| 摘要 |
1,222,993. Ethyl acrylate. STANDARD OIL CO. 20 Feb., 1968 [20 March, 1967], No. 8125/68. Heading C2C. [Also in Division B1] Ethyl acrylate is separated from ethyl alcohol, acrylonitrile, acrylic acid, diethyl ether, and beta ethoxy ethyl propionate (BEEP), as present in the reaction product from the synthesis of ethyl acrylate from acrylonitrile and ethyl alcohol, by submitting the mixture to distillation in a system comprising four fractionating columns. The bulk of the ether is removed from the head of the first column; and a mixture containing acrylic acid and BEEP is withdrawn from the base. A sidestream from the first column, comprising ethyl acrylate, ethyl alcohol, acrylonitrile and residual ether is distilled in an extractive distillation (extrillation) column while introducing water into the upper portion of the column; the vapours passing from the head of this column are condensed to give a condensate which is passed to a decanter where it separates into an aqueous phase and an organic (i.e. acrylic ester) phase, and organic phase is distilled in a further column, which contains an internal decanter, to obtain ethyl acrylate as bottoms fraction. The ethyl acrylate may be further purified, if desired, by passing it over a molecular sieve type desiccant, or by vacuum distillation. The mixture of ethyl alcohol and water withdrawn from the sump of the extrillation column is distilled, together with the ether from the first column, and the separated water is returned to the upper portion of the extrillation column. The aqueous phase from the internal decanter of the acrylic ester purification column is passed to the external decanter associated with the extrillation column, and the aqueous phase from the external decanter is introduced into the upper portion of the extrillation column. |
