Process for distillative purification of unsaturated carboxylic anhydrides

A process for distillative removal of an unsaturated carboxylic anhydride of general formula (I):

• R—C(O)—O—C—(O)—R (I),
• wherein R is an unsaturated organic radical having 2 to 12 carbon atoms, comprising discharging the unsaturated carboxylic anhydride of general formula (1) in gaseous form from a sidestream take-off of a distillative purification apparatus and condensing said unsaturated carboxylic anhydride of general formula (1) in gaseous form in an atomized liquid circulating stream of said unsaturated carboxylic anhydride of general formula (I),
• wherein said unsaturated carboxylic anhydride is condensed in an apparatus comprising a container that is sealed to the atmosphere and which is linked to the sidestream take-off via a fitting, an output line through which condensed unsaturated carboxylic anhydride of the general formula (I) is withdrawn from said container and of, which a portion thereof is fed back to the container via an inlet line, a nozzle being located at the end of the inlet line, through which the condensed unsaturated carboxylic anhydride is atomized into the container and thus a negative pressure is generated in which the gaseous unsaturated carboxylic anhydride of the general formula (I) can be condensed from the sidestream take-off of said distillative purification apparatus,
• wherein the unsaturated carboxylic anhydride of the general formula (I) is methacrylic anhydride or acrylic anhydride.