Alkylaromatics production

A process for producing an alkylaromatic compound, the process comprising:

• (a) introducing a first feed comprising an alkylatable aromatic compound and a second feed comprising an alkene into a first alkylation reaction zone comprising a first alkylation catalyst comprising a molecular sieve selected from the group consisting of zeolite beta, a molecular sieve having a Constraint Index of 2-12, and a molecular sieve of the MCM-22 family;
• (b) operating said first alkylation reaction zone under conditions effective to cause alkylation of said alkylatable aromatic compound by said alkene to produce said alkylaromatic compound, said conditions being such that said alkylatable aromatic compound is in the vapor phase;
• (c) withdrawing from said first alkylation reaction zone a first effluent comprising at least a portion of said alkylaromatic compound and unreacted alkylatable aromatic compound;
• (d) treating at least part of said unreacted alkylatable aromatic compound to remove catalyst poisons by contacting said unreacted alkylatable aromatic compound with a material capable of removing sulfur-containing and/or nitrogen-containing impurities from said unreacted alkylatable aromatic compound therefrom and produce a treated unreacted alkylatable aromatic stream;
• (e) introducing at least part of said treated unreacted alkylatable aromatic stream and a third feed comprising said alkene into a second alkylation reaction zone comprising a second alkylation catalyst comprising zeolite beta and/or a molecular sieve of the MCM-22 family;
• (f) operating said second alkylation reaction zone under conditions effective to cause alkylation of at least a portion of said unreacted alkylatable aromatic compound by said alkene to produce said alkylaromatic compound, said conditions being such that said alkylatable aromatic compound is in the liquid phase;
• and
• (g) withdrawing from said second alkylation reaction zone a second effluent comprising said alkylaromatic compound.