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US 4,520,218 AGranted
Production of dialkylated aromatics
AssigneeUop LLC
InventorsRoy C. Berg, Thomas P. Malloy, Bipin V. Vora
Life of this patent
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Abstract
A process is disclosed for producing a mixture of mono- and diallkylated aromatic hydrocarbons suitable for use as a detergent or as a surfactant in enhanced oil recovery processes. Two alkylation reaction stages are used in series, with a separate amount of an acyclic olefin being charged to each reaction stage. The effluent of the second alkylation reaction stage is separated by fractionation to form a mixture of mono- and dialkylated hydrocarbons. A portion of this mixture is recycled to the second alkylation reaction stage, with remainder being withdrawn as the product stream.
Claims16
A process for the production of dialkylated aromatic hydrocarbons which comprises the steps of:
- (a) alkylating a feed aromatic hydrocarbon with a first portion of a feed acyclic olefinic hydrocarbon in a first alkylation stage of a multi-stage alkylation zone maintained at alkylation-promoting conditions to produce a first alkylation stage effluent stream which comprises the feed aromatic hydrocarbon and a monoalkylated aromatic hydrocarbon;
- (b) admixing the first alkylation stage effluent stream, a hereinafter characterized recycle stream and a second portion of the feed acyclic olefinic hydrocarbon to form a composite stream, said composite stream having a mole ratio of unalkylated aromatic hydrocarbon to monoalkylated aromatic hydrocarbon of less than about 1:1, and passing said composite stream into a subsequent second alkylation stage of the alkylation zone maintained at alkylation-promoting conditions to further alkylate said monoalkylated aromatic hydrocarbons and to produce a second alkylation stage effluent stream which comprises the feed aromatic hydrocarbon, the monoalkylated hydrocarbon, and a dialkylated hydrocarbon;
- (c) fractionating said alkylation zone effluent stream which comprises the feed aromatic hydrocarbon, the monoalkylated hydrocarbon, and the dialkylated hydrocarbon in a fractionation zone, to produce a first process stream which comprises the monoalkylated aromatic hydrocarbon and the aromatic dialkylated hydrocarbon;
- and,
- (d) withdrawing a first portion of the first process stream as a product stream containing said dialkylated aromatic hydrocarbon and passing a second portion of the first process stream into the second alkylation stage of said alkylation zone as the previously referred to recycle stream to form said composite stream having a mole ratio of unalkylated feed aromatic hydrocarbon to monoalkylated aromatic hydrocarbon of less than about 1:1 to increase the production of dialkylated aromatic hydrocarbons.
2 more elements
A process for the production of dialkylated aromatic hydrocarbons which comprises the steps of:
- (a) passing a first feed stream which comprises a C.sub.6 -plus normal paraffinic hydrocarbon and a hereinafter characterized first recycle stream into a catalytic dehydrogenation zone to produce a dehydrogenation zone effluent stream which comprises a mixture of the C.sub.6 -plus normal paraffinic hydrocarbon and a corresponding normal olefinic hydrocarbon;
- (b) passing a first portion of the dehydrogenation zone effluent stream and a second feed stream which comprises an aromatic hydrocarbon into a first alkylation stage of a multi-stage alkylation zone maintained at alkylation-promoting conditions to produce a first alkylation stage effluent stream which comprises the feed aromatic hydrocarbon, the normal paraffinic hydrocarbon and a monoalkylated aromatic hydrocarbon;
- (c) admixing the first alkylation stage effluent stream, a hereinafter characterized second recycle stream, and a second portion of the dehydrogenation zone effluent stream to form a composite stream, said composite stream having a mole ratio of unalkylated aromatic hydrocarbon to monoalkylated aromatic hydrocarbon of less than about 1:1, and passing said composite stream into a second alkylation stage of the alkylation zone maintained at alkylation-promoting conditions to further alkylate said monoalkylated aromatic hydrocarbon and to produce a second alkylation stage effluent stream which comprises the feed aromatic hydrocarbon, the normal paraffinic hydrocarbon, a monoalkylated aromatic hydrocarbon and a dialkylated aromatic hydrocarbon;
- (d) fractionating the second alkylation stage effluent stream in a fractionation zone to produce a first process stream which is rich in the monoalkylated and dialkylated aromatic hydrocarbons, a second process stream which is rich in the feed aromatic hydrocarbon and a third process stream which is rich in the normal paraffinic hydrocarbon;
- (e) passing at least a portion of said third process stream into the dehydrogenation zone as the previously referred to first recycle stream of step (a);
- (f) passing at least a portion of said second process stream into the first alkylation stage of said alkylation zone;
- and
- (g) withdrawing a first portion of said first process stream from the process as a product stream containing said dialkylated aromatic hydrocarbons, and passing a second portion of the first process stream into the second alkylation stage of the alkylation zone as the previously referred to second recycle stream to form said composite stream having a mole ratio of unalkylated feed aromatic hydrocarbon to monoalkylated aromatic hydrocarbon of less than about 1:1 to increase the production of said dialkylated aromatic hydrocarbons.
5 more elements
Dependencies are inferred from the claim text.