Method and device for manufacturing compounds from isobutyric acid and acetic anhydride

A device and a method for manufacturing compounds from isobutyric acid and acetic anhydride are provided. The method for manufacturing compounds from isobutyric acid and acetic anhydride includes the following steps. Isobutyric acid is reacted with acetic anhydride to obtain a first mixture, wherein the first mixture includes isobutyric anhydride and acetic acid. The first mixture is subjected to a first purification process to obtain isobutyric anhydride and acetic acid. The isobutyric anhydride is subjected to a pyrolysis process to obtain a second mixture, wherein the second mixture includes dimethyl ketene, isobutyric acid and isobutyric anhydride. A gas-liquid separation process is performed on the second mixture to obtain dimethyl ketene gas and a liquid, wherein the liquid includes isobutyric acid and isobutyric anhydride. The liquid is collected, and then the isobutyric acid in the liquid is reacted with acetic anhydride.