Abstract: 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 impurity differing from the target product and from water comprising: a) crystallizing the target product and water; b) separating the crystals from the mother liquor created in step a); c) melting at least part of the separated crystals to form a melt; and d) recycling at least part of said melt to step b). The invention further relates to a method for the production of a purified phase, containing a target product and water, a method for the production of a polymer based on (meth)acrylic acid, polymers that may be obtained by means of said method, chemical products, such as fibers or molded bodies, and the use of polymers.

Abstract: The present invention relates to superabsorbent polymer comprising acrylic acid made by the process comprising the steps of heating an aqueous glycerine solution to form glycerine; transporting the glycerine to the dehydration reactor; dehydrating the glycerine to an acrolein-comprising dehydration product; gas phase oxidating of the acrolein-comprising dehydration product to obtain an acrylic acid-comprising monomer gas; bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; working-up the quench phase to obtain an acrylic acid-comprising monomer phase; and polymerizing the acrylic acid-comprising monomer phase; wherein a plurality of gas bubbles is generated and wherein the dehydration occurs at least partially in the liquid phase. The superabsorbent polymer has certain properties for biodegradability and sustainability. Further, at least about 25% of the acrylic acid is based on glycerine.

Abstract: The present invention relates to a process for production of acrylic acid, comprising at least the following steps: a. dehydration of glycerine to an acrolein-comprising dehydration product; b. gas phase oxidation of the dehydration product to obtain an acrylic acid-comprising monomer gas; c. bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; d. work-up of the quench phase to obtain an acrylic acid-comprising monomer phase; whereby, during the dehydration a liquid phase a1 and a gas phase a2 is present, whereby in the liquid phase a1 a plurality of gas bubbles is generated, as well as a process for production of polymers by polymerization of acrylic acid, preferably for production of water-absorbing polymers, the water-absorbing polymers obtainable by this process, a composite, a process for production of a composite, the composite obtainable by this process, and further chemical products.

Abstract: The present invention relates to a process for production of acrylic acid, comprising the steps of a) dehydration of glycerine to an acrolein-comprising dehydration product; b) gas phase oxidation of the dehydration product to obtain an acrylic acid-comprising monomer gas; c) bringing into contact of the monomer gas with a quench agent to obtain an acrylic acid-comprising quench phase; and d) work-up of the quench phase to obtain an acrylic acid-comprising monomer phase; whereby, during the dehydration a liquid phase a1 and a gas phase a2 is present, whereby in the liquid phase a1 a plurality of gas bubbles is generated, as well as a process for production of polymers by polymerization of acrylic acid, preferably for production of water-absorbing polymers, the water-absorbing polymers obtainable by this process, a composite, a process for production of a composite, the composite obtainable by this process, and further chemical products.

Abstract: 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 impurity differing from the target product and from water comprising: a) crystallizing the target product and waters; b) separating the crystals from the mother liquor created in step a); c) melting at least part of the separated crystals to form a melt; and d) recycling at least part of said melt to step b). The invention further relates to a method for the production of a purified phase, containing a target product and water, a method for the production of a polymer based on (meth)acrylic acid, polymers that may be obtained by means of said method, chemical products, such as fibers or molded bodies, and the use of polymers.

Abstract: A process for the preparation of (meth)acrylic acid is disclosed that includes: (a) contacting a product gas containing (meth)acrylic acid obtained from a gas phase oxidation with an aqueous phase in a quenching unit to obtain an aqueous quenched phase, (b) distilling the quenched phase in a distillation unit to obtain a bottom product and a top product, and (c) crystallizing at least the bottom product in a crystallization unit to obtain pure (meth)acrylic acid. An organic separating agent can be added after the quenching unit, such as at the latest in the crystallization unit. Also disclosed are a device for the preparation of (meth)acrylic acid, a process for the preparation of a polymer from the (meth)acrylic acid, a device for the preparation of the polymer, a polymer obtainable by this process, and the use of the (meth)acrylic acid or the polymer in a chemical product, such as fibers or shaped articles.

Abstract: The present invention relates to a process for the production of acrolein, comprising the following steps: (a) bringing into contact of an aqueous glycerine phase in an acrolein reaction area to obtain an aqueous acrolein reaction phase; (b) depleting the acrolein from the acrolein reaction phase to obtain an acrolein phase and a depleted acrolein reaction phase; (c) conducting back at least a part of the depleted acrolein reaction phase into the acrolein reaction area. The invention further relates to a process for production of acrylic acid as well as of water-absorbing polymer structures, composites, in particular hygiene articles, comprising these water-absorbing polymer structures, a process for production of the composites and further chemical products based on the acrylic acid obtained by the inventive process and also the use of this acrylic acid in chemical products.

Abstract: A process for the preparation of (meth)acrylic acid is disclosed that includes: (a) contacting a product gas containing (meth)acrylic acid obtained from a gas phase oxidation with an aqueous phase in a quenching unit to obtain an aqueous quenched phase, (b) contacting the quenched phase with an organic separating agent in an extraction unit to give a first phase and at least one other phase, (c) crystallizing at least one of the first phase and the at least one other phase, such as by a suspension crystallization, in a crystallization unit to obtain a pure (meth)acrylic acid. Also disclosed are a device for the preparation of (meth)acrylic acid, a process for the preparation of a polymer from the (meth)acrylic acid, a device for the preparation of the polymer, a polymer obtainable by this process, and the use of the (meth)acrylic acid or the polymer in a chemical product, such as fibers or shaped articles.

Abstract: The invention relates to a reactor at least comprising, connected with each other in fluid-communicating fashion: a reaction area, whereby the reaction area comprises at least one solid-state catalyst; a coolable heat exchanger area, whereby the heat exchanger area comprises at least one housing, whereby the housing accommodates at least partially an insert, whereby the insert comprises a plurality of elements, a process for oxidation of a hydrocarbon using the reactor, an oxidized hydrocarbon product obtainable by this process, chemical products, such as fibers, sheets, formed bodies and the like based on this oxidized hydrocarbon product as well as the use of this oxidized hydrocarbon product in chemical products of this type.

Abstract: A separating tray for a column for distillation of a polymerizable material is disclosed. The separating tray comprising at least one tray plate with a plurality of openings and at least one attachment. The at least one attachment divides the plurality of openings into groups. Also, the at least one attachment defines apertures through which a fluid can flow.

Abstract: The invention relates to a process for preparing ETBE from technical mixtures which comprise at least 1-butene, isobutene, n-butane and 2-butenes, by reacting the isobutene present, distillatively removing a fraction comprising 1-butene and isobutene and again reacting the isobutene present therein to give ETBE.