METHOD FOR DISTILLING (METH)ACRYLIC ACID

摘要

PROBLEM TO BE SOLVED: To stably distill a solution of (meth)acrylic acid over a long period. SOLUTION: A method for distilling (meth)acrylic acid comprises using a distillation column in which at least a part of trays are weirless perforated plates. In the method, openings of the weirless perforated plates are located on each point of intersection of an oblique lattice composed of a first parallel line group at a regular interval and a second parallel line group at a regular interval obliquely intersecting the first line group. The value of the ratio (u/S)/(B/A) is≥0.67 for the ratio u/S of the total area u of the whole openings to the column cross-sectional area S and the local opening ratio B/A which is the ratio of the total area B of the openings of a region composed of a parallelogram surrounded by the oblique lattice to the area A of the region. The amount of a liquid spreading and descending the edge of the openings is≥0.035 m3/m×h. The column diameter of the distillation column is≥1.2 m and the oxygen concentration in the gas in the column is 0.008-0.1 mol%. COPYRIGHT: (C)2005,JPO&NCIPI