and (5) continuously introducing said mixture into the bottom of said reaction zone wherein said liquid phase is vaporized.

Claim 24

Dependent Claim 24 words

A process according to claim 20 wherein an inert, condensible fluid is present in said mixture to raise the dew point of said mixture.

Claim 25

Dependent Claim 16 words

An improved process according to claim 21 wherein said inert, condensible fluid is a saturated hydrocarbon.

Claim 26

Dependent Claim 29 words

A process according to claim 20 wherein said liquid phase of said mixture comprises from 2 to about 12 percent by weight of the total weight of said mixture.

Claim 27

Dependent Claim 35 words

A process according to claim 20 wherein the velocity of said stream and the amount of gas in said stream are maintained at levels sufficient to maintain said liquid entrained in said gas until vaporized.

Claim 28

Dependent Claim 51 words

A process according to claim 20 wherein the stream flowing upwardly through the fluidized bed is generally uniform in composition and moving in a manner through said bed such that the entire bed is maintained in a fluidized condition and with essentially no dead spaces through which gases do not pass.

Claim 29

Dependent Claim 28 words

A process according to claim 20 wherein additional monomer in liquid or gaseous form is added below the reaction zone to replace monomer polymerized and withdrawn as product.

Claim 30

Dependent Claim 33 words

A process according to claim 20 wherein additional monomer is added to replace monomer polymerized and withdrawn as product by injection into said stream prior to entry of said stream into the reactor.

Claim 31

Dependent Claim 17 words

A process according to claim 20 wherein gas distributor means is provided immediately below said reaction zone.

Claim 32

Dependent Claim 22 words

A process according to claim 20 wherein the internal pressure within said reactor is from about 250 psig to about 500 psig.

Claim 33

Dependent Claim 44 words

A process according to claim 20 wherein said polymer is produced by reaction of an alpha olefin monomer having from two to four carbon atoms alone or in admixture with one or more other alpha olefin monomers having from two to eight carbon atoms.

Claim 34

Dependent Claim 31 words

An improved process according to claim 30 wherein said monomer is ethylene alone or in admixture with one or more other alpha olefin monomers having from two to eight carbon atoms.

Claim 35

Dependent Claim 31 words

An improved process according to claim 31 wherein said monomer is propylene alone or in admixture with one or more other alpha olefin monomers having from two to eight carbon atoms.

Claim 36

Dependent Claim 16 words

An improved process according to claim 20 wherein said polymer is produced from vinyl chloride monomer.

Annuity Stage	Window Opens	Payment Deadline	Surcharge Period Until	Estimated Fee	Status
3.5 Years (Year 4)	1989-05-12	1989-11-11	1990-05-13	$2000.00	Window Closed / Lapsed
7.5 Years (Year 8)	1993-05-12	1993-11-11	1994-05-13	$3760.00	Window Closed / Lapsed
11.5 Years (Year 12)	1997-05-12	1997-11-11	1998-05-13	$7700.00	Window Closed / Lapsed

Method for fluidized bed polymerization

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