Abstract: In one aspect, a process for the preparation of a superabsorbent polymer is described herein. In some embodiments, the process comprises (I) preparing acrylic acid, wherein the process comprises (a1) provision of a fluid F1 having a composition comprising from about 5 to about 20 wt. % of hydroxypropionic acid, salts thereof, or mixtures thereof; from about 0.1 to about 5 wt. % of inorganic salts; from about 0.1 to about 30 wt. % of organic compounds which differ from hydroxypropionic acid; from 0 to about 50 wt. % of solids; and from about 20 to about 90 wt. % of water; (a2) dehydration of said hydroxypropionic acid to give a fluid F2 containing acrylic acid; and (a3) purification of said fluid F2 to give a purified acrylic acid phase comprising acrylic acid having a purity of at least 70 wt. %; and (II) polymerizing the acrylic acid of (I) to form a superabsorbent polymer.

Abstract: The present invention relates to a process for the production of polymers, such as water-absorbing polymer structures, by radical polymerization of acrylic acid, whereby the acrylic acid has been obtained by a synthesis process which comprises as a process step the splitting of an organic material by means of an enzyme or at least one component of an enzyme. The invention also relates to the water-absorbing polymers obtainable by this process, water-absorbing polymers which are based to at least about 25 wt % upon partially neutralized acrylic acid, a composite, a process for the production of a composite, the composite obtainable by this production, the use of acrylic acid in the production of polymers, preferably in the production of water-absorbing polymer structures, a device for the production of acrylic acid, and a process for the production of acrylic acid.

Abstract: In one aspect, a process for the preparation of a superabsorbent polymer is described herein. In some embodiments, the process comprises (I) preparing acrylic acid, wherein the process comprises (a1) provision of a fluid F1 having a composition comprising from about 5 to about 20 wt. % of hydroxypropionic acid, salts thereof, or mixtures thereof; from about 0.1 to about 5 wt. % of inorganic salts; from about 0.1 to about 30 wt. % of organic compounds which differ from hydroxypropionic acid; from 0 to about 50 wt. % of solids; and from about 20 to about 90 wt. % of water; (a2) dehydration of said hydroxypropionic acid to give a fluid F2 containing acrylic acid; and (a3) purification of said fluid F2 to give a purified acrylic acid phase comprising acrylic acid having a purity of at least 70 wt. %; and (II) polymerizing the acrylic acid of (I) to form a superabsorbent polymer.

Abstract: In one aspect, a process for the preparation of a superabsorbent polymer is described herein. In some embodiments, the process comprises (I) preparing acrylic acid, wherein the process comprises (a1) provision of a fluid F1 having a composition comprising from about 5 to about 20 wt. % of hydroxypropionic acid, salts thereof, or mixtures thereof; from about 0.1 to about 5 wt. % of inorganic salts; from about 0.1 to about 30 wt. % of organic compounds which differ from hydroxypropionic acid; from 0 to about 50 wt. % of solids; and from about 20 to about 90 wt. % of water; (a2) dehydration of said hydroxypropionic acid to give a fluid F2 containing acrylic acid; and (a3) purification of said fluid F2 to give a purified acrylic acid phase comprising acrylic acid having a purity of at least 70 wt. %; and (II) polymerizing the acrylic acid of (I) to form a superabsorbent polymer.

Abstract: The invention relates to producing a superabsorbent polymer comprising (I) producing a (meth)acrylic acid comprising the steps of (a) synthesizing a crude (meth)acrylic acid phase; (b) distillatively working-up the crude (meth)acrylic acid phase to obtain a (meth)acrylic acid phase and a dimer phase comprising (meth)acrylic acid dimers and/or (meth)acrylic acid oligomers; (c) splitting at least a part of the (meth)acrylic acid dimers or of the (meth)acrylic acid oligomers or both from the dimer phase to obtain a (meth)acrylic acid-comprising a low boiling phase and a high boiling phase comprising less (meth)acrylic acid than the low boiling phase; (d) separating at least a part of the (meth)acrylic acid from the low boiling phase by forming crystals to obtain a pure (meth)acrylic acid, and a residue; (II) polymerizing a monomer phase comprising the pure (meth)acrylic acid to obtain a polymer phase; and (III) working-up the polymer phase to obtain the polymer.

Abstract: In some embodiments, a process for producing a polymer comprises (I) producing a pure (meth)acrylic acid comprising the steps of (a) synthesizing a crude (meth)acrylic acid phase; (b) distillatively working-up the crude (meth)acrylic acid phase to obtain a (meth)acrylic acid phase and a dimer phase comprising (meth)acrylic acid dimers or (meth)acrylic acid oligomers or both; (c) splitting at least a part of the (meth)acrylic acid dimers or of the (meth)acrylic acid oligomers or both from the dimer phase to obtain a (meth)acrylic acid-comprising low boiling phase and a high boiling phase comprising less (meth)acrylic acid than the low boiling phase; (d) separating at least a part of the (meth)acrylic acid from the low boiling phase to obtain a pure (meth)acrylic acid, and a residue; (II) polymerizing a monomer phase comprising the pure (meth)acrylic acid to obtain a polymer phase; and (III) working-up the polymer phase to obtain the polymer.

Abstract: The present invention relates to processes for purifying a composition containing (meth)acrylic acid, at least one impurity and water, wherein the composition has a water content in the range of 0.55 to 90, based on the composition, to form a purified phase containing (meth)acrylic acid and at least one impurity, wherein, in the purified phase, the quantity of at least one impurity is less than 7% by weight, based on (meth)acrylic acid in the purified phase.

Abstract: The present invention relates to a process for production of acrylic acid, comprising at least the following steps: a. dehydrating glycerine to a dehydration product comprising acrolein; b. gas phase oxidation of the dehydration product comprising acrolein to obtain a monomer gas comprising an acrylic acid; c. bringing into contact the monomer gas with a quench means to obtain a quench phase comprising acrylic acid; and d. processing the quench phase comprising acrylic acid to obtain a monomer phase comprising acrylic acid. The present invention may also relate to a process for preparation of polymers by radical polymerization of acrylic acid, the water-absorbing polymers obtainable by this process, water-absorbing polymers based to at least 25 wt % upon partially neutralized acrylic acid, a composite, a device for preparation of acrylic acid, a process for preparation of acrylic acid, and the acrylic acid obtainable by this process.

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: The present invention relates to a process for the production of polymers, such as water-absorbing polymer structures, by radical polymerization of acrylic acid, whereby the acrylic acid has been obtained by a synthesis process which comprises as a process step the splitting of an organic material by means of an enzyme or at least one component of an enzyme. The invention also relates to the water-absorbing polymers obtainable by this process, water-absorbing polymers which are based to at least about 25 wt % upon partially neutralized acrylic acid, a composite, a process for the production of a composite, the composite obtainable by this production, the use of acrylic acid in the production of polymers, preferably in the production of water-absorbing polymer structures, a device for the production of acrylic acid, and a process for the production of acrylic acid.

Abstract: A process for production of (meth)acrylic acid is disclosed. The process includes synthesizing and distillatively working-up a crude (meth)acrylic acid phase to obtain a (meth)acrylic acid phase and a dimer phase including (meth)acrylic acid dimers and/or (meth)acrylic acid oligomers. At least a part of the (meth)acrylic acid dimers and/or of the (meth)acrylic acid oligomers from the dimer phase is split to obtain a (meth)acrylic acid including a low-boiling phase and a high-boiling phase including less (meth)acrylic acid than the low-boiling phase. At least a part of the (meth)acrylic acid from the low-boiling phase is separated by forming of one or more crystals to obtain a pure (meth)acrylic acid and a residue. Also disclosed is a device for production of (meth)acrylic acid, a process for production of a polymer as well as chemical products based on or including (meth)acrylic acid or a polymer as well as the use of (meth)acrylic acid or polymers in chemical products.

Abstract: The present invention relates to a process for the production of acrylic acid (AA) comprising the steps wherein: a) a 1st gas mixture comprising propylene, oxygen, an inert gas and steam is subjected to a 1st catalytic oxidation reaction stage thereby converting the propylene in the presence of a catalyst mainly into acrolein being contained in a 2nd gas mixture from said 1st catalytic oxidation reaction, b) said 2nd gas mixture from the 1st catalytic oxidation reaction stage is subjected to a 2nd catalytic oxidation reaction stage thereby converting the acrolein in the presence of a catalyst mainly into AA, being contained in a product gas, c) said product gas is subjected to a quench tower, wherein said AA is recovered as an aqueous solution comprising said AA being contained in the process water, wherein a process vent gas is obtained at the top of said quench tower, wherein, said 1st gas mixture has a steam/propylene ratio of >0.

Abstract: The present invention relates to processes for purifying a composition containing (meth)acrylic acid, at least one impurity and water, wherein the composition has a water content in the range of 0.55 to 90, based on the composition, to form a purified phase containing (meth)acrylic acid and at least one impurity, wherein, in the purified phase, the quantity of at least one impurity is less than 7% by weight, based on (meth)acrylic acid in the purified phase.

Abstract: The present invention relates to a process for the production of acrylic acid (AA) comprising the steps wherein: a) a 1st gas mixture comprising propylene, oxygen, an inert gas and steam is subjected to a 1st catalytic oxidation reaction stage thereby converting the propylene in the presence of a catalyst mainly into acrolein being contained in a 2nd gas mixture from said 1st catalytic oxidation reaction, b) said 2nd gas mixture from the 1st catalytic oxidation reaction stage is subjected to a 2nd catalytic oxidation reaction stage thereby converting the acrolein in the presence of a catalyst mainly into AA, being contained in a product gas, c) said product gas is subjected to a quench tower, wherein said AA is recovered as an aqueous solution comprising said AA being contained in the process water, wherein a process vent gas is obtained at the top of said quench tower, wherein, said 1st gas mixture has a steam/propylene ratio of >0.

Abstract: The invention relates to a process for the oxidation of unsaturated hydrocarbons, wherein an unsaturated hydrocarbon, an oxygen-containing oxidizing agent, a palladium complex as the catalyst containing a ligand of the formula (I) wherein R is a saturated, halogenated alkyl radical having from about 1 to about 20 carbon atoms, and optionally auxiliary substances in a liquid phase based on (?1) from about 10 to about 100 wt. % of a protic polar solvent and (?2) from 0 to about 90 wt. % of an aprotic polar solvent, the sum of components (?1) and (?2) being about 100 wt. %, at a temperature in a range from about 30 to about 300° C. under a pressure in a range from about 1 to about 200 bar, such that a liquid phase containing oxygen-containing hydrocarbons is obtained.

Abstract: A method of producing aliphatic and cycloaliphatic diols by catalytic hydrogenation of dicarboxylic acid esters by the use of a copper chromite catalyst in which the copper content (calculated as CuO) is 40-47 wt. %, and the chromium content (calculated as Cr.sub.2 O.sub.3) is 40-47 wt. %, and barium is also present in the amount of up to 10 wt. % (calculated as BaO) under mild temperature and pressure conditions is disclosed. The method produces diols without the formation of high boiling materials and does not require purification of the product diols by overhead distillation.