| 摘要 |
<p>Continuous preparation of alkyl ester of (meth)acrylic acid (A) comprises supplying (meth)acrylic acid, 1-5C alkanol and acid esterifying catalyst (a) to a reaction zone (5,6); adding the discharged reaction mixture to a rectification unit (I); isolating the alkyl ester of (meth)acrylic acid containing in main stream (23) and a sump stream (22); supplying a partial flow of the sump stream; and isolating the separated sump stream (40). Continuous preparation of alkyl ester of (meth)acrylic acid (A) comprises reacting (meth)acrylic acid and 1-5C alkanol in homogeneous, liquid, solvent-free phase with increased temperature and in presence of a acid esterifying catalyst, where (meth)acrylic acid, alkanol and acid esterified catalyst are supplied to a reaction zone (5,6) (that water formed during a retention time are separated rectificative as a component of a alkanol comprising mixture in one of the reaction zone mounted rectification unit (III), in which obtained distillate is isolated in a alkanol containing organic and a water containing aqueous phase, the organic phase is led back into (III) and the aqueous phase is removed, and a reaction mixture (21) is discharged from the reaction zone); initiating the mixture into a rectification unit (I) and the alkyl ester of (meth)acrylic acid containing in main stream (23) and a sump stream (22) are isolated under addition of water; supplying a partial flow of the sump stream (22) from (I) of a residue column unit (IV) comprising a column boiler (61) and recycling into a main stream (29) in (I) and isolating the separated sump stream (40); where (IV) comprises a rectification column (62) in addition to the column boiler, and the ascending vapors from the column boiler are initiated into the rectification column, and resulting liquid at the lowest stage of the rectifying column is led into the column boiler, where the rectification column is operated in a manner, such that the water content of the resulting liquid at the lowest stage is smaller than 0.1 wt.%.</p> |
