Purification of methacrylic or acrylic acid by distillation separation

摘要

The continuous separation by distillation of liquid mixtures containing (meth)acrylic acid as main component, by continually supplying the mixture to a distillation device comprising a distillation flask and condenser connected via a pipe. At least some of the energy needed for boiling the mixture in the flask is passed through the device. Some of the flask contents at a pressure (Px) are continually removed and then heated at a pressure (Py) greater than Px to a temperature (Ty`), which is greater than the b.pt. (Tx) of the flask contents at Px, but less than the b.pt. (Ty) of the same contents at Py. The superheated removed flask contents are depressurised and returned to the distillation device.