Class 562/898 - Purification or recovery

Subclass of Class 562 - Organic compounds -- part of the class 532-570 series
Definition: Processes wherein the carboxylic acid anhydride is separated
No. of patents: 34
Last issue date: 01/17/2006

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Number	Title	Issue Date
6987201	Acetic anhydride, method of purifying crude acetic anhydride, and method of producing polyoxytetramethylene glycol using acetic anhydride 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 tetra...	01/17/2006
6469206	Process for the preparation of triflic anhydride 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 ...	10/22/2002
5801279	Method for removing iodine compounds contained in organic medium 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 pro...	09/01/1998
5516735	Method for stabilizing rhodium compound 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 pr...	05/14/1996
5502249	Process for the removal of iodine from acetyl compounds Disclosed is a process for the removal of iodine, including I2, I- 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...	03/26/1996
5385875	Method for stabilizing rhodium compound 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 ...	01/31/1995
5362365	Purification of acetic anhydride or acetic anhydride and acetic acid using ozone 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 p...	11/08/1994
5300198	Process for the separation of ethylidene diacetate from acetic anhydride 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...	04/05/1994
5292948	Continuous process for the preparation of acetic anhydride or mixtures of acetic anhydride and acetic acid 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 c...	03/08/1994
5264087	Method for refining acetic anhydride by distillation 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 t...	11/23/1993
5244545	Process for removing acetone from carbonylation processes 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 c...	09/14/1993
5175363	Method for purification of carboxylic acids and anhydrides 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....	12/29/1992
5169982	Process for separating iodine and its compounds from the products obtained on subjecting dimethylether, methyl acetate or methanol to carbonylation 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-containi...	12/08/1992
5097069	Process for decomposing ଱,ଲ-unsaturated carbonyl compounds in refining acetic anhydride and/or acetic acid 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 ଱,³...	03/17/1992
4945172	Preparation of N-formyl-L-aspartic anhydride N-formyl-L-aspartic anhydride is prepared using a minimum excess of formic acid. Acetic anhydride and a C3 -C6 secondary alcohol are added to the reaction mixture to consume excess formic acid. The reaction is suitable for further re...	07/31/1990
4908477	Removal of organic iodine compounds from carbonylation products of methanol methyl acetate and dimethyl ether 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-...	03/13/1990
4792420	Purification of carboxylic acid anhydrides Carboxylic acid anhydrides are freed from small amounts of halogen and halide moieties by treatment with hydrogen and carbon monoxide in the presence of a supported Group VIII noble metal catalyst....	12/20/1988
4737318	Recovery of acetic anhydride Acetic anhydride is recovered from a mixture of acetic anhydride, acetic acid and water by contacting the mixture with at least one extraction solvent selected from the group consisting of a hydrophobic, organic solvent, a ketone and an ester to extract a...	04/12/1988
4664753	Process for separating iodine and its compounds from the carbonylation products obtained by subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction The disclosure relates to a process for separating iodine and its compounds from the carbonlyation products acetic acid, acetic anhydride or ethylidene diacetate obtained by subjecting dimethylether, methyl acetate or methanol to a carbonylation reaction....	05/12/1987
4650615	Purification of carboxylic acid anhydrides contaminated with halogen or halides Carboxylic acid anhydrides are freed from small amounts of halogen and halide moieties by treatment with a phenyl or an alkyl phosphine....	03/17/1987
4556644	Process for purifying and recovering contaminated catalyst solution obtained in the carbonylation of methyl acetate and/or dimethylether The disclosure relates to a process for purifying and recovering a contaminated catalyst solution which is obtained in the carbonylation of methyl acetate and/or dimethylether, the catalyst solution containing carbonyl complexes of noble metals of group V...	12/03/1985
4476237	Separation of tars from carbonylation reaction mixtures Tarry residues often are formed in carbonylation reactions, such as those in which esters or ethers are carbonylated to produce ethylidene diacetate or carboxylic acid anhydrides, such as acetic anhydride. Such residues contain Group VIII noble metal cata...	10/09/1984
4476238	Separation of tars from carbonylation reaction mixtures Tarry residues often are formed in carbonylation reactions, such as those in which esters or ethers are carbonylated to produce ethylidene diacetate or carboxylic acid anhydrides, such as acetic anhydride. Such residues contain Group VIII noble metal cata...	10/09/1984
4442304	Process for purifying and recovering contaminated catalyst solution obtained in the carbonylation of methyl acetate and/or dimethylether The disclosure relates to a process for purifying and recovering a contaminated catalyst solution which is obtained in the carbonylation of methyl acetate and/or dimethylether, the catalyst solution containing carbonyl complexes of noble metals of group V...	04/10/1984
4440570	Process for purifying and recovering contaminated catalyst solution obtained in the carbonylation of methyl acetate and/or dimethylether The disclosure relates to a process for purifying and recovering a contaminated catalyst solution which is obtained in the carbonylation of methyl acetate and/or dimethylether, the catalyst solution containing carbonyl complexes of noble metals of group V...	04/03/1984
4434241	Catalyst recovery process from tar from carbonylation reactions The present invention provides a process for the recovery of rhodium, lithium, and iodine values from tar which is generated during carbonylation reactions. The process comprises sequentially extracting the tar with water and then leaching the remaining t...	02/28/1984
4434240	Recovery of noble metal values from carbonylation residues Heavy residues produced by noble metal catalyzed carbonylation reactions and containing Group VIII noble metals, particularly rhodium, are treated with reagents to precipitate solids containing substantially all of the noble metal contained in the residue...	02/28/1984
4388217	Process for the recovery of catalyst values Disclosed is a process for the recovery of catalyst values from a catalyst-tar solution derived from a production system in which acetic anhydride is prepared by carbonylating methyl acetate in the presence of rhodium, lithium and methyl iodide. The catal...	06/14/1983
4364907	Process for recovery of rhodium values Disclosed is a process for the recovery of residual rhodium from tar obtained by submitting a rhodium-containing catalyst-tar solution to an extraction using methyl iodide and aqueous hydrogen iodide, thereby recovering catalyst values in the aqueous phas...	12/21/1982
4341741	Recovery of rhodium from carbonylation residues Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. Such residues contain noble metal, typically rhodium, used as a catalyst, which must be recovered before the residues...	07/27/1982
4340570	Recovery of rhodium from carbonylation residues Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. Such residues contain noble metal, typically rhodium used as a catalyst, which must be recovered before the residues ...	07/20/1982
4340569	Treatment of carbonylation residues Residues are formed in the carbonylation of esters or ethers, particularly in the production of acetic anhydride or ethylidene diacetate. When such residues contain noble metal, typically rhodium, used as a catalyst, the noble metals must be recovered bef...	07/20/1982
4246195	Purification of carbonylation products Carbonylation products of methyl acetate such as acetic anhydride are purified with respect to iodine contaminants by treatment with cesium acetate, potassium acetate or sodium acetate....	01/20/1981
4107002	Process for the purification of crude acetic anhydride A process for the purification of crude acetic anhydride by continuous fractional distillation, which comprises first introducing the anhydride into an evaporator, thereafter removing from the evaporator the non-distillable components contained in the cru...	08/15/1978

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Class 562/898 - Purification or recovery