Heavy aromatics process

Claim 2

A process for converting to BTX a C 9 + monocyclic aromatic hydrogen distillate which boils below about 500° F., said distillate having an average content per benzene ring of about 0.5 to 3.0 alkyl groups of more than one carbon atom, which process comprises: contacting said distillate and hydrogen with a steamed zeolite catalyst at a temperature of 650° F. to 800° F., a pressure of about 50 to 750 psig, a WHSV of about 0.5 to 30 and a hydrogen to hydrocarbon mol ratio of about 0.5 to 10, said catalyst comprising a crystalline zeolite having a Constraint Index of 1 to 12, a silica to alumina ratio of at least 12, and a platinum group metal incorporated in cationic from with said zeolite prior to final catalyst particle formation and prior to any calcination or steaming of said zeolite, said steamed catalyst having been steamed under conditions effective to reduce its alpha value by at least 25 percent.

Claim 3

The process described in claim 1 wherein the alpha value of said catalyst after steaming is between about 20 and 150.

Claim 4

The process described in claim 1 wherein said crystalline aluminosilicate zeolite is ZSM-5 or ZSM-11.

Claim 5

The process described in claim 2 wherein said crystalline aluminosilicate zeolite is ZSM-5 or ZSM-11.

Claim 6

The process described in claim 1 or claim 2 or claim 3 or claim 4 wherein said platinum group metal is platinum and the platinum content of said catalyst is about 0.001 to 1.0% by weight of said zeolite in said catalyst.

Claim 7

A process for converting a C 9 + monocyclic aromatic hydrocarbon distillate by-product from a catalytic xylene isomerization process into liquid product rich in benzene, toluene and xylenes and gaseous product rich in alkanes having more than one carbon atom which process comprises contacting said by-product and hydrogen with a zeolite catalyst at a temperature of 650° F. to 800° F., a pressure of about 50 to 750 psig, a WHSV of about 0.5 to 30 and a hydrogen to hydrocarbon mol ratio of about 0.5 to 10, said catalyst comprising a crystalline zeolite having a Constraint Index of 1 to 12, a silica to alumina ratio of at least 12, and a platinum group metal incorporated in cationic form with said zeolite prior to final catalyst particle formation and prior to any calcination or steaming of said zeolite, said catalyst having been steamed under conditions effective to reduce its alpha value by at least 25 percent.

Claim 8

A process for converting a C 9 + monocyclic aromatic hydrocarbon distillate by-product from a catalytic xylene isomerization process into liquid product rich in benzene, toluene and xylenes and gaseous product rich in alkanes having more than one carbon atom which process comprises contacting said by-product and hydrogen with a zeolite catalyst at a temperature of 650° F. to 800° F., a pressure of about 50 to 750 psig, a WHSV of about 0.5 to 30 and a hydrogen to hydrocarbon mol ratio of about 0.5 to 10, said catalyst comprising a crystalline zeolite having a Constraint Index of 1 to 12, a silica to alumina ratio of at least 12, and a platinum group metal incorporated in cationic form with said zeolite prior to final catalyst particle formation and prior to any calcination or steaming of said zeolite, said catalyst having been steamed under conditions effective to reduce its alpha value by at least 25 percent.

Claim 9

The process described in claim 6 wherein the alpha value of said catalyst after steaming is between about 20 and 150.

Claim 10

The process described in claim 6 or 7 wherein said platinum group metal is platinum, and said zeolite is ZSM-5.

Claim 11

The process described in claim 6 or 7 wherein said platinum group metal is platinum and it is present in from about 0.001 to about 1.0% by weight.

Claim 12

In a process for manufacturing para xylene from a liquid hydrocarbon feed consisting essentially of C 8 monocyclic aromatic hydrocarbons including para xylene, which process comprises crystallizing and recovering the para xylene isomer from said feed and catalytically isomerizing the para isomer depleted remainder with a first catalyst comprising a crystalline aluminosilicate zeolite having a Constraint Index of 1 to 12 and a silica to alumina ratio of at least 12 thereby replenishing the depleted isomer with concomitant formation of C 9 + alkylaromatic by-product; the improvement, which comprises separating said alkylaromatic by-product and contacting it in the presence of hydrogen with a second catalyst comprising a crystalline zeolite having a Constraint Index of 1 to 12, a silica to alumina ratio of at least 12, and a platinum group metal incorporated in cationic form with said zeolite prior to final catalyst particle formation and prior to any calcination or steaming of said zeolite, said second catalyst having been steamed under conditions effective to reduce its alpha value into the range of 20 to 150.

Claim 13

In a process for manufacturing para xylene from a liquid hydrocarbon feed consisting essentially of C 8 monocyclic aromatic hydrocarbons including para xylene, which process comprises crystallizing and recovering the para xylene isomer from said feed and catalytically isomerizing the para isomer depleted remainder with a first catalyst comprising a crystalline aluminosilicate zeolite having a Constraint Index of 1 to 12 and a silica to alumina ratio of at least 12 thereby replenishing the depleted isomer with concomitant formation of C 9 + alkylaromatic by-product; the improvement, which comprises separating said alkylaromatic by-product and contacting it in the presence of hydrogen with a second catalyst comprising a crystalline zeolite having a Constraint Index of 1 to 12, a silica to alumina ratio of at least 12, and a platinum group metal incorporated in cationic form with said zeolite prior to final catalyst particle formation and prior to any calcination or steaming of said zeolite, said second catalyst having been steamed under conditions effective to reduce its alpha value into the range of 20 to 150.

Claim 14

The improvement described in claim 10 wherein said crystalline aluminosilicate zeolite in said first catalyst is ZSM-5 or ZSM-11, and said crystalline aluminosilicate zeolite in said second catalyst is ZSM-5 or ZSM-11.