Hydrogenation process

A process for producing phenol and/or cyclohexanone, the process comprising:

• (A) contacting a first feed comprising benzene with hydrogen in the presence of a hydroalkylation catalyst to produce a first effluent stream comprising cylcohexylbenzene and cyclohexenyl benzene;
• (B) oxidizing a second feed comprising at least a portion of the cylcohexylbenzene present in the first effluent stream to produce a second effluent stream comprising cyclohexylbenzene hydroperoxide;
• (C) cleaving a third feed comprising at least a portion of the cyclohexylbenzene hydroperoxide in the second effluent stream to produce a third effluent stream comprising phenol, cyclohexanone and cyclohexenylbenzene;
• and
• (D) contacting a fourth feed comprising at least a portion of the cyclohexenylbenzene in the first effluent stream and/or the third effluent stream with hydrogen in the presence of an eggshell hydrogenation catalyst to produce a fourth effluent stream comprising cyclohexylbenzene;
• wherein the eggshell hydrogenation catalyst comprises at least one metal component selected from Groups 6 to 10 of the Periodic Table of Elements and at least one support, such that more than 50 wt % of the at least one metal component present in the hydrogenation catalyst is deposited in a peripheral outer layer of the support.

A process for producing phenol and/or cyclohexanone, the process comprising:

• (a) reacting benzene with hydrogen in the presence of a hydroalkylation catalyst under conditions effective to produce a hydroalkylation reaction effluent comprising cyclohexylbenzene and olefinic byproducts, benzene, and hydrogen;
• (b) removing a purge stream from the hydroalkylation reaction effluent, said purge stream comprising hydrogen and benzene;
• (c) washing the purge stream with a further stream containing cyclohexylbenzene to produce a benzene-depleted purge gas stream containing hydrogen and a wash stream containing cyclohexylbenzene and benzene;
• (d) separating an impure product stream comprising cyclohexylbenzene and olefinic byproducts from the hydroalkylation reaction effluent in the reacting step (a);
• (e) contacting the impure product stream of the separating step (d) with the benzene-depleted purge gas stream in the presence of an eggshell hydrogenation catalyst under conditions such that hydrogen in the benzene-depleted purge gas stream reacts with the olefinic by-products to produce a hydrogenated product stream and a hydrogen-depleted purge gas stream;
• wherein the eggshell hydrogenation catalyst comprises at least one metal component selected from Groups 6 to 10 of the Periodic Table of Elements and at least one support, such that more than 50 wt % of the at least one metal component present in the hydrogenation catalyst is deposited in a peripheral outer layer of the support;
• (f) purging said hydrogen-depleted purge gas stream;
• (g) oxidizing at least a portion of the cyclohexylbenzene in said hydrogenated product stream of the contacting step (e) to cyclohexylbenzene hydroperoxide;
• and
• (h) cleaving at least a portion of the cyclohexylbenzene hydroperoxide produced in (g) to produce a cleavage product stream comprising phenol and cyclohexanone.

A process for producing phenol and/or cvclohexanone, the process comprising:

• (a) reacting benzene with hydrogen in the presence of a hydroalkylation catalyst under conditions effective to produce a hydroalkylation reaction effluent comprising cyclohexylbenzene and olefinic byproducts;
• (b) removing a purge stream from the hydroalkylation reaction effluent, said purge stream comprising hydrogen and benzene;
• (c) washing the purge stream with a further stream containing cyclohexylbenzene to produce a benzene-depleted purge gas stream containing hydrogen and a wash stream containing cyclohexylbenzene and benzene;
• (d) separating an impure product stream comprising cyclohexylbenzene and at least a portion of the olefinic byproducts from the hydroalkylation reaction effluent;
• (e) contacting the impure product stream with the benzene-depleted purge gas stream in the presence of a hydrogenation catalyst under conditions such that hydrogen in the benzene-depleted purge gas stream reacts with the olefinic byproducts to produce a hydrogenated product stream and a hydrogen-depleted purge gas stream;
• (f) purging said hydrogen-depleted purge gas stream;
• (g) oxidizing at least a portion of the cyclohexylbenzene in the hydrogenated product stream to cyclohexylbenzene hydroperoxide;
• (h) cleaving at least a portion of the cyclohexylbenzene hydroperoxide produced in (g) to produce a cleavage product stream comprising phenol, cyclohexenylbenzene, and cyclohexanone;
• (i) separating out a product stream comprising phenol and cyclohexanone and a recycle stream comprising cyclohexenylbenzene and residual cyclohexylbenzene;
• and
• (j) contacting the recycle stream with a gas stream comprising hydrogen in the presence of an eggshell hydrogenation catalyst under conditions such that hydrogen in the gas stream reacts with cyclohexenylbenzene to produce a hydrogenated recycle stream comprising cyclohexylbenzene and a hydrogen-depleted gas stream;
• wherein the eggshell hydrogenation catalyst comprises at least one metal component selected from Groups 6 to 10 of the Periodic Table of Elements and at least one support, such that more than 50 wt % of the at least one metal component present in the hydrogenation catalyst is deposited in a peripheral outer layer of the support.