CA1115446A - Process - Google Patents
ProcessInfo
- Publication number
- CA1115446A CA1115446A CA312,576A CA312576A CA1115446A CA 1115446 A CA1115446 A CA 1115446A CA 312576 A CA312576 A CA 312576A CA 1115446 A CA1115446 A CA 1115446A
- Authority
- CA
- Canada
- Prior art keywords
- terephthalic acid
- glycol
- suspension
- reaction vessel
- reactor
- Prior art date
- Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
- Expired
Links
- 238000000034 method Methods 0.000 title abstract description 7
- KKEYFWRCBNTPAC-UHFFFAOYSA-N Terephthalic acid Chemical compound OC(=O)C1=CC=C(C(O)=O)C=C1 KKEYFWRCBNTPAC-UHFFFAOYSA-N 0.000 claims abstract description 56
- LYCAIKOWRPUZTN-UHFFFAOYSA-N Ethylene glycol Chemical compound OCCO LYCAIKOWRPUZTN-UHFFFAOYSA-N 0.000 claims abstract description 43
- WGCNASOHLSPBMP-UHFFFAOYSA-N hydroxyacetaldehyde Natural products OCC=O WGCNASOHLSPBMP-UHFFFAOYSA-N 0.000 claims abstract description 17
- 239000000725 suspension Substances 0.000 claims abstract description 13
- IJGRMHOSHXDMSA-UHFFFAOYSA-N Atomic nitrogen Chemical compound N#N IJGRMHOSHXDMSA-UHFFFAOYSA-N 0.000 claims abstract description 10
- 238000005886 esterification reaction Methods 0.000 claims description 15
- 238000006243 chemical reaction Methods 0.000 claims description 8
- 229910001873 dinitrogen Inorganic materials 0.000 claims description 6
- 239000002253 acid Substances 0.000 claims description 4
- 239000007787 solid Substances 0.000 claims description 4
- 238000010924 continuous production Methods 0.000 claims description 3
- 239000007788 liquid Substances 0.000 claims description 3
- 239000007789 gas Substances 0.000 abstract description 4
- 229910052757 nitrogen Inorganic materials 0.000 abstract description 2
- 230000032050 esterification Effects 0.000 description 11
- AEMRFAOFKBGASW-UHFFFAOYSA-N Glycolic acid Natural products OCC(O)=O AEMRFAOFKBGASW-UHFFFAOYSA-N 0.000 description 6
- 239000000376 reactant Substances 0.000 description 4
- 238000003860 storage Methods 0.000 description 3
- RTZKZFJDLAIYFH-UHFFFAOYSA-N Diethyl ether Chemical compound CCOCC RTZKZFJDLAIYFH-UHFFFAOYSA-N 0.000 description 2
- 239000000463 material Substances 0.000 description 2
- 238000005086 pumping Methods 0.000 description 2
- 239000002002 slurry Substances 0.000 description 2
- 239000012190 activator Substances 0.000 description 1
- 238000010923 batch production Methods 0.000 description 1
- 230000015572 biosynthetic process Effects 0.000 description 1
- 230000004048 modification Effects 0.000 description 1
- 238000012986 modification Methods 0.000 description 1
- -1 polyethylene terephthalate Polymers 0.000 description 1
- 229920000139 polyethylene terephthalate Polymers 0.000 description 1
- 239000005020 polyethylene terephthalate Substances 0.000 description 1
- 229920000642 polymer Polymers 0.000 description 1
- 238000002360 preparation method Methods 0.000 description 1
- 239000002994 raw material Substances 0.000 description 1
- 230000035484 reaction time Effects 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 238000007086 side reaction Methods 0.000 description 1
Classifications
-
- B—PERFORMING OPERATIONS; TRANSPORTING
- B01—PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL
- B01J—CHEMICAL OR PHYSICAL PROCESSES, e.g. CATALYSIS OR COLLOID CHEMISTRY; THEIR RELEVANT APPARATUS
- B01J8/00—Chemical or physical processes in general, conducted in the presence of fluids and solid particles; Apparatus for such processes
- B01J8/0015—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor
- B01J8/0025—Feeding of the particles in the reactor; Evacuation of the particles out of the reactor by an ascending fluid
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
-
- C—CHEMISTRY; METALLURGY
- C08—ORGANIC MACROMOLECULAR COMPOUNDS; THEIR PREPARATION OR CHEMICAL WORKING-UP; COMPOSITIONS BASED THEREON
- C08G—MACROMOLECULAR COMPOUNDS OBTAINED OTHERWISE THAN BY REACTIONS ONLY INVOLVING UNSATURATED CARBON-TO-CARBON BONDS
- C08G63/00—Macromolecular compounds obtained by reactions forming a carboxylic ester link in the main chain of the macromolecule
- C08G63/78—Preparation processes
- C08G63/785—Preparation processes characterised by the apparatus used
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Chemical Kinetics & Catalysis (AREA)
- Health & Medical Sciences (AREA)
- Medicinal Chemistry (AREA)
- Polymers & Plastics (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
- Polyesters Or Polycarbonates (AREA)
Abstract
PROCESS
Abstract of the Disclosure This invention concerns a method of charging dry terephthalic acid into a reactor which may contain glycol and be under elevated pressure and elevated temperature. According to the invention a suspension of terephthalic acid in a gas such as nitrogen is formed and this suspension is charged into the reactor.
Abstract of the Disclosure This invention concerns a method of charging dry terephthalic acid into a reactor which may contain glycol and be under elevated pressure and elevated temperature. According to the invention a suspension of terephthalic acid in a gas such as nitrogen is formed and this suspension is charged into the reactor.
Description
~1544~5 This invention relates to a process for charging dry terephthalic acid to a reactor. More partic-ularly the invention relates to a process for adding dry -terephthalic acid to a reactor which contains glycol.
In the preparation o~ polyethylene terephthalate from glycol and terephthalic acid it is desirable to use these materials in the molar ratio of 1:1 or as closely as possible to minimi~e side reactions such as ether formation and to avoid having to recover unused glycol. In a batch process terephthalic acid may be charged to the reactor by pumping a premixed glycol/terephthalic acid paste to the reactor or by adding preweighed amounts of reactants ta a partially cooled vessel at atmospheric pressure.
Once the raw materials have been added the reactor may be brought to the desired pressure and temperature for the esterification reaction.
In a continuous process the esterification reactor must be maintained at elevated temperatures and pressure while the reactants are continuously metered into the vessel. Customarily this has been achieved by using a slurry pump which is capable of pumping a paste of glycol and terephthalic acid into a pressurized vessel. This method is limited by the fact that the paste viscosity gets very high when the ratio of glycol/terephthalic acid is low. The prior art has not provided a satisfactory solution to the problem of adding terephthalic acid to a reactor which contains hot glycol and may be under pressure.
According to the present invention glycol and terephthalic acid may be added to the esterification , .
- . . , .. .. , , -~ ~15 ~
reactor separately. According to this invention terephthalic acid is mixed with a gas such as nitrogen under pressure'to form a suspension of terephthalic acid in the gas and this suspension is metered under pressure into the esterification reactor. The'glycol is separately pumped into the'reactor in the proper amount to provide the'desired ratio of glycol to terephthalic acid in the esterification reactor. Normally the esterification reactor is maintained under pressure and 10' the reaction is run at a temperature in the range of about 250 to 270 C. Accordingly, in a continuous process for reacting terephthalic acid with liquid glycol in an esterification reaction vesseI maintained at elevated temperatures and pressures the'improvement comprises forming a suspension of dry, solid particulate terepht~alic acid in nitrogen gas under pressure, maintaining said suspension under pressure and charging said suspension into said reaction vessel to which glycol is being charged separately.
The'invention is illustrated in the following example'which is more fully explained by reference to the accompanying drawing which shows the flow of materials in the system. In the'drawing it is shown that terephthalic acid is passed from storage (not shown) to an intermediate hopper 1 from which it is discharged through a double valve system 2 and 3 into weigh'tank 4 where it is deposited on porous diaphragm 5 which is spaced apart from the bottom of the weigh tank 4. ~itrogen gas from storage (not shown~ is passed into the bottom of weigh tank 4 through conduit 6 and activator valve 7 at a point below porous disphragm 5.
~!j,C
~ ~ 5 4~
The nitrogen gas is under a pressure of about 80 psi-which is sufficiently great that it passes through the diaphragm and forms a suspension of terephthalic ~cld and nitrogen gas. The suspension is passed through conduit 8 and discharge valve 9 into esterification reactor 10 which is equipped with a separation column 11, a condenser 12 and an agitator 13. As terephthalic acid is passed into esterification reactor lO ethylene glycol is pumped through .
rc ,. , ..... .;
conduit 14 from storage, not shown, in the proper amount to provide the desired ratio of glycol to terephthalic acid.
Esterification reactor 10 is maintained at a pressure of 70 psig and a temperature of about 270 C. Excess nitrogen gas 1s vented out of esterification reactor 10 through the column llo In continuous operation low molecular weight polymer is continuously withdrawn from esterification reactor 10 in an amount about equal to the amount of terephthalic acid and glycol charged into the esterification reactor 10.
The above description shows that dry terephthalic acid can be charged into a vessel maintained at high temperature and pressure and that the terephthalic acid can be charged continuously. The esterification reaction is carried out using low ratios of glycol to acid ... .
preferably in the range of from about 1.05:1 to 1.7:1.
Lower ratios than 1:1 can be charged successfully by use of - the present system.
The invention provides several advantages over processes shown in the prior art. Glycol and terephthalic acid may be charged into a reactor in any desired ratios.
` In addition~ the reactant vessel may be maintained at a ~ high temperature and pressure while the dry terephthalic - acid is being charged. If desired~ two or more weigh tanks can be used to ensure that the terephthalic acid can charge continuously~ The reactants~ particularly the glycol~ can ~; be preheated to a desired temperature before being charged into the reactor and this shortens the reaction time.
Charglng terephthalic acid to a reactor by the ... ..
.. . .. ~.- -s~
present system is accurate and reproducible. It eliminates the need for preparing slurries or pastes which when low ratios of glycol to acid are used are very viscous and difficult to convey into the reaction vessel, particularly when the vessel is under pressure.
While certain representative embodiments ànd details have been shown for the purpose of illustrating the invention it will be apparent to those skilled in this art that various changes and modifications may be made therein without departlng from the sp1r1t or soope of the lnvention. ~, .' ' ' , : . .
.
. ' , .
.. . .. .- .. ... .
In the preparation o~ polyethylene terephthalate from glycol and terephthalic acid it is desirable to use these materials in the molar ratio of 1:1 or as closely as possible to minimi~e side reactions such as ether formation and to avoid having to recover unused glycol. In a batch process terephthalic acid may be charged to the reactor by pumping a premixed glycol/terephthalic acid paste to the reactor or by adding preweighed amounts of reactants ta a partially cooled vessel at atmospheric pressure.
Once the raw materials have been added the reactor may be brought to the desired pressure and temperature for the esterification reaction.
In a continuous process the esterification reactor must be maintained at elevated temperatures and pressure while the reactants are continuously metered into the vessel. Customarily this has been achieved by using a slurry pump which is capable of pumping a paste of glycol and terephthalic acid into a pressurized vessel. This method is limited by the fact that the paste viscosity gets very high when the ratio of glycol/terephthalic acid is low. The prior art has not provided a satisfactory solution to the problem of adding terephthalic acid to a reactor which contains hot glycol and may be under pressure.
According to the present invention glycol and terephthalic acid may be added to the esterification , .
- . . , .. .. , , -~ ~15 ~
reactor separately. According to this invention terephthalic acid is mixed with a gas such as nitrogen under pressure'to form a suspension of terephthalic acid in the gas and this suspension is metered under pressure into the esterification reactor. The'glycol is separately pumped into the'reactor in the proper amount to provide the'desired ratio of glycol to terephthalic acid in the esterification reactor. Normally the esterification reactor is maintained under pressure and 10' the reaction is run at a temperature in the range of about 250 to 270 C. Accordingly, in a continuous process for reacting terephthalic acid with liquid glycol in an esterification reaction vesseI maintained at elevated temperatures and pressures the'improvement comprises forming a suspension of dry, solid particulate terepht~alic acid in nitrogen gas under pressure, maintaining said suspension under pressure and charging said suspension into said reaction vessel to which glycol is being charged separately.
The'invention is illustrated in the following example'which is more fully explained by reference to the accompanying drawing which shows the flow of materials in the system. In the'drawing it is shown that terephthalic acid is passed from storage (not shown) to an intermediate hopper 1 from which it is discharged through a double valve system 2 and 3 into weigh'tank 4 where it is deposited on porous diaphragm 5 which is spaced apart from the bottom of the weigh tank 4. ~itrogen gas from storage (not shown~ is passed into the bottom of weigh tank 4 through conduit 6 and activator valve 7 at a point below porous disphragm 5.
~!j,C
~ ~ 5 4~
The nitrogen gas is under a pressure of about 80 psi-which is sufficiently great that it passes through the diaphragm and forms a suspension of terephthalic ~cld and nitrogen gas. The suspension is passed through conduit 8 and discharge valve 9 into esterification reactor 10 which is equipped with a separation column 11, a condenser 12 and an agitator 13. As terephthalic acid is passed into esterification reactor lO ethylene glycol is pumped through .
rc ,. , ..... .;
conduit 14 from storage, not shown, in the proper amount to provide the desired ratio of glycol to terephthalic acid.
Esterification reactor 10 is maintained at a pressure of 70 psig and a temperature of about 270 C. Excess nitrogen gas 1s vented out of esterification reactor 10 through the column llo In continuous operation low molecular weight polymer is continuously withdrawn from esterification reactor 10 in an amount about equal to the amount of terephthalic acid and glycol charged into the esterification reactor 10.
The above description shows that dry terephthalic acid can be charged into a vessel maintained at high temperature and pressure and that the terephthalic acid can be charged continuously. The esterification reaction is carried out using low ratios of glycol to acid ... .
preferably in the range of from about 1.05:1 to 1.7:1.
Lower ratios than 1:1 can be charged successfully by use of - the present system.
The invention provides several advantages over processes shown in the prior art. Glycol and terephthalic acid may be charged into a reactor in any desired ratios.
` In addition~ the reactant vessel may be maintained at a ~ high temperature and pressure while the dry terephthalic - acid is being charged. If desired~ two or more weigh tanks can be used to ensure that the terephthalic acid can charge continuously~ The reactants~ particularly the glycol~ can ~; be preheated to a desired temperature before being charged into the reactor and this shortens the reaction time.
Charglng terephthalic acid to a reactor by the ... ..
.. . .. ~.- -s~
present system is accurate and reproducible. It eliminates the need for preparing slurries or pastes which when low ratios of glycol to acid are used are very viscous and difficult to convey into the reaction vessel, particularly when the vessel is under pressure.
While certain representative embodiments ànd details have been shown for the purpose of illustrating the invention it will be apparent to those skilled in this art that various changes and modifications may be made therein without departlng from the sp1r1t or soope of the lnvention. ~, .' ' ' , : . .
.
. ' , .
.. . .. .- .. ... .
Claims (3)
1. In a continuous process for reacting terephthalic acid with liquid glycol in an esterification reaction vessel maintained at elevated temperatures and pressures the improvement which comprises forming a suspension of dry, solid particulate terephthalic acid in nitrogen gas under pressure, maintaining said suspension under pressure and charging said suspension into said reaction vessel to which glycol is being charged separately.
2. The improvement of claim 1 wherein the suspension of dry, solid particulate terephthalic acid in the nitrogen gas is maintained and charged to said reaction vessel at a pressure higher than that maintained in said reaction vessel.
3. The improvement of claim 2 wherein the liquid glycol and suspended dry, solid terephthalic acid are charged to the reaction vessel in amounts to provide a molar ratio of glycol to acid ranging from about 1:1 to about 1.7:1 in said reaction vessel.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US86133377A | 1977-12-16 | 1977-12-16 | |
| US861,333 | 1977-12-16 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1115446A true CA1115446A (en) | 1981-12-29 |
Family
ID=25335519
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA312,576A Expired CA1115446A (en) | 1977-12-16 | 1978-10-03 | Process |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS5490138A (en) |
| BR (1) | BR7808100A (en) |
| CA (1) | CA1115446A (en) |
| DE (1) | DE2850951A1 (en) |
| FR (1) | FR2411631A1 (en) |
| GB (1) | GB2010294B (en) |
| IT (1) | IT1111091B (en) |
| NL (1) | NL188096C (en) |
Families Citing this family (14)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0958857A1 (en) * | 1998-05-14 | 1999-11-24 | Bp Chemicals S.N.C. | Process for the introduction of a catalyst into a gas phase polymerisation reaction |
| US6906164B2 (en) | 2000-12-07 | 2005-06-14 | Eastman Chemical Company | Polyester process using a pipe reactor |
| EP1453883B1 (en) | 2000-12-07 | 2012-11-21 | Grupo Petrotemex, S.A. de C.V. | Low cost polyester process using a pipe reactor |
| US7943094B2 (en) | 2006-12-07 | 2011-05-17 | Grupo Petrotemex, S.A. De C.V. | Polyester production system employing horizontally elongated esterification vessel |
| US7649109B2 (en) | 2006-12-07 | 2010-01-19 | Eastman Chemical Company | Polyester production system employing recirculation of hot alcohol to esterification zone |
| US7863477B2 (en) | 2007-03-08 | 2011-01-04 | Eastman Chemical Company | Polyester production system employing hot paste to esterification zone |
| US7847053B2 (en) | 2007-07-12 | 2010-12-07 | Eastman Chemical Company | Multi-level tubular reactor with oppositely extending segments |
| US7829653B2 (en) | 2007-07-12 | 2010-11-09 | Eastman Chemical Company | Horizontal trayed reactor |
| US7842777B2 (en) | 2007-07-12 | 2010-11-30 | Eastman Chemical Company | Sloped tubular reactor with divided flow |
| US7868129B2 (en) | 2007-07-12 | 2011-01-11 | Eastman Chemical Company | Sloped tubular reactor with spaced sequential trays |
| US7872090B2 (en) | 2007-07-12 | 2011-01-18 | Eastman Chemical Company | Reactor system with optimized heating and phase separation |
| US7868130B2 (en) | 2007-07-12 | 2011-01-11 | Eastman Chemical Company | Multi-level tubular reactor with vertically spaced segments |
| US7872089B2 (en) | 2007-07-12 | 2011-01-18 | Eastman Chemical Company | Multi-level tubular reactor with internal tray |
| US7858730B2 (en) | 2007-07-12 | 2010-12-28 | Eastman Chemical Company | Multi-level tubular reactor with dual headers |
Family Cites Families (6)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US3393944A (en) * | 1966-10-25 | 1968-07-23 | Petrocarb Inc | Method for pneumatically injecting solid particles into a high pressure zone |
| US4020049A (en) * | 1967-09-14 | 1977-04-26 | The Goodyear Tire & Rubber Company | Process for preparing polyester resin |
| DE1667010C3 (en) * | 1967-12-23 | 1975-10-09 | Dynamit Nobel Ag, 5210 Troisdorf | Method and device for the reliable filling of oxidation-sensitive materials |
| NL7016364A (en) * | 1970-10-21 | 1972-04-25 | ||
| ES419510A1 (en) * | 1972-12-15 | 1976-04-16 | Huels Chemische Werke Ag | Process for the esterification of terephthalic acid in the gas phase |
| US4018671A (en) * | 1975-01-14 | 1977-04-19 | Marathon Oil Company | Intermittent catalyst addition system |
-
1978
- 1978-10-03 CA CA312,576A patent/CA1115446A/en not_active Expired
- 1978-11-08 GB GB7843627A patent/GB2010294B/en not_active Expired
- 1978-11-24 DE DE19782850951 patent/DE2850951A1/en active Granted
- 1978-12-11 NL NLAANVRAGE7812037,A patent/NL188096C/en not_active IP Right Cessation
- 1978-12-11 JP JP15298578A patent/JPS5490138A/en active Granted
- 1978-12-11 BR BR7808100A patent/BR7808100A/en unknown
- 1978-12-12 IT IT52265/78A patent/IT1111091B/en active
- 1978-12-13 FR FR7835040A patent/FR2411631A1/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| BR7808100A (en) | 1979-08-07 |
| FR2411631A1 (en) | 1979-07-13 |
| JPS5490138A (en) | 1979-07-17 |
| GB2010294B (en) | 1982-08-11 |
| DE2850951A1 (en) | 1979-06-21 |
| GB2010294A (en) | 1979-06-27 |
| JPS6317089B2 (en) | 1988-04-12 |
| NL7812037A (en) | 1979-06-19 |
| NL188096C (en) | 1992-04-01 |
| DE2850951C2 (en) | 1989-04-20 |
| NL188096B (en) | 1991-11-01 |
| FR2411631B1 (en) | 1982-04-30 |
| IT1111091B (en) | 1986-01-13 |
| IT7852265A0 (en) | 1978-12-12 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |