Xylene isomerization process to exhaustively convert ethylbenzene and non-aromatics

A process for isomerizing a feed which contains 0-20 weight percent paraffins and an aromatic C.sub.8 mixture of ethylbenzene and xylene in which the para-xylene is less than that at thermal equilibrium, which comprises contacting the feed, under isomerization conditions, with a two component catalyst system comprising component (1) and component (2) wherein

• component (1) comprises a zeolite of a constraint index of about 1 to about 12 and of an ortho-xylene sorption time of greater than 50 minutes based on its capacity of sorb 30% of the equilibrium capacity of ortho-xylene at 120.degree. C. and an ortho xylene partial pressure of 4.5.+-.0.8 mm of mercury and 0.05 to 10 wt % of a hydrogenation component and is effective, under said isomerization conditions, to deethylate benzene, and
• component (2) comprises ZSM-5 and a metal which is a strong hydrogenative, wherein ZSM-5 has a crystal size the minimum dimension of which ranges up to about 0.10.mu., and wherein said ZSM-5 is characterized by an alpha value of less than 100, wherein the metal comprises 0.01 to 10 weight percent of component (2);
• wherein the amount of component (2) in the catalyst system is at least 50 percent by volume of the catalyst system
• wherein isomerization conditions include a temperature of from about 400.degree. to 1000.degree. F., a pressure of from about 0 to 1000 psig, a WHSV of between 0.5 and 100 and a H.sub.2 /HC molar ratio of between about 0.5 and 10;
• and
• whereby the ethylbenzene content of the feed is exhaustively converted;
• wherein exhaustively converted is deethylation of at least half the ethylbenzene and includes hydrocracking of at least one-third of said 0-20 weight percent of paraffins.

The process for isomerizing a feed which contains 0-20 weight percent paraffins and ethylbenzene and xylene, in which the para-xylene is less than that at thermal equilibrium of the mixture of ortho-, meta- and para-xylene contained in the feed, which comprises contacting the feed under isomerization conditions with a two component catalyst system comprising component (1) and component (2) wherein

• component (1) comprises ZSM-5, and a metal which is a strong hydrogenative metal, wherein the ZSM-5 has a crystal size the minimum dimension of which is greater than 1.mu. and wherein ZSM-5 has an alpha value greater than 100, and wherein the metal comprises about 0.01 to about 10 weight percent of component (1);
• and
• component (2) comprises a zeolite and a hydrogenative metal, wherein said zeolite has a constraint index within the approximate range of 1 to 12 and which is characterized by a xylene sorption capacity greater than 1 gram/100 grams of zeolite and an ortho-xylene sorption time for 30 percent of said capacity of than 10 minutes, where the sorption capacity and sorption times are measured at 120.degree. C. and a xylene pressure of 4.5.+-.0.8 mm of mercury wherein component (2) comprises at least 50 percent by volume of the catalyst system.
• wherein isomerization conditions include a temperature of from about 400.degree. to 1000.degree. F., a pressure of from about 0 to 1000 psig, a WHSV of between 0.5 and 100 and a H.sub.2 /HC molar ratio of between about 0.5 and 10;
• whereby the ethylbenzene content of the feed is exhaustively converted,
• wherein exhaustively converted is deethylation of at least half of the ethylbenzene and includes hydrocracking of at least one-third of said 0-20 weight percent of paraffins.

A process for isomerizing a feed which contains an aromatic C.sub.8 mixture comprising ethylbenzene and xylenes in which the para-xylene is less than that at thermal equilibrium and which contains 0-20 weight percent paraffins, which process comprises cascading the feed over a catalyst system comprising component (1) and component (2) wherein

• component (1) comprises ZSM-5 and a metal which is a strong hydrogenation metal, wherein ZSM-5 is characterized by a crystal size, the minimum dimension of which is about at least 1.mu., and by an alpha value of at least 100 and wherein the metal comprises 0.05 to 10 weight percent of said component (1), and
• component (2) comprises ZSM-5 zeolite and a metal which is a strong hydrogenative metal, wherein ZSM-5 has a crystal size less than 1 micron and an alpha value of less than 100, wherein the metal comprises 0.05 to 10 weight percent of the component (2) wherein component (2) comprises at least 50 percent by volume of the catalyst system
• wherein cascading is undertaken under conditions including a temperature of from about 400.degree. to 1000.degree. F., a pressure of from about 0 to 1000 psig a WHSV of between 0.5 and 100 and a H.sub.2 /HC molar ratio of between about 0.5 and 10,
• whereby at least half of the ethylbenzene content of the feed is converted by deethylation and at least one third of said 0-20 weight percent paraffins is hydrocracked.