US4640963A
Expired / Lapsed
US
⏱️ 0.0 years remaining
Method and apparatus for recycle of entrained solids in off-gas from a gas-phase polyolefin reactor
Assignee: BP Corp North America Inc
•
Filing: 1985-02-15
•
Granted: 1987-02-03
•
Expires: 2005-02-15
Abstract
Abstract In a process for quench-cooled, vapor-phase polymerization of olefin monomer comprising (a) contacting an olefin monomer, or mixture of olefin monomers, with a polymerization catalyst in the presence of hydrogen in a reactor vessel to form polymer product, and (b) removing, condensing and recycling off-gas from such reactor, an improvement comprises separating entrained polymerizing solid fines from said off-gas and recycling such solids directly to the reactor without substantial continued polymerization of such solids while in the presence of a substantially different concentration of hydrogen than in the reactor.
Inventors
- 👤 David R. Kreider
- 👤 Albert McCullum
- 👤 Philip M. Rose
- 👤 Chi-Hung Lin
Bibliographic Details
Application Number
—
Jurisdiction
US
Data Source
google_patents
Last Synchronized
2026-10-30 11:10
CPC Classifications
B; B01; B01J; B01J19/00; B01J19/26; B01J19/18; B01J19/1868; B01J19/1881; B01J8/00; B01J8/0015; B01J8/004; B01J8/08; B01J8/10; B01J8/18; B01J8/24; B01J8/36; B01J8/38; B01J8/382; C; C08; C08F; C08F10/00; B01J2219/00; B01J2219/00049; B01J2219/00051; B01J2219/00074; B01J2219/00087; B01J2219/00103; B01J2219/00121; B01J2219/00123; B01J2219/00162; B01J2219/18; B01J2219/182; B01J2219/19; B01J2219/194; B01J2219/1941; B01J2219/1943; Y; Y02; Y02P; Y02P20/00; Y02P20/50; Y02P20/582
Claims Analysis
Total Claims: 16
Claim 1
Independent Claim
89 words
In a process for quench-cooled, vapor-phase polymerization of olefin monomer comprising (a) contacting an olefin monomer, or mixture of olefin monomers, with a polymerization catalyst in the presence of hydrogen in a reactor vessel to form polymer product, and (b) removing, condensing and recycling off-gas from such reactor, the improvement comprising separating entrained polymerizing solid fines from said off-gas and recycling such solids directly to the reactor without substantial continued polymerization of such solids while in the presence of a substantially different concentration of hydrogen than in the reactor.
Claim 2
Dependent Claim
89 words
In a process for quench-cooled, vapor-phase polymerization of olefin monomer comprising (a) contacting an olefin monomer, or mixture of olefin monomers, with a polymerization catalyst in the presence of hydrogen in a reactor vessel to form polymer product, and (b) removing, condensing and recycling off-gas from such reactor, the improvement comprising separating entrained polymerizing solid fines from said off-gas and recycling such solids directly to the reactor without substantial continued polymerization of such solids while in the presence of a substantially different concentration of hydrogen than in the reactor.
Claim 3
Dependent Claim
13 words
The process of claim 1 wherein the reactor vessel is a stirred-bed reactor.
Claim 4
Dependent Claim
14 words
The process of claim 1 wherein the reactor vessel is a fluidized bed reactor.
Claim 5
Dependent Claim
21 words
The process of claim 1 wherein entrained polymer fines and solid catalyst particles are separated from the off-gas by a cyclone.
Claim 6
Dependent Claim
34 words
The process of claim 4 wherein scrubbed off-gas is used as a motive gas through an eductor to entrain separated polymer fines in such scrubbed off-gas and return such entrained fines to the reactor.
Claim 7
Dependent Claim
100 words
The process of claim 5 wherein said eductor comprises (i) an eductive chamber; (ii) an inlet conduit with an opening at one end through which separated fines may enter and joined at the other end to the eductive chamber; (iii) a discharge conduit with an inlet end and an outlet end, the inlet end joined to the eductive chamber and the outlet end joined to a fines return line to the reactor, the inlet end having a smaller cross-section than the outlet end; and (iv) a motive gas nozzle opening into the eductive chamber and aimed towards the discharge conduit.
Claim 8
Dependent Claim
82 words
The process of claim 6 wherein said eductor comprises a generally cylindrical body with a cylindrical chamber therein, an opening at the top of said body through which separated fines may enter, a conical formation in the lower portion of such cylindrical body with an opening at the bottom thereof into a larger-in-cross-section conduit, and a gas stream nozzle which is spaced above the bottom opening of said conical formation and which has an inlet end coupled to a motive gas stream.
Claim 9
Dependent Claim
39 words
The process of claim 6 wherein the pressure differential between the pressure at the bottom of the cyclone and the pressure of the motive gas stream at the nozzle in the eductor is between about 5 and 80 psig.
Claim 10
Dependent Claim
17 words
The process of claim 1 wherein the olefin monomer is ethylene, propylene, butene or a mixture thereof.
Claim 11
Dependent Claim
24 words
The process of claim 1 wherein the olefin monomer is propylene of a mixture or propylene and a minor amount of a copolymerizable alpha-olefin.
Claim 12
Dependent Claim
120 words
In a process for quench-cooled, vapor-phase polymerization of propylene or a mixture of propylene and a copolymerizable alpha-olefin comprising (a) contacting such olefin with a polymerization catalyst in the presence of hydrogen in a horizontal, stirred-bed reactor to form polymer product, and (b) removing, condensing and recycling off-gas from such reactor, the improvement comprising separating entrained polymerizing solid fines from said off-gas by a cyclone, transferring such separated fines to an eductor, entraining separated fines in the eductor with a motive gas essentially free of solids and returning such entrained fines from the eductor directly to the reactor without substantial continued polymerization of such solids while in the presence of a substantially different concentration of hydrogen than in the reactor.
Claim 13
Dependent Claim
120 words
In a process for quench-cooled, vapor-phase polymerization of propylene or a mixture of propylene and a copolymerizable alpha-olefin comprising (a) contacting such olefin with a polymerization catalyst in the presence of hydrogen in a horizontal, stirred-bed reactor to form polymer product, and (b) removing, condensing and recycling off-gas from such reactor, the improvement comprising separating entrained polymerizing solid fines from said off-gas by a cyclone, transferring such separated fines to an eductor, entraining separated fines in the eductor with a motive gas essentially free of solids and returning such entrained fines from the eductor directly to the reactor without substantial continued polymerization of such solids while in the presence of a substantially different concentration of hydrogen than in the reactor.
Claim 14
Dependent Claim
100 words
The process of claim 11 wherein said eductor comprises (i) an eductive chamber; (ii) an inlet conduit with an opening at one end through which separated fines may enter and joined at the other end to the eductive chamber; (iii) a discharge conduit with an inlet end and an outlet end, the inlet end joined to the eductive chamber and the outlet end joined to a fines return line to the reactor, the inlet end having a smaller cross-section than the outlet end; and (iv) a motive gas nzozle opening into the eductive chamber and aimed towards the discharge conduit.
Claim 15
Dependent Claim
144 words
The process of claim 12 wherein said eductor comprises a generally cylindrical body with a cylindrical chamber therein, an opening at the top of said body through which separated fines may enter, a conical formation in the lower portion of such cylindrical body with an opening at the bottom thereof into a larger-in-crosssection conduit, and a gas stream nozzle which is spaced above the bottom opening of said conical formation and which has an inlet end coupled to a motive gas stream and wherein the conical formation inside said coaxial cylindrical body has a slope to the axis of the conical formation of between about five and thirty degrees and wherein the pressure differential between the pressure at the bottom of the cyclone and the pressure of the motive gas stream at the nozzle in the eductor is between about 5 and 80 psig.
Claim 16
Dependent Claim
38 words
The process of claim 12 wherein scrubbed off-gas is used as a motive gas through an eductor to entrain separated polymer fines and solid catalyst particles in such scrubbed off-gas and return such entrained fines to the reactor.
References Cited (Backward Citations)
USPTO Annuity & Maintenance Windows
| Annuity Stage | Window Opens | Payment Deadline | Surcharge Period Until | Estimated Fee | Status |
|---|---|---|---|---|---|
| 3.5 Years (Year 4) | 1990-02-02 | 1990-08-04 | 1991-02-03 | $2000.00 | Window Closed / Lapsed |
| 7.5 Years (Year 8) | 1994-02-02 | 1994-08-04 | 1995-02-03 | $3760.00 | Window Closed / Lapsed |
| 11.5 Years (Year 12) | 1998-02-02 | 1998-08-04 | 1999-02-03 | $7700.00 | Window Closed / Lapsed |