Abstract: Disclosed is a process for the preparation of a modified vanadium/phosphorus mixed oxide catalyst for the partial oxidation of n-butane to maleic anhydride. The catalyst comprises vanadyl pyrophosphate as main component and niobium as a promoter element in an amount corresponding to an atomic ratio of vanadium to niobiurn in the range of 250:1 to 60:1. The catalyst exhibits improved activity, improved yield of maleic anhydride, and optimal performance from the very beginning of its catalytic lifetime.

Abstract: An improved process for the production of maleic anhydride by the catalytic oxidation of n-butane. Maleic anhydride is produced by reacting n-butane gas with oxygen gas or an oxygen-containing gas, in the presence of a vanadium phosphorus oxide catalyst. A trialkyl phosphite or trialkyl phosphate component is continuously added to the gases in an amount of from about 0.5 ppm to about 4 ppm by weight of elemental phosphorus in the trialkyl phosphate or trialkyl phosphite component. Heat is applied to the gases at a temperature of from about 400° C. to about 440° C. while maintaining a maximum temperature of gases present in the reaction of about 480° C. A simultaneous conversion of n-butane to maleic anhydride of about 84% or more and a conversion of n-butane to by-product acrylic acid of about 1.5% or less is achieved.

Abstract: Aliphatic carboxylic acids of formulae (Ib) R1—COOH(Ia) and R2—COOH wherein R1 is tertiary C4-20-alkyl and R2 together are —(CH2)n— with n=3 to 10, are produced by oxidizing an aliphatic or alicyclic ketone of the formula (II): wherein R1 and R2 are as defined above, with molecular oxygen in the presence of a soluble manganese (II) compound. The process has a high selectivity and is carried out under very mild conditions. It is especially useful for the production of dicarboxylic acids, such as, adipic acid, from cyclic ketones.

Abstract: Active vanadium/phosphorus mixed oxide catalyst for the conversion of non-aromatic hydrocarbons, e.g., n-butane, into maleic anhydride. The catalyst is prepared from the catalyst precursor, that is, prepared by the reaction of a source of vanadium in an organic medium in the presence of a phosphorus source. The organic medium is (a) isobutyl alcohol or a mixture of isobutyl alcohol and benzyl alcohol and (b) a polyol. The catalyst precurso is transformed into the active catalyst by an activation process that includes a heat treatment that includes applying a temperature of up to 600° C.

Abstract: A process for preparing a catalyst for maleic anhydride production wherein a +5 vanadium compound such as V2O5, an anhydrous phosphoric acid, and optionally promoters are admixed in an organic alcohol solvent, the admixture is rapidly brought to reflux and thereafter refluxed to reduced the vanadium compound to the desired degree, the reflux mixture is cooled, precursor crystals are separated by filtration and then dried and calcined.

Abstract: A process for the preparation of a vanadium/phosphorus mixed oxide catalyst precursor is described, comprising the reaction of a vanadium source in selected organic media in the presence of a phophorus source. The medium comprises: (a) isobutyl alcohol or a mixture of isobutyl alcohol and benzyl alcohol and (b) a polyol in the weight ratio (a) to (b) of 99:1 to 5:95. After its activation, the vanadium/phosphorus mixed oxide catalyst precursor is an excellent catalyst in the conversion of non-aromatic hydrocarbons like n-butane to malic anhydride.

Abstract: A process for the production of gamma-butyrolactone. Starting from maleic and/or succinic anhydride the conversion takes place in the vapor phase of a Cu/Cr catalyst.

Abstract: A process for the production of gamma-butyrolactone. Starting from maleic and/or succinic anhydride the conversion takes place in the presence of a catalyst composed of copper oxide and zinc oxide.

Abstract: Cycloaliphatic epoxy compounds represented by general formula (I): ##STR1## wherein R.sup.1 and R.sup.2 are hydrogen atoms, or R.sup.1 and R.sup.2 taken together represent an epoxy group, R.sup.3 and R.sup.4 are the same or different and each represents a hydrogen atom or a methyl group, and Q is a linear or branched alkanediyl group with 2 to 16 carbon atoms and with the proviso that the adjacent nitrogen and oxygen atoms are not attached to the same carbon atom. The cycloaliphatic epoxy compounds can be used to produce cured epoxy resin compositions exhibiting superior mechanical properties, e.g., tensile and flexural strength and toughness.

Abstract: Disclosed is a process for the production of gamma-butyrolactone from maleic anhydride or succinic anhydride by hydrogenation in the presence of a catalyst composition comprising the mixed oxides of copper, zinc and zirconium.

Abstract: An assembly for separating milling elements from a worked suspension, having several parts which are movable with respect to each other. Slots are formed between the parts. Neighboring moving parts engage each other, thereby being able to perform a limited relative movement in such a way that a first moving part is continuously moved within its total range of movement, with the other moving parts successively following in a delayed, chain reaction-like discontinuous movement.