Purification Or Recovery Patents (Class 562/898)
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Patent number: 10166694Abstract: Disclosed is the integration of the production of acetic anhydride from ketene, and the acetylation of wood using acetylation fluid comprising acetic acid and acetic anhydride. The invention involves recovering acetylation fluid from wood acetylation, and sending this to an acetic anhydride distillation unit belonging to the acetic anhydride production plant.Type: GrantFiled: July 17, 2015Date of Patent: January 1, 2019Assignee: Tricoya Technologies Ltd.Inventor: Stephen John Benstead
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Patent number: 10106485Abstract: The present invention concerns a process for manufacturing a fraction comprising carboxylic acid anhydride by reaction of a fraction comprising carboxylic acid with a ketene, and the use of the fraction comprising carboxylic acid anhydride in a process for acylation of polysaccharides.Type: GrantFiled: December 1, 2015Date of Patent: October 23, 2018Assignee: Rhodia Acetow GmbHInventors: Thomas Krumrey, Andreas Hummel, Dirk Hölter
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Patent number: 9856202Abstract: Process for the recovery of carboxylic acid, in particular acetic acid containing carboxylic anhydride in particularacetic anhydride and other impurities, which comprises: (a) treating a fraction, in particular a fraction originating from a wood treatment process, containing carboxylic acid and impurities with a metal salt in the presence of water, (b) treating at least part of the fraction obtained from step (a) to remove metal salt and, (c) treating at least part of the fraction obtained from step (b) by distillation, stripping or membrane separation to recover at least a purified carboxylic acid fraction.Type: GrantFiled: May 6, 2015Date of Patent: January 2, 2018Assignee: SOLVAY ACETOW GMBHInventors: Thomas Krumrey, Andreas Hummel
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Patent number: 8759576Abstract: In one embodiment, the invention is to a process for purifying acetic anhydride. The process includes the steps of feeding a liquid crude acetic anhydride stream directly to a distillation column and separating the liquid crude acetic anhydride stream to produce a light ends stream, a sidedraw and a residue stream. The sidedraw comprises substantially pure acetic anhydride product. The distillation column is operated at a pressure less than 101 kPa. The substantially pure acetic anhydride product comprises greater than 98 wt. % acetic anhydride, has a permanganate time of greater than 10 minutes, and has an APHA color of less than 10.Type: GrantFiled: September 6, 2012Date of Patent: June 24, 2014Assignee: Celanese International CorporationInventors: R. Jay Warner, Melchoir Meilchen, Nathan Kirk Powell
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Patent number: 6987201Abstract: The present invention provides acetic anhydride, a method of purifying crude acetic anhydride, and a method of producing polyoxytetramethylene glycol using acetic anhydride. A method of producing polyoxytetramethylene glycol by ring-opening-polymerizing tetrahydrofuran in the presence of acetic anhydride and an acid catalyst, wherein said ring-opening polymerization is conducted using acetic anhydride having a diketene concentration of 10 ppm or less to produce polyoxytetramethylene glycol.Type: GrantFiled: February 16, 2001Date of Patent: January 17, 2006Assignee: Daicel Chemical Industries, Ltd.Inventors: Seiji Nishioka, Ryosuke Maeda, Toshifumi Fukui, Mitsuru Yamashita
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Patent number: 6469206Abstract: Disclosed is a process for the preparation of trifluoromethanesulfonic acid anhydride by the steps of (1) forming a mixed anhydride comprising a trifluoromethanesulfonyl acyl residue and a carboxyl residue by contacting trifluoromethanesulfonic acid or a derivative thereof with a carboxyl compound selected from ketene, dialkyl ketenes, carboxylic acids, and derivatives of carboxylic acids and (2) subjecting the mixed anhydride to reactive distillation wherein the mixed anhydride undergoes disproportionation to produce triflic anhydride and a higher boiling carboxylic acid anhydride.Type: GrantFiled: February 26, 2001Date of Patent: October 22, 2002Assignee: Eastman Chemical CompanyInventors: Robert Thomas Hembre, Robert Lin
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Publication number: 20010029309Abstract: The present invention provides acetic anhydride, a method of purifying crude acetic anhydride, and a method of producing polyoxytetramethylene glycol using acetic anhydride.Type: ApplicationFiled: February 16, 2001Publication date: October 11, 2001Inventors: Seiji Nishioka, Ryosuke Maeda, Toshifumi Fukui, Mitsuru Yamashira
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Patent number: 5801279Abstract: An object of the present invention is to provide an operating method which can reduce the amount of silver or mercury dissolved in a solution after contact and can increase the usage of silver or mercury without installing new treating facilities in a process for removing iodine compounds contained in an organic medium, particularly acetic acid or a mixture of acetic acid or acetic anhydride, by contacting them with a cation exchange resin in which at least 1% of the active sites are converted to a silver form or a mercury form.The operating method described above is characterized by carrying out the operation while elevating the temperatures in stages while contacting the organic medium, particularly acetic acid or a mixture of acetic acid and acetic anhydride, containing the iodine compounds with a cation exchange resin.Type: GrantFiled: April 8, 1997Date of Patent: September 1, 1998Assignee: Daicel Chemical Industries, Ltd.Inventors: Hiroyuki Miura, Masanobu Kayajima, Takashi Sato
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Patent number: 5516735Abstract: A concentrated catalyst solution provided in the carbonylation reaction in which methyl acetate or dimethyl ether is chemically bonded with carbon monoxide in the presence of a catalyst system comprising a rhodium compound and an alkali metal iodide to produce acetic anhydride is subjected to a carbonylation treatment with carbon monoxide or a mixture of carbon monoxide and hydrogen before it is applied to a process for separating the tar contained in the catalyst solution, thereby increasing the iodide ion content of the catalyst solution, thus enabling the rhodium compound to be stabilized.When the concentration of the iodide ion in the concentrated catalyst solution is increased by this method, there is no possibility of the balances between the rhodium concentration and, the alkali metal concentration and the iodine concentration of the carbonylation reaction system being disturbed even when the catalyst solution as reprocessed is returned to the carbonylation reaction system.Type: GrantFiled: October 21, 1994Date of Patent: May 14, 1996Assignee: Daicel Chemical Industries, Ltd.Inventor: Hiroto Tanigawa
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Patent number: 5502249Abstract: Disclosed is a process for the removal of iodine, including I.sub.2, I.sup.- and iodine-containing organic compounds, from acetic acid or anhydride wherein an acetyl product stream comprising (i) acetic acid or acetic anhydride and (ii) iodine, one or more iodine-containing compounds or a mixture thereof is subjected to distillation in the presence of a packing material comprising iron, nickel, copper, or an alloy thereof.Type: GrantFiled: May 31, 1994Date of Patent: March 26, 1996Assignee: Eastman Chemical CompanyInventors: Carl F. Fillers, Jerry A. Barron, Eric D. Middlemas
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Patent number: 5385875Abstract: A concentrated catalyst solution used in a carbonylation reaction in which methyl acetate or dimethyl ether is chemically bonded with carbon monoxide in the presence of a catalyst system comprising a rhodium compound and an alkali metal iodide to produce acetic anhydride is subjected to a carbonylation treatment with carbon monoxide, or a mixture of carbon monoxide and hydrogen, before it is applied to a process for separating the tar contained in the catalyst solution, thereby increasing the iodide ion content of the catalyst solution and enabling the rhodium compound to be stabilized.The balances between the rhodium concentration, the alkali metal concentration and the iodine concentration of the carbonylation reaction system are not disturbed, even when the catalyst solution as reprocessed is returned to the carbonylation reaction system.Type: GrantFiled: January 24, 1994Date of Patent: January 31, 1995Assignee: Daicel Chemical Industries, Ltd.Inventor: Hiroto Tanigawa
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Patent number: 5362365Abstract: Acetic acid and/or acetic anhydride containing methyl crotonate, vinyl acetate, or both as impurities, is contacted with ozone in an amount of excess molar to the carbon-carbon double bond in said methyl crotonate and/or vinyl acetate and the impurities produced by ozone-treatment are removed off by distillation. A large quantity of impurities such as aldehydes are produced after treatment by treating acetic acid and/or acetic anhydride containing much amount of unsaturated compounds as impurities with ozone. Distilling the ozone-treated acetic acid and/or acetic anhydride make it possible to remove methyl crotonate and vinyl acetate, which are unsaturated compounds difficult to remove by the conventional separation methods, to give high-quality acetic acid and/or acetic anhydride excellent in the residence time in the potassium permanganate test.Type: GrantFiled: July 6, 1993Date of Patent: November 8, 1994Assignee: Daicel Chemical Industries, Ltd.Inventors: Hiroyuki Niijima, Kazuyuki Akita
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Patent number: 5300198Abstract: A distillation process for the separation of acetic anhydride from a mixture thereof with ethylidene diacetate wherein the mixture of acetic anhydride and ethylidene diacetate is fed to the mid section of a distillation column and a small amount of acetic acid is fed separately to the lower section of the column. The addition of the acetic acid suppresses tar formation during the distillation process.Type: GrantFiled: April 5, 1993Date of Patent: April 5, 1994Assignee: Eastman Kodak CompanyInventors: Donald W. Lane, Ronnie D. Lilly
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Patent number: 5292948Abstract: Disclosed is a continuous process for the preparation of acetic anhydride which comprises carbonylating a mixture comprising (i) methyl iodide and (ii) methyl acetate and/or dimethyl ether in the presence of a rhodium catalyst and a promoter wherein the concentration of mesityl oxide in the carbonylation mixture is suppressed by the presence therein of at least 100 ppm of dissolved ferrous and/or cobaltous ion.Type: GrantFiled: May 28, 1993Date of Patent: March 8, 1994Assignee: Eastman Kodak CompanyInventors: Joseph R. Zoeller, Charles E. Outlaw, Regina M. Moncier
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Patent number: 5264087Abstract: Disclosed is a continuous method for refining acetic anhydride produced by the reaction of ketene and acetic acid by means of a vacuum distillation system to provide a refined material comprised of at least 99.5 weight percent acetic anhydride, not more than 0.5 weight percent acetic acid and not more than about 90 parts per million (ppm) diketene.Type: GrantFiled: October 13, 1992Date of Patent: November 23, 1993Assignee: Eastman Kodak CompanyInventors: H. Ford Lowery, Steven L. Cook, Vicky K. Pinto
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Patent number: 5244545Abstract: Disclosed is an improved process for the removal of acetone from a production system wherein acetic anhydride is produced by contacting a mixture comprising methyl iodide and methyl acetate and/or dimethyl ether with carbon monoxide in the presence of a carbonylation catalyst or catalyst system. The process comprises two distillation steps wherein acetone is separated from a mixture of methyl acetate, methyl iodide and acetone.Type: GrantFiled: October 9, 1991Date of Patent: September 14, 1993Assignee: Eastman Kodak CompanyInventors: Steven L. Cook, Robert M. Schisla, Jr., Charles E. Outlaw, Joseph R. Zoeller
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Patent number: 5175363Abstract: Disclosed is a method for reducing olefinic impurities in solutions of carboxylic acids and/or anhydrides. The invention is especially useful for removing substantially all, i.e., greater than 90 percent of trace amounts of olefinic impurities.Type: GrantFiled: January 28, 1991Date of Patent: December 29, 1992Assignee: Eastman Kodak CompanyInventors: Joseph R. Zoeller, Regina M. Moncier
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Patent number: 5169982Abstract: Iodine and its compounds are separated from the carbonylation products acetic acid, acetic anhydride or ethylidene diacetate obtained on subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction in the presence of an iodine-containing catalyst. The quantity of total iodine contaminating the carbonylation products is reduced to less than 20 ppb iodine by treating the products at 20.degree.-200.degree. C. with peracetic acid, diacetyl peroxide or a compound yielding these two agents under the reaction conditions, and separating them distillatively.Type: GrantFiled: September 16, 1986Date of Patent: December 8, 1992Assignee: Hoechst AktiengesellschaftInventors: Erpenbach Heinz, Klaus Gehrmann, Peter Horstermann
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Patent number: 5097069Abstract: Unsaturated ketones such as mesityl oxide may be removed from acetic anhydride, or mixtures of acetic anhydride and acetic acid, by heating a solution comprising (1) acetic anhydride, or a mixture of acetic anhydride and acetic acid, (2) an .alpha.,.beta.-unsaturated ketone, (3) ferrous (Fe II) and/or cobaltous (Co II) ion, (4) a cation selected from alkali metals, alkaline earth metals, quaternary organoammonium, quaternary organophosphonium and mixtures thereof, and (5) iodide ion.Type: GrantFiled: April 8, 1991Date of Patent: March 17, 1992Assignee: Eastman Kodak CompanyInventors: Joseph R. Zoeller, Charles E. Outlaw, Regina M. Moncier
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Patent number: 4945172Abstract: N-formyl-L-aspartic anhydride is prepared using a minimum excess of formic acid. Acetic anhydride and a C.sub.3 -C.sub.6 secondary alcohol are added to the reaction mixture to consume excess formic acid. The reaction is suitable for further reactions without modification.Type: GrantFiled: November 28, 1989Date of Patent: July 31, 1990Assignee: The Nutra Sweet CompanyInventors: John B. Hill, Hugh L. Dryden, Jr., Robert Erickson
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Patent number: 4908477Abstract: Organic iodine compounds are separated from carbonylation products of methanol, methyl acetate and dimethyl ether and from mixtures of such carbonylation products by a process wherein the iodine compounds are removed by liquid phase extraction with a non-aromatic hydrocarbon.Type: GrantFiled: March 9, 1987Date of Patent: March 13, 1990Assignee: BASF AktiengesellschaftInventors: Horst Hartmann, Waldhelm Hochstein, Gerd Kaibel, Franz-Josef Mueller