# US 7,745,552 B2 · Fouling prevention in polymerization reactors

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- Number: US 7,745,552 B2
- Document ID: US7745552B2
- Status: Granted
- Kind: B2
- Application number: 12/157,972
- Filed: 2008-06-13
- Published: 2009-01-01
- Granted: 2010-06-29
- Earliest claimed: 2007-06-29
- Assignees: ExxonMobil Research and Engineering Company
- Inventors: Gabor Kiss; Robert P. Reynolds, Jr.; Charles K. Morgan; John W. Chu; Megan Meier
- Web page: https://patentgrep.com/patent/US7745552B2

## CPC

- B01J 4/002: {Nozzle-type elements (nozzle-type reactors B01J19/26)}
- B01J 4/001: {Feed or outlet devices as such, e.g. feeding tubes}
- B01J 19/18: Stationary reactors having moving elements inside (B01J19/08, B01J19/26 take precedence)
- B01J 19/26: Nozzle-type reactors, i.e. the distribution of the initial reactants within the reactor is effected by their introduction or injection through nozzles
- C08F 10/00: Homopolymers and copolymers of unsaturated aliphatic hydrocarbons having only one carbon-to-carbon double bond
- B01J 2219/00094: Jackets
- B01J 2219/00247: Fouling of the reactor or the process equipment
- B01J 2219/00254: Formation of unwanted polymer, such as "pop-corn"
- B01J 2219/1923: square or square-derived
- C08F 110/06: Propene
- C08F 210/06: Propene
- Y02P 20/54: using solvents, e.g. supercritical solvents or ionic liquids
- Y10S 526/918: Polymerization reactors for addition polymer preparation
- B01J: CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- C08F: MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVING CARBON-TO-CARBON UNSATURATED BONDS
- Y02P: CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
- Y10S: TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS

## Abstract

Reactor designs and processes for operating such reactor designs to minimize or eliminate fouling in homogeneous polymerization processes (solution and supercritical). The process includes providing a reactor with one or more feed entry ports, wherein the reactor feed components are fed through each of the one or more feed entry ports at a linear velocity of greater than or equal to 0.3 m/min. The one or more feed entry ports may also be optionally extended beyond the interior reactor wall by greater than or equal to 2% of the internal radius of the reactor to further decrease the propensity for fouling. A stirred reactor may also include a stirrer feed port for purging the stirrer with a stirrer purge stream at a linear velocity of greater than or equal to 0.3 m/min to decrease stirrer fouling.

## Claims

### Claim 1

A process for reducing reactor fouling in a homogeneous polymerization process, comprising:
(a) providing one or more reactors with one or more feed entry ports wherein the reactors are configured in parallel, in series, or a combination thereof;
(b) feeding to the one or more reactors through the one or more feed entry ports one or more reactor feed streams comprising: 1) an olefin monomer, 2) one or more catalyst systems, 3) optional one or more comonomers, 4) optional one or more scavengers, 5) optional one or more diluents or solvents, and 6) combinations thereof,
wherein the one or more reactors arc at a temperature above the solid-fluid phase-transition temperature of the polymerization system and a pressure no lower than 10 MPa below the cloud point pressure of the polymerization system and less than 1500 MPa,
wherein the polymerization system for each reactor is in its dense fluid state and comprises the olefin monomers, any comonomer present, any diluent or solvent present, any scavenger present, and the polymer product,
wherein the catalyst system for each reactor train comprises one or more catalyst precursors, one or more activators, and optionally, one or more catalyst supports, and
wherein the linear velocity of the one or more reactor feed streams passing through each of the one or more feed entry ports is greater than or equal to 0.3 m/min.

### Claim 2 (depends on 1)

The process of claim 1 wherein in (b) the polymerization system for each reactor comprises less than 40 wt % of optional one or more diluents or solvents.

### Claim 3 (depends on 1)

The process of claim 1 wherein in (b) the polymerization system for each reactor, is above its critical temperature and critical pressure.

### Claim 4 (depends on 1)

The process of claim 1 wherein in (b) the polymerization system for each reactor comprises less than 40 wt % of optional one or more diluents or solvents and is above its critical temperature and critical pressure.

### Claim 5 (depends on 1)

The process of claim 1 wherein the linear velocity of the reactor feed streams passing through each of the one or more feed entry ports is greater than or equal to 1.0 m/min.

### Claim 6 (depends on 1)

The process of claim 1 wherein the linear velocity of the reactor feed streams passing through each of the one or more feed entry ports is greater than or equal to 10.0 m/min.

### Claim 7 (depends on 1)

The process of claim 1 wherein one or more of the feed entry ports extend beyond the interior wall of the one or more reactors by greater than or equal to 2% the internal radius of the reactor measured at the axial position of the one or more feed entry ports.

### Claim 8 (depends on 1)

The process of claim 1 wherein one or more of the feed entry ports extend beyond the interior wall of the one or more reactors by greater than or equal to 10% of the internal radius of the reactor measured at the axial position of the one or more feed entry ports.

### Claim 9 (depends on 1)

The process of claim 1 wherein one or more of the feed entry ports extend beyond the interior wall of the one or more reactors by greater than or equal to 20% of the internal radius of the reactor measured at the axial position of the one or more feed entry ports.

### Claim 10 (depends on 1)

The process of claim 1 wherein the one or more reactors arc chosen from tank, loop, tubular, and combinations thereof.

### Claim 11 (depends on 10)

The process of claim 10 wherein the one or more reactors comprise a tank with a stirrer mechanism.

### Claim 12 (depends on 11)

The process of claim 11 further comprising purging the stirrer mechanism with a stirrer purge stream.

### Claim 13 (depends on 12)

The process of claim 12 wherein the stirrer purge stream comprises 1) an olefin monomer, 2) optional one or more comonomers, 3) optional one or more scavengers, 4) optional one or more diluents or solvents, and 5) combinations thereof.

### Claim 14 (depends on 13)

The process of claim 13 wherein the stirrer purge stream enters the reactor interior where the stirrer shaft enters the reaction zone through a stirrer feed entry port.

### Claim 15 (depends on 14)

The process of claim 14 wherein the linear velocity of the stirrer purge stream passing through the stirrer feed entry port is greater than or equal to 0.3 m/min.

### Claim 16 (depends on 14)

The process of claim 14 wherein the linear velocity of the stirrer purge stream passing through the stirrer feed entry port is greater than or equal to 1.0 m/min.

### Claim 17 (depends on 14)

The process of claim 14 wherein the linear velocity of the stirrer purge stream passing through the stirrer feed entry port is greater than or equal to 10.0 m/min.

### Claim 18 (depends on 15)

The process of claim 15 wherein the stirrer feed entry port extends beyond the interior wall of the tank reactor with a stirrer mechanism by greater than or equal to 2% of the axial length of the reactor interior.

### Claim 19 (depends on 15)

The process of claim 15 wherein the stirrer feed ,entry port extends beyond the interior wall of the tank reactor with a stirrer mechanism by greater than or equal to 5% of the axial length of the reactor interior.

### Claim 20 (depends on 15)

The process of claim 15 wherein the stirrer feed entry port extends beyond the interior wall of the tank reactor with a stirrer mechanism by greater than or equal to 10% of the axial length of the reactor interior.

### Claim 21 (depends on 18)

The process of claim 18 wherein the tank reactor with a stirrer mechanism has length-to-diameter ratios of 1:1 to 20:1.

### Claim 22 (depends on 18)

The process of claim 18 wherein the tank reactor with a stirrer mechanism includes up to six feed entry ports along its length.

### Claim 23 (depends on 18)

The process of claim 18 wherein the tank reactor with a stirrer mechanism is operated in up to six zones.

### Claim 24 (depends on 1)

The process of claim 1 wherein the olefin monomer of (b) comprises propylene.

### Claim 25 (depends on 1)

The process of claim 1 wherein the optional one or more comonomers of (b) comprise one or more of ethylene, propylene, butenes, hexenes, octenes, decenes, or dodecenes, and combinations thereof.

### Claim 26 (depends on 1)

The process of claim 1 wherein the one or more catalyst systems of (b) comprise one or more catalysts chosen from Ziegler Natta catalysts, metallocene catalysts, nonmetallocene metal-centered, heteroaryl ligand catalysts, and late transition metal catalysts.

### Claim 27 (depends on 1)

The process of claim 1 wherein the one or more catalyst systems comprise one or more activators chosen from, aluminoxane activators, aluminum alkyl activators, ionizing activators, non-ionizing activators, and combinations thereof.

### Claim 28 (depends on 1)

The process of claim 1 wherein in (b) the polymerization system for each reactor comprises greater than 60 wt % of optional one or more diluents or solvents.

### Claim 29 (depends on 1)

The process of claim 1 wherein the one or more catalyst systems comprise one or more catalyst supports chosen from talcs, inorganic oxides, and inorganic chlorides, polystyrene, polystyrene divinyl benzene polyolefins, zeolites, clays, inorganic oxides, silica, fumed silica, alumina, silica-alumina, magnesia, titania, zirconia, magnesium chloride, montmorillonite phyllosilicate, porous acrylic polymers, nanoconaposites, spherulitcs, polymeric beads and combinations thereof.

### Claim 30 (depends on 1)

The process of claim 1 wherein the one or more scavengers are chosen from trimethylaluminum, tricthylaluminum, triisobutylaluminum, tri-n-hexylaluminum, tri-n-octylaluminum, and combinations thereof.

### Claim 31 (depends on 10)

The process of claim 10 wherein the one or more reactors comprise a tubular reactor.

### Claim 32 (depends on 31)

The process of claim 31 wherein the tubular reactor has a length-to-diameter ratio of 10:1 to 50,000:1.

### Claim 33 (depends on 31)

The process of claim 31 wherein the tubular reactor includes up to 10 feed entry ports along its length.

### Claim 34 (depends on 31)

The process of claim 31. wherein the tubular reactor has a length of 100-4000 meters and an internal diameter of less than 12.5 cm.

### Claim 35 (depends on 31)

The process of claim 31 wherein the tubular reactor is operated in multiple zones.

### Claim 36 (depends on 31)

The process of claim 31 wherein the tubular reactor is operated with a Reynolds number greater than 2000.

### Claim 37 (depends on 10)

The process of claim 10 wherein the one or more reactors comprise a loop reactor.

### Claim 38 (depends on 37)

The process of claim 37 wherein the loop reactor has a diameter of 41 to 61 cm and a length of 100 to 200 meters.

### Claim 39 (depends on 10)

The process of claim 10 wherein the one or more reactors comprise two or more reactors in series.

### Claim 40 (depends on 39)

The process of claim 39 wherein, the two or more reactors in series comprise a tubular reactor followed by a stirred tank reactor.

### Claim 41 (depends on 39)

The process of claim 39 wherein the two or more reactors in series comprise a tubular reactor followed by a loop reactor.

### Claim 42

A process for reducing reactor fouling in a homogeneous polymerization process, comprising providing a tank, loop, or tubular reactor with one or more feed entry ports, and feeding to the reactor feed streams comprising: 1) an olefin monomer, 2) one or more catalyst systems, 3) optional one or more comonomers, 4) optional one or more scavengers, 5) optional one or more diluents or solvents, and 6) combinations thereof, wherein the linear velocity of the reactor feed streams passing through each of the one or more feed entry ports is greater than or equal to 0.3 m/min.

### Claim 43 (depends on 42)

The process of claim 42 wherein the linear velocity of the reactor feed streams passing through each of the one or more feed entry ports is greater than or equal to 1.0 m/min.

### Claim 44 (depends on 42)

The process of claim 42 wherein the linear velocity of the reactor feed streams passing through each of the one or more feed entry ports is greater than or equal to 10.0 m/min.

### Claim 45 (depends on 42)

The process of claim 42 wherein one or more of the feed entry ports extend beyond the interior wall of the reactor by greater than or equal to 2% of the internal radius of the reactor measured at the axial position of the one or more feed entry ports.

### Claim 46 (depends on 42)

The process of claim 42 wherein one or more of the feed entry ports extend beyond the interior wall of the reactor by greater than or equal to 10% of the internal radius of the reactor measured at the axial position of the one or more feed entry ports.

### Claim 47 (depends on 42)

The process of claim 42 wherein one or more of the feed entry ports extend beyond the interior wall of the reactor by greater than or equal to 20% of the internal radius of the reactor measured at the axial position of the one or more feed entry ports.

### Claim 48 (depends on 42)

the process of claim 42 wherein the tank reactor includes a stirrer mechanism.

### Claim 49 (depends on 48)

The process of claim 48 wherein the stirrer mechanism further includes a stirrer feed entry port that enters the reactor interior where the stirrer shall enters the reaction zone for feeding a stirrer purge stream.

### Claim 50 (depends on 49)

The process of claim 49 wherein the stirrer purge stream comprises: 1) an olefin monomer, 2) optional one or more comonomers, 3) optional one or more scavengers, 4) optional one or more diluents or solvents, and 5) combinations thereof.

### Claim 51 (depends on 50)

The process of claim 50 wherein the linear velocity of the stirrer purge stream is greater than or equal to 0.3 m/min.

### Claim 52 (depends on 50)

The process of claim 50 wherein the linear velocity of the stirrer purge stream is greater than or equal to 1.0 m/min.

### Claim 53 (depends on 50)

The process of claim 50 wherein the linear velocity of the stirrer purge stream is greater than or equal to 10.0 m/min.

### Claim 54 (depends on 51)

The process of claim 51 wherein the stirrer feed entry port extends beyond the interior wall of the reactor by greater than or equal to 2% of the axial length of the reactor interior.

### Claim 55 (depends on 51)

The process of claim 51 wherein the stirrer feed entry port extends beyond the interior wall of the reactor by greater than or equal to 5% of the axial length of the reactor interior,

### Claim 56 (depends on 51)

The process of claim 51 wherein the stirrer feed entry port extends beyond the interior wall of the reactor by greater than or equal to 10% of the axial length of the reactor interior.