Process for producing cumene

Abstract

A process for producing cumene is provided which comprises the step of contacting benzene and propylene under at least partial liquid phase alkylating conditions with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch −1 .

What we claim is:  
     
         1 . A process for producing cumene which comprises the step of contacting benzene and propylene under at least partial liquid phase alkylating conditions with a particulate molecular sieve alkylation catalyst, wherein the particles of said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch −1 .  
     
     
         2 . The process of  claim 1  wherein the particles of said alkylation catalyst have a surface to volume ratio of about 100 to about 150 inch −1 .  
     
     
         3 . The process of  claim 1  wherein the molecular sieve of the alkylation catalyst is selected from MCM-22, PSH-3, SSZ-25, MCM-36, MCM-49, MCM-56, faujasite, mordenite and zeolite beta.  
     
     
         4 . The process of  claim 1  wherein said alkylating conditions include a temperature of about 10° C. to about 125° C., a pressure of about 1 to about 30 atmospheres, and a benzene weight hourly space velocity (WHSV) of about 5 hr −1  to about 50 hr −1.    
     
     
         5 . A process for producing cumene which comprises the steps of: 
 i) contacting benzene and propylene with a particulate molecular sieve alkylation catalyst under at least partial liquid phase alkylating conditions to provide a product containing cumene and a polyisopropylbenzene fraction;    ii) separating the polyisopropylbenzene fraction from the product; and    iii) contacting the polyisopropylbenzene fraction and benzene with a particulate molecular sieve transalkylation catalyst under at least partial liquid phase transalkylating conditions, wherein the particles of at least said alkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch −1 .    
     
     
         6 . The process of  claim 5  wherein the particles of said alkylation catalyst have a surface to volume ratio of about 100 to about 150 inch −1 .  
     
     
         7 . The process of  claim 5  wherein the molecular sieve of the alkylation catalyst is selected from MCM-22, PSH-3, SSZ-25, MCM-36, MCM-49, MCM-56, faujasite, mordenite and zeolite beta.  
     
     
         8 . The process of  claim 5  wherein said alkylating conditions include a temperature of about 10° C. to about 125° C., a pressure of about 1 to about 30 atmospheres, and a benzene weight hourly space velocity (WHSV) of about 5 hr −1  to about 50 hr −1 .  
     
     
         9 . The process of  claim 5  wherein the particles of said transalkylation catalyst have a surface to volume ratio of about 80 to less than 200 inch −1 .  
     
     
         10 . The process of  claim 5  wherein the molecular sieve of the transalkylation catalyst is selected from MCM-22, PSH-3, SSZ-25, MCM-36, MCM-49, MCM-56, ZSM-5, faujasite, mordenite and zeolite beta.  
     
     
         11 . The process of  claim 5  wherein said said transalkylating conditions include a temperature of about 100° C. to about 200° C.; a pressure of 20 to 30 barg, a weight hourly space velocity of 1 to 10 on total feed and benzene/polyisopropylbenzene weight ratio 1:1 to 6:1.