Abstract: The amount of water required to effect efficient separation of a mixture of sulfuric acid and carboxylic acids by distillation, is reduced, by diluting the mixture while in the distillation column in a prescribed manner with sufficient water to provide a water:sulfuric acid mole ratio of about 1:1. The heat generated by the internal dilution reduces the energy requirement of the column. Feeding the dilution water to the column below the feed mixture is a key element of the process.

Abstract: Unsaturated carboxylic acids are prepared by the catalytic vapor phase oxidation of unsaturated aldehydes. A novel process for the preparation of these catalysts is disclosed. The catalyst has the following formula:Mo.sub.12 P.sub.a X.sup.1.sub.b V.sub.c As.sub.d Cu.sub.e Sb.sub.f X.sup.2.sub.g O.sub.xwhereina-g represent the number of atoms of the particular element depicted;X.sup.1 and X.sup.2 are other elements; andx is the number of oxygens required to satisfy the valence requirements of the other elements present.

Abstract: Methacrolein is produced by the catalytic vapor phase oxidation of isobutylene (including compounds converted to isobutylene). The catalyst has the following formula: Mo.sub.a P.sub.b Fe.sub.c Co.sub.d Ni.sub.e Bi.sub.f Te.sub.g Sb.sub.h Cs.sub.i Zr.sub.j X.sub.k O.sub.x wherein a-k represent the number of atoms of the particular element depicted, X is another element and x is the number of oxygens present.

Abstract: Methacrolein is produced by the catalytic vapor phase oxidation of isobutylene (including compounds converted to isobutylene). The catalyst has the following formula: Mo.sub.a P.sub.b Fe.sub.c Co.sub.d Ni.sub.e Bi.sub.f Te.sub.g Sb.sub.h Cs.sub.i Zr.sub.j X.sub.k O.sub.x wherein a-k represent the number of atoms of the particular element depicted, X is another element and x is the number of oxygens present.

Abstract: A process for the direct oxidation of isobutane or propane to methacrylic acid or acrylic acid respectively is disclosed. The process encompasses contacting a feed gas containing isobutane or propane and oxygen with a specific catalyst which is composed of molybdenum, antimony and phosphorus combined with oxygen. The atomic ratio of molybdenum to antimony to phosphorous is from about 9 to about 24; about 0.25 to about 2; and about 0.75 to about 2 respectively. The catalytic oxidation to methacrylic or acrylic acid is accomplished at a temperature of from about 200.degree. C. to about 450.degree. C. The methacrylic or acrylic acid is removed from the feed gases exiting from the reaction zone and the remainder of the exited feed stream may be recycled to again contact the catalyst.