Method for producing and purifying aqueous phases

• Main Authors: LEISTNER JOERG, HENGSTERMANN AXEL, MOSLER JUERGEN, JANSENS PETER
• Format: Patent
• Language: Chinese; English
• Published: 28.10.2009
• Subjects: ACYCLIC OR CARBOCYCLIC COMPOUNDS; APPARATUS THEREFOR; CHEMISTRY; COMPOSITIONS BASED THEREON; GENERAL METHODS OF ORGANIC CHEMISTRY; MACROMOLECULAR COMPOUNDS OBTAINED BY REACTIONS ONLY INVOLVINGCARBON-TO-CARBON UNSATURATED BONDS; METALLURGY; ORGANIC CHEMISTRY; ORGANIC MACROMOLECULAR COMPOUNDS; PERFORMING OPERATIONS; PHYSICAL OR CHEMICAL PROCESSES OR APPARATUS IN GENERAL; SEPARATION; THEIR PREPARATION OR CHEMICAL WORKING-UP; TRANSPORTING

The present invention relates to a method for purifying an unpurified phase, containing a target product, preferably (meth)acrylic acid, water, and at least one contamination differing from the target product and from water, to obtain a purified phase, comprising a process stage comprising the following process steps: a) the target product and water are crystallized from the unpurified phase while forming a suspension containing a mother liquor and crystals, wherein said crystallizing is carried out at a temperature T1 within the range of Te - 15 DEG C <= T1 <= Te + 3 DEG C (Te = eutectic temperature of the unpurified phase); b) the crystals are at least partially separated from the mother liquor; c) at least part of the separated crystals is melted to form a melt, wherein said melting is carried out at a temperature T2 within the range of T1< T2 <= T1 + 20 DEG C; and d) at least part of the melt is returned to step b), wherein the part of the melt that is not returned is present as a purified phase. The inve