Patent EA-003270-B1 (EA)
Title: Aromatic conversion process and zeolite catalyst useful therein
Inventor: HENDRIKSEN DAN E
IPC: C07C2/86
Filed: 1997-05-29
Abstract: 1. A zeolite bound zeolite catalyst which does not contain significant amounts of non-zeolitic binder and comprises: (a) first crystals of a large pore size first zeolite selected from the group consisting of MAZ, EMT and MOR, and (b) a binder comprising second crystals of a second zeolite present in an amount of from 10 to 60% by weight based on the weight of the first crystals, wherein the particle size of crystals of the second zeolite is less than the particle size of crystals of the first zeolite. 2. The catalyst recited in Claim 1 wherein the crystals of the second zeolite are intergrown and form at least a partial coating on the crystals of the first zeolite. 3. The catalyst recited in Claim 1 or 2 wherein the crystals of the second zeolite are resistant to attrition. 4. The catalyst recited in any of Claims 1 to 3 which contains less than 5% by weight of non-zeolitic binder based on the combined weight of the first zeolite and the second zeolite. 5. The catalyst recited in any of Claims 1 to 4 wherein the crystals of the first zeolite have an average particle size greater than 0.1 micron and the crystals of the second zeolite have an average particle size less than that of the crystals of the first zeolite. 6. The catalyst recited in Claim 5 wherein the average particle size of the crystals of the first zeolite is from 1 to 6 microns and the average particle size of the crystals of the second zeolite is from 0.1 to 0.5 microns. 7. The catalyst recited in any of Claims 1 to 6 wherein the structure type of the first zeolite and the second zeolite is the same, and is preferably MOR. 8. The catalyst recited in any of Claims 1 to 7 wherein the first zeolite and/or the second zeolite is an aluminosilicate zeolite or a gallium silicate zeolite. 9. The catalyst recited in any of Claims 1 to 8 which is preparable from a silica bound extrudate comprising the first crystals of first zeolite by converting the silica in the extrudate to the second zeolite. 10. A process for performing a conversion of aromatic hydrocarbons, said conversion being alkylation, transalkylation or isomerization, which comprises (i) contacting, under alkylation conversion conditions, a zeolite bound zeolite catalyst and a feedstream containing aromatic hydrocarbon and at least one olefin; or (ii) contacting, under transalkylation conversion conditions, a zeolite bound zeolite catalyst and an aromatic hydrocarbon feedstream containing a polyalkyl aromatic hydrocarbon having at least two alkyl groups each independently of from 2 to 4 carbon atoms; or (iii) contacting, under isomerization conversion conditions, a zeolite bound zeolite catalyst and a feedstream containing isomerizable monocyclic alkylaromatic hydrocarbons, isomerizable bicyclic alkylaromatic hydrocarbons, or mixtures thereof: wherein the catalyst does not contain significant amounts of non-zeolitic binder and comprises (a) first crystals of a large pore size first zeolite, and (b) a binder comprising second crystals of a second zeolite, wherein the particle size of crystals of the second zeolite is less than the particle size of crystals of the first zeolite. 11. The process recited in Claim 10 wherein the second crystals are intergrown and form at least a partial coating on the first crystals. 12. The process recited in Claim 10 or 11 wherein the catalyst contains less than 5% by weight of non-zeolitic binder based on the combined weight of first zeolite and second zeolite. 13. The process recited in any preceding Claim wherein the first crystals have an average particle size greater than 0.1 micron and the second crystals have an average particle size less than that of the first crystals. 14. The process recited in any preceding Claim wherein the average particle size of the first crystals is from 1 to 6 microns and/or the average particle size of the second crystals is from 0.1 to 0.5 microns. 15. The process recited in any preceding Claim wherein the first zeolite and/or the second zeolite are each independently a composition having the following molar relationship: X2O3:(n) YO2, wherein X is aluminum, boron, titanium, and/or gallium, Y is silicon, tin, and/or germanium, and n has a value greater than 2. 16. The process recited in any preceding Claim wherein the first zeolite is an aluminosilicate zeolite and has a silica to alumina mole ratio of from 2:1 to 150:1. 17. The process recited in any preceding Claim wherein the first zeolite and the second zeolite is each independently selected from the structure group consisting of MAZ, MEI, AFI, EMT, OFF, BEA, and MOR. 18. The process recited in any preceding Claim wherein the second zeolite has the same structure as the first zeolite. 19. The process recited in any preceding Claim wherein the conversion comprises alkylation (i). 20. The process recited in Claim 19 wherein the aromatic hydrocarbon is benzene, toluene, xylene, or a mixture of any two or more thereof. 21. The process recited in Claim 19 or 20 wherein the olefin is ethylene, propylene, butene-1, trans-butene-2, cis-butene-2, pentene- 1, hexene- 1, octene- 1, nonene- 1, decene- 1, undecene- 1, dodecene- 1, tridecene- 1, or a mixture of any two or more thereof. 22. The process recited in Claim 19, 20, or 21 wherein the feedstream has a molar ratio of aromatic hydrocarbons to olefins of at least 4:1. 23. The process recited in any of Claims 19 to 22 wherein the conversion conditions include a temperature of from 37 to 316 degree C (100 to 600 degree F) and/or a pressure of from 0.34 to 6.90 MPag (50 to 1000 psig) and/or a weight hourly space velocity of from 0.5 to 50. 24. The process recited in any of Claims 10 to 18 wherein the conversion comprises transalkylation (ii). 25. The process recited in Claim 24 wherein the first zeolite and/or second zeolite is BEA or MAZ. 26. The process recited in Claim 24 or 25 wherein the polyalkyl aromatic hydrocarbon is dimethylbenzene, trimethylbenzene, diethylbenzene, triethylbenzene, diethylmethylbenzene, diisopropylbenzene, triisopropylbenzene, diisopropyltoluene, dibutylbenzene or a mixture of any two or more thereof. 27. The process recited in Claim 24, 25 or 26 wherein the feedstream has a molar ratio of aromatic hydrocarbon to polyalkyl aromatic hydrocarbon of from 1:1 to 50:1. 28. The process recited in any of Claims 24 to 27 wherein the conversion conditions include a temperature of from 37 to 316 degree C (100 to 600 degree F) and/or a pressure of from 0.34 to 6.90 MPag (50 to 1000 psig) and/or a weight hourly space velocity of from 0.1 to 100. 29. The process recited in any of Claims 10 to 18 wherein the conversion comprises isomerization (iii). 30. The process recited in Claim 29 wherein the first zeolite is a MOR structure type and/or the second zeolite is a BEA type. 31. The process recited in Claim 29 or 30 wherein the first zeolite is at least partially in the hydrogen form. 32. The process recited in any of Claims 29 to 31 wherein the second zeolite has less acidity than the first zeolite. 33. The process recited in any of Claims 20 to 24 wherein the zeolite bound zeolite catalyst further comprises at least one hydrogenation metal. 34. The process recited in any of Claims 29 to 33 wherein the isomerization conditions comprise a temperature of from 250 degree to 600 degree C and/or a pressure of from 20 kPa to 5.07 MPa (0.2 to 50 atm abs) and/or a weight hourly space velocity of from 0.1 to 100 and/or a hydrogen/hydrocarbon molar ratio of from 0.1 to 10. 35. The process recited in any of Claims 20 to 26 wherein the alkylaromatic hydrocarbons are selected from the group consisting of: (a) monocyclic alkylaromatic hydrocarbons represented by the formula: wherein: each R<1> is independently an alkyl group having 1 to 4 carbon atoms; and x is 2 or 3; and (b) bicyclic alkylaromatic hydrocarbons represented by the formula: wherein R<2> and R<3> is each independently an alkyl group having 1 to 4 carbon atoms; and y and z is each independently 0, 1 or 2, provided that the sum of y and z is 2, 3, or 4. 36. The process recited in Claim 35 wherein the feed comprises monocyclic alkylaromatic hydrocarbons of formula I wherein R<1> is methyl or ethyl and x is 2. 37. The process recited in Claim 35 or 36 wherein the feed comprises bicyclic alkylaromatic hydrocarbons of formula II wherein each of R<2> and R<3> is methyl, y is 1 and z is 1. 38. The process recited in any of Claims 20 to 28 wherein the feed is an aromatic C8 mixture of ethylbenzene and xylenes in which the paraxylene concentration is at less than thermodynamic equilibrium.