Process for the Reduction of Alkylation Catalyst Deactivation Utilizing Low Silica to Alumina Ratio Catalyst

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

• (a) introducing an input stream comprising an aromatic hydrocarbon, and an alkylating agent comprising an alkene into a preliminary alkylation system comprising a preliminary alkylation catalyst having a first SiO2/Al2O3 ratio, said preliminary alkylation catalyst is a molecular sieve;
• (b) operating said preliminary alkylation system under alkylation conditions to produce said alkylaromatic compound, said conditions being such that said aromatic hydrocarbon is at least partly in the liquid phase;
• (c) withdrawing from said preliminary alkylation system a first output stream comprising said alkylaromatic compound, unreacted aromatic hydrocarbon and about 100 ppb or less of catalyst poisons;
• (d) introducing at least part of said first output stream and an alkylating agent into a first alkylation system comprising a first alkylation catalyst having a second SiO2/Al2O3 ratio, said first alkylation catalyst is a molecular sieve;
• and
• wherein the preliminary alkylation catalyst and the first alkylation catalyst are different in that the preliminary alkylation catalyst has a lower SiO2/Al2O3 ratio than the first alkylation catalyst whereby the frequency at which any alkylation catalyst is removed for replacement, regeneration or reactivation is reduced as compared to either alkylation catalyst alone;
• (e) operating said first alkylation system under alkylation conditions to produce said alkylaromatic compound, said conditions being such that said aromatic hydrocarbon is at least partly in the liquid phase;
• (f) withdrawing from said first alkylation system a second output stream comprising said alkylaromatic compound.

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

• (a) introducing an input stream comprising an aromatic hydrocarbon, and an alkylating agent comprising an alkene into a preliminary alkylation system comprising a preliminary alkylation catalyst having a first SiO2/Al2O3 ratio, said preliminary alkylation catalyst is a molecular sieve zeolite beta or zeolite Y;
• (b) operating said preliminary alkylation system under alkylation conditions to produce said alkylaromatic compound, said conditions being such that said aromatic hydrocarbon is at least partly in the liquid phase;
• (c) withdrawing from said preliminary alkylation system a first output stream comprising said alkylaromatic compound, unreacted aromatic hydrocarbon and about 100 ppb or less of catalyst poisons;
• (d) introducing at least part of said first output stream and an alkylating agent into a first alkylation system comprising a first alkylation catalyst having a second SiO2/Al2O3 ratio, said first alkylation catalyst is a molecular sieve zeolite MCM-22;
• and
• wherein the preliminary alkylation catalyst and the first alkylation catalyst are different in that the preliminary alkylation catalyst has a lower SiO2/Al2O3 ratio than the first alkylation catalyst whereby the frequency at which any alkylation catalyst is removed for replacement, regeneration or reactivation is reduced as compared to either alkylation catalyst alone;
• (e) operating said first alkylation system under alkylation conditions to produce said alkylaromatic compound, said conditions being such that said aromatic hydrocarbon is at least partly in the liquid phase;
• (f) withdrawing from said first alkylation system a second output stream comprising said alkylaromatic compound.