Abstract:
PROBLEM TO BE SOLVED: To improve a method of purifying a raw melt of at least one monomer by crystallization. SOLUTION: There is provided the method for the purification of a crude melt of at least one monomer by crystallization, in which the crude melt to be purified is subjected to a suspension crystallization, the monomer crystals produced during the suspension crystallization and suspended in the residual melt are separated from the residual melt by using a first mechanical separation operation and, in at least one further crystallization stage, the residual melt remaining after the first mechanical separation operation and/or the monomer crystals which have been separated off and if necessary washed are further purified after they have been melted, wherein the residual melt and/or the remelted monomer crystals are subjected to at least one further mechanical solid/liquid separation operation on their way into the one or more further crystallization stages. COPYRIGHT: (C)2010,JPO&INPIT
Abstract:
PROBLEM TO BE SOLVED: To provide a method of separating methacrolein from a liquid phase P containing acrylic acid as a main component and an aimed product and methacrolein as an accessory component.SOLUTION: The separation is conducted in crystallization and acrylic acid in the formed crystal material and methacrolein in a remaining mother liquid are concentrated.
Abstract:
PROBLEM TO BE SOLVED: To provide a process for acylphosphine oxides, which provides solids in a simple and cost-effective manner.SOLUTION: The present invention relates to a process for the preparation of solid acylphosphine oxides by converting an acylphosphine oxide which is in the form of a melt or in dispersed form into the solid state of aggregation with mechanical stress, shearing/internal agitation of the melt.
Abstract:
A process for transporting a liquid monomer phase which has been withdrawn from a storage vessel and comprises methacrylic monomers to an extent of ≧90% by weight, in a tank truck or in a tanker ship, in which the liquid monomer phase is subjected to a separating operation on the route from the storage vessel into the tank of a tank truck or of a tanker ship in order to separate polymer of the monomer present in dissolved form in the liquid monomer phase.
Abstract:
A process for purifying removal of acrylic acid, methacrylic acid, N-vinylpyrrolidone or p-xylene crystals from their suspension in mother liquor by means of a wash column with forced transport, whose shell of the process chamber is a metal wall, the wash column additionally being enveloped by a thermal insulation material having a water vapor barrier and a specific heat flow of >0.1 W/m2 and
Abstract:
Separating a three carbon precursor compound of the acrylic acid as main component containing acrylic acid and glyoxal as byproduct in a product mixture of a heterogeneously catalyzed partial gas phase oxidation, comprises producing a liquid phase containing at least 70 wt.% of acrylic acid and at least 200 mol.ppm of glyoxal, crystallatively separating the glyoxal from the acrylic acid and concentrating the acrylic acid in the formed crystallisate and the glyoxal in the remaining mother liquor during the crystallization.
Abstract:
Separating acrylic acid from a product gas from the gas-phase oxidation of a C 3 precursor on a heterogeneous catalyst comprises transferring acrylic acid and benzoic acid into a liquid phase P, stripping off low boilers to give a liquid phase P* with an acrylic acid content C of at least 80 wt.% and a benzoic acid content of at least 0.01% of C, and crystallizing acrylic acid from liquid phase P*.
Abstract:
L'invention concerne un procédé de séparation en continu d'un produit X sous la forme d'un cristallisat finement divisé formé d'une phase liquide P contenant le produit cible X et des composants différents du produit cible X par cristallation en suspension de refroidissement dans l'espace secondaire parcouru en continu par la phase liquide P d'un échangeur de chaleur indirect dans le cadre du passage continu simultané à travers l'espace primaire de l'échangeur de chaleur indirect par un agent réfrigérant ainsi que du retrait continu d'une suspension de cristallisat S, présentant un degré de cristallisation Y, de l'espace secondaire, dans lequelle le réglage du degré de cristallation Y se fait sur la base d'un bilan thermique réalisé en continu à l'aide d'un ordinateur.