Abstract: A two-stage process for producing tetrahydrofuran and gammabutyrolactone in varying proportions from maleic, succinic anhydride or fumaric acid esters, by vapor phase hydrogenation. The first stage occurs on a copper-based catalyst to produce a mixture of tetrahydrofuran, gammabutyrolactone and butanediol. The second stage occurs on an acidic silica rich silica-alumina type catalyst to convert butanediol to tetrahydrofuran.

Abstract: A process for the production of N-methyl-pyrrolidone obtained by reaction of gammabutyrolactone and mononmethylamine; wherein the synthesis is carried out by a continuous non catalytic process in liquid phase, via three distinct reaction stages connected in series.

Abstract: Process for the production of 1,4-butanediol by mixed phase catalytic hydrogenation of gamma-butyrolactone, succinic anhydride esters, or mixtures thereof.

Abstract: A process for the preparation of oxidation catalysts containing vanadium-phosphorus mixed oxides, consisting of: a) contacting a phosphorus compound with a vanadium compound in an organic solvent under conditions allowing the preparation, recovery, drying of said precursor, b) submitting the precursor, prior to calcination, to a treatment by contacting with a stream of dry inert gas containing vapors of an aliphatic anhydride, having from 4 to 8 carbon atoms, preferably acetic anhydride, at a temperature not exceeding 200° C., c) calcinating the precursor under an atmosphere containing air, steam, or inert gas or a mixture of them at a temperature between 350° C. and 550° C. at controlled rate of temperature increase during the time necessary to obtain active catalysts, d) using of said catalysts for the production of maleic anhydride by oxidation of aliphatic hydrocarbons.

Abstract: In producing maleic anhydride by catalytic oxidation of n-butane in vapor phase using oxygen or enriched air as oxidation medium, the reaction mixture consists of butane, oxygen and a recycling exhaust gas recovered from the absorption stage by a solvent of the maleic anhydride produced in the reaction. In the instant process the carbon monoxide and the carbon dioxide concentration in the reactor mixture are held to on optimum level by performing the reaction on a suitable V.P.O. catalyst, and by feeding to the recycling gases, in addition to butane and oxygen, a carbon dioxide rich gas stream.The carbon dioxide rich gas stream can be produced either by selective absorption and desorption of carbon dioxide from a gaseous stream purged from the recycling exhaust gases or by selective separation on membranes of a carbon dioxide rich stream from the purge gas stream, or by selective catalytic oxidation of carbon monoxide to carbon dioxide of a gaseous stream purged from the recycling exhaust gases.