Rhone-Poulenc Industries

Philagro

Rhone-Progil

Georges Biola

Gerard Schneider

Yves Komorn

Jean C Daumas

Alain Fabre

Bernard Buathier

Andre Combes

Henri Guerpillon

Eric Limongi

Michel Martin

Robert Tarolle

Jean Font

Robert Masotti

Beta-methylthiopropionaldehyde is prepared from methylmercaptan and an acrolein-containing gaseous mixture derived as an off-gas from the catalytic oxidation of propylene.

Process for the manufacture of beta-methylthiopropionaldehyde

Acrylic acid is separated from its solutions in tri-n-butyl phosphate by establishing from such a solution a vapor phase comprising substantially all of the acrylic acid and a portion of the solvent, at a temperature below the degradation point of the acrylic acid; next partially or totally condensing said vapor phase; and then distilling the acrylic acid from such condensation product, while maintaining an amount of acrylic acid at the base of the distillation column, and conducting the distillation under conditions such that neither solvent degradation nor acrylic acid crystallization results.

Separation of acrylic acid from solutions thereof in tri-n-butyl

Process for the dehalogenation of halogen-containing aromatic amines takes place by the action of hydrogen in the presence of a controlled-action hydrogenation catalyst, at a temperature of between 280.degree. and 420.degree. C., the active phase of the catalyst containing, in addition to the main catalyst metal, a minor amount of an auxiliary hydrogen catalyst consisting of a second metal which is different from the first.

Process for the dehalogenation of halogen-containing aromatic compounds

A process for the dehalogenation of halogen-containing aromatic compounds takes place in the vapor phase, at a temperature of between 280.degree. and 420.degree. C., by the action of hydrogen in the presence of a controlled-action hydrogenation catalyst deposited on an alumina-based support wherein the support used is modified, at least on the surface, by the incorporation of a metal in the form of a salt or an oxide, this incorporation consisting in treating the support with the said metal salt or metal oxide and then carrying out a calcination at a temperature ranging from about 500.degree. to 1,000.degree. C.

A single-stage reactor in the form of two concentric tubes and, one acting as a central stack and the other as a wall of reactor, widening out towards the top; a gas diffuser at the bottom of the stack, enabling gas to be injected into the liquid column above the diffuser, while a vesicle remover is located in the upper part of reactor; pipes and for feeding in the reagents, and a pipe for forcing back the gaseous phase at the top of reactor; a connection inclined by over 45.degree. to an extension of the horizontal and establishing direct communication between the bottom of reactor and a decanting chamber; and a vertical degassing tube located between connection and decanting chamber. Application of this arrangement to the reaction between finely divided aluminum, hydrogen and at least one olefin having 2 to 30 carbon atoms, at a temperature of from 100.degree. to 200.degree. and a pressure of 30 to 200 bars, in a perfectly homogeneous medium for the preparation of alkylaluminums.

Arrangement for preparing alkylaluminums

Propylene oxide is separated from the crude reaction product resulting from the oxidation of propylene, which separation is effected by distilling said reaction product in the presence of a neutral ester of phosphoric acid.

Distillation of propylene oxide from propylene oxidation reaction

Propylene oxide is continuously produced by oxidation of propylene, and wherein the gaseous products of oxidation are washed with a neutral ester of phosphoric acid to prevent undesirable, competing side reactions.

Method for continuous production of propylene oxide

A liquid phase continuous process for producing propylene oxide comprising oxidizing propylene with a molecular oxygen-containing gas in a solvent which is (a) water-insoluble and (b) as immiscible with organic carboxylic acids as possible; condensing the gaseous reaction products; adding water to the condensed reaction products to dissolve any undissolved acids contained therein; separating the aqueous phase from the resulting two-phase (aqueous and organic) system; recycling the organic phase to the reaction; and removing from the reaction a liquid containing propylene oxide and recovering the propylene oxide therefrom.

Process for the continuous preparation of propylene oxide

Process for the synthesis of methyl mercaptan by the reaction of methanol with hydrogen sulfide wherein a high degree of conversion and enhanced selectivity for the product are obtained by dividing the quantity of catalyst utilized in the reaction into a minimum of three separate portions to form a plurality of reactive catalyst zones and introducing the total amount of hydrogen sulfide reagent into the first of such catalyst zones and thereafter introducing equivalent or alternatively different amounts of the methanol reagent into the consecutive interconnected catalytic zones to react with hydrogen sulfide flowing therethrough while maintaining a molar ratio of hydrogen sulfide to methanol between 1.1 and 2.5. By subdividing the catalyst into separate beds and introducing the reagents consecutively into the catalytic zones, it is possible to maintain the temperature of the reaction mixture within the optimum range and, therefore, to minimize deterioration of the catalyst due to excessive temperature and substantially eliminate the formation of undesired by-products.

Growing community of inventors

Venissieux, France

Georges Biola