Abstract: A process is disclosed for producing an alpha-, beta-ethylenically unsaturated monocarboxylic acid compound which comprises the aldol-type condensation of a saturated aliphatic monocarboxylic acid compound under vapor phase conditions in the presence of a hydrocarbon of 6 to 12 carbon atoms and a solid catalyst.

Abstract: Formic acid cannot be easily removed from acetic acid by distillation because of the closeness of their vapor pressures. Formic acid can be readily removed from acetic acid by extraction distillation. Typical extractive distillation agents are carboxylic acids in the range of hexamoic acid to neodecanoic acid with or without solvents such as methyl benzoate, acetophenone and nitrobenzene.

Abstract: Propanoic acid cannot be completely removed from propanoic-water mixtures by distillation because of the presence of the minimum azeotrope. Propanoic acid can be readily removed from mixtures containing it and water by using extractive distillation in which the extractive distillation agent is an acid amide. Typical examples of effective agents are acetamide; dimethylformamide and methyl glutaronitrile; formamide, adiponitrile and N,N-dimethylacetamide.

Abstract: The invention provides a means for greatly saving the thermal energy consumption in the dehydrating distillation of an aqueous solution of a carboxylic acid such as acetic acid by use of an azeotropically distilling entrainer boiling at a lower temperature than the carboxylic acid and immiscible with water. The improvement proposed by the invention comprises taking at least a part of the entrainer phase separated from the condensate coming from the column top or at least a part of the side-cut fluid abstracted from the refluxing fluid inside the column, evaporating the thus taken fluid into vapor and introducing the vapor into the distillation column at a stage for the introduction of the starting feed or below.

Abstract: Formic acid cannot be completely removed from formic acid - water mixtures by distillation because of the presence of the maximum azeotrope. Formic acid can be readily removed from mixtures containing it and water by using extractive distillation in which the extractive distillation agent is a sulfone. Typical examples of effective agents are thiophan sulfone; dimethyl sulfone and adiponitrile; phenyl sulfone, adiponitrile and acetophenone.

Abstract: Process is disclosed for treating the reaction product of propionic acid and formaldehyde to recover methacrylic acid from an aqueous effluent wherein said effluent contains methacrylic acid, unreacted formaldehyde, unreacted propionic acid, water and by-products.

Abstract: A method for separating carboxylic acids from mixtures with non-acids by an extractive distillation method using a lactam with a 5- or 6-membered ring, preferably N-methyl-2-pyrrolidone, as an extractant to extract the acids from the mixture with non-acids, followed by separating the extracted acids from the extractant by rectification.

Abstract: A process to recover acrylic acid or methacrylic acid by using a split quench process which allows acrylic acid or methacrylic acid to be recovered from the resulting aqueous solutions by a combination of solvent extraction and azeotropic dehydration that minimizes the amount of solvent required.

Abstract: In purifying methyl methacrylate by feeding a feed mixture containing methanol, methyl methacrylate and 0.

Abstract: Water is removed from methanesulfonic acid to produce an anhydrous product of high purity by spraying wet methanesulfonic acid (MSA) onto the walls of a vertical, heated tube which is maintained at reduced pressure. The water evaporates as the acid flows down the walls of the tube and dry MSA is removed at the bottom.

Abstract: A process is provided for the recovery of organic acids from dilute aqueous solutions. The acid in the form of its calcium salt is treated with a tertiary amine carbonate and the resulting trialkylammonium salt of the acid is isolated and heated to give the acid plus a tertiary amine.

Abstract: A method of recovering or extracting chemicals, such as furfural, formic acid, acetic acid and other organic compounds from acidic hydrolysates of plants or vegetable matter, especially spent sulfite liquors after conversion of the pentosans into pentoses and then into furfural by heating the hydrolysate in an acidic environment. The conversion of the pentosans pentoses into furfural, preferably with acidulation, is accomplished in a counterflow or countercurrent flow heat exchanger and a reactor, preferably a tubular reactor. The hydrolysate which has additionally been heated and converted in the reactor is used as a heating medium or heat carrier for heating up the hydrolysate which is converted in the counterflow heat exchanger, whereupon there is recovered as the distillate furfural in conjunction with the formic acid, acetic acid and the like.

Abstract: This invention provides an improved process for the separation and recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream derived from an adipic acid manufacturing operation involving nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream.The main byproducts which are recovered are high purity dimethyl succinate, dimethyl glutarate and dimethyl adipate.

Abstract: In a process for the continuous preparation of pure organic solutions of percarboxylic acids having 2 to 5 carbon atoms, by(a) contacting aqueous hydrogen peroxide with a carboxylic acid containing 2 to 5 carbon atoms in the presence of an acid catalyst at a feed molar ratio of H.sub.2 O.sub.2 to carboxylic acid of 0.

Abstract: In one embodiment, this invention provides a process for converting a dilute aqueous filtrate byproduct stream from adipic acid manufacture into a concentrated methanolic solution which does not solidify at ambient temperatures.In another embodiment, this invention provides an improved process for the separation and recovery of byproducts associated with the isolation of C.sub.4 -C.sub.6 dicarboxylic acids contained in a waste byproduct stream derived from an adipic acid manufacturing operation involving nitric acid oxidation of a cyclohexanone/cyclohexanol feedstream in the presence of a catalyst.

Abstract: An aqueous solution of acrylic acid and water containing 30 wt. % or less acrylic acid, can be concentrated to 40-60 wt. % acrylic acid in the overhead of a distillation column through the addition of certain salts that reverse the relative volatility between acrylic acid and water. Suitable salts can be ferrous, lithium and calcium chlorides.

Abstract: A process for the production of anhydrous or substantially anhydrous formic acid by hydrolysis of methyl formate which is carried out in a column having an upper fractionating section, a middle hydrolysis section and a lower extraction section and in which(a) the hydrolysis is carried out in the middle section of the columm, with water and methyl formate in countercurrent,(b) the resulting formic acid is extracted, in the lower section of the column, by means of a carboxylic acid amide which is fed into the lower end of the middle section of the column,(c) the extract phase, consisting in the main of formic acid and the carboxylic acid amide, is distillatively dehydrated, or substantially dehydrated, in the lower section of the column,(d) the methanol and uncovered methyl formate are removed by fractional distillation in the upper section of the column and(e) the pure formic acid or concentrated aqueous formic acid is distilled from the anhydrous or substantially anhydrous extract phase in a second column, le

Abstract: C.sub.2 -C.sub.6 monocarboxylic and dicarboxylic acids are scrubbed from gas phase mixtures of such acids and water by gas absorption techniques utilizing a liquid solvent comprising a polyoxyalkylene glycol or a monoalkyl or dialkyl ether thereof. The solvent enriched with the acid is subjected to distillation to recover a substantially anhydrous acid product.

Abstract: Formic acid is purified by extractive distillation of its aqueous solutions using a basic extractant, followed by distillation of the bottom mixture first obtained, the extractant used being N-formylmorpholine.

Abstract: A process is provided for producing ultra-pure propionic acid, i.e., acid containing less than 20 parts by weight of iodine per billion parts by weight of acid, wherein crude acid containing water and iodine contaminants is distilled in a single distillation zone and no waste streams requiring treatment or disposal are obtained.

Abstract: Aqueous solutions of methane sulfonic acid are dehydrated and purified in a two-step fractionation process.

Abstract: A process for treating an aqueous solution containing organic compounds and having a high chemical oxygen demand (COD) by distilling the aqueous solution at a pH not lower than 9, and recovering the water of low chemical oxygen demand (COD) from said aqueous solution. The aqueous solution containing the organic compounds to be treated is derived from the reaction mixture of the oxidation system of methyl-substituted aromatic compound in the liquid phase with molecular oxygen or a molecular oxygen-containing gas, in the presence of a heavy metal catalyst but in the substantial absence of a lower aliphatic acid solvent, to form the corresponding aromatic acid.

Abstract: Formic acid is isolated from mixtures containing formic acid, methyl formate, methanol and water by fractional distillation, the mixture being fed into the upper half of the distillation column and 5 to 15 theoretical plates being maintained above the feed point and 10 to 25 theoretical plates below the feed point. The formic acid is withdrawn at the bottom end of the column as an azeotrope with water, the azeotrope being in the liquid state or preferably in the vapor state.

Abstract: A method for extraction of acrylic acid and/or methacrylic acid from a solution containing the same by treating the said solution with an organic solvent, which is characterized by using a mixture of methylethylketone and a xylene as the organic solvent. By such method, the extraction of acrylic acid and/or methacrylic acid is accomplished efficiently and economically.

Abstract: Process for the manufacture of succinic anhydride by eliminating water from succinic acid using a chemically inert hydrophilic solvent which does not form an azeotropic mixture with water, and fractional distillation.