US 4,774,377 AGranted

Alkylation/transalkylation process

AssigneeUop LLC

InventorsPaul T. Barger, Gregory J. Thompson, Raymond R. Herber, Tamotsu Imai

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Abstract

An alkylation-transalkylation process for the production of a monoalkylated aromatic compound is disclosed which maximizes the production of desirable monoalkylaromatic compounds, while limiting transalkylation catalyst deactivation. The process entails the combination of an alkylation reaction zone, a first separation zone, a second separation zone, and a transalkylation reaction zone wherein the alkylation catalyst and transalkylation catalyst are dissimilar and where the alkylation catalyst is comprised of phosphoric acid material and the transalkylation catalyst is comprised of a crystalline aluminosilicate material. The transalkylation catalyst deactivation is reduced by transalkylating only dialkylated aromatic compounds.

Claims16

Dependent claims

A process for the production of alkylated aromatics which comprises the steps of:

(a) passing a feedstream comprising an alkylating agent and an aromatic substrate to an alkylation reaction zone and into contact with a solid phosphoric acid containing catalyst under conditions providing for the liquid phase alkylation of said aromatic substrate;
(b) separating in a first separation zone the product from the alkylation reaction zone and a hereinafter described transalkylation reaction zone product into fractions comprising (1) an aromatic substrate fraction, (2) a substantially pure monoalkylated aromatic fraction, and (3) a fraction comprising compounds with boiling points higher than the desired monoalkylated aromatic;
(c) separating in a second separation zone the fraction comprising compounds with boiling points higher than the desired monoalkylated aromatic of the first separation zone into a dialkylated aromatic-rich fraction, and into fractions with higher and lower boiling points than the dialkylated aromatic-rich fraction;
(d) passing a feed stream of an aromatic substrate and the separated dialkylated aromatic-rich hydrocarbon fraction of the second separation zone to a transalkylation reaction zone containing crystalline aluminosilicate catalyst under conditions providing for the transalkylation of said dialkylated aromatic-rich hydrocarbon fraction to produce a transalkylation reaction zone product;
(e) introducing the transalkylation reaction zone product from step (d) into the separation zone of step (b);
and,
(f) recovering the monoalkylaromatic fraction.

4 more elements

A process for the liquid phase production of a monoalkylbenzene which comprises the steps of:

(a) reacting a C.sub.2 -C.sub.14 monoolefin alkylating agent with benzene in the presence of a solid phosphoric acid containing alkylation catalyst under conditions providing for the liquid phase alkylation of said benzene;
(b) separating in a first separation zone said alkylation reaction zone effluent stream, a transalkylation reaction zone effluent stream as hereinafter characterized, and a benzene containing feed stream into (1) a benzene-rich feed fraction, (2) a substantially pure monoalkylbenzene product fraction, and (3) a fraction rich in compounds with boiling points higher than the desired monoalkylbenzene;
(c) separating in a second separation zone the fraction rich in compounds with boiling points higher than the desired monoalkylbenzene of the first separation zone into a dialkylbenzene-rich fraction, and into fractions with higher and lower boiling points than the dialkylbenzene-rich fraction;
(d) transalkylating the dialkylbenzene-rich fraction with a first portion of the separated benzene-rich feed fraction in the presence of a transalkylation reaction zone catalyst comprising an inorganic oxide-bound crystalline aluminosilicate material in a transalkylation reaction zone under transalkylation reaction conditions to produce a transalkylation reaction zone effluent stream;
(e) supplying the effluent of the transalkylation reaction zone to said first separation zone as said transalkylation reaction zone effluent stream;
(f) passing a second portion of said unreacted benzene-rich feed fraction to said alkylation reaction zone as a portion of the alkylation reaction zone feed;
and,
(g) recovering said monoalkylbenzene product fraction from the separation zone.

5 more elements

A process for the liquid phase production of cumene which comprises the steps of:

(a) reacting propylene with benzene in the presence of a solid phosphoric acid containing alkylation catalyst in an alkylation reaction zone operating at a temperature of from 100.degree.-390.degree. C., a pressure of from 1-130 atmospheres, a liquid hourly space velocity of from 0.5 to 50 hr.sup.-1, and a benzene to propylene molar feed ratio of from 1:1 to 20:1;
(b) passing the alkylation reaction zone effluent stream, the transalkylation reaction zone effluent stream as hereinafter characterized, and a benzene containing feed stream into a first separation zone wherein entering hydrocarbons are separated into an unreacted benzene-rich feed fraction, a substantially pure cumene product fraction, and a fraction rich in compounds with boiling points higher than cumene;
(c) separating in a second separation zone the fraction rich in compounds with boiling points higher than cumene of the first fractionation zone into a diisopropylbenzene-rich fraction and into fractions with boiling points higher and lower than that of the dipropylbenzene-rich fraction;
(d) transalkylating the diisopropylbenzene fraction with a first portion of the separated benzene-rich feed fraction in the presence of a transalkylation reaction zone catalyst comprising from 5% to 95% by weight of mordenite, from 5% to 95% by weight of Al.sub.2 O.sub.3, at a transalkylation reaction zone temperature of from 100.degree. C. to 390.degree. C., a pressure of from 1 to 130 atmospheres, a liquid hourly space velocity of from 0.1 to 50 hr.sup.-1 and a benzene to diisopropylbenzene molar feed ratio of from 1:1 to 50.1 to produce a transalkylation reaction zone effluent stream;
(e) supplying the effluent stream of the transalkylation reaction zone to said first separation zone as said transalkylation reaction zone effluent stream;
(f) passing a second portion of said unreacted benzene-rich feed fraction to said alkylation reaction zone as a portion of the alkylation reaction zone feed;
and,
(g) recovering said cumene product fraction from the separation zone.

5 more elements

Dependencies are inferred from the claim text.