US3359340A - Production of polyphenyls - Google Patents
Production of polyphenyls Download PDFInfo
- Publication number
- US3359340A US3359340A US510031A US51003165A US3359340A US 3359340 A US3359340 A US 3359340A US 510031 A US510031 A US 510031A US 51003165 A US51003165 A US 51003165A US 3359340 A US3359340 A US 3359340A
- Authority
- US
- United States
- Prior art keywords
- benzene
- percent
- benzoic acid
- feed
- biphenyl
- 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 - Lifetime
Links
- 229920006389 polyphenyl polymer Polymers 0.000 title claims description 8
- 238000004519 manufacturing process Methods 0.000 title description 4
- UHOVQNZJYSORNB-UHFFFAOYSA-N Benzene Chemical compound C1=CC=CC=C1 UHOVQNZJYSORNB-UHFFFAOYSA-N 0.000 claims description 81
- WPYMKLBDIGXBTP-UHFFFAOYSA-N benzoic acid Chemical compound OC(=O)C1=CC=CC=C1 WPYMKLBDIGXBTP-UHFFFAOYSA-N 0.000 claims description 30
- 238000000034 method Methods 0.000 claims description 18
- 239000005711 Benzoic acid Substances 0.000 claims description 14
- 235000010233 benzoic acid Nutrition 0.000 claims description 14
- ZUOUZKKEUPVFJK-UHFFFAOYSA-N diphenyl Chemical compound C1=CC=CC=C1C1=CC=CC=C1 ZUOUZKKEUPVFJK-UHFFFAOYSA-N 0.000 description 25
- 239000004305 biphenyl Substances 0.000 description 13
- 235000010290 biphenyl Nutrition 0.000 description 13
- RYGMFSIKBFXOCR-UHFFFAOYSA-N Copper Chemical compound [Cu] RYGMFSIKBFXOCR-UHFFFAOYSA-N 0.000 description 12
- 229910052802 copper Inorganic materials 0.000 description 12
- 239000010949 copper Substances 0.000 description 12
- 239000000047 product Substances 0.000 description 11
- YJTKZCDBKVTVBY-UHFFFAOYSA-N 1,3-Diphenylbenzene Chemical group C1=CC=CC=C1C1=CC=CC(C=2C=CC=CC=2)=C1 YJTKZCDBKVTVBY-UHFFFAOYSA-N 0.000 description 7
- 238000000197 pyrolysis Methods 0.000 description 7
- OKTJSMMVPCPJKN-UHFFFAOYSA-N Carbon Chemical compound [C] OKTJSMMVPCPJKN-UHFFFAOYSA-N 0.000 description 6
- 239000000654 additive Substances 0.000 description 6
- 230000015572 biosynthetic process Effects 0.000 description 6
- 229910052799 carbon Inorganic materials 0.000 description 6
- 238000006243 chemical reaction Methods 0.000 description 6
- CURLTUGMZLYLDI-UHFFFAOYSA-N Carbon dioxide Chemical compound O=C=O CURLTUGMZLYLDI-UHFFFAOYSA-N 0.000 description 4
- 239000000463 material Substances 0.000 description 4
- 230000000996 additive effect Effects 0.000 description 3
- 230000000694 effects Effects 0.000 description 3
- 239000002253 acid Substances 0.000 description 2
- 239000001569 carbon dioxide Substances 0.000 description 2
- 229910002092 carbon dioxide Inorganic materials 0.000 description 2
- 238000009833 condensation Methods 0.000 description 2
- 230000005494 condensation Effects 0.000 description 2
- 238000002474 experimental method Methods 0.000 description 2
- 239000007787 solid Substances 0.000 description 2
- 239000000126 substance Substances 0.000 description 2
- 239000006200 vaporizer Substances 0.000 description 2
- XLYOFNOQVPJJNP-UHFFFAOYSA-N water Substances O XLYOFNOQVPJJNP-UHFFFAOYSA-N 0.000 description 2
- 229910001868 water Inorganic materials 0.000 description 2
- NOGFHTGYPKWWRX-UHFFFAOYSA-N 2,2,6,6-tetramethyloxan-4-one Chemical compound CC1(C)CC(=O)CC(C)(C)O1 NOGFHTGYPKWWRX-UHFFFAOYSA-N 0.000 description 1
- ILYSAKHOYBPSPC-UHFFFAOYSA-N 2-phenylbenzoic acid Chemical compound OC(=O)C1=CC=CC=C1C1=CC=CC=C1 ILYSAKHOYBPSPC-UHFFFAOYSA-N 0.000 description 1
- 239000005749 Copper compound Substances 0.000 description 1
- 229910000599 Cr alloy Inorganic materials 0.000 description 1
- -1 aliphatic organic compounds Chemical class 0.000 description 1
- 238000004458 analytical method Methods 0.000 description 1
- RBHJBMIOOPYDBQ-UHFFFAOYSA-N carbon dioxide;propan-2-one Chemical compound O=C=O.CC(C)=O RBHJBMIOOPYDBQ-UHFFFAOYSA-N 0.000 description 1
- 238000001311 chemical methods and process Methods 0.000 description 1
- 239000007795 chemical reaction product Substances 0.000 description 1
- 238000004587 chromatography analysis Methods 0.000 description 1
- 239000000788 chromium alloy Substances 0.000 description 1
- 239000000571 coke Substances 0.000 description 1
- 238000010276 construction Methods 0.000 description 1
- 238000010411 cooking Methods 0.000 description 1
- 150000001880 copper compounds Chemical class 0.000 description 1
- 238000005260 corrosion Methods 0.000 description 1
- 230000007797 corrosion Effects 0.000 description 1
- 239000012043 crude product Substances 0.000 description 1
- 238000000354 decomposition reaction Methods 0.000 description 1
- 238000004821 distillation Methods 0.000 description 1
- 239000011491 glass wool Substances 0.000 description 1
- 238000010438 heat treatment Methods 0.000 description 1
- 230000006698 induction Effects 0.000 description 1
- 230000002401 inhibitory effect Effects 0.000 description 1
- 239000007788 liquid Substances 0.000 description 1
- 230000000737 periodic effect Effects 0.000 description 1
- 238000000746 purification Methods 0.000 description 1
- 238000000926 separation method Methods 0.000 description 1
- 239000011593 sulfur Substances 0.000 description 1
- 229910052717 sulfur Inorganic materials 0.000 description 1
- 239000012808 vapor phase Substances 0.000 description 1
- 239000002699 waste material Substances 0.000 description 1
Classifications
-
- C—CHEMISTRY; METALLURGY
- C07—ORGANIC CHEMISTRY
- C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
- C07C2/00—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms
- C07C2/76—Preparation of hydrocarbons from hydrocarbons containing a smaller number of carbon atoms by condensation of hydrocarbons with partial elimination of hydrogen
Definitions
- Biphenyl and, to a lesser extent, terphenyl are conventionally manufactured by the noncatalytic pyrolysis of benzene.
- At the high temperature required by this pyrolytic condensation usually about 800 C., there is normally considerable unwanted further condensation and decomposition resulting in the formation of tar, excessive noncondensable gas, and coke.
- These undesirable effects cause waste of benzene and make the separation of a pure or light colored product difi'icult and unduly expensive.
- Cooking in the reactor tubes also necessitates periodic shut-downs and burning out procedures.
- reactor tubes of difierent materials of construction have been tried and some materials, particularly chromium alloys and copper, have been found to be useful in reducing tar and carbon formation.
- this additive in the benzene feed not only increases biphenyl production by to 150 percent or more, depending upon the conditions, but it also essentially eliminates tar and carbon formation at conventional process temperatures, thereby providing a crude pro-duct which is light yellow rather than black and which consists essentially of a solution of biphenyl in benzene with a small amount of terphenyl also present. Since the benzoic acid additive is ordinarily decarboxylated to benzene during the process, this additive is not found in the reaction product under preferred operating conditions but merely serves as additional feed as far as material balance and product purity are concerned.
- the process is run at a temperature Within the range known to cause conversion of benzene to biphenyl, i.e., about 600900' C.
- the pyrolysis according to the present invention is carried out at 650850 C.
- the benzene conversion varies according to the process temperature and inversely in proportion to the rate at which the benzene is passed through the reactor. This rate is perhaps best defined in terms of residence time, that is, the calculated average time taken for a molecule of benzene to pass through the pyrolysis reactor under process conditions. A residence time of 01-10 seconds has been found suitable and a time of 0.55 seconds is preferred. These residence times are similar to those of the prior art.
- the function of the copper appears to be as an additional aid in inhibiting tar and carbon formation.
- the copper may be present as the inner surface of the reactor or as a permeable bed within the reactor composed of pieces of copper or finely divided copper deposited on the surface of an inert support. Metallic copper or a substance which becomes copper during the process can be used.
- the reactor may contain a bed of an inert material coated or impregnated with a copper compound which is reduced or decomposed to copper under process conditions.
- EXAMPLE 1 The experimental pyrolysis equipment comprised three heating stages: a vaporizer consisting of a flask packed with glass wool and maintained at about 250275 C., a preheater which was a high-silica glass tube 1 x 14 inches electrically heated to 350400 C., and a reactor similar to the preheater but containing a 9 /240 inch bed of cut up 16 mesh copper screen and heated over this length at the pyrolysis temperature by an induction furnace.
- a vaporizer consisting of a flask packed with glass wool and maintained at about 250275 C.
- a preheater which was a high-silica glass tube 1 x 14 inches electrically heated to 350400 C.
- the liquid feed was introduced into the vaporizer by a metering pump, the vaporized feed then passed successively through the preheater and the reactor, and the condensable effluent was collected in a water-cooled flask vented through a cold trap in a solid carbon dioxide-acetone bath.
- a solution of 1 percent by weight benzoic acid in benzene was made up and 361 g. of this solution was passed through the pyrolysis apparatus at a uniform rate over a period of 3 hours and at a reactor temperature of 680 C.
- the product collected in the water-cooled flask was a light yellow solution amounting to 356.4 g.
- Vapor phase chromatographic analysis of this product showed that it was essentially benzene containing 10 percent by weight of biphenyl and 1.0 percent of terphenyl. Distillation of a portion of this product confirmed this analysis.
- the isolated polyphenyl fraction was a light yellow crystalline solid.
- the cold trap contained 2.4 g. of condensate which was essentially pure benzene. No significant amount of benzoic acid or tar was found in the pyrolyzed product. The above values indicate a conversion of benzene to polyphenyl of 11.1 percent,
Landscapes
- Chemical & Material Sciences (AREA)
- Organic Chemistry (AREA)
- Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)
Description
United States Patent Ofiice 3,359,340 Patented Dec. 19, 1967 3,359,340 PRODUCTION OF POLYPHENYLS Clare R. Hand, Sanford, Mich., assignor to The Dow Chemical Company, Midland, Mich., a corporation of Delaware No Drawing. Filed Nov. 26, 1965, Ser. No. 510,031 3 Claims. (Cl. 260-670) This invention relates to a chemical process and it is particularly concerned with an improved method for making polyphenyls such as biphenyl and terphenyl.
Biphenyl and, to a lesser extent, terphenyl are conventionally manufactured by the noncatalytic pyrolysis of benzene. At the high temperature required by this pyrolytic condensation, usually about 800 C., there is normally considerable unwanted further condensation and decomposition resulting in the formation of tar, excessive noncondensable gas, and coke. These undesirable effects cause waste of benzene and make the separation of a pure or light colored product difi'icult and unduly expensive. Cooking in the reactor tubes also necessitates periodic shut-downs and burning out procedures.
Various expedients have been employed to inhibit the formation of carbon and tar in this process or to increase the yield of biphenyl. For example, one or the other of these objectives has been sought by employing additives to the benzene feed such as water, carbon dioxide, sulfur, and aliphatic organic compounds. While such additives have been found to offer some advantage, they also introduce obvious difficulties into the process including corrosion of equipment, complications in equipment design and product purification, and so on.
Additionally, reactor tubes of difierent materials of construction have been tried and some materials, particularly chromium alloys and copper, have been found to be useful in reducing tar and carbon formation.
It has now been found that in the process wherein benzene is thermally condensed to make polyphenyls such as biphenyl and terphenyl by subjecting its vapor to a pyrolyzing temperature, increased conversion of benzene and sharply reduced tar and carbon formation are both obtained when the benzene feed contains 0.1-5 percent by weight of benzoic acid. The presence of this additive in the benzene feed not only increases biphenyl production by to 150 percent or more, depending upon the conditions, but it also essentially eliminates tar and carbon formation at conventional process temperatures, thereby providing a crude pro-duct which is light yellow rather than black and which consists essentially of a solution of biphenyl in benzene with a small amount of terphenyl also present. Since the benzoic acid additive is ordinarily decarboxylated to benzene during the process, this additive is not found in the reaction product under preferred operating conditions but merely serves as additional feed as far as material balance and product purity are concerned.
It is known that some biphenyl is formed when benzoic acid is passed through a hot tube. However, the increased conversion caused by its presence in this new process is far above that which would be obtained even if all of the benzoic acid were converted to biphenyl, so this effect and particularly the effect of minimizing tar and carbon production are unexpected and could not have been predicted. For best results, 0.52 percent by weght of benzoic acid is added to the benzene feed. As the concentration of benzoic acid in the benzene feed to the process is raised above about 5 percent, an increasing amount of unconverted acid is found in the effluent prodnet. For the purpose of this invention, benzoic anhydride is the obvious equivalent of benzoic acid and it can be employed in its place if desired.
The process is run at a temperature Within the range known to cause conversion of benzene to biphenyl, i.e., about 600900' C. Preferably, the pyrolysis according to the present invention is carried out at 650850 C.
The benzene conversion varies according to the process temperature and inversely in proportion to the rate at which the benzene is passed through the reactor. This rate is perhaps best defined in terms of residence time, that is, the calculated average time taken for a molecule of benzene to pass through the pyrolysis reactor under process conditions. A residence time of 01-10 seconds has been found suitable and a time of 0.55 seconds is preferred. These residence times are similar to those of the prior art.
Best results are obtained when a copper surface is present in the reactor. The function of the copper appears to be as an additional aid in inhibiting tar and carbon formation. The copper may be present as the inner surface of the reactor or as a permeable bed within the reactor composed of pieces of copper or finely divided copper deposited on the surface of an inert support. Metallic copper or a substance which becomes copper during the process can be used. For example, the reactor may contain a bed of an inert material coated or impregnated with a copper compound which is reduced or decomposed to copper under process conditions.
Known additives or improvements other than the presence of copper can also be used in conjunction with the present invention. For example, water or carbon dioxide can be added to the benzene-benzoic acid feed and under some conditions somewhat improved results may thereby be obtained. Usually, however, such advantage is small.
EXAMPLE 1 The experimental pyrolysis equipment comprised three heating stages: a vaporizer consisting of a flask packed with glass wool and maintained at about 250275 C., a preheater which was a high-silica glass tube 1 x 14 inches electrically heated to 350400 C., and a reactor similar to the preheater but containing a 9 /240 inch bed of cut up 16 mesh copper screen and heated over this length at the pyrolysis temperature by an induction furnace. The liquid feed was introduced into the vaporizer by a metering pump, the vaporized feed then passed successively through the preheater and the reactor, and the condensable effluent was collected in a water-cooled flask vented through a cold trap in a solid carbon dioxide-acetone bath.
A solution of 1 percent by weight benzoic acid in benzene was made up and 361 g. of this solution was passed through the pyrolysis apparatus at a uniform rate over a period of 3 hours and at a reactor temperature of 680 C. The product collected in the water-cooled flask was a light yellow solution amounting to 356.4 g. Vapor phase chromatographic analysis of this product showed that it was essentially benzene containing 10 percent by weight of biphenyl and 1.0 percent of terphenyl. Distillation of a portion of this product confirmed this analysis. The isolated polyphenyl fraction was a light yellow crystalline solid. The cold trap contained 2.4 g. of condensate which was essentially pure benzene. No significant amount of benzoic acid or tar was found in the pyrolyzed product. The above values indicate a conversion of benzene to polyphenyl of 11.1 percent,
a 91 percent yield of biphenyl based on that conversion, and a 9 percent yield of terphenyl. The benzoic acid was assumed in these calculations to have been converted to benzene or polyphenyls. Recovered condensable products represented 100 percent of the theoretical quantity.
EXAMPLES 2-3 Using the apparatus of Example 1 except that the pyrolysis reactor was an open tube, two experiments were performed at a reactor temperature of 800 C. and a feed rate of 82.8 g. per hour. In the first experiment the feed was pure benzene; in the second the feed was benzene containing 1.14 percent by weight of benzoic acid. The results are listed in the following table.
Condensed Product Ex. Percent No. Benzoic in feed Percent Percent Percent Color Biphenyl Terphenyl Tar 2 0 13.6 4.1 2 Black. 3 1.14 14.9 4. 0 1 Lt. yellow.
EXAMPLES 4-6 Condensed Product Ex Percent Benzoic No Acid in Feed Percent Biphenyl Percent Terphenyl A trace of benzoic acid was present in the condensed product of Example 6.
I claim:
1. In a process for making a polyphenyl by subjecting benzene vapor to a pyrolytic temperature, the improvement wherein said benzene contains 0.l-5 percent by weight of benzoic acid.
2. The process of claim 1 wherein the benzene vapor is subjected to a pyrolytic temperature in the presence of copper.
3. The process of claim 1 wherein the temperature is 650-850 C.
References Cited UNITED STATES PATENTS 5/1934 Tschunkur et al 260-670 1/1939 Conover et a1 260670 30 PAUL M. COUGHLAN, JR., Primary Examiner.
C. R. DAVIS, Assistant Examiner.
Claims (1)
1. IN A PROCESS FOR MAKING A POLYPHENYL BY SUBJECTING BENZENE VAPOR TO A PYROLYTIC TEMPERATRUE, THE IMPROVEMENT WHEREIN SAID BENZENE CONTAINS 0.1-5 PERCENT BY WEIGHT OF BENZOIC ACID.
Priority Applications (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US510031A US3359340A (en) | 1965-11-26 | 1965-11-26 | Production of polyphenyls |
Applications Claiming Priority (1)
| Application Number | Priority Date | Filing Date | Title |
|---|---|---|---|
| US510031A US3359340A (en) | 1965-11-26 | 1965-11-26 | Production of polyphenyls |
Publications (1)
| Publication Number | Publication Date |
|---|---|
| US3359340A true US3359340A (en) | 1967-12-19 |
Family
ID=24029078
Family Applications (1)
| Application Number | Title | Priority Date | Filing Date |
|---|---|---|---|
| US510031A Expired - Lifetime US3359340A (en) | 1965-11-26 | 1965-11-26 | Production of polyphenyls |
Country Status (1)
| Country | Link |
|---|---|
| US (1) | US3359340A (en) |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4828459A (en) * | 1971-07-29 | 1973-04-14 |
Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1957988A (en) * | 1931-05-08 | 1934-05-08 | Ig Farbenindustrie Ag | Production of diphenyl substances |
| US2143509A (en) * | 1935-07-19 | 1939-01-10 | Monsanto Chemicals | Preparation of benzene derivatives |
-
1965
- 1965-11-26 US US510031A patent/US3359340A/en not_active Expired - Lifetime
Patent Citations (2)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| US1957988A (en) * | 1931-05-08 | 1934-05-08 | Ig Farbenindustrie Ag | Production of diphenyl substances |
| US2143509A (en) * | 1935-07-19 | 1939-01-10 | Monsanto Chemicals | Preparation of benzene derivatives |
Cited By (1)
| Publication number | Priority date | Publication date | Assignee | Title |
|---|---|---|---|---|
| JPS4828459A (en) * | 1971-07-29 | 1973-04-14 |
Similar Documents
| Publication | Publication Date | Title |
|---|---|---|
| US2282327A (en) | Pyrolysis of diphenyl-ethane compounds | |
| US2110829A (en) | Production of styrene and related compounds | |
| US3359340A (en) | Production of polyphenyls | |
| US3234264A (en) | 1-cyano and 1-carbamoyl-3-alkylbicyclo [1.1.0] butanes and processes for preparing the same | |
| US2232705A (en) | Process and apparatus for making lower aliphatic acid anhydrides | |
| US2422252A (en) | Transposition of dichlorobutenes | |
| Johnson et al. | Some Reactions of Triphenylgermane | |
| US2198185A (en) | Production of aryl substituted olefins | |
| US2308415A (en) | Pyrolysis of diphenyl ethane compounds | |
| Coonradt et al. | The Chlorination of Thiophene. I. Addition Products | |
| US2679506A (en) | Preparation of dimethyl tin dichloride by direct reaction | |
| US2451350A (en) | Preparation of unsaturated ketones | |
| US2182313A (en) | Pyrolysis of secondary-butylbenzene derivatives | |
| US4367349A (en) | Liquid phase synthesis of hexafluoroisobutylene | |
| US3256334A (en) | Cyclic ketones | |
| US3173760A (en) | Process for the preparation of a boron trihalide | |
| US1978069A (en) | Producing diphenyl | |
| US2904579A (en) | Process for preparing nitriles | |
| US3794686A (en) | Process for continuously producing acetylacetone | |
| US3336339A (en) | delta-lactones of 5-hydroxy-3-keto-6, 6-bis(perfluoroalkyl)-4-hexenoic acids and preparation thereof | |
| US1541176A (en) | Process for the manufacture of styrol or its homologues | |
| US3222407A (en) | Production of vinyl chloride | |
| US1315525A (en) | Process of making acetone | |
| US2410820A (en) | Production of vinyl cyanide | |
| US3322816A (en) | Process for preparing dicyanoacetylene |