Patent application number | Description | Published |
20110028675 | CYCLOHEXANONE PRODUCTION PROCESS WITH MULTIPLE POST-DISTILLATION - The present invention relates to a method for continuously preparing cyclohexanone from phenol making use of a catalyst comprising at least one catalytically active metal selected from platinum and palladium comprising hydrogenating phenol to form a product stream comprising cyclohexanone and unreacted phenol; separating at least part of the product stream, or at least part of the product stream from which one or more components having a lower boiling point than cyclohexanone have been removed, into a first fraction comprising cyclohexanone and a second fraction comprising phenol and cyclohexanol, using distillation; separating the second fraction into a third fraction, rich in cyclohexanol, and a fourth fraction, rich in phenol, using distillation;—subjecting at least part of the fourth fraction to a further distillation step, thereby forming a fifth fraction and a sixth fraction, wherein the fifth fraction is enriched in phenol compared to the sixth fraction, and wherein the sixth fraction comprises side-products having a higher boiling point than phenol, and phenol; and which method is characterized in the additional step of continuously or intermittently separating at least part of the sixth fraction to yet a further distillation step, thereby forming a seventh fraction and an eight fraction, wherein the seventh fraction is enriched in phenol compared to the eight fraction, and wherein the eight fraction comprises side-products having a higher boiling point than phenol. | 02-03-2011 |
20110028763 | CYCLOHEXANONE PRODUCTION PROCESS WITH IMPURITIES REMOVAL - The present invention relates to a method for preparing cyclohexanone from phenol in a first process, the first process being a cyclohexanone production process comprising hydrogenating phenol to form a product stream comprising cyclohexanone, phenol and side-products (RSP), including cyclohexanol and undesirable side-product; separating at least part of the product stream having a lower boiling point than cyclohexanone have been removed, into a first fraction comprising cyclohexanone and a second fraction comprising phenol, cyclohexanol and RSP, using distillation; and separating the second fraction into a third fraction, rich in cyclohexanol and comprising RSP, and a fourth fraction, rich in phenol and comprising RSP, using distillation. The invention further relates to an installation for carrying out a method of the invention. | 02-03-2011 |
20110054142 | CYCLOHEXANONE PRODUCTION PROCESS WITH MODIFIED POST-DISTILLATION - The present invention relates to a method for continuously preparing cyclohexanone from phenol making use of a catalyst comprising at least one catalytically active metal selected from platinum and palladium comprising a) hydrogenating phenol to form a product stream comprising cyclohexanone and unreacted phenol; b) separating at least part of the product stream, or at least part of the product stream from which one or more components having a lower boiling point than cyclohexanone have been removed, into a first fraction comprising cyclohexanone and a second fraction comprising phenol and cyclohexanol, using distillation; c) separating the second fraction into a third fraction, rich in cyclohexanol, and a fourth fraction, rich in phenol and, using distillation; d) subjecting at least part of the fourth fraction to a further distillation step, thereby forming a fifth fraction and a sixth fraction, wherein the fifth fraction is enriched in phenol compared to the sixth fraction, and wherein the sixth fraction comprises side-products having a higher boiling point than phenol, and phenol, wherein step d) is carried out in a vacuum distillation column equipped with trays in the lower part of the column, and wherein in the upper part of the column, i.e. in the part above the feed inlet, packing material is present instead of trays in at least part of said upper part, which packing material has a comparable or improved separating efficiency, and provides a reduction of the pressure drop by at least 30%, preferably more than 50%, as compared to the case with trays in the upper part, under otherwise similar distillation conditions. | 03-03-2011 |
20120323042 | CATALYSED PHENOL HYDROGENATION - The invention relates to a method for hydrogenating an aromatic compound. The invention in particular relates to a method for preparing cyclohexanone, cyclohexanol or a mixture thereof in a continuous way by catalytically hydrogenating phenol fed into a reactor comprising a supported hydrogenation catalyst, comprising a dopant selected from the group of alkali metal hydroxides, alkaline earth metal hydroxides, alkaline earth metal oxides, carbonates of alkali metals and carbonates of alkaline earth metals, and in which process during the hydrogenation of phenol continuously or intermittently water is fed into the reactor, the weight to weight ratio of water fed into the reactor to phenol fed into the reactor on average being 0.1 or less. | 12-20-2012 |
20130211072 | CAPROLACTAM RECOVERY WITH MEMBRANE TREATMENT - The invention relates to a process for treating an aqueous solution containing ε-caprolactam, ammonium sulphate and one or more other impurities, comprising one or more organic impurities from a caprolactam production process and optionally other salts than ammonium sulphate, by means of a membrane process, thereby obtaining a retentate and a permeate, in which process the membrane used is selected from the group of polyether sulphone membranes, sulphonated polyether sulphone membranes, polyester membranes, polysulphone membranes, aromatic polyamide membranes, polyvinyl alcohol membranes, polypiperazine membranes, cellulose acetate membranes, titanium oxide membranes, zirconium oxide membranes and aluminium oxide membranes, having a molecular weight cut off in the range of 100-1000 g/mol; and wherein more than 60 wt. % of the caprolactam in the aqueous solution is passed through a membrane to the permeate side, to obtain a purified caprolactam containing permeate stream, and wherein at least 50 wt. % of the organic impurities are retained in the retentate solution. | 08-15-2013 |
Patent application number | Description | Published |
20150158802 | PROCESS FOR THE PRODUCTION OF A MIXTURE COMPRISING CYCLOHEXANONE AND CYCLOHEXANOL FROM PHENOL - The present invention provides a process for continuously preparing a mixture of cyclohexanone and cyclohexanol comprising, a) hydrogenating phenol with gaseous hydrogen, in the presence of platinum or palladium, in a hydrogenation reactor, to produce a hydrogenation product stream comprising cyclohexanone, cyclohexanol, phenol and hydrogen; b) cooling the hydrogenation product stream to a temperature such that the fraction of phenol by mass in a first gas phase is lower than the fraction of phenol by mass in a first liquid phase; c) separating the first gas phase from the first liquid phase; d) returning at least part of the first gas phase to the hydrogenation reactor; e) heating the first liquid phase; f) purifying the first liquid phase by distillation; characterized in that heat is transferred from the hydrogenation product stream in step b) to another part of the process by means of in-process heat exchange; a mixture of cyclohexanone and cyclohexanol obtained by the process; and a chemical plant suitable for continuously preparing mixture of cyclohexanone and cyclohexanol according to the process. | 06-11-2015 |
20150218008 | PROCESS FOR PREPARING CRYSTALLINE AMMONIUM SULFATE PRODUCT - The invention relates to a process for preparing a crystalline ammonium sulfate product, which process comprises: a) subjecting in a crystallizer a feed solution of ammonium sulfate to crystallization to form a first slurry of ammonium sulfate crystals; b) subjecting the first slurry of ammonium sulfate crystals to a first size classification to yield a first coarse ammonium sulfate crystal fraction and a first fine ammonium sulfate crystal fraction; c) recycling at least part of the first fine ammonium sulfate crystal fraction to the feed solution of ammonium sulfate; and d) recovering a crystalline ammonium sulfate product from the first coarse ammonium sulfate crystal fraction, characterized in that: e) a second size classification is carried out on a second slurry of ammonium sulfate crystals to yield a second coarse ammonium sulfate crystal fraction and a second fine ammonium sulfate crystal fraction. | 08-06-2015 |
20150224421 | PROCESS FOR INITIATING AN AMMONIUM SULFATE CRYSTALLIZATION PROCESS - A continuous process for producing crystal-line ammonium sulfate, said process comprising a start-up operation followed by a steady-state operation, wherein the start-up operation comprises: i) in a crystallizer, evaporating solvent from an approximately saturated ammonium sulfate solution; ii) replacing evaporated solvent with further approximately proximately saturated ammonium sulfate solution; iii) introducing to the crystallizer seed crystals of ammonium sulfate; iv) continuing to evaporate solvent, until a desired degree of supersaturation is reached; and v) recovering crystalline ammonium sulfate from ammonium sulfate solution in a recovery unit, and the steady-state operation comprises: vi) continuously feeding approximately saturated ammonium sulfate solution into the crystallizer and continuously withdrawing ammonium sulfate crystals from the crystallizer, such that the total combined volume of ammonium sulfate solution and ammonium sulfate crystals within the crystallizer remains constant; and vii) recovering crystalline ammonium sulfate from ammonium sulfate solution in a recovery unit, characterized in that the degree of supersaturation in the crystallizer during the start-up operation is maintained between | 08-13-2015 |