Process for separating methanol from the reaction products obtained in the etherification of C.sub.4 through C.sub.7 isoolefins with methanol
AssigneeDeutsche Texaco Aktiengesellschaft
InventorsGunther Osterburg, Milan Prezelj
Life of this patent
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Abstract
The reaction product from etherification of C.sub.4 -C.sub.7 isoolefins with methanol in the presence of an acidic catalyst is washed with water in the presence of inert hydrocarbons thereby removing methanol and a part of the tertiary alcohol. The aqueous extract solution bottoms is distilled to separate methanol as overhead. Tertiary alcohols are withdrawn as a side stream from a tray of the distillation column with a high concentration thereof and fed into the washing column.
Claims7
The process for separating methanol from the reaction products of the etherification of C.sub.4 -C.sub.7 isoolefins with methanol which comprises
- washing the etherification reaction products at 20.degree. C.-60.degree. C., immediately after etherification, with water in the presence of inert hydrocarbons and a recycle stream containing a high concentration of a tertiary alcohol thereby forming (i) a raffinate and (ii) an aqueous extract bottoms containing alcohols including methanol and the tertiary alcohol in said washing operation;
- maintaining a methanol:water weight ratio of 1:1.5 to 1:10 in said washing operation;
- passing said aqueous extract bottoms to a distillation column;
- distilling said aqueous extract bottoms in said distillation column thereby forming distillation overhead containing methanol;
- withdrawing a side stream containing the tertiary alcohol from a tray of said distillation column containing a high concentration of the tertiary alcohol;
- and
- passing said withdrawn side stream as said recycle stream to said washing operation.
The process for separating methanol from the reaction products of the etherification of C.sub.4 -C.sub.7 isoolefins with methanol which comprises
- distilling the etherification reaction products from a first stage etherification operation thereby separating overhead containing unreacted hydrocarbons including C.sub.4 -C.sub.7 isoolefins and bottoms containing product ether and alcohols including methanol and a tertiary alcohol;
- reacting said overhead with methanol in a second stage etherification operation thereby forming second stage product stream containing product ether and alcohols including methanol and a tertiary alcohol;
- combining (i) said bottoms containing product ether and alcohols including methanol and the tertiary alcohol, (ii) said second stage product stream containing product ether and alcohols including methanol and the tertiary alcohol, and (iii) a recycle stream containing a high concentration of the tertiary alcohol thereby forming a combined stream;
- washing said combined stream at 20.degree. C.-60.degree. C. with water in the presence of inert hydrocarbons thereby forming (i) a raffinate and (ii) an aqueous extract bottoms containing alcohols including methanol and the tertiary alcohol in said washing operation;
- distilling said aqueous extract bottoms in a distillation column thereby forming (i) overhead containing methanol and (ii) bottoms containing water;
- recovering said overhead containing methanol;
- withdrawing a side stream containing the tertiary alcohol from a tray of said distillation column containing a high concentration of the tertiary alcohol;
- and
- passing said withdrawn side stream, as said recycle stream, to said combining operation.
Dependencies are inferred from the claim text.