US 7,247,762 B2 · Process for xylene isomerization and ethylbenzene conversion

Abstract

A process for the isomerization of xylenes and the conversion of ethylbenzene to benzene and ethane using a catalyst system comprising two catalysts. The first catalyst is unselectivated and comprises: (a) an intermediate pore size zeolite, e.g., ZSM-5; (b) at least one hydrogenation component to deethylate ethylbenzene, e.g. Group VIII and/or Group VIIIB metal; and (c) an amorphous binder, said first catalyst requiring at least 50 minutes to sorb 30% of the equilibrium capacity of ortho-xylene at 120° C. and at an ortho-xylene partial pressure of 4.5±0.8 mm of mercury. The second catalyst comprises an intermediate pore size zeolite, e.g., ZSM-5, and requires less than 50 minutes to sorb 30% of the equilibrium capacity of ortho-xylene at 120° C. and at an ortho-xylene partial pressure of 4.5±0.8 mm of mercury. The amount of first catalyst present in the catalyst system is a volume greater than 55 percent based on the sum of the volumes of the first catalyst and second catalyst.

Claims36

Dependent claims

A process for isomerizing xylenes present in a feed containing ethylbenzene comprising:

contacting said feed under conversion conditions with a catalyst system containing a first catalyst and a second catalyst, said first catalyst being unselectivated and comprising:
(a) an intermediate pore size zeolite;
(b) Re to deethylate ethylbenzene;
and (c) an amorphous binder, said first catalyst requiring at least 50 minutes to sorb 30% of the equilibrium capacity of ortho-xylene at 120° C. and at an ortho-xylene partial pressure 4.5±0.8 mm of mercury;
and said second catalyst comprises an intermediate pore size zeolite and requires less than 50 minutes to sorb 30% of the equilibrium capacity of ortho-xylene at 120° C. and at an ortho-xylene partial pressure of 4.5±0.8 mm of mercury;
wherein the amount of said first catalyst present in said catalyst system is an amount greater than 55 percent and by volume based on the sum of the volumes of the first catalyst and second catalyst.

3 more elements

A process for upgrading a non-equilibrium feed mixture containing ethylbenzene and at least one xylene isomer with a catalyst system comprising a first catalyst and a second catalyst, said process comprising:

(i) contacting said feed mixture under ethylbenzene conversion conditions with a first catalyst effective under said ethylbenzene conversion conditions to deethylate ethylbenzene in said feed mixture and produce an ethylbenzene-depleted product, wherein said first catalyst consists essentially of :
(a) ZSM-5 having an alpha value from about 100 to about 300 and a crystal size of at least 1μ;
(b) Re, and mixtures and, (c) a binder selected from the group consisting of silica, alumina, and mixtures thereof;
said first catalyst requiring at least 50 minutes to sorb 30% of the equilibrium capacity or ortho-xylene at 120 ° C. and at an ortho-xylene partial pressure of 4.5±0.8 mm of mercury;
and,
(ii) contacting the ethylbenzene-depleted product under xylene isomerization conditions with a second catalyst comprising (a) ZSM-5 having an alpha value less than about 100 and a crystal size no greater than 0.10μ;
(b) a hydrogenation component;
and (c) a binder comprising silica, alumina, or mixtures thereof, said second catalyst requiring less than 50 minutes to sorb 30% of the equilibrium capacity of ortho-xylene at 120 ° C. and at an ortho-xylene partial pressure of 4.5±0.8 mm of mercury;
wherein the amount of said first catalyst present in said catalyst system is an amount greater than 55 percent by volume based on the sum of the volumes of the first catalyst and second catalyst.

6 more elements

Dependencies are inferred from the claim text.

Process for xylene isomerization and ethylbenzene conversion

Life of this patent

Process for xylene isomerization and ethylbenzene conversion

Life of this patent

Abstract

Claims36