CA1091678A - Process for recovering maleic anhydride by condensation - Google Patents
Process for recovering maleic anhydride by condensationInfo
- Publication number
- CA1091678A CA1091678A CA304,164A CA304164A CA1091678A CA 1091678 A CA1091678 A CA 1091678A CA 304164 A CA304164 A CA 304164A CA 1091678 A CA1091678 A CA 1091678A
- Authority
- CA
- Canada
- Prior art keywords
- maleic anhydride
- water
- anhydride
- temperature
- process according
- 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
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C51/00—Preparation of carboxylic acids or their salts, halides or anhydrides
- C07C51/54—Preparation of carboxylic acid anhydrides
- C07C51/573—Separation; Purification; Stabilisation; Use of additives
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Engineering & Computer Science (AREA)
- Oil, Petroleum & Natural Gas (AREA)
- Vaporization, Distillation, Condensation, Sublimation, And Cold Traps (AREA)
- Furan Compounds (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Abstract
ABSTRACT OF THE DISCLOSURE
A PROCESS FOR RECOVERING
MALEIC ANHYDRIDE BY CONDENSATION
A process for recovering maleic anhydride from gaseous compositions comprising maleic anhydride and water by condensing the composition at a temperature in the range of from about 20°C to about 50°C and a pressure of less than about 200 millimeters of mercury.
A PROCESS FOR RECOVERING
MALEIC ANHYDRIDE BY CONDENSATION
A process for recovering maleic anhydride from gaseous compositions comprising maleic anhydride and water by condensing the composition at a temperature in the range of from about 20°C to about 50°C and a pressure of less than about 200 millimeters of mercury.
Description
~ J~ILti'7~
BACKGRO~D OF T~E I~ENTION
_ This invention concerns a process for recovering maleic Qnhydride from gaseous compositions which comprise water as well as maleic anhydride.
The process i5 carried out by condensing the gas under select temperature and pressure conditions. In this ~ay, maleic anhydride is collected aa a condensate while light impurities such a8 water and acids re~ain in the vapor phase.
This process i8 particularly adaptable to the recovery of maleic anhydride which is normally lost during the li~lt stripping of crude maleic anhydride. Crude maleic anhydride is produced by the vapor phase oxidation of a hydrocarbon ~eed, and is recovered by absorption from the oxidation effluent using a liquid solvent ~ollowed by distillation of the anhydride-rich absorbent. United States Patent 3,818,680 to Marquis thoroughly de-scribes a typical process ~or producing crude maleic anhydride using a liq-uid intramolecular carboxylic acid absorbent. Other oreanic absorbents can be used such as those disclosed in United States Patents 2,574,644, 3,o40,o59; 2,893,924j 3,891,680 and 3,850,~58.
It is conventional practice to further refine the crude maleic anhydride by stripping off low-boiling impurities using reduced pressure distillation. In general, the low-boiling impurities comprise carboxylic acids such as acetic and acrylic acids and water. However, under even the best of operating conditions, the overhead vapor will also contain some maleic anhydride which is either lost through the vacuum system or recovered through an elaborate absorption and recycle process. Thus, the overhead vapor comprises maleic anhydride and water. Conventional absorption pro-cessing has been tried as a method of recovering the anhydride, but has several drawbacks. In particular, a significant proportion of the impur-ities must also be absorbed and recycled to insure complete anhydride re-covery. Thus, using absorption to recover the anhydride from the light `'~
, , 1~)9~i7~
stripper overhead vapor is a relatively inefficient process.
Accordingly, it would be advantageous to provide a process forrecovering maleic anhydride from gaseous mixtures also containing water and low-boiling impurities which while recovering the anhydride leaves the water and other i~purlties in the ~as.
Several United S-tates patentu discuss the recovery of maleic an-hydride from gaseous compositions also containine water. In general, these methods use partial condensation of maleic anhydride e~ected by cooling the gaseous compo~ition to temperatures above 50C so as to minimize con-densation of water. Such practice, however, results in only partial re-covery of maleic anhydride contaminated with some maleic acid, since any attempt at complete recovery requires cooling the gas below the water dew point. If the water dew point is reached, the maleic anhydride will hydrol-yze to maleic and fumaric acids. Thus, for example, British Patent 822,612 teaches diluting the effluent gas from the oxidation reactor with an inert gas until the anhydride partial pressure is less than 2.24 millimeters of mercury and cooling the gas to about 20C. Similarly, United States Patent
BACKGRO~D OF T~E I~ENTION
_ This invention concerns a process for recovering maleic Qnhydride from gaseous compositions which comprise water as well as maleic anhydride.
The process i5 carried out by condensing the gas under select temperature and pressure conditions. In this ~ay, maleic anhydride is collected aa a condensate while light impurities such a8 water and acids re~ain in the vapor phase.
This process i8 particularly adaptable to the recovery of maleic anhydride which is normally lost during the li~lt stripping of crude maleic anhydride. Crude maleic anhydride is produced by the vapor phase oxidation of a hydrocarbon ~eed, and is recovered by absorption from the oxidation effluent using a liquid solvent ~ollowed by distillation of the anhydride-rich absorbent. United States Patent 3,818,680 to Marquis thoroughly de-scribes a typical process ~or producing crude maleic anhydride using a liq-uid intramolecular carboxylic acid absorbent. Other oreanic absorbents can be used such as those disclosed in United States Patents 2,574,644, 3,o40,o59; 2,893,924j 3,891,680 and 3,850,~58.
It is conventional practice to further refine the crude maleic anhydride by stripping off low-boiling impurities using reduced pressure distillation. In general, the low-boiling impurities comprise carboxylic acids such as acetic and acrylic acids and water. However, under even the best of operating conditions, the overhead vapor will also contain some maleic anhydride which is either lost through the vacuum system or recovered through an elaborate absorption and recycle process. Thus, the overhead vapor comprises maleic anhydride and water. Conventional absorption pro-cessing has been tried as a method of recovering the anhydride, but has several drawbacks. In particular, a significant proportion of the impur-ities must also be absorbed and recycled to insure complete anhydride re-covery. Thus, using absorption to recover the anhydride from the light `'~
, , 1~)9~i7~
stripper overhead vapor is a relatively inefficient process.
Accordingly, it would be advantageous to provide a process forrecovering maleic anhydride from gaseous mixtures also containing water and low-boiling impurities which while recovering the anhydride leaves the water and other i~purlties in the ~as.
Several United S-tates patentu discuss the recovery of maleic an-hydride from gaseous compositions also containine water. In general, these methods use partial condensation of maleic anhydride e~ected by cooling the gaseous compo~ition to temperatures above 50C so as to minimize con-densation of water. Such practice, however, results in only partial re-covery of maleic anhydride contaminated with some maleic acid, since any attempt at complete recovery requires cooling the gas below the water dew point. If the water dew point is reached, the maleic anhydride will hydrol-yze to maleic and fumaric acids. Thus, for example, British Patent 822,612 teaches diluting the effluent gas from the oxidation reactor with an inert gas until the anhydride partial pressure is less than 2.24 millimeters of mercury and cooling the gas to about 20C. Similarly, United States Patent
2,762,449; United States Patent 2,812,037; and French Patent 1,303,126 teach partial condensation processes for recovering maleic anhydride by cooling the eas to temperatures between 50 -60C from gas compositions com-prising the anhydride and relatively lo~ concentrations of water. In sum-mary, prior art teaches recovery of maleic anhydride by cooling maleic an-hydride gases at about one atmosphere pressure.
The prior art partial condensations are particularly useful where the concentration of anhydride is relatively high and concentration of water relatively low, usually less than 5 volume %, such that the over-all effi-ciency of the recovery is not significantly reduced by leaving minor amounts of anhydride in the gas. However, it is still desirable to provide a pro-cess which provides essentially complete recovery of anhydride even where the concentration of water is relatively high, typically more than 10 ~09.L~
volume %.
SUMMARY OF THE INVE~TIO~
It has now been found th~t maleic anhyaride in a gaseous composi-tion with water c~n be recovered, without significant water contamination, by condensing the composition at a temperature between about 20C and 50C, preferably between about 25C and 40C and a pressure of less tban about 200 mm, preferably from about 25 mm to about 100 ~n.
DE~AILED DESCRIPTION OF THE I~VENTION
According to this invention, maleic anhydride can be recovered from gaseous mixtures with water without appreciable loss of the anhydride, and without appreciable loss of efficiency by condensing the gas containing water and maleic anhydride at reduced pressure. Generally, gas streams containing both water and maleic anhydride cannot be condensed because of the possibil-ity that enough water will condense with the anhydride to cause hydrolysis ; of the anhydride to maleic acid. Maleic acid readily isomerizes to solid fhmaric acid which is insoluble. However, it has been found that under the ; select conditions of this invention, such gaseous mixtures can be condensed to recover maleic anhydride without consequent water condensation. Conden-sation of the mixtures can be carried out at a temperature between about 20 C and 50 C at a reduced pressure of less than about 200 mm.
In a preferred embodiment, the process is used to recover residual maleic anhydride contained in the gaseous overheads from the distillation of crude maleic anhydride. Such compositions generally comprise from about 1 to about 30 percent by volume maleic anhydride and from about 10 to about 70 percent by volume water. In accordance with this invention, the overhead vapor containing residual maleic anhydride and low-boiling impurities is passed to a condenser system. The condenser system is maintained at a tem-perature of from about 20 C to 50C at a pressure of less than 200 milli-meters of mercury. The condensate from the condenser system, containing liquid maleic anhydride, can be recycled and the vaporous impurities can be ~0916~
vented through the vacuum system.
The following example further illustrates the process oY this in-vention applied to the recovery of maleic anhydride from the light stripper overhead vapors of a crude maleic anhydride distillation process, and sue-gests additional embodiments within the scope of the followine claims.
Example A crude maleic anhydride product stream wae obtained by oxidizing n-butane according to the process described in United States Patent
The prior art partial condensations are particularly useful where the concentration of anhydride is relatively high and concentration of water relatively low, usually less than 5 volume %, such that the over-all effi-ciency of the recovery is not significantly reduced by leaving minor amounts of anhydride in the gas. However, it is still desirable to provide a pro-cess which provides essentially complete recovery of anhydride even where the concentration of water is relatively high, typically more than 10 ~09.L~
volume %.
SUMMARY OF THE INVE~TIO~
It has now been found th~t maleic anhyaride in a gaseous composi-tion with water c~n be recovered, without significant water contamination, by condensing the composition at a temperature between about 20C and 50C, preferably between about 25C and 40C and a pressure of less tban about 200 mm, preferably from about 25 mm to about 100 ~n.
DE~AILED DESCRIPTION OF THE I~VENTION
According to this invention, maleic anhydride can be recovered from gaseous mixtures with water without appreciable loss of the anhydride, and without appreciable loss of efficiency by condensing the gas containing water and maleic anhydride at reduced pressure. Generally, gas streams containing both water and maleic anhydride cannot be condensed because of the possibil-ity that enough water will condense with the anhydride to cause hydrolysis ; of the anhydride to maleic acid. Maleic acid readily isomerizes to solid fhmaric acid which is insoluble. However, it has been found that under the ; select conditions of this invention, such gaseous mixtures can be condensed to recover maleic anhydride without consequent water condensation. Conden-sation of the mixtures can be carried out at a temperature between about 20 C and 50 C at a reduced pressure of less than about 200 mm.
In a preferred embodiment, the process is used to recover residual maleic anhydride contained in the gaseous overheads from the distillation of crude maleic anhydride. Such compositions generally comprise from about 1 to about 30 percent by volume maleic anhydride and from about 10 to about 70 percent by volume water. In accordance with this invention, the overhead vapor containing residual maleic anhydride and low-boiling impurities is passed to a condenser system. The condenser system is maintained at a tem-perature of from about 20 C to 50C at a pressure of less than 200 milli-meters of mercury. The condensate from the condenser system, containing liquid maleic anhydride, can be recycled and the vaporous impurities can be ~0916~
vented through the vacuum system.
The following example further illustrates the process oY this in-vention applied to the recovery of maleic anhydride from the light stripper overhead vapors of a crude maleic anhydride distillation process, and sue-gests additional embodiments within the scope of the followine claims.
Example A crude maleic anhydride product stream wae obtained by oxidizing n-butane according to the process described in United States Patent
3,864,280, which issued February 4, 1975 to Schneider. The concentrations of components in the product stream are shown in Table I. For such a com-position, the dew points of water and maleic anhydride at various total pres-sures are given in Table II. The stream was condensed by passing it through a condenser cooled by a countercurrent flow of air through the ~acket. In a typical run, for example, 2 g mols/hr of this stream was passed through a condenser with a heat transfer area of 0.3 sq. ft.
As condensation proceeded, crystals of maleic anhydride were formed on the heat exchanger walls. The exhaust from the condenser was scrubbed and analyzed for its composition by potentiometric titration for organic acids and by gas chromatography for complete composition.
The condensed maleic anhydride was then analyzed for trace impur-ities such as maleic acid, fumaric acid, light organic acids and other organic impurities by various methods such as freeæing point, preferential solubility in chloroform, infra-red spectrometry and gas chromatography.
Table III lists the run conditions and the results of these analy-ses. ~fficiency of maleic anhydride recovery by this condensation process was obtained from analyses of the condensed maleic anhydride and the exhaust gas composition leaving the condenser in operation. Data in Table III shows that maintaining a temperature of more than about 20C, preferably more than about 30C, and a pressure of less than about 50 mm Hg results in undetect-ably small amount of water condensation or hydration of condensed maleic ~O~t;~
anhydride to malelc acid of fumarlc acid. Other oreanic impurities were also rejected under these conditions to provide high quality of maleic an-hydride shown by increased color stability.
Typical Composition of Crude Maleic Anhvdride Distillation Overhead Component Volume %
n-butane 0.69 water 49.39 oxygen 5.13 nitrogen 21. 87 carbon oxides 1.84 acetic acia 6.68 acrylic acid 5.56 butyric acid 0.18 maleic anhydride 8.66 Total 100.00 ~ABLE II
Dew Points For Water and Maleic Anhydride in Stream With Composition of_Table 1 Condenser Pressure De~ Point Temperature~F
mm Hg WaterMaleic Anhydride TABLE III
ppm Maleic Condenser Wt.% Organic & Fumaric Run Co~denser Pressure MA Condenser Acids in Acids in No. Temp. (C) (mm Hg) Efficiency % Condensed MA Condensed MA
1 37. ô 20 86 0.2 < 300 2 37.8 25 ô2 0.42 <300 3 37. 8 30 79 o . l~g<300
As condensation proceeded, crystals of maleic anhydride were formed on the heat exchanger walls. The exhaust from the condenser was scrubbed and analyzed for its composition by potentiometric titration for organic acids and by gas chromatography for complete composition.
The condensed maleic anhydride was then analyzed for trace impur-ities such as maleic acid, fumaric acid, light organic acids and other organic impurities by various methods such as freeæing point, preferential solubility in chloroform, infra-red spectrometry and gas chromatography.
Table III lists the run conditions and the results of these analy-ses. ~fficiency of maleic anhydride recovery by this condensation process was obtained from analyses of the condensed maleic anhydride and the exhaust gas composition leaving the condenser in operation. Data in Table III shows that maintaining a temperature of more than about 20C, preferably more than about 30C, and a pressure of less than about 50 mm Hg results in undetect-ably small amount of water condensation or hydration of condensed maleic ~O~t;~
anhydride to malelc acid of fumarlc acid. Other oreanic impurities were also rejected under these conditions to provide high quality of maleic an-hydride shown by increased color stability.
Typical Composition of Crude Maleic Anhvdride Distillation Overhead Component Volume %
n-butane 0.69 water 49.39 oxygen 5.13 nitrogen 21. 87 carbon oxides 1.84 acetic acia 6.68 acrylic acid 5.56 butyric acid 0.18 maleic anhydride 8.66 Total 100.00 ~ABLE II
Dew Points For Water and Maleic Anhydride in Stream With Composition of_Table 1 Condenser Pressure De~ Point Temperature~F
mm Hg WaterMaleic Anhydride TABLE III
ppm Maleic Condenser Wt.% Organic & Fumaric Run Co~denser Pressure MA Condenser Acids in Acids in No. Temp. (C) (mm Hg) Efficiency % Condensed MA Condensed MA
1 37. ô 20 86 0.2 < 300 2 37.8 25 ô2 0.42 <300 3 37. 8 30 79 o . l~g<300
4 37.8 5 78 0.8 <300 32.2 30 ô2 0.7 ~300 6 23.9 30 85 1.881000-2000 7 21.1 30 94 2 ~ 72500-5000
Claims (6)
PROPERTY OR PRIVILEGE IS CLAIMED ARE DEFINED AS FOLLOWS:
1. A process for recovering maleic anhydride from gaseous composi-tions comprising maleic anhydride and water, comprising cooling said com-position to a temperature in the range of from about 20°C to about 50°C at a pressure less than about 200 millimeters of mercury.
2. A process according to Claim 1 wherein the gaseous composition comprises from about 1 to about 30 percent by volume maleic anhydride and from about 10 to about 70 percent by volume water.
3. A process according to Claim 1 wherein the composition is cooled to a temperature of from about 25°C to about 40°C at a pressure less than about 50 millimeters of mercury.
4. A process according to Claim 3 wherein the composition is cooled to a temperature of about 30°C.
5. In a process for stripping low-boiling impurities from crude maleic anhydride produced by the vapor phase oxidation of a hydrocarbon feedstock; the improvement which comprises, passing the lights stripper overhead vapor through a condenser system maintained at a temperature in the range of from about 20°C to 50°C at less than about 200 millimeters of mercury pressure.
6. A process according to Claim 5 wherein maleic anhydride recov-ered in the condenser system is recycled to the lights stripper.
Applications Claiming Priority (2)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US80973477A | 1977-06-24 | 1977-06-24 | |
| US809,734 | 1977-06-24 |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| CA1091678A true CA1091678A (en) | 1980-12-16 |
Family
ID=25202106
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| CA304,164A Expired CA1091678A (en) | 1977-06-24 | 1978-05-26 | Process for recovering maleic anhydride by condensation |
Country Status (8)
| Country | Link |
|---|---|
| JP (1) | JPS5412318A (en) |
| BE (1) | BE868363A (en) |
| CA (1) | CA1091678A (en) |
| DE (1) | DE2826919A1 (en) |
| FR (1) | FR2395265A1 (en) |
| GB (1) | GB1593610A (en) |
| IT (1) | IT1096763B (en) |
| NL (1) | NL7806705A (en) |
Families Citing this family (3)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| EP0029317B1 (en) * | 1979-11-20 | 1986-03-19 | Imperial Chemical Industries Plc | Production of maleic anhydride |
| US5972174A (en) * | 1998-01-13 | 1999-10-26 | Huntsman Petrochemical Corporation | Process for the purification of maleic anhydride |
| JP2005035959A (en) * | 2003-07-18 | 2005-02-10 | Nippon Shokubai Co Ltd | Method for producing maleic anhydride |
Family Cites Families (11)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US2211160A (en) * | 1937-02-05 | 1940-08-13 | Nat Aniline & Chem Co Inc | Process of recovering maleic anhydride |
| US2215070A (en) * | 1938-05-11 | 1940-09-17 | Hercules Powder Co Ltd | Method for the production of maleic anhydride |
| FR1140176A (en) * | 1955-01-13 | 1957-07-16 | Basf Ag | Process for producing maleic anhydride |
| FR1151540A (en) * | 1955-04-20 | 1958-01-31 | Montedison Spa | Process for separating pure crystalline maleic anhydride directly from gas and water vapor mixtures which contain it |
| US2951555A (en) * | 1958-07-11 | 1960-09-06 | Monsanto Chemicals | Recovery of maleic anhydride |
| DE1084239B (en) * | 1959-02-11 | 1960-06-30 | Gea Luftkuehler Ges M B H | Method and device for the continuous separation of sublimation products from hot carrier gases |
| GB969283A (en) * | 1961-07-03 | 1964-09-09 | Halcon International Inc | Recovery of maleic anhydride |
| LU40406A1 (en) * | 1961-07-17 | 1961-09-18 | ||
| FR1303126A (en) * | 1961-07-27 | 1962-09-07 | Saint Gobain | Process for the separation of maleic anhydride from gas mixtures |
| FR1338255A (en) * | 1962-11-08 | 1963-09-20 | Harpener Bergbau Ag | Improvements in processes for obtaining maleic anhydride |
| CH533591A (en) * | 1970-08-25 | 1973-02-15 | Prolizenz Ag | Process for the production of maleic anhydride |
-
1978
- 1978-05-26 GB GB23605/78A patent/GB1593610A/en not_active Expired
- 1978-05-26 CA CA304,164A patent/CA1091678A/en not_active Expired
- 1978-06-16 FR FR7818152A patent/FR2395265A1/en active Granted
- 1978-06-20 DE DE19782826919 patent/DE2826919A1/en active Granted
- 1978-06-21 NL NL7806705A patent/NL7806705A/en not_active Application Discontinuation
- 1978-06-22 BE BE188773A patent/BE868363A/en not_active IP Right Cessation
- 1978-06-22 IT IT24854/78A patent/IT1096763B/en active
- 1978-06-23 JP JP7633178A patent/JPS5412318A/en active Granted
Also Published As
| Publication number | Publication date |
|---|---|
| FR2395265A1 (en) | 1979-01-19 |
| NL7806705A (en) | 1978-12-28 |
| IT1096763B (en) | 1985-08-26 |
| BE868363A (en) | 1978-10-16 |
| JPS5412318A (en) | 1979-01-30 |
| DE2826919A1 (en) | 1979-01-18 |
| FR2395265B1 (en) | 1983-06-03 |
| JPS5747194B2 (en) | 1982-10-07 |
| IT7824854A0 (en) | 1978-06-22 |
| GB1593610A (en) | 1981-07-22 |
| DE2826919C2 (en) | 1987-05-21 |
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Legal Events
| Date | Code | Title | Description |
|---|---|---|---|
| MKEX | Expiry |