Abstract: A stabilized heteropoly molybdate catalyst precursor in calcined form and containing anionic molybdenum in defect state is surface impregnated with certain metal cations. The stabilized precursor is one obtained by incorporating into the reaction product of a molybdate and a soluble phosphate, silicate or arsenate, an aqueous chloride ion and a compound of phosphotungstate, silicotungstate, vanadium arsenate, silico-arsenate, phosphovanadate, or silicovanadate, followed by drying and calcining. During the chloride ion stabilization step other metals may be optionally incorporated in forming the stabilized precursor.The obtained precursor is catalytically active in the conversion of the unsaturated aldehydes to the corresponding unsaturated carboxylic acids with or without incorporation of the metal cation during the chloride ion stabilization step.

Abstract: In a process for oxidation of methacrolein to methacrylic acid the carbon monoxide present in the recycle gas can be selectively oxidized to carbon dioxide with substantially no oxidation of the methacrolein content. A preferred catalyst for such an oxidation is a crystalline alumino silicate having pores of about 4-5 angstroms diameter and containing within the pores at least one metal or compound of the noble metal group, particularly platinum.

Abstract: In the production of acrylic acid by a two-stage, vapor-phase catalytic oxidation of propylene, a composite oxide catalyst expressed by the formula Mo.sub.a Bi.sub.b Ni.sub.c Co.sub.d Fe.sub.e Na.sub.f Mn.sub.g B.sub.h K.sub.i Si.sub.j O.sub.x is used in the first-stage reaction, which is carried out under specific reaction and operational conditions, and the second-stage reaction is carried under specific reaction and operational conditions while oxygen is supplied by a specific mode.

Abstract: The gas phase catalytic oxidation of an unsaturated aldehyde with molecular oxygen at 240.degree. to 450.degree. C. to give the corresponding unsaturated carboxylic acid is conducted in the presence of a catalyst of the following formula:Mo.sub.12 P.sub.a Q.sub.b R.sub.c X.sub.d Y.sub.e Z.sub.f O.sub.gwherein Mo is molybdenum, P is phosphorus, O is oxygen, Q is calcium and/or magnesium, R is at least one metal element selected from the group consisting of potassium, rubidium, cesium and thallium, X is at least one element selected from the group consisting of boron, silicon, manganese, iron, cobalt, zinc, germanium, uranium, tin, lead, chromium, titanium, tantalum, antimony, niobium and bismuth, Y is at least one metal element selected from the group consisting of vanadium, copper and nickel, Z is strontium and/or barium, and wherein the subscripts represent the atomic ratio of each component and a is 0.5 to 6, b is 0.2 to 6, c is 0.2 to 6, d is 0.

Abstract: Catalysts having improved attrition resistance are produced by incorporating a substantially uniform appearing coating of completely calcined, catalytically active oxide material onto an inert porous support containing sorbed aqueous silica sol. Such catalysts are useful in the gas phase oxidation of unsaturated aldehydes to unsaturated acids, especially acrolein to acrylic acid.

Abstract: In a process for producing acrylic acid which comprises contacting with water an acrylic acid-containing reaction product gas which has been obtained by the catalytic vapor phase oxidation of an olefinic compound of a general formula, CH.sub.2 .dbd.CHX, wherein X represents at least one group selected from the group consisting of CH.sub.

Abstract: The present invention relates to a method for the regeneration of deactivated PMA based catalysts by imbibing an aqueous volatile base within the pore structure of the deactivated catalyst so as to form a fluid phase within the pore structure, adding a volatile acid to the fluid phase to form a precipitate. The precipitate is thereafter dried and calcined to yield the regenerated catalyst. A second method for regeneration is also provided and includes the steps of imbibing a volatile solvent within the pore structure of the deactivated catalyst, adding a volatile acid to the system, and then adding a volatile base to the system to form a precipitate within the pore structure. The precipitate is again dried and calcined to yield the regenerated catalyst.

Abstract: The synthesis of 1RS,4SR,5RS-4-(4,8-dimethyl-5-hydroxy-7-nonen-1-yl)-4-methyl-3,8-dioxabicy clo[3.2.1]octane-1-acetic acid and related compounds is described. The above acetic acid compound and its isomer are contragestational agents.

Abstract: The synthesis of 1RS,4SR,5RS-4-(4,8-dimethyl-5-hydroxy-7-nonen-1-yl)-4-methyl-3,8-dioxabicy clo[3.2.1]octane-1-acetic acid is described. The bicyclo acetic acid compound is useful as a uteroevacuant agent.

Abstract: The presence of solid polymer in distillation columns and their associated reboilers used for the recovery of methacrylic and acetic acids produced by the oxidation of methacrolein may be minimized by the use of inhibitors and introduction of molecular oxygen at a rate above a predetermined threshold value, which is a function of the operating temperature of the equipment. For a given temperature, the amount of solids has been found to be greatly increased below the threshold value of oxygen, while above the threshold value, the rate of appearance of solids has been found to be minimized and further increases in oxygen rate have only a minimal effect. At a typical operation temperature of 120.degree. C., the threshold value of about 0.1 SLH O.sub.2 /100 gm of liquid. A gas containing a relatively high concentration of oxygen is preferred.

Abstract: Catalysts for the oxidation of unsaturated aldehydes, said catalysts being expressed by the formulaA.sub.a B.sub.b C.sub.c Mo.sub.d P.sub.e O.sub.fwherein A represents at least one element selected from K, Rb, Cs and Tl; B represents at least one element selected from Be, Ag, Y, La, Nd, Sm and Hf; C represents at least one element selected from V, Cr, Ba, Sr, Al, Sn, Pb, Mn, Zr, W and Bi; a, b, c, d, e and f are the number of the atoms of A, B, C, Mo, P and O, respectively; and when d is 12, a, b and e are independently 0.05 to 12, c is 0 to 12, and f is the number of oxygen atoms which satisfies the valences of the other elements.

Abstract: A catalyst composition for use in preparing unsaturated carboxylic acids by the vapor-phase oxidation of unsaturated aldehydes, said catalyst composition comprising an oxide composition containing as essential ingredients (1) phosphorus, (2) molybdenum and (3) X in which X is at least one element selected from the group consisting of thallium and metals of Groups IA and II of the periodic table, characterized in that said oxide composition has a surface area of 4 to 20 m.sup.2 /g and a pore volume of 0.08 to 0.5 ml/g, whereby said catalyst composition has an excellent reproducibility of catalytic activity and a process for preparing aforesaid catalyst composition.

Abstract: Pure acrylic acid may be obtained from an aqueous solution containing acrylic acid by fractional crystallization wherein a salt is added to the aqueous solution that eliminates the eutectic point between acrylic acid and water.

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: A novel catalyst expressed by the formulaA.sub.a B.sub.b Ce.sub.c Mo.sub.d P.sub.e O.sub.fwherein A represents at least one element selected from K, R.sub.b, C.sub.s and Tl; B represents at least one element selected from Be, Sr, Zn, Pb, Sb, Bi, Cr, Ag, Ga, Y, Ge, Te, La, Nd and Sm; a, b, c, d, e and f are the number of the atoms of A, B, Ce, Mo, P and O, respectively; and when d is 12, a, b, c and e are independently 0.05 to 12, and f is the number of oxygen atoms which satisfies the valences of the other elementsis provided. This catalyst, when used in a reaction for preparing unsaturated carboxylic acids by oxidizing unsaturated aldehydes in the vapor phase, exhibits superior catalytic activity and does not cause reduction in activity by impurities such as olefins.

Abstract: In an oxidation process for converting methacrolein to methacrylic acid, methacrylic acid is recovered by cooling and condensing the effluent from the oxidation, followed by azeotropic distillation of the condensate with a suitable solvent, such as methyl n-propyl ketone. The condensed effluent contains methacrylic acid and water as the major components along with by-product acetic acid, a minor amount of unreacted methacrolein and impurities. Substantially dry crude methacrylic acid is separated as a bottom product from the azeotropic distillation and an azeotrope of water and the solvent is taken overhead and condensed. After condensation, solvent-rich and water-rich phases form and are separated. The solvent-rich phase is returned to the distillation column as a reflux, while the water-rich phase is sent to a stripping column for recovery of residual solvent. Water is withdrawn from the bottom of the stripping column and recycled or discarded, as desired.

Abstract: A process for the preparation of a .alpha.,.beta.-unsaturated carboxylic acid by reacting formaldehyde, another aldehyde and a mineral acid salt of a secondary amine to form an intermediate Mannich base salt; oxidizing the Mannich base salt to the corresponding aminoacid salt; thermally cracking the aminoacid salt to yield an aqueous reaction products mixture of an .alpha.,.beta.-unsaturated carboxylic acid and the mineral acid salt of the secondary amine; and separating and isolating the aqueous reaction products.

Abstract: Methacrylic acid or acrylic acid is produced by the oxidation of methacrolein or acrolein respectively, with molecular oxygen in the vapor phase in the presence of a catalytic oxide of molybdenum and phosphorus, promoted with chromium or at least one element selected from the group consisting of thallium, rubidium, cesium, potassium, titanium, and arsenic, or a mixture thereof, wherein at least part of the molybdenum employed in the preparation of the catalyst is supplied in the form of molybdenum trioxide. The oxidation of methacrolein in the presence of a catalyst wherein all the molybdenum employed in the preparation of the catalyst has been supplied by molybdenum trioxide gives especially desirable high yields and selectivities to methacrylic acid.

Abstract: In a process for producing methacrylic acid by two step oxidation comprising a first oxidation step of producing methacrolein by reacting isobutylene with molecular oxygen in the presence of a diluent gas and a catalyst, and a second oxidation step of producing methacrylic acid by reacting methacrolein with molecular oxygen in the presence of a diluent gas and a catalyst, the improvement comprises using nitrogen as the diluent gas in the first oxidation step and nitrogen and steam as the diluent gas in the second oxidation step, mixing the reaction products obtained in the first and second oxidation steps, separating and recovering methacrolein and methacrylic acid from the mixture and feeding the recovered methacrolein back into the second oxidation step as a starting material.

Abstract: A process for the preparation of an unsaturated carboxylic acid which comprises reacting an unsaturated aldehyde with molecular oxygen in the vapor phase in the presence of an oxidation catalyst composition having the following empirical formulaMo.sub.a P.sub.b Cr.sub.c Q.sub.d L.sub.e O.sub.fwherein Q is at least one element selected from the group consisting of Tl, Rb, Cs and K; L is at least one element selected from the group consisting of Sr, Zn, Cd, V, Nb, B, Pb, Bi and W; and a, b, c, d, e and f each represent the number of atoms of each element; the atomic ratio of a:b:c:d:e is 12:0.1-8:0.1-8:0.1-8:0.01-6; and f is the number of oxygen atoms determined by the valence requirement of the other elements present.