Abstract: The present invention provides a distillation separation method whereby tertiary butyl acetate is separated by distillation as an overhead stream from a bottoms acetic acid stream with the proviso that water is incorporated in the system such that the bottoms acetic acid stream contains water in amount of 0.1 to 5 wt %.

Abstract: Polycarboxylic acids are purified by contacting a crude polycarboxylic acid with a solvent to produce a substantially pure polycarboxylic acid. The solvent is chosen so that the impurities are soluble in the solvent and the polycarboxylic acid is insoluble in the solvent.

Abstract: A process for recovering a desired organic acid from a solution includes the steps of: providing an aqueous solution including at least one desired organic acid or its acid anion; adjusting the proton concentration in the aqueous solution to a desired level, with the desired proton concentration being selected, at least in part, by the amount of available protons needed to associate with the acid anions of the desired organic acid(s) to be recovered and/or acid anions that are weaker than the desired organic acids; and recovering at least a portion of the at least one desired organic acid from the aqueous phase. The desired proton concentration can be based on the amount of available protons being greater than, less than or substantially equal, to the amount of protons needed to associate with the anion of the desired organic acid(s) and acid anions that are weaker than the desired organic acid(s).

Abstract: Carbonyl compounds (e.g. acetone and acetaldehyde) are often present as impurities in oxygenated organic liquids such as acetic acid made by the carbonylation of methanol or in phenol produced by the oxidation of cumene. These impurities can render petrochemical products unsuitable for long-term storage or otherwise adversely affect downstream processing operations. It has now been found that detrimental carbonyl impurities can be easily removed from oxygenated organic liquids by contact with resins having amine functional groups.

Abstract: Disclosed is a method to manufacture high purity acetic acid. Although described in relation to that produced by a low water carbonylation process the present invention is applicable to other mechanisms for production of acetic acid which results in formation of permanganate reducing compounds such as acetaldehyde and its derivatives, and alkyl iodide impurities in intermediate process streams. It has been found that permanganate reducing compounds and alkyl iodides may be conveniently removed from a light phase of an intermediate stream in the reaction process by employing a multiple distillation process coupled with an optional post extraction of acetaldehyde. The distillation process involves first distilling a light phase to concentrate the permanganate reducing compounds, and in particular the acetaldehyde, and then separating the permanganate reducing compounds and alkyl iodides in a second distillation tower.

Abstract: A process for methylating an alpha carbon adjacent to an electron withdrawing group includes reacting dimethyl ether with a molecule containing the alpha carbon and the electron withdrawing group to substitute a methyl group on the alpha carbon. The process can be conducted in a vapor phase and can be represented by Equation I: R(CH2)nCH2-EWG+CH3OCH3→R(CH2)nCH(CH3)-EWG+CH3OH  (I) where EWG is the electron withdrawing group, and R is H when n is 0, 1 or 2, and R is alkyl, EWG or aryl when n>2. For example, the molecule reacted with dimethyl ether can be acetic acid, propionic acid, methyl acetate, methyl propionate, acetonitrile, propionitrile and acetone. The process is catalyzed by an acid catalyst containing a Lewis acid functionality. When the electron withdrawing group is an acid, a methyl ester can be formed by esterifying the electron withdrawing group with methanol liberated from dimethyl ether.

Abstract: A process for removing higher organic iodides, including hexyl iodide, from an acetic acid product obtained by carbonylating methanol and/or a reactive derivative thereof in the presence of a finite concentration of water, Group VIII noble metal catalyst, methyl iodide as co-catalyst, and optionally a catalyst promoter, which process includes the step of subjecting an aqueous composition comprising acetic acid and at least one higher organic iodide to distillation in a column, or section of a column, separating water overhead from a dry acetic acid fraction, wherein the water concentration on the feed tray of the column, or section of the column, is greater than 8% by weight and the water concentration in the head of the column, and/or section of the column, is greater than 70% by weight.

Abstract: There is described a process for the production of a substantially anhydrous salt of an organic acid which comprises reacting a basic compound of a metal with the appropriate organic acid, removing a substantial proportion of water present so as to produce the salt or its hydrate as a liquid phase and then dissolving the liquid phase in a non-aqueous solvent.

Abstract: A method for reducing the carbonyl value of a composition containing carboxylic acid or carboxylic acid derivative includes contacting the composition containing carboxylic acid or carboxylic acid derivative with an amount of a catalyst and active methylene compound effective to lower the carboxyl value of the composition.

Abstract: A method of removing organic iodides from non-aqueous organic media includes contacting the organic media with a silver or mercury-exchanged cationic ion exchange substrate at a temperature greater than about 50° C. The method is particularly effective for removing high molecular weight organic iodides from organic media such as acetic acid or acetic anhydride. Particular species removed include decyl iodides and dodecyl iodides from organic media such as acetic acid.

Abstract: Macroporous, strong-acid polysiloxane ion exchange resins which have been converted to the silver or mercury form are utilized to remove iodides from non-aqueous organic media. In a particularly preferred method, hexyl iodide is removed from acetic acid.

Abstract: For the removal of trace quantities of iodine-containing contaminants from corrosive liquid feed streams, an alternative with distinct advantages over the prior art is provided. The treatment method involves the use of a crystalline manganese phosphate which has been cation-exchanged with an iodine-reactive metal. This inorganic adsorbent may be used in unbound form, or it can bound with a substantially insoluble porous inorganic refractory metal oxide binder. A reactivation technique for this material is also presented.

Abstract: A method for recovering methyl acetate and residual acetic acid in a two-stage process for producing pure terephthalic acid having a first oxidation stage and a second purification stage.

Abstract: Disclosed is a method to manufacture high purity acetic acid. Although described in relation to that produced by a low water carbonylation process the present invention is applicable to other mechanisms for production of acetic acid which results in formation of permanganate reducing compounds such as acetaldehyde, propionic acid, and alkyl iodide impurities in intermediate process streams. It has been found that permanganate reducing compounds and alkyl iodides may be conveniently removed from a light phase of an intermediate stream in the reaction process by employing a multiple distillation process coupled with an optional extraction of acetaldehyde. The distillation process involves first distilling a light phase to concentrate the permanganate reducing compounds, and in particular the acetaldehyde, and then separating the permanganate reducing compounds and alkyl iodides in a second distillation tower.

Abstract: A process as provided for producing an acetic acid process stream having less than 400 ppm propionic acid and less than 1500 ppm water. Methanol or a reactive derivative thereof and carbon monoxide is fed to a carbonylation reactor in which there is maintained during the course of the process a liquid reaction composition containing an iridium carbonylation catalyst, methyl iodide co-catalyst, a promoter, water at a concentration of less than about 8% by weight, methyl acetate, acetic acid, and propionic acid by-product and its precursors. Liquid reaction composition is withdrawn from the carbonylation reactor and introduced to a flash zone to form a vapor fraction comprising water, acetic acid product, propionic acid by-product, methyl acetate, methyl iodide and propionic acid precursors, and a liquid fraction comprising involatile iridium catalyst, involatile optional promoter or promoters, acetic acid and water.

Abstract: For the removal of trace quantities of iodine-containing contaminants from corrosive liquid feed streams, an adsorbent with distinct advantages over prior-art materials is provided. The treatment method involves the use of a metal phthalocyanine compound where the metal selected from the group consisting of silver, mercury, copper, lead, thallium, palladium, or mixtures thereof. Such metals are known to be reactive with the iodine-containing contaminants in the feed stream. Furthermore, the metal phthalocyanine is deposited on a carrier material selected from the group consisting of an activated carbon, a phenolic polymer, and an inorganic refractory metal oxide. Such adsorbent materials have proven substantially insoluble even in corrosive liquid feed streams associated with the invention. Reactivation and regeneration techniques, which are generally incompatible with prior-art adsorbent materials, are also disclosed.

Abstract: Dilute solutions of fermentation sales may be concentrated by extracting water using low-miscibility, low-molecular-weight secondary and tertiary amines, e.g. triethylamine (TEA), diisopropyl amine (DIA), N,N-diethylmethylamine (DEMA), and mixtures thereof. At 30.degree. C.-55.degree. C., which corresponds to typical fermentation temperatures, these low-molecular-weight amines or their mixtures, can extract large amounts of water from dilute aqueous solutions containing fermentation salts. Thus, dilute fermentation salt solutions can be concentrated by selectively removing water. At these low temperatures, the amine phase contains 20-35% water and a much reduced quantity of fermentation salt. When the temperature is raised, water phases out of the amine, allowing the amine to be recycled and reused to extract additional water. Using this approach, about 82.

Abstract: An improved process for preparing an aromatic dicarboxylic acid wherein the improvement resides in dehydrating and recovering solvent from a feed stream having from 20% to 40% by weight water via azeotropic distillation with organic phase reflux using an entrainer selected from isobutyl acetate, n-propyl acetate or an entrainer with a boiling point between isobutyl acetate and n-propyl acetate.

Abstract: Provided is a process for producing acetic acid by carrying out reaction of methyl formate in the presence of a Group VIII metal catalyst, at least one iodine compound, acetic acid and carbon monoxide, continuously drawing a reaction mixture from a reactor, introducing the reaction mixture into a flash distillation zone, separating an evaporated component and an unevaporated component, recycling the unevaporated component to the reaction zone, and obtaining acetic acid from the evaporated component, wherein formic acid and methyl formate are allowed to coexist in the flash distillation zone and/or the recycling zone. According to this process, no loss of methyl formate and formic acid is caused and only methyl formate is used as a starting material with basically requiring no supply of carbon monoxide.

Abstract: A solution is provided to the long sought inorganic alternative to resin based adsorbents for iodide clean-up service for corrosive organic liquid. The solution involves the use of a solid inorganic adsorbent comprising a combination of a silica-rich zeolite molecular sieve, which has been cation-exchanged with an iodide-reactive metal selected from silver, mercury, copper, lead, thallium, palladium or mixtures thereof, with a substantially insoluble, porous refractory inorganic oxide binder. Reactivation and regeneration technique for the spent inorganic adsorbent are also covered.

Abstract: This invention relates to methods of removing acetic acid from cyclohexane in the direct oxidation of cyclohexane to adipic acid, especially after recycling catalyst which is precipitated by introduction of additional cyclohexane. The removal of acetic acid is preferably conducted by use of rather small amounts of wash-water in one to three stage extractors. A two stage reactor is preferable as being more efficient.

Abstract: A method for purifying acetic acid containing at least one component selected from the group consisting of unsaturated compounds and carbonyl compounds as an impurity involves the step of purifying the acetic acid with a distillation column having at least 30 plates by operating the distillation column at a pressure ranging from 40 to 760 mmHg and a reflux ratio of at least 4, and yields a high-quality acetic acid which rates high in the potassium permanganate test without needing of the addition of any chemical to the acetic acid to be purified and a large amount of energy, and is economical.

Abstract: A process for the recovery of a carbonylation product from a liquid reaction composition of an iridium-catalysed carbonylation reaction of a carbonylatable reactant comprises subjecting the composition to a vaporization with or without the addition of heat to produce a vapor-fraction and a liquid fraction, the vapor fraction comprises carbonylation product and the liquid fraction has a water concentration of at least 0.5% by weight to stabilize the iridium catalyst.

Abstract: Optically active .alpha.-bromo- or .alpha.-chlorocarboxylic compounds of the formula ##STR1## wherein X is bromine or chlorine;M is hydrogen, NR.sub.4.sup.+1 or a cation of an alkali or alkaline earth metal;R.sup.1 is hydrogen or lower alkyl;n is 0 or 1;R is hydrogen, C.sub.1 -C.sub.20 alkyl, or C.sub.1 -C.sub.20 alkyl substituted in the terminal position with --NR.sup.2.sub.2, --COOR.sup.2, --OR.sup.3, a free or protected --CHO group or a ring A;R.sup.2 is hydrogen or a lower alkyl;R.sup.3 is hydrogen or a protecting group;ring A is an unsubstituted or substituted ring; and* is a center of chirality,are prepared by enantioselectively hydrogenating, in the presence of a ruthenium complex of an optically active diphosphine ligand, a (Z)-.alpha.,.beta.-unsaturated compound of the general formula ##STR2## wherein R, n, X and M are as defined above.

Abstract: A process for the purification of a C.sub.2 to C.sub.4 carboxylic acid and/or an anhydride thereof having halide impurities, which process comprises the steps of (a) exposing the impure acid and/or anhydride to electromagnetic radiation under conditions of intensity, wavelength and temperature, and for a time, sufficient to convert at least a portion of the halide impurities to lower--and/or higher-boiling halide components and (b) separating the lower--and/or higher-boiling halide components formed in step (a) from the C.sub.2 to C.sub.4 carboxylic acid and/or anhydride. Also, a process for the purification of a C.sub.2 to C.sub.

Abstract: 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.

Abstract: The present invention is a reactive distillation process for methyl acetate hydrolysis comprising a rectifying section a reaction section and a stripping section. A water stream is fed into the upper portion of the rectifying or reaction zone and a methyl acetate stream is fed into the lower portion of the reaction zone which contains packings made of ion exchange resin. The products, acetic acid and methanol, are continuously produced from the bottom of the apparatus.

Abstract: The present invention relates to a process for producing a highly purified acetic acid characterized in that in the process for producing acetic acid comprising the step of continuously reacting methanol and/or an aqueous solution of methyl acetate with carbon monoxide in a reactor, a treatment is conducted to limit the concentration of unsaturated compounds in crude acetic acid obtained in the process to 5 ppm or lower, and the resultant crude acetic acid is ozonized. The present invention also relates to a process for producing a highly purified acetic acid, characterized by comprising the step of continuously reacting methanol and/or an aqueous solution of methyl acetate with carbon monoxide in a reactor while maintaining the concentration of acetaldehyde in a reaction fluid in the reactor at 1500 ppm or lower.

Abstract: In a process for purifying a carboxylic acid fraction obtained by liquid phase carbonylation of an alkyl alcohol and/or its reactive derivative in which volatile iridium- and/or volatile co-promoter contaminants are converted to involatile forms by contacting with an iodide in the absence of carbon monoxide or at a partial pressure less than that of the carbonylation reaction. The involatile contaminants are then separated from the carboxylic acid.

Abstract: A process for purifying acetic acid which comprises: introducing a feedstock aqueous solution of acetic acid having an acetic acid concentration of from 10 to 50% by weight into an extractor; supplying an extracting medium containing isopropyl acetate in an amount from 0.6 to 3.

Abstract: A process by which iodine compounds contained in crude acetic anhydride or a mixture of crude acetic anhydride and crude acetic acid can be converted into methyl iodide having a low boiling point and which can be separated by distillation and efficiently removed by the combination of the conversion step with the heat treatment step and distillation step. The process includes the steps of heat-treating the crude acetic anhydride or the mixture of crude acetic anhydride and crude acetic acid in the presence of methanol and/or methyl acetate in a treatment tank and distilling the heat-treated crude acetic anhydride or the heat-treated mixture of crude acetic anhydride and crude acetic acid, in the presence of an alkali metal salt and/or an alkaline earth metal salt if necessary.

Abstract: The present invention is directed to a process for the recovery of an organic acid. The organic acid is generated from the manufacture of a cellulose ester. The first step of the process is to remove the organic acid from the manufacture of cellulose ester. The acid is in the form of a weak acid stream comprising of the organic acid and water. The weak acid stream is resolved, via a solvent extraction, to form an extractor overhead stream and raffinate stream. The raffinate stream comprises solvent, water, and alcohol. The alcohol is produced in the recovery process by hydrolysis of the solvent after the solvent extraction. The raffinate stream is resolved into a overhead stream and a bottom stream. The overhead stream comprises water, alcohol, and solvent. Excess organic acid is added to the overhead stream to form a feed stream. The feed stream is catalyzed, via ion exchange resins, whereby a portion of the alcohol is esterified to the solvent.

Abstract: Formic acid is difficult to separate from acetic acid by conventional distillation or rectification because of the proximity of their boiling points. Formic acid can be readily separated from acetic acid by using azeotropic distillation. Effective agents are acetonitrile and isopropyl acetate.

Abstract: A high purity acetic acid is prepared by reacting methanol with carbon monoxide in the presence of a rhodium catalyst, iodide salts, and methyl iodide, wherein an acetaldehyde concentration in the reaction liquid is maintained at 400 ppm or lower. This may be attained by contacting the liquid containing carbonyl impurities with water to separate and remove the carbonyl impurities. After that, the liquid can be returned to the reactor.

Abstract: A process for the removal of aldehydes and acetals from industrially prepared acetic acid, wherein the contaminated acetic acid is reacted in the presence of a Bronstedt acid and 0.05 to 1% by weight of water and, if required, of 3 to 10 equivalents, calculated on aldehyde and acetal, of a high boiling polyhydric alcohol, and isolating the purified acetic acid by fractional distillation.

Abstract: Formic acid is difficult to separate from acetic acid by conventional distillation or rectification because of the close proximity of their boiling points. Formic acid can be readily separated from acetic acid by using extractive distillation. Effective agents are propionic acid, butyric acid, valeric acid and 2-ethyl hexanoic acid.

Abstract: In a process for producing acetic anhydride and acetic acid by reacting methanol and methyl acetate, optionally together with dimethyl ether, with carbon monoxide, acetic anhydride and acetic acid are effectively produced with the use of a sequence of production facilities by carrying out separation of low-boiling point fraction mainly consisting of methyl iodide, methyl acetate and dimethyl ether with the use of at least two distillation zones, separating catalyst drops entrained from the vapor-liquid separation zone in at least one distillation zone and further by controlling the pressurization of the vapor-liquid separation zone and the above distillation zones under 5 bar to a pressure greater than atmospheric pressure.

Abstract: This invention embodies a process for releasing acidic organic compounds in high yield and good purity from aqueous solutions of their salts which comprises converting the salts by carbon dioxide to their corresponding free acidic organic compounds and metal hydrogen carbonates, removing the acidic organic compounds from the mixture by extraction with an essentially water-insoluble organic solvent, and re-extracting the organic phase with carbon dioxide containing water. Using this process, the acidic organic compounds are completely released from their corresponding salts, i.e., the organic solution is free of salt. The acidic organic compounds released by the claimed process are organic compounds which contain acidic protons which can be replaced by metals. Some examples are carboxylic acids, sulfonic acids, phosphonic acids, phenols, naphthols, and aliphatic alcohols.

Abstract: A method of purifying the oxidate product formed by the liquid phase oxidation of C.sub.4 -C.sub.8 paraffinic hydrocarbons comprises adding a strong acid catalyst to the oxidate product to catalyze the break down of Michael addition products of unsaturated carbonyls and carboxylic acids so that the carbonyls can be distilled off during the initial stages of purification.

Abstract: 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.

Abstract: A process for recovering and reusing a solvent and optical isomers, characterized by using a simulated moving packed bed which comprises an inlet for an eluent, an outlet for an extract containing an optical isomer strongly adsorbable on the packing, an inlet for a liquid containing an optical isomer mixture and an outlet for a raffinate containing an optical isomer weakly adsorbable on the packing in this order in a packed bed containing packings for optical resolution and arranged in a solvent circulation passage, and in which the inlets and the outlets are intermittently and successively moved in the direction of liquid flow in the packed bed: recovering the solvent and the optical isomer(s) from The resultant extract and/or raffinate; returning the recovered solvent into the solvent circulation passage; or when the solvent is not recovered, heating the extract or raffinate to racemize an undesired optical isomer and reusing the resultant solution containing a racemic modification for the separation of the

Abstract: The present invention provides an improved process for selectively producing acetic acid and/or methyl acetate by the gas phase carbonylation of methanol with carbon monoxide; an improved process for producing acetic anhydride directly from the methyl acetate; and a novel method for sustaining the life time of a carbonylation or a hydroformylation catalyst by pretreating the carbon monoxide or the synthesis gas to be used in carrying out the gas phase carbonylation or the hydroformylation.

Abstract: Corrosion metal contaminants are removed from a liquid composition comprising a carboxylic acid and/or an anhydride thereof, a rhodium carbonylation catalyst, and a carbonylation catalyst co-promoter by using a chelating resin selective for the removal of corrosion metals rather than carbonylation catalyst and co-promoter.

Abstract: The present invention discloses a method for removing iodine compounds from acetic acid, in which the iodine compound is removed by using a solid adsorbent in the form of an activated carbon fiber having a large strength, a large bulk density, and a large specific surface, so that the treatment of large amounts should be possible, that the acetic acid should not be contaminated during the extraction of foreign materials from the adsorbent, and that the adsorbent can be repeatedly used by regenerating it. The method includes the steps of: preparing a filter in the usual manner by using an activated carbon fiber as the adsorbent; and making acetic acid containing an iodide pass through the activated carbon fiber filter, whereby the iodide in acetic acid is removed by being adsorbed by the activated carbon fiber filter.

Abstract: A process is provided for making bulk calcium magnesium acetate in a substantially pure crystalline form. The crystalline CMA contains less than about 0.5% of water soluble impurities.

Abstract: In a process for the production of acetic acid by carbonylation of methanol in the presence of a rhodium carbonylation catalyst, methyl iodide and an iodide salt stabiliser the improvement resides in maintaining a finite concentration of water of up to about 10% by weight and a methyl acetate concentration of at least 2% by weight in the liquid reaction composition and recovering the acetic acid product by passing the liquid reaction composition through a flash zone to produce a vapour fraction which is passed to a single distillation column from which an acetic acid product is removed.

Abstract: Disclosed is a method and apparatus for recovering acetic acid from an acetic acid/water waste stream which includes a dehydration column into which the stream is fed and a liquid-liquid extraction system for recovering acetic acid from the condensate of the overhead stream of the dehydration column. Optionally, low pressure and/or high pressure absorber systems are provided to process vapor and/or liquid streams associated with the recovery system and/or the plant in which the acetic acid is used to further the recovery of acetic acid and reduce atmospheric pollution.

Abstract: Disclosed is a process for the purification of carboxyl streams such as product streams comprising one or more carboxyl compounds selected from carboxylic acids, carboxylic anhydrides and alkylidene dicarboxylates. The process provides a means for the reduction of the iodine content of carboxyl compound product streams which are contaminated with one or more iodine compounds.

Abstract: Disclosed is a method for recovering carboxylic acids having from one to ten carbon atoms, and particularly formic acid, acetic acid and mixtures of formic and acetic acids, from aqueous solutions, in which the aqueous solution is contacted with solvent consisting essentially of mixed trialkylphosphine oxides in counter-current liquid-liquid extraction flow in a contacting step to thereby transfer the acids from the aqueous solution to the solvent, thus producing a raffinate relatively low in acid content and a rich solvent. The rich solvent is preferably dehydrated to separate water therefrom and yield a dehydrated rich solvent. The dehydrated rich solvent then has the acids stripped from it and the resulting lean solvent is then returned to the liquid-liquid extraction step, while the separated acids are split into their constituent components in a distillation operation.

Abstract: In a process for removing iodide compounds from a liquid composition comprising carboxylic acids having 2 to 6 carbon atoms or anhydrides thereof, by passing the liquid composition through a silver, mercury, palladium and/or rhodium-exchanged strong acid cation exchange resin, prior to contacting with the metal-exchanged resin the composition is contacted with a cation exchanger in the acid form to remove at least a portion of the metal ion contaminants in the liquid composition which have been found to displace the silver, mercury, palladium and/or rhodium from the metal-exchanged resin.