Sulzer Chemtech Ag

Sulzer Management Ag

Futerro S.a.

Schumann Sasol Gmbh & Co. Kg

Sulzcr Chemtech Ag

Manfred Stepanski

Joseph C Gentry

Rahul Khandelwal

Erik Temmel

Claudia Pudack

Randi Wytcherley

B Bryant Slimp, Jr

Kimberly Anderson

Meta Naulita-ellis

Celine Rioual

Christoph Kirschner

Andrzej Kuszlik

Peter Faessler

Hans-Peter Brack

Philippe Coszach

Ferdinand Richter

François Loviat

Florian Lippuner

Bernhard J Jans

Mansour M M Ahmad

Severine Dette

Halbe Jansen

Mathias Pfeil

Norbert Matzat

Axel König

Herbert Engstler

Gunther Hildebrand

Peter Fässler

Mansour MM Ahmad

A method for preparing a purified styrene composition includes providing a crude hydrocarbon composition containing styrene, subjecting the crude hydrocarbon composition to a distillation in a divided-wall column to produce an overhead hydrocarbon stream, a bottom hydrocarbon stream and a side hydrocarbon stream and subjecting the side hydrocarbon stream to at least one crystallization step to obtain a purified styrene composition.

Process and apparatus for preparing purified styrene composition using divided-wall column and crystallization unit

A method for preparing a purified styrene composition with a styrene yield of at least 80%. The method comprises providing a crude composition containing styrene, and subjecting the crude composition to at least one crystallization step. The at least one crystallization step comprises at least one static crystallization stage and at least one dynamic crystallization stage.

Process and apparatus for preparing purified styrene composition from styrene containing feedstock

A method for preparing a purified styrene composition is provided. The method includes providing a crude composition and subjecting the crude composition to at least one crystallization step. The crude composition contains 70% by weight or more styrene based on the total weight of the crude composition. The at least one crystallization step comprises at least one of a static crystallization stage and a dynamic crystallization stage. The crude composition contains at least one impurity selected from the group consisting of: color inducing species, oxygenates, sulfur species, alpha-methylstyrene, and mixtures thereof.

A plant for preparing a purified isomeric methylene diphenyl diisocyanate monomer from a mixture of different isomeric monomers is disclosed herein. The plant can comprise a distillation apparatus, which comprises: a) a distillation column including a structured packing, b) a source for a mixture of different isomeric methylene diphenyl diisocyanate monomers, c) an evaporator, d) an overhead vapor condenser, e) optionally, an overhead vacuum system and f) a flow-controlled reflux system. The overhead vapor condenser comprises a shell and tube arrangement and is embodied so as to directly subcool the condensate to less than 47&#xb0; C. The flow-controlled reflux system comprises a heater, which is embodied so as to reheat a partial stream of the condensate formed in the overhead vapor condenser up to 190&#xb0; C.

Plant and method for purifying an isomeric monomer

A process for the separation of a substance from a liquid feed mixture and for the purification of the substance by fractional layer crystallization, wherein the liquid feed mixture comprises the substance to be separated and purified in a concentration of less than 50% by weight, which comprises the subsequent steps in the given order: (a) feeding the liquid feed mixture into a crystallization zone, in which at least one surface is provided, so that at least a part of the surface contacts the liquid feed mixture, (b) cooling the at least one surface of the crystallization zone to a temperature below the equilibrium freezing temperature of the liquid feed mixture so that a crystal layer enriched in the substance to be separated and purified is deposited on the at least one cooled surface, whereby a mother liquid having a lower concentration of the substance to be separated and purified than the liquid feed mixture is formed from the liquid feed mixture, (c) removing at least a portion of the mother liquid from the crystallization zone, (d) adding a further portion of liquid feed mixture into the crystallization zone, (e) allowing further deposition of a crystal layer enriched in the substance to be separated and purified to take place on the at least one cooled surface, (f) optionally carrying out a sweating stage and removing a sweating residue and (g) melting the crystal layer to obtain the separated and purified substance.

Semi-continuous crystallization method and apparatus

A process for purifying a crude composition includes a monoterpene compound selected from the group consisting of monocyclic monoterpene alcohols, monocyclic monoterpene ketones, bicyclic epoxy monoterpenes and mixtures of two or more of the aforementioned compounds, such as preferably a monocyclic monoterpene alcohol. The process comprises performing a layer crystallization with a melt of the crude composition, and the melt of the crude composition subjected to the layer crystallization includes oxygen-containing solvent in a concentration of 20 ppm to 2% by weight. The oxygen-containing solvent is selected from the group consisting of water, C1-6-alcohols, C1-6-carboxylic acids, C1-6-ketones, C1-6-aldehydes, C1-12-ethers, C1-12-esters and mixtures of two or more of the aforementioned solvents.

Process for purifying a crude composition including a monoterpene compound, such as a monocyclic monoterpene alcohol, by layer melt crystallization

A process for desalinating water is disclosed. The process comprises the steps of passing a feed stream of saline solution' in a first desalination step through a reverse osmosis membrane desalination plant&#x2032; comprising at least one reverse osmosis desalination unit&#x2032; to form a first product water stream&#x2032; having a reduced salt concentration relative to that of the feed stream of saline solution&#x2032; and a first byproduct stream&#x2032; having an increased salt concentration relative to that of the feed stream of saline solution&#x2032; characterized in that the first byproduct stream&#x2032; is passed in a second desalination step through a falling film crystallization unitto form a second product water streamhaving a reduced salt concentration relative to that of the first byproduct stream&#x2032; and a second byproduct streamhaving an increased salt concentration relative to that of the first byproduct stream&#x2032;. The invention further relates to an apparatusfor carrying out said process. The present invention further relates also to the use of the process or apparatusfor the reduction of the volume of the first byproduct stream&#x2032; of a reverse osmosis membrane desalination plant&#x2032;, preferably an in-land desalination plant&#x2032;, or in a device or plant or process for producing desalinated water, for salt production, for co-production of power and desalinated water, or for air conditioning.

Apparatus, use of apparatus and process for desalination of water

The present invention relates to a method for purifying a crude benzoic acid () containing 5 to 20% by weight of byproducts and 80 to 95% by weight of benzoic acid, by means of distillation, wherein the distillation is performed in a plant comprising a first distillation system (), which comprises a divided wall column (). Preferably, the divided wall column () comprises: an upper portion having an upper undivided section () for concentrating low-boiling components, wherein the low-boiling components have a lower boiling point than benzoic acid, and an outlet for removal of the low-boiling components from the column (), a lower portion having a lower undivided section () for concentrating high-boiling components, wherein the high-boiling components have a higher boiling point than benzoic acid, and an outlet for removal of the high-boiling components from the column (), and a central portion arranged between the upper portion and the lower portion having at least one vertical dividing wall () for dividing the central portion into at least one feed section () and at least one withdrawal section (), the feed section () having an inlet for the feed of crude benzoic acid () and the withdrawal section having a side draw outlet for the purified benzoic acid ().

Method for purification of benzoic acid

The invention relates to a process for purification of a stream containing a cyclic ester of an alpha-hydroxycarboxylic acid of formula (I), wherein each R independently represents hydrogen or an aliphatic hydrocarbon having 1 to 6 carbon atoms comprising the steps of: (a) separating the cyclic ester-containing stream into one or more cyclic ester-containing vapor fractions and one or more cyclic ester-containing liquid fractions; (b) condensing a cyclic ester-containing vaporized fraction as obtained in step (a) to obtain a cyclic ester-containing condensate; (c) subjecting at least part of the cyclic ester-containing condensate as obtained in step (b) to melt crystallization to obtain a purified cyclic ester-containing stream and a residue stream; and (d) recovering the purified cyclic ester-containing stream as obtained in step (c). The invention further relates to an apparatus suitable for carrying out the present process.

Process and apparatus for purification of a stream containing a cyclic ester of an alpha-hydroxycarboxylic acid

A process for desalinating water is disclosed. The process comprises the steps of passing a feed stream of saline solution' in a first desalination step through a reverse osmosis membrane desalination plant&#x2032; comprising at least one reverse osmosis desalination unit&#x2032; to form a first product water stream&#x2032; having a reduced salt concentration relative to that of the feed stream of saline solution&#x2032; and a first byproduct stream&#x2032; having an increased salt concentration relative to that of the feed stream of saline solution&#x2032; characterized in that the first byproduct stream&#x2032; is passed in a second desalination step through a suspension crystallization unitto form a second product water streamhaving a reduced salt concentration relative to that of the first byproduct stream&#x2032; and a second byproduct streamhaving an increased salt concentration relative to that of the first byproduct stream&#x2032;. The invention further relates to an apparatusfor carrying out said process. The present invention further relates also to the use of the process or apparatusfor the reduction of the volume of the first byproduct stream of a reverse osmosis membrane desalination plant&#x2032;, preferably an in-land desalination plant&#x2032;, or in a device or plant or process for producing desalinated water, for salt production, for co-production of power and desalinated water, or for air conditioning.

Apparatus and process for desalination of water

Disclosed is a method to prepare a polylactic acid comprising the steps of performing a ring opening polymerization using a catalyst and either a catalyst killer compound or an endcapping additive to obtain a raw polylactic acid of MW greater than 10,000 g/mol, purifying the raw polylactic acid by removing and separating low boiling compounds comprising lactide and impurities from the raw polylactic acid by devolatization of the low boiling compounds as a gas phase stream, and purifying the lactide from the devolatization and removing the impurities from the gas phase stream of evaporated low boiling compounds by means of crystallization by desublimation from the gas phase, wherein the lactide is purified and the removed impurities include a catalyst residue and a compound containing at least one hydroxyl group such that the purified lactide is then polymerized by feeding it back into the ring opening polymerization. The invention further relates to an apparatus for carrying out the method comprising a polymerization reactor for performing a ring opening polymerization to obtain a raw polylactic acid, a devolatization apparatus for separating low boiling compounds comprising lactide and impurities from a raw polylactic acid, and a crystallization apparatus for purifying a lactide and removing impurities by means of a desublimation and a crystallization in the same crystallization apparatus.

Method for the manufacture of a polyhydroxy-carboxylic acid

The present invention relates to a method for the purification of an ionic liquid by means of fractional crystallization in which a part of the ionic liquid is crystallized and the crystallizate formed is separated from the liquid remainder. In this respect the ionic liquid is charged with a certain amount of at least one entrainer substance.

Method of purifying ionic liquids

In the process according to the invention for fractionating substances, particularly paraffins, oils, fats and waxes, which, when crystallized, have poor adhesion to the substantially vertical crystallization surfaces (39) of a crystallizer, screen-like supporting structures, e.g. perforated metal sheets (31) bent in a zig-zag, are disposed between the crystallization surfaces (39) of a crystallizer. The crystals (51) becoming detached from the crystallization surfaces (39) during the sweating phase are left suspended in horizontal strips in the triangular zones (41) on the perforated sheet (31) and remain in thermal contact with the crystallization surface (39) and sweat out the liquid phase (55). The mother liquor (55) drips off, in some cases also between the crystals (51) and the crystallization surface (39), with the result that drip channels are melted by the heated mother liquor and thus opened.

Process for fractional crystallization of substances, a crystallizer

A process for fractional crystallization of paraffin from mineral oil based and synthetic crude paraffin, wherein crude paraffin having a high oil content is crystallized in a crystallizer equipped with perforated metal sheets (31) extending in a zig-zag in the spaces between the heat exchanger surfaces (39). The paraffin-containing melt is only solidified to an extent such that the fractions and oils for discharge remain liquid and are run off without total solidification of the melt. The perforated sheets (31) support the layers of crystals (43) and during sweating the paraffin is detached in strips from the heat exchanger surface (39) and is adapted to rest on the sloping perforated sheets (31). The inclination of the perforated sheets (31) guides and moves the paraffin strips (53), so that the paraffin strips remain in contact with the heat exchanger surfaces (39) while being pressed by their own weight along the inclined surface (30) towards the heat exchanger surfaces (39).

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Buchs, Switzerland

Manfred Stepanski