Alkylaromatics Production

A process for producing ethylbenzene from a feed comprising benzene, ethylene and ethane in a multistage reaction system, said reaction system comprising at least first and second series-connected alkylation reaction zones each containing an alkylation catalyst and having operating conditions, and at least one transalkylation reaction zone comprising a transalkylation catalyst, the process comprising the steps of:

• (a) controlling said operating conditions of said first alkylation reaction zone by adjusting temperature or pressure effective to cause (i) part of said benzene of said feed to be in the vapor phase and part of said benzene of said feed to be in the liquid phase, and (ii) the ratio of the volume of liquid to the volume of vapor in said first reaction zone is from about 0.5 to about 10 to maintain a diethylbenzene/ethylbenzene weight ratio of less than 15%;
• (b) reacting said benzene and said ethylene of said feed in the presence of said alkylation catalyst to form a first effluent, said first effluent comprising said ethylbenzene, unreacted benzene, any unreacted ethylene, polyethylbenzene, and said ethane;
• (c) withdrawing said first effluent from said first alkylation reaction zone and without removing said ethane from said first effluent, supplying said first effluent to said second alkylation reaction zone;
• (d) controlling said operating conditions of said second alkylation reaction zone by adjusting temperature or pressure effective to cause (i) part of said benzene of said first effluent to be in the vapor phase and part of said benzene of said first effluent to be in the liquid phase, and (ii) the ratio of the volume of vapor in said second reaction zone is from about 0.5 to about 10 to maintain a diethylbenzene/ethylbenzene weight ratio of less than 15%;
• (e) reacting said benzene and said ethylene of said first effluent in the presence of said alkylation catalyst to form a second effluent comprising additional ethylbenzene, unreacted benzene, any unreacted ethylene, polyethylbenzene, and said ethane, wherein said alkylation catalysts in each of said first and second alkylation reaction zones comprise a molecular sieve independently selected from the group consisting of zeolite Beta, faujacite, zeolite Y, Ultrastable Y (USY), Dealuminized Y (Deal Y), mordenite, TEA-mordenite, ZSM-3, ZSM-4, ZSM-5, ZSM-18, and ZSM-20, and mixtures thereof;
• (f) separating said polyethylbenzene from said second effluent, and
• (g) contacting at least portion of said polyethylbenzene with additional benzene in the presence of a transalkylation catalyst under transalkylating conditions in said transalkylation zone, to form additional ethylbenzene, said transalkylation catalyst comprises a molecular sieve selected from the group consisting of MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, MCM-36, MCM-49, MCM-56, and mixtures thereof.

A process for producing cumene from a feed comprising benzene, propylene and propane in a multistage reaction system, said reaction system comprising at least first and second series-connected alkylation reaction zones each containing an alkylation catalyst and having operating conditions, and at least one transalkylation reaction zone comprising a transalkylation catalyst, the process comprising the steps of:

• (a) controlling said operating conditions of said first alkylation reaction zone by adjusting temperature or pressure effective to cause (i) part of said benzene to be in the vapor phase and part of said benzene to be in the liquid phase, and (ii) the ratio of the volume of liquid to the volume of vapor in said first reaction zone is from about 0.5 to about 10 to maintain a di-isopropylbenzene/isopropylbenzene weight ratio of less than 15%;
• (b) reacting said benzene and said propylene of said feed in the presence of said alkylation catalyst to form a first effluent, said first effluent comprising said cumene, unreacted benzene, any unreacted propylene, polyisopropylbenzene, and said propane;
• (c) withdrawing said first effluent from said first alkylation reaction zone and without removing said propane from said first effluent, supplying said first effluent to said second alkylation reaction zone;
• (d) controlling said operating conditions of said second alkylation reaction zone by adjusting temperature or pressure effective to cause (i) part of said benzene to be in the vapor phase and part of said benzene to be in the liquid phase, and (ii) the ratio of the volume of vapor in said second reaction zone is from about 0.5 to about 10 to maintain a di-isopropylbenzene/isopropylbenzene weight ratio of less than 15%;
• (e) reacting said benzene and said propylene of said first effluent in the presence of said alkylation catalyst to form a second effluent, wherein said alkylation catalyst in each of said first and second alkylation reaction zones comprise a molecular sieve independently selected from the group consisting of zeolite Beta, faujacite, zeolite Y, Ultrastable Y (USY), Dealuminized Y (Deal Y), mordenite, TEA-mordenite, ZSM-3, ZSM-4, ZSM-5, ZSM-18, and ZSM-20;
• (f) separating said polyisopropylbenzene from said second effluent, and
• (g) contacting at least portion of said polyisopropylbenzene with additional benzene in the presence of a transalkylation catalyst under transalkylating conditions in said transalkylation zone, to form additional cumene, said transalkylation catalyst comprises a molecular sieve selected from the group consisting of MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, MCM-36, MCM-49, MCM-56, and mixtures thereof.

A process for producing sec-butylbenzene from a feed comprising benzene, 1-butene or 2-butene and butane in a multistage reaction system, said reaction system comprising at least first and second series-connected alkylation reaction zones each containing an alkylation catalyst and having operating conditions, and at least one transalkylation reaction zone comprising a transalkylation catalyst, the process comprising the steps of:

• (a) controlling said operating condition of said first alkylation reaction zone by adjusting temperature or pressure effective to cause (i) part of said benzene of said feed to be in the vapor phase and part of said benzene of said feed to be in the liquid phase, and (ii) the ratio of the volume of liquid to the volume of vapor in said first reaction zone is from about 0.5 to about 10 to maintain a di-sec-butylbenzene/sec-butylbenzene weight ratio of less than 15%;
• (b) reacting said benzene and said 1-butene or 2-butene of said feed in the presence of said alkylation catalyst to form a first effluent, said first effluent comprising said sec-butylbenzene, unreacted benzene, any unreacted 1-butene or 2-butene, polybutylbenzene, and said butane;
• (c) withdrawing said first effluent from said first alkylation reaction zone and without removing said butane from said first effluent, supplying said first effluent and said 1-butene or 2-butene to said second alkylation reaction zone;
• and
• (d) controlling said operating conditions of said second alkylation reaction zone by adjusting temperature or pressure effective to cause (i) part of said benzene of said first effluent to be in the vapor phase and part of said benzene of said first effluent to be in the liquid phase, and (ii) the ratio of the volume of liquid to the volume of vapor in said second reaction zone is from about 0.5 to about 10 to maintain a di-sec-butylbenzene/sec-butylbenzene weight ratio of less than 15%;
• (e) reacting said benzene and said 1-butene or 2-butene of said first effluent in the presence of said alkylation catalyst to form a second effluent comprising additional sec-butylbenzene, unreacted benzene, and any unreacted 1-butene or 2-butene, polybutylbenzene, and said propane, wherein said alkylation catalysts in each of said first and second alkylation reaction zones comprise a molecular sieve independently selected from the group consisting of zeolite Beta, faujacite, zeolite Y, Ultrastable Y (USY), Dealuminized Y (Deal Y), mordenite, TEA-mordenite, ZSM-3, ZSM-4, ZSM-5, ZSM-18, and ZSM-20, and mixtures thereof;
• (f) separating said polybutylbenzene from said second effluent of said second alkylation reaction zone, and
• (g) contacting at least portion of said polybutylbenzene with additional benzene in the presence of a transalkylation catalyst under transalkylating conditions in said transalkylation reaction zone, to form additional sec-butylbenzene, said transalkylation catalyst comprises a molecular sieve selected from the group consisting of MCM-22, PSH-3, SSZ-25, ERB-1, ITQ-1, ITQ-2, MCM-36, MCM-49, MCM-56, and mixtures thereof.