Process for removing an alkanol impurity from an organic carbonate stream
AssigneeShell Oil Company
InventorsEvert VAN DER HEIDE, Garo Garbis VAPORCIYAN, Cornelis Leonardus Maria VROUWENVELDER
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Abstract
The invention relates to a process for removing an alkanol impurity from a stream containing an organic carbonate and the alkanol impurity, comprising contacting the stream with a catalyst to effect reaction of the alkanol impurity with the organic carbonate.
Claims4
Process for making a diaryl carbonate, comprising contacting, in the presence of a transesterification catalyst, an aryl alcohol with a stream containing a dialkyl carbonate from which stream an alkanol impurity has been removed in accordance with a process for removing an alkanol impurity from a stream containing an organic carbonate and the alkanol impurity, comprising contacting the stream with a catalyst to effect reaction of the alkanol impurity with the organic carbonate,
- wherein the organic carbonate is a di(C1-C5)alkyl carbonate and the alkanol impurity is an ether alkanol, and
- wherein the stream containing an organic carbonate and the alkanol impurity is obtained by a process for the preparation of a di(C1-C5)alkyl carbonate and an alkanediol comprising:
- (a) reacting an alkylene carbonate and an alkanol in the presence of a transesterification catalyst to obtain a product mixture containing unconverted alkylene carbonate, unconverted alkanol, di(C1-C5)alkyl carbonate, alkanediol and an alkanol impurity;
- (b) separating unconverted alkylene carbonate and alkanediol from the product mixture to obtain a top stream containing unconverted alkanol, di(C1-C5)alkyl carbonate and the alkanol impurity;
- (c) recovering the alkanediol;
- and
- (d) separating unconverted alkanol from the top stream containing unconverted alkanol di(C1-c5)alkyl carbonate and the alkanol impurity obtained in step (b) to obtain a bottom stream containing di(C1-C5)alkyl carbonate and the alkanol impurity,
- which process for the preparation of a di(C1-C5)alkyl carbonate and an alkanediol further comprises
- (e) contacting the bottom stream containing di(C1-C5)alkyl carbonate and the alkanol impurity obtained in step (d) with a catalyst to effect reaction of the alkanol impurity with the di(C1-C5)alkyl carbonate.
Process for making a diaryl carbonate, comprising contacting a stream containing a dialkyl carbonate and an alkanol impurity with a catalyst to effect reaction of the alkanol impurity with the dialkyl carbonate in accordance with a process for removing an alkanol impurity from a stream containing an organic carbonate and the alkanol impurity, comprising contacting the stream with a catalyst to effect reaction of the alkanol impurity with the organic carbonate,
- wherein the organic carbonate is a di(C1-C5)alkyl carbonate and the alkanol impurity is an ether alkanol, and
- then contacting, in the presence of a transesterification catalyst, an aryl alcohol with the stream containing the dialkyl carbonate,
- wherein the stream containing an organic carbonate and the alkanol impurity is obtained by a process for the preparation of a di(C1-C5)alkyl carbonate and an alkanediol comprising:
- (a) reacting an alkylene carbonate and an alkanol in the presence of a transesterification catalyst to obtain a product mixture containing unconverted alkylene carbonate, unconverted alkanol, di(C1-C5)alkyl carbonate, alkanediol and an alkanol impurity;
- (b) separating unconverted alkylene carbonate and alkanediol from the product mixture to obtain a top stream containing unconverted alkanol, di(C1-C5)alkyl carbonate and the alkanol impurity;
- (c) recovering the alkanediol;
- and
- (d) separating unconverted alkanol from the top stream containing unconverted alkanol di(C1-C5)alkyl carbonate and the alkanol impurity obtained in step (b) to obtain a bottom stream containing di(C1-C5)alkyl carbonate and the alkanol impurity,
- which process for the preparation of a di(C1-C5)alkyl carbonate and an alkanediol further comprises
- (e) contacting the bottom stream containing di(C1-C5)alkyl carbonate and the alkanol impurity obtained in step (d) with a catalyst to effect reaction of the alkanol impurity with the di(C1-C5)alkyl carbonate.
Dependencies are inferred from the claim text.