Abstract:
The present invention relates to a continuous method for hydrogenating organic compounds in a multiphase system in the presence of a homogeneous or heterogeneous catalyst, characterized in that the method is carried out in two stages, wherein the first stage is carried out in a loop reactor having an external heat exchanger and the second stage is carried out in a bubble column reactor having restricted backmixing. In addition, the present invention relates to a hydrogenation reactor (1) in a high-columnar shape having a concentric guide tube (2) arranged in the lower reactor region and an upwards-directed mixing nozzle (3) via which the starting materials and reaction mixture can be fed, a pump (4) and also a heat exchanger (5) which are situated in an external pump circuit which leads from the reactor to the mixing pump and having one or more gas- and liquid-permeable internals (10) which are mounted in the upper region of the reactor, wherein the ratio of the total length to diameter of the hydrogenation reactor (1) is in the range from 5:1 to 100:1 and the ratio of the volume of the upper region of the reactor to the volume of the lower region of the reactor is 0.05:1 to 10:1.
Abstract:
The present invention relates to 3,5-diethyl-2-propyl-tetrahydropyran of formula (I)
and its stereoisomers and mixtures thereof, to a method for preparing 3,5-diethyl-2-propyl-tetrahydropyran or a stereoisomer thereof or a mixture of stereoisomers thereof, to the composition obtainable by this method, to the use of 3,5-diethyl-2-propyl-tetrahydropyran or of a stereoisomer or of a mixture of stereoisomers thereof or of said composition as an aroma chemical and to the use thereof for modifying the scent character of a fragranced composition, to an aroma chemical containing 3,5-diethyl-2-propyl-tetrahydropyran or a stereoisomer or a mixture of stereoisomers thereof or said composition, and to a method of preparing a fragranced composition or for modifying the scent character of a fragranced composition.
Abstract:
The invention relates to a method for producing isocyanates by thermally splitting carbamates, a carbamate splitting gas comprising the corresponding isocyanate and the corresponding alcohol being obtained, the invention being characterized in that the carbamate splitting gas is quenched in the presence of an ether functioning as an inhibitor for the back reaction of the isocyanate and the alcohol.
Abstract:
The present invention relates to a method for continuously delivering a fluid used as a feedstock in a chemical reaction by means of a positive displacement pump comprising spatially separated delivery valves and a fluid-filled transfer line between the positive displacement pump and delivery valves, characterized in that an auxiliary fluid, which is a product or a reactant of the chemical reaction and has a melting point that is below the melting point or below the saturation temperature of the fluid to be delivered, is present in the transfer line. The present invention further relates to the use of a product of an aromatic compound resulting from hydrogenation as an auxiliary fluid for delivering an aromatic compound, and to the use of an alcohol or an ester of alcohol and carboxylic acid as an auxiliary fluid for delivering carboxylic acids or carboxylic acid derivatives.