| abstract |
(57) [Abstract] [PROBLEMS] To provide a method for producing diketene by using a liquid ejector without a driving device without using a vacuum pump. In a method for producing diketene by pressurizing a reduced pressure ketene gas to be absorbed in an absorbing liquid, a liquid ejector is used to maintain a pressurized condition, and is a circulating liquid of the ejector. As the ketene gas absorption liquid, diketene, acetone, a mixed liquid of diketene and acetic anhydride, hexane, methylpyrrolidone, or the like is used, and the temperature of the ketene absorption liquid is maintained at -20 ° C to 20 ° C. |