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CA1057764A - Supported catalyst for the oxidation of o-xylene or naphthalene to phthalic anhydride - Google Patents

Supported catalyst for the oxidation of o-xylene or naphthalene to phthalic anhydride

Info

Publication number
CA1057764A
CA1057764A CA224A CA224A CA1057764A CA 1057764 A CA1057764 A CA 1057764A CA 224 A CA224 A CA 224A CA 224 A CA224 A CA 224A CA 1057764 A CA1057764 A CA 1057764A
Authority
CA
Canada
Prior art keywords
weight
supported catalyst
anatase
active material
catalyst
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
Application number
CA224A
Other languages
French (fr)
Inventor
Kurt Blechschmitt
Paul Hornberger
Peter Reuter
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
BASF SE
Original Assignee
BASF SE
Priority date (The priority date 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 date listed.)
Filing date
Publication date
Priority claimed from DE2421406A external-priority patent/DE2421406C2/en
Application filed by BASF SE filed Critical BASF SE
Application granted granted Critical
Publication of CA1057764A publication Critical patent/CA1057764A/en
Expired legal-status Critical Current

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Classifications

    • YGENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02PCLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00Technologies relating to chemical industry
    • Y02P20/50Improvements relating to the production of bulk chemicals
    • Y02P20/52Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

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  • Furan Compounds (AREA)
  • Catalysts (AREA)
  • Low-Molecular Organic Synthesis Reactions Using Catalysts (AREA)

Abstract

ABSTRACT OF THE DISCLOSURE

A process for the catalytic oxidation of o-xylene or naphthalene with air to form phthalic anhydride wherein a supported catalyst is used comprising an inert nonporous carrier and applied thereto a thin layer of catalytically active material which comprises from 1 to 40% by weight of vanadium pentoxide and from 60 to 99% by weight of anatase and which has a vanadium pentoxide content of from 0.05 to 4% by weight based on the supported catalyst wherein the catalytically active material contains from 0.01 to 0.15% by weight of rubidium or caesium in the form of a compound devoid of sulfur, based on anatase.

Description

~0577~4 This invention relates to a process for the catalytic oxidation of o-xylene or naphthalene wlth air to form phthalic anhydride.
Canadi`an patents Nos. 846,837 and 862,735 disclose supported catalysts which consist of a nonporous carrier material and an active material applied thereto in a thin layer and containing essentially vanadium pentoxide and titanium dioxide. These catalysts which are suitable for the production of phthalic anhydride by air oxidation of o-xylene or naphthalene have contents, based on the active material, of for example from 1 to 30% by weight of vanadium pentoxide, from 99 to 70%
by weight of titanium dioxide and, based on the supported catalyst, from 0.05 to 3% by weight of vanadium pentoxide.
It has been found that surprisingly these catalysts when they are devoid of alkali metal compounds in the catalytically active material display a very high activity in the catalytic oxidation of o-xylene in a tube reactor at only fairly low bath temperatures. The strong activity is evidenced by the fact ' that there develops in the catalyst filling of the tube a hot spot having a very narrow extent and a temperature of more than 500 C. There is therefore the risk that there may be partial decomposition of the hydrocarbon to maleic acid and to oxides of the hydrocarbon resulting in a decrease in the yield and quality of the phthalic anhydride. Since this hot spot is too high the bath temperature has to be decreased and a drop in temperature of only 20C may cause cessation of the reaction.
When alkali metal compounds are added to these catalysts or use is made in their production of a commercially available type of anatase (which contains 0.2% by weight or more of an alkali metal in the form of the oxide to avoid conversion into rutile) the oxidation of crude hydrocarbons, which always contain sulfur, results in the ~ormation of alkali metal sulfates or purosulfates which not only retard the catalytic effect but also form melts with the vanadium pentoxide so that some of the vanadium pentoxide is removed from the catalyst.
Moreover inactivation of the vanadium pentoxide takes place.
We have now found a process for the catalytic oxidation of o-xylene or naphthalene with air to form phthalic anhydride wherein a supported catalyst is used comprising an inert nonporous carrier and applied thereto a thin layer of catalytically active material which comprises from 1 to 40% by weight of vanadium pentoxide and from 60 to 99% by weight of anatase and which has a vanadium pentoxide content of from 0.05 to 4% by weight based on the supported catalyst wherein the catalytically active material contains from 0.01 to 0.15% by weight of rubidium or caesium in the form of a compound devoid of sulfur, based on anatase.
The catalysts advantageously contain sintered or fused silicates, porcelain, aluminas, silicon carbide, rutile , or quartz as the inert nonporous material. The carrier advantageously has the shape of a sphere having a diameter of from 4 to 12 mm.
The catalytic material applied to the carrier advantageously has a layer thickness of for example from 0.04 to 0.2 mm. The active material advantageously forms from about 3 to 10% by weight of the supported catalyst.
The anatase advantageously has an internal surface area of from 8 to 15 m2 per gram and a particle size of less than 1 micron, for example from 0.4 to 0.8 micron. The catalytically active material contains from 0.01 to 0.15%
3Q and preferably from 0.01 to 0.1% by weight of rubidium or caesium, based on the anatase.

/~

10577~4 The said alkali metals are added to the catalytical-ly active material in the form of compolmds devoid of ~ulfur, for example in the form of their oxides or other oxygen-containing compounds such as carbonates or acetate~ in the production of the catalysts.
In addition to the said constituent3 the active ma-terial may contain from 0.1 to 3~ by weight and particularly from 0.2 to 1% by weight of phosphorus in the form of a com-pound and preferably in the form of pho~phoric acid or a ni-trogenous compound thereof such as an ammonium salt and/orfrom 0.1 to 15~ by weight of a compound and conveniently an oxide of the element~ aluminum, zirconium, antimony, arsenic, niobium, chromium, molybdenum, tungsten, cobalt or nickel.
The catalysts may be prepared by conventional me-thods, for example by mixing a vanadium compound which is con-verted into vanadium pentoxide when heated such as ammonium vanadate or the oxalate, formate, acetate, tartrate or sali-cylate of vanadium in water or an organic solvent such as formamide, diethylacetamide, ammonium thiocyanate, fu~ed urea or an alcohol ~ith finely divided anatase with the addition fo rubidiwn carbonate solution or caesium carbonate ~olution with or without ammonium dihydrogen pho~phat~ and spraying the mixture, which usually has a pasty consistency, onto the carrier which has been preheated to ]50 to 450C, ~or example in a coating drum. The finely divided ana-ta~e may be obtained for e~ample by grinding, advantageously in a colloid mill When used for the production of phthalic anhydride the new supported catalysts are placed in conventional manner for example in a tubular reactor whose tube3 have a diameter of from 25 to 40 mm and contacted with the mixture of hydro-carbon and air.
The dlameter of the 3phere~ of carrier i~ convenien-_~_ lOS'~7f~

tly cho3en so that it is about one third o the diameter of the tubes. When a tube hav~ng an internsl width of 25 mm is used, s~heres havlng a diameter of from 7.5 to 8.2 mm are ad-vantageou~ly used. The same spheres or tho~e having a diame-ter which is about one third of the diameter of the tubes may be used in the ca~se of tubes of larger diameter.
In carrying out the oxidàtion the ttlbes are surroun-ded by a salt bath melt having a temperature of from about 360 to 425C to control the temperature. The hydrocarbon is passed together with air which has previously been advanta-geously heated to 150 to 300C through the tube~, the maximum temperature (hot spot) occurring in the fir~t thrid of the layer of catalyst and not being allowed to e~ceed 500C for a long time. The hourly loading of the catalyst i~ generally from about ~000 to 10,000 liter~ of air with about 40 g of hydrocarbon for each 1000 liters of air. The maximum internal temperature (hot spot) is controlled with the salt bath tem-peratvre.
The following Examples illu~trate the invention.
EXAMPI.E I
1,800 g of steatite ~pheres of 6 mm diameter are heated to 300C in a coating drum. The hot spheres are sprayed, ~hilst maintaining the above temperature, with a suspension consi~ting of 400 g of finely ground alkali-free anatase ha-ving an internal surface area of 11 m2/g, 42.2 g of vanadyl oxalate in 400 ml of water, 140 ml of formamide, 200 ml of ~,rater and 0.58 g of rubidium carbonate 1mtil they have taken up 6~ o~ catalytic material.
The catalytic material contains 93.89~ by weight of a~ata~e, 6% by weight of vanadium pentoxide and 0.11~ by weight of Rb20, correspon~ing to 0.10% by wei~ht of rubidium.
The cata]"yst i9 introduced into a tube of 25 mm lOS77~4 internal diameter and 3 m length, surrounded by a salt bath 5,000 liters (S.T.P,) of air per hour are pa3sed through the catalyst bed. Using a salt bath temperature of 375C and charging the air with 40 g of o-xylene per cubic meter (S.T.P.), the yield i9 109~ by weight of phthalic anhydride, based on 100~ pure o-xylene, after 40 days' operation, 110% by weight after 55 dsys and lll~o by weight after 80 days.

1,800 g of steatite spheres of 6 mm diameter are heated to 300C in a coating drum. The hot spheres are sprayed, whilst maintaining the above temperature, with a suspension consisting of 400 g of finely ground alkali-free anatase having an internal surface area of 11 m2/g, 42.2 g of vanadyl oxalate in 400 ml of water, 140 ml of formamide, 200 ml of water and 0.40 g of caesium carbonate until they have taken up 6 . O~o of catalytic material.
The catalytic material contains 93. 92~o by weight of anatase, 6.0~o by weight of vanadium pentoxide and 0,08% by weight of Cs20, corre3ponding to 0.076% by weight of caesium The catalyst is introduced into a tube of 25 mm internal diameter and 3 m length, surrounded by a salt bath.
5,000 liter~ (S.T.P,) of air per hour are passed through the catalyst bed. At a salt bath temperature of 380C and char-ging the air with from 40 to 42 g of 0-xylene/cubic meter, a yield of 109.5~o by weight of phthalic anhydride, based on lOO~o pure o-xylene, is obtained.

Claims (9)

The embodiments of the invention in which an exclusive property or privilege is claimed are defined as follows:
1. A process for the catalytic oxidation of o-xylene or naphthalene with air to form phthalic anhydride wherein a supported catalyst is used comprising an inert nonporous carrier and applied thereto a thin layer of catalytically active material which comprises from 1 to 40%
by weight of vanadium pentoxide and from 60 to 99% by weight of anatase and which has a vanadium pentoxide content of from 0.05 to 4% by weight based on the supported catalyst wherein the catalytically active material contains from 0.01 to 0.15% by weight of rubidium or caesium in the form of a compound devoid of sulfur, based on anatase.
2. A process as claimed in claim 1 the catalytically active material in the supported catalyst contains from 0.01 to 0.1% by weight of rubidium or caesium, based on anatase.
3. A process as claimed in claim 1 wherein the active material in the supported catalyst constitutes from 3 to 10% by weight of the supported catalyst.
4. A process as claimed in claim 1 wherein the anatase in the supported catalyst has an internal surface area of from 8 to 15 m2 per gram.
5. A process as claimed in claim 1 wherein the carrier of the supported catalyst is in the form of spheres having a diameter of from 4 to 12 mm.
6. A process as claimed in claim 1 wherein the anatase in the supported catalyst has a particle size of less than 1 micron.
7. A process as claimed in claim 1 wherein the anatase in the supported catalyst has a particle size of from 0.4 to 0.8 micron.
8. A process as claimed in claim 1 wherein the active material of the catalyst additionally contains from 0.1 to 3%
by weight of phosphorus in the form of a compound.
9. A process as claimed in claim 1 wherein the active material of the catalyst contains from 0.1 to 15% by weight of an oxide of aluminum, zirconium, antimony, arsenic, niobium, chromium, molybdenum, tungsten, cobalt or nickel.
CA224A 1974-05-03 1975-04-15 Supported catalyst for the oxidation of o-xylene or naphthalene to phthalic anhydride Expired CA1057764A (en)

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
DE2421406A DE2421406C2 (en) 1972-12-12 1974-05-03 Process for the production of phthalic anhydride

Publications (1)

Publication Number Publication Date
CA1057764A true CA1057764A (en) 1979-07-03

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Family Applications (1)

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JP (2) JPS50150688A (en)
CA (1) CA1057764A (en)
IT (1) IT1049403B (en)

Families Citing this family (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US7022643B2 (en) 2002-08-20 2006-04-04 Nippon Shokubai Co., Ltd. Production process for catalyst
JP4295521B2 (en) 2003-02-13 2009-07-15 株式会社日本触媒 Catalyst for producing acrylic acid and method for producing acrylic acid
WO2010001732A1 (en) 2008-06-30 2010-01-07 株式会社日本触媒 Method of packing solid particulate substance into fixed-bed multitubular reactor
JP2011121048A (en) 2009-12-09 2011-06-23 Rohm & Haas Co Method for blending and loading solid catalyst material into tubular structure

Family Cites Families (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
DE2212964C3 (en) * 1972-03-17 1980-01-31 Basf Ag, 6700 Ludwigshafen Supported catalyst containing vanadium pentoxide, titanium dioxide and optionally zirconium dioxide, phosphorus and other metal oxides

Also Published As

Publication number Publication date
JPS50150688A (en) 1975-12-03
JPS5695337A (en) 1981-08-01
IT1049403B (en) 1981-01-20
JPS5815176B2 (en) 1983-03-24

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