USRE29459E - Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation - Google Patents

Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation Download PDF

Info

Publication number
USRE29459E
USRE29459E US05/529,304 US52930474A USRE29459E US RE29459 E USRE29459 E US RE29459E US 52930474 A US52930474 A US 52930474A US RE29459 E USRE29459 E US RE29459E
Authority
US
United States
Prior art keywords
range
silica
iaddend
iadd
alumina
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
Application number
US05/529,304
Inventor
John J. Brodbeck
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.)
Chevron USA Inc
Original Assignee
Chevron Research Co
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
Application filed by Chevron Research Co filed Critical Chevron Research Co
Priority to US05/529,304 priority Critical patent/USRE29459E/en
Application granted granted Critical
Publication of USRE29459E publication Critical patent/USRE29459E/en
Anticipated expiration legal-status Critical
Expired - Lifetime legal-status Critical Current

Links

Classifications

    • C—CHEMISTRY; METALLURGY
    • C07—ORGANIC CHEMISTRY
    • C07C—ACYCLIC OR CARBOCYCLIC COMPOUNDS
    • C07C5/00—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms
    • C07C5/22—Preparation of hydrocarbons from hydrocarbons containing the same number of carbon atoms by isomerisation
    • C07C5/27—Rearrangement of carbon atoms in the hydrocarbon skeleton
    • C07C5/2729—Changing the branching point of an open chain or the point of substitution on a ring
    • C07C5/2732—Catalytic processes
    • C07C5/2735—Catalytic processes with metal oxides
    • 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
    • B01J21/00—Catalysts comprising the elements, oxides, or hydroxides of magnesium, boron, aluminium, carbon, silicon, titanium, zirconium, or hafnium
    • B01J21/16—Clays or other mineral silicates
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/61—Surface area
    • B01J35/615—100-500 m2/g
    • 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
    • B01J35/00—Catalysts, in general, characterised by their form or physical properties
    • B01J35/60—Catalysts, in general, characterised by their form or physical properties characterised by their surface properties or porosity
    • B01J35/66—Pore distribution
    • Y—GENERAL 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
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P20/00—Technologies relating to chemical industry
    • Y02P20/50—Improvements relating to the production of bulk chemicals
    • Y02P20/52—Improvements relating to the production of bulk chemicals using catalysts, e.g. selective catalysts

Definitions

  • This invention relates to a method for the improvement of the catalyzed isomerization of lower alkyl polyalkyl-substituted aromatic hydrocarbons, particularly to the equilibration of non-equilibrium xylene feeds effected by silica-alumina composites. More particularly, it relates to novel catalyst parameters which result in a substantial reduction in the loss to disproportionation by-products normally experienced in the subject isomerization process.
  • An undesirable aspect in conventional practice in the foregoing staged conversion and recovery cycle is that a substantial fraction of the process feed is lost because of a concurrent disproportionation reaction.
  • a process for the production of p-xylene in which a p-xylene-reduced xylene mixture is isomerized in an extinction recycle process the formation of disproportionation products such as benzene, toluene, and trimethyl benzenes represents an appreciable loss of xylene product or a large process burden where these components of the product stream are recycled to the process together with fresh feed.
  • the use of the isomerization catalysts herein results in a large reduction in the disproportionation loss experienced with conventional silica-alumina isomerization catalysts. As much as 40 percent and more of the former loss to disproportionation products is eliminated by employing the high surface area-high pore radius silica-alumina catalysts of the present invention.
  • lower alkyl aromatic hydrocarbon isomerization conditions is meant a temperature in the range 700° F. to 1000° F., preferably from about 750° F. to 900° F., and at a liquid hourly space velocity in the range 0.1 to 10, and at a pressure below about 200 p.s.i.g., preferably below about 50 p.s.i.g.
  • Aromatic hydrocarbons having an aromatic carbocyclic carbon atom content (ring carbon atoms) in the range below about 13 and which have from 2 to about 4, preferably 2 to 3, lower alkyl groups are satisfactory feeds for the process herein.
  • a lower alkyl group is meant an alkyl group having a carbon atom content of less than 4.
  • isomerization catalysts comprising silica-alumina which have a surface area in the range 250-400 square meters per gram and for which at least 40 percent of the .[.pores have.]. .Iadd.pore volume is from pores having .Iaddend.a radius greater than 45 A., are satisfactory for use in the instant process.
  • the mother liquor remaining after removal by crystallization of p-xylene from an isomeric xylene mixture i.e., a p-xylene reduced xylene feed
  • the catalyst is a silica-alumina composite containing about 80 percent of silica, about 20 percent of alumina, the foregoing percentages being by weight, a surface area of 270-350 square meters per gram, with at least about 70 percent of the .[.pores having.]. .Iadd.pore volume is from .Iaddend. a radius greater than 45 A., and with the particle sizing being in the range 0.06-0.1 inch.
  • the isomerization is carried out in a fixed bed reactor system under the following conditions:
  • the effluent from the above isomerization stage is cooled as required and passed to a stripper column where water and the light aromatics produced in the isomerization are taken as an overhead fraction and the bottoms portion is passed to a second distillation column from which the xylene fraction is recovered as an overhead stream while the heavy aromatic, trimethyl benzenes and the like, produced in the isomerization are withdrawn from the process or a fraction thereof is recycled to the isomerization stage.
  • silica-alumina catalysts useful herein are rigid three dimensional networks characterized by uniform pores having relatively large pore diameters. It appears that the combination of physical characteristics, the particular surface area range and uniformly high pore radius, of the catalyst permits a diffusivity relationship favoring the desired isomerization reaction relative to the unwanted disproportionation reaction within the liquid hourly space velocity range specified above.
  • Preferred catalyst composites contain silica and alumina in the weight ratio 70-90 and 10-30 respectively, preferably about 80 to 20.
  • useful composites may contain minor amounts, about 5 to 15 parts, of such metal oxides as magnesia, zirconia, thoria, beryllia, and the rare earth metal oxides.
  • Silica-alumina catalyst composites having the necessary characteristics for use herein are conveniently prepared by the simultaneous co-precipitation or co-gellation (co-gel method) of a mixture of compounds of silicon and aluminum.
  • the surface areas of the dried or partially dried composites are in general steamed-down to the useful range at temperatures in the range 500-1300° F., surface area determinations being made by the well known B.E.T. Method using nitrogen (cf. G. M. Schwab, "Handbuck der Katalyse," volume 4, page 195).
  • aromatic hydrocarbon feeds desirably employed in the process of the invention include p-xylene reduced (i.e., containing less than the equilibrium amount) C 8 aromatic hydrocarbon mixtures, m-xylene, p-xylene, o-xylene, ethylbenzene, o-cymene, p-cymene, m-cymene, non-equilibrium enzyme mixtures, m-diisopropylbenzene, p-diisopropylbenzene, p-diethylbenzene, m-diethylbenzene, 3-isopropylethylbenzene, m-(n-propyl)-toluene, misitylene, 1,3-dimethylnaphthalene, 1,4-diethylnaphthalene, 1,5-diisopropylnaphthalene, 1,3,5-trimethylnaphthalene, and the like polyalkyl aromatic
  • a series of silica-alumina catalysts (80-20 weight ratio) were prepared by the co-gellation method and extruded (one-tenth inch diameter) and tempered. Three catalysts having the characteristics:
  • reaction conditions were:
  • a silica-alumina catalyst composite was prepared which corresponded to catalyst C in the above examples except that sufficient of magnesium chloride was included in the co-gellation preparative mixture to provide for 5 parts of magnesia in the resulting catalyst.
  • This catalyst had a surface area of 336 square meters per grams, with about 69 percent of the .[.pores.]. .Iadd.pore volume .Iaddend.thereof .Iadd.from pores .Iaddend.having a pore radius greater than 45 A.
  • the isomerization and disproportionation activities were substantially the same as for catalyst C.
  • the magnesia additive had reduced the coking activity (rate of coke lay-down) by about one-half of that for catalyst C.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Organic Chemistry (AREA)
  • Chemical Kinetics & Catalysis (AREA)
  • Engineering & Computer Science (AREA)
  • Materials Engineering (AREA)
  • Dispersion Chemistry (AREA)
  • Catalysts (AREA)
  • Organic Low-Molecular-Weight Compounds And Preparation Thereof (AREA)

Abstract

Disproportionation losses in the isomerization of C8 aromatic hydrocarbons are reduced by the use of silica-alumina catalyst composites with high surface areas and having .[.pore.]. .Iadd.most of its pore volume from pores of .Iaddend. radii .[.in the main.]. above about 45° A.

Description

FIELD OF INVENTION
This invention relates to a method for the improvement of the catalyzed isomerization of lower alkyl polyalkyl-substituted aromatic hydrocarbons, particularly to the equilibration of non-equilibrium xylene feeds effected by silica-alumina composites. More particularly, it relates to novel catalyst parameters which result in a substantial reduction in the loss to disproportionation by-products normally experienced in the subject isomerization process.
BACKGROUND OF INVENTION
It is known to isomerize lower alkyl-substituted aromatic hydrocarbons at elevated temperatures by passing the vaporized feed into contact with a solid silica-alumina catalyst composite for the purpose of altering the isomer distribution of the hydrocarbon feed. The usual objective is to convert the feed into a mixture of isomeric compounds which more nearly approximates the known isomer equilibration composition for the specific feed composite or mixture. In practice, the foregoing equilibration process is coupled with a subsequent separation process utilizing physical or chemical means for the preferential and selective removal of a desired isomer from the equilibrate. By recycle of the residue from the separation stage and repetition of the overall operation one is able to convert a single isomeride or isomeric mixture to a desired specie of the equilibration set.
An undesirable aspect in conventional practice in the foregoing staged conversion and recovery cycle is that a substantial fraction of the process feed is lost because of a concurrent disproportionation reaction. For example, in a process for the production of p-xylene in which a p-xylene-reduced xylene mixture is isomerized in an extinction recycle process, the formation of disproportionation products such as benzene, toluene, and trimethyl benzenes represents an appreciable loss of xylene product or a large process burden where these components of the product stream are recycled to the process together with fresh feed. In a typical petroleum refinery operation it is usually preferred not to recycle such by-products. Consequently, as much as 30-40% of the xylene feed is converted through the disproportionation reaction to less desirable product.
.Iadd.SUMMARY OF THE INVENTION .Iaddend.
It has now been found that in the isomerization of lower alkyl polyalkyl-substituted aromatic hydrocarbons relative rate differences between the concurrent isomerization and disproportionation reactions of these feeds can be effectively utilized by the employment of a silica-alumina catalyst composite having a surface area in the range 250-400 square meters per gram--preferably 270-350 square meters per gram--and wherein at least 40% of the .[.pores.]. .Iadd.pore volume .Iaddend.of the catalyst .[.have.]. .Iadd.is from pores having .Iaddend.a radius greater than 45 A., preferably greater than 50 A., and less than about 100 A. Surprisingly, the use of the isomerization catalysts herein results in a large reduction in the disproportionation loss experienced with conventional silica-alumina isomerization catalysts. As much as 40 percent and more of the former loss to disproportionation products is eliminated by employing the high surface area-high pore radius silica-alumina catalysts of the present invention.
By lower alkyl aromatic hydrocarbon isomerization conditions is meant a temperature in the range 700° F. to 1000° F., preferably from about 750° F. to 900° F., and at a liquid hourly space velocity in the range 0.1 to 10, and at a pressure below about 200 p.s.i.g., preferably below about 50 p.s.i.g.
Aromatic hydrocarbons having an aromatic carbocyclic carbon atom content (ring carbon atoms) in the range below about 13 and which have from 2 to about 4, preferably 2 to 3, lower alkyl groups are satisfactory feeds for the process herein.
By a lower alkyl group is meant an alkyl group having a carbon atom content of less than 4.
In general, isomerization catalysts comprising silica-alumina which have a surface area in the range 250-400 square meters per gram and for which at least 40 percent of the .[.pores have.]. .Iadd.pore volume is from pores having .Iaddend.a radius greater than 45 A., are satisfactory for use in the instant process.
In a preferred embodiment of the invention the mother liquor remaining after removal by crystallization of p-xylene from an isomeric xylene mixture, i.e., a p-xylene reduced xylene feed, is used as a feed source for a catalyzed xylene isomerization stage in which the catalyst is a silica-alumina composite containing about 80 percent of silica, about 20 percent of alumina, the foregoing percentages being by weight, a surface area of 270-350 square meters per gram, with at least about 70 percent of the .[.pores having.]. .Iadd.pore volume is from .Iaddend. a radius greater than 45 A., and with the particle sizing being in the range 0.06-0.1 inch. The isomerization is carried out in a fixed bed reactor system under the following conditions:
______________________________________                                    
Temperature, ° F.                                                  
                       750-900                                            
Pressure, atmosphere   1.1                                                
Co-feed water-ammonia:                                                    
Water, p.p.m. of xylene                                                   
                       5 × 10.sup.4                                 
Ammonia, p.p.m. of xylene                                                 
                       100                                                
______________________________________
The effluent from the above isomerization stage is cooled as required and passed to a stripper column where water and the light aromatics produced in the isomerization are taken as an overhead fraction and the bottoms portion is passed to a second distillation column from which the xylene fraction is recovered as an overhead stream while the heavy aromatic, trimethyl benzenes and the like, produced in the isomerization are withdrawn from the process or a fraction thereof is recycled to the isomerization stage.
The silica-alumina catalysts useful herein are rigid three dimensional networks characterized by uniform pores having relatively large pore diameters. It appears that the combination of physical characteristics, the particular surface area range and uniformly high pore radius, of the catalyst permits a diffusivity relationship favoring the desired isomerization reaction relative to the unwanted disproportionation reaction within the liquid hourly space velocity range specified above.
Preferred catalyst composites contain silica and alumina in the weight ratio 70-90 and 10-30 respectively, preferably about 80 to 20.
In addition, useful composites may contain minor amounts, about 5 to 15 parts, of such metal oxides as magnesia, zirconia, thoria, beryllia, and the rare earth metal oxides.
Silica-alumina catalyst composites having the necessary characteristics for use herein are conveniently prepared by the simultaneous co-precipitation or co-gellation (co-gel method) of a mixture of compounds of silicon and aluminum. The surface areas of the dried or partially dried composites are in general steamed-down to the useful range at temperatures in the range 500-1300° F., surface area determinations being made by the well known B.E.T. Method using nitrogen (cf. G. M. Schwab, "Handbuck der Katalyse," volume 4, page 195).
Representative and suitable co-gel-type preparative methods are to be found in the procedures as disclosed in U.S. 3,280,040, U.S. 3,399,132 and U.S. 3,401,125, except that the material other than the precursors for the silica, alumina, or other metal oxide components contemplated herein are omitted. General background information is to be found in the paper, "Control of Physical Structure of Silica-Alumina Catalyst," K. D. Ashley and W. B. Innes, Industrial & Engr. Chem., volume 44, 1952. On the other hand, the pH ranges for the co-gellation, working techniques including ion exchange and base exchange means as disclosed are in general desirably employed as disclosed in the above patent references.
Representative aromatic hydrocarbon feeds desirably employed in the process of the invention include p-xylene reduced (i.e., containing less than the equilibrium amount) C8 aromatic hydrocarbon mixtures, m-xylene, p-xylene, o-xylene, ethylbenzene, o-cymene, p-cymene, m-cymene, non-equilibrium enzyme mixtures, m-diisopropylbenzene, p-diisopropylbenzene, p-diethylbenzene, m-diethylbenzene, 3-isopropylethylbenzene, m-(n-propyl)-toluene, misitylene, 1,3-dimethylnaphthalene, 1,4-diethylnaphthalene, 1,5-diisopropylnaphthalene, 1,3,5-trimethylnaphthalene, and the like polyalkyl aromatic hydrocarbons. The polymethylbenzenes and mixtures thereof are preferred feeds.
The following examples further illustrate the invention.
EXAMPLES 1-3
A series of silica-alumina catalysts (80-20 weight ratio) were prepared by the co-gellation method and extruded (one-tenth inch diameter) and tempered. Three catalysts having the characteristics:
______________________________________                                    
                      Percent                                             
                      .[.pores >45°.].                             
            Surface   .Iadd.pore volume.Iaddend.                          
            area,     .Iadd.from 45A..Iaddend.                            
            M.sup.2 /g.                                                   
                      radius                                              
Catalyst:                                                                 
A             293          0                                              
B             327         20                                              
C             274         68                                              
______________________________________
were tested for disproportionation activity using a xylene feed with the following results:
______________________________________                                    
Catalyst:     Relative disproportionation                                 
______________________________________                                    
A             1.0                                                         
B             .71                                                         
C             .60                                                         
______________________________________
In the foregoing comparison, the process feed had the hydrocarbon composition:
______________________________________                                    
                      Wt. percent                                         
m-Xylene                53.3                                              
Ethylbenzene            25.2                                              
p-Xylene                8.8                                               
o-Xylene                6.6                                               
Toluene                 4.7                                               
Other (paraffins and naphthenes)                                          
                        1.4                                               
______________________________________
and contained in addition 500 p.p.m. (based upon hydrocarbon) of ammonia and 2.5 × 104 p.p.m. of water. The reaction conditions were:
______________________________________                                    
Temperature, ° F.                                                  
                       750                                                
Pressure, ATM           1                                                 
LHSV, v./v./hr.:                                                          
3 hr. at 1.76                                                             
18.5 hrs. at 0.88                                                         
______________________________________
These data demonstrate that for a minor disproportionation activity .[.the pore radius.]. .Iadd.at least 40% of the pore volume .Iaddend.of a silica-alumina catalyst composite should in the main be .Iadd.from pores having a pore radius .Iaddend.above about 45 A., that is few or none (less than 10 percent) of the catalyst .[.pores should have.]. .Iadd.pore volume should be from pores having .Iaddend.a radius less than about 45 A.
EXAMPLE 4
A silica-alumina catalyst composite was prepared which corresponded to catalyst C in the above examples except that sufficient of magnesium chloride was included in the co-gellation preparative mixture to provide for 5 parts of magnesia in the resulting catalyst. This catalyst had a surface area of 336 square meters per grams, with about 69 percent of the .[.pores.]. .Iadd.pore volume .Iaddend.thereof .Iadd.from pores .Iaddend.having a pore radius greater than 45 A. The isomerization and disproportionation activities were substantially the same as for catalyst C. However, the magnesia additive had reduced the coking activity (rate of coke lay-down) by about one-half of that for catalyst C.
The foregoing demonstrates that the addition of a minor amount of magnesia to a silica-alumina isomerization catalyst effectively reduces coke formation without impairing the isomerization activity or increasing the disproportionation activity of the catalyst.

Claims (9)

What is claimed is:
1. The process for the catalytic isomerization of an alkyl substituted polyalkyl aromatic hydrocarbon feed which comprises contacting the feed with a silica-alumina isomerization catalyst at a temperature in the range from about 700° F. to 1000° F., at a liquid hourly space velocity in the range from about 0.1 to 10, and at a pressure below about 200 p.s.i.g., wherein said catalyst consists essentially of a silica and alumina composite having a surface area in the range from about 250 to 400 square meters per gram, wherein at least 40 percent of the catalyst .Iadd.pore volume is from .Iaddend.pores .[.have.]. .Iadd.having .Iaddend.a radius greater than about 45 A., said feed having an aromatic carbocyclic carbon atom content below about 13, and having from 2 to about 4 of the same or different lower alkyl substituent groups; and said composite having a silica to alumina weight ratio in the range from about 70-90 to about 10-30, respectively.
2. The process as in claim 1 further characterized in that the feed is a polymethylbenzene, in that the surface area is in the range from about 270-350 square meters per gram, and in that at least about 70 percent of the .Iadd.pore volume is from .Iaddend.pores .[.have.]. .Iadd.having .Iaddend.a radius greater than 45 A.
3. The process as in claim 2 further characterized in that less than about 10 percent of the .Iadd.pore volume is from .Iaddend.pores .[.have.]. .Iadd.having .Iaddend.a radius less than 45 A.
4. The process as in claim 2 further characterized in that the composite contains, in addition to the silica and alumina, an amount in the range from about 5 to 15 parts by weight of an oxide selected from the group consisting of magnesia, zirconia, thoria and beryllia.
5. The process as in claim 4 further characterized in that the oxide is magnesia and in that the silica to alumina weight ratio is about 80 to 20, respectively.
6. The process as in claim 1 further characterized in that the composite contains, in addition to the silica and alumina, an amount in the range from about 5 to 15 parts by weight of an oxide selected from the group consisting of magnesia, zirconia, thoria, and beryllia.
7. The process as in claim 5 further characterized in that the feed is a p-xylene reduced C8 aromatic hydrocarbon mixture.
8. The process as in claim 1 further characterized in that the pore radius is greater than 50 A.
9. The process as in claim 1 further characterized in that the temperature is in the range from about 750° F. to 900° F.
US05/529,304 1970-01-14 1974-12-05 Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation Expired - Lifetime USRE29459E (en)

Priority Applications (1)

Application Number Priority Date Filing Date Title
US05/529,304 USRE29459E (en) 1970-01-14 1974-12-05 Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
US294870A 1970-01-14 1970-01-14
US05/529,304 USRE29459E (en) 1970-01-14 1974-12-05 Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation

Related Parent Applications (1)

Application Number Title Priority Date Filing Date
US294870A Reissue 1970-01-14 1970-01-14

Publications (1)

Publication Number Publication Date
USRE29459E true USRE29459E (en) 1977-10-25

Family

ID=26671063

Family Applications (1)

Application Number Title Priority Date Filing Date
US05/529,304 Expired - Lifetime USRE29459E (en) 1970-01-14 1974-12-05 Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation

Country Status (1)

Country Link
US (1) USRE29459E (en)

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3211798A (en) * 1962-06-21 1965-10-12 Sinclair Research Inc Method for transalkylation and isomerization of methyl benzenes
US3214485A (en) * 1962-06-21 1965-10-26 Sinclair Research Inc Method for the isomerization of methyl benzenes
US3293314A (en) * 1965-03-04 1966-12-20 Chevron Res Equilibration of lower alkyl substituted aromatic hydrocarbons
US3793384A (en) * 1971-03-12 1974-02-19 Ici Ltd Hydrocarbon conversion processes and catalysts

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US3211798A (en) * 1962-06-21 1965-10-12 Sinclair Research Inc Method for transalkylation and isomerization of methyl benzenes
US3214485A (en) * 1962-06-21 1965-10-26 Sinclair Research Inc Method for the isomerization of methyl benzenes
US3293314A (en) * 1965-03-04 1966-12-20 Chevron Res Equilibration of lower alkyl substituted aromatic hydrocarbons
US3793384A (en) * 1971-03-12 1974-02-19 Ici Ltd Hydrocarbon conversion processes and catalysts

Similar Documents

Publication Publication Date Title
US4899012A (en) Catalyst for the isomerization of aromatics
US5043502A (en) Production of xylenes from light aliphatic hydrocarbons via dehydrocyclodimerization and methylation
US5138112A (en) Process for converting a C2 -C6 aliphatic hydrocarbon to high octane transportable fuel
US6593504B1 (en) Selective aromatics transalkylation
US3551509A (en) Moving bed process using sieve catalyst to make xylenes by toluene disproportionation and transalkylation with c9-c10 alkylbenzenes
US6114592A (en) Selective aromatics disproportionation process
US2960545A (en) Demethylation process for pseudocumene
US3598879A (en) Alkyl transfer of alkyl aromatics with group i-a,ii-a,iv,or rare earth metals on boria alumina
US3888938A (en) Process for obtaining 2,6-dimethylnaphthalene-rich or 2,7-dimethylnaphthalene-rich product
US3211798A (en) Method for transalkylation and isomerization of methyl benzenes
US3637881A (en) Alkylaromatic isomerization process
US4387261A (en) Treatment of effluent resulting from conversion of methanol to gasoline in order to decrease durene and produce distillate
US3691247A (en) Selectively removing monoalkylbenzenes from mixtures thereof with dialkylbenzenes
US3548017A (en) Xylene isomerization process
US4041089A (en) Process for the isomerization of dimethylnaphthalenes using a mordenite/alumina catalyst
USRE29459E (en) Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation
US4255606A (en) Improved para- and ortho-xylene isomerization by adding pentane
US4059645A (en) Alkylaromatic isomerization process
US3597491A (en) Alkyl transfer of alkyl aromatics with croup vi-b metals on type y zeolites
US3647898A (en) Equilibration of lower alkyl substituted polyalkyl aromatic hydrocarbons with reduced disproportionation
USRE27639E (en) Certificate of correction
US3120569A (en) Process for the isomerization of alkyl benzenes in the presence of an iodidecontaining compound
USRE30157E (en) Xylene isomerization
US3088984A (en) Process for the isomerization of alkyl benzenes in the presence of a used hydrocracking catalyst
US5081084A (en) Catalyst for isomerizing alkylaromatics