Abstract: A method for reliably avoiding backflow in the transport of a liquid under pressure via a transport pipe (1), in which a shut-off device (2) with differential pressure switching is arranged, into a container (3) which is under pressure and which comprises the liquid to be transported and/or another liquid is proposed, wherein a pressure accumulator (4) which is filled with the liquid to be transported up to a certain level and above the liquid level, in direct contact with the liquid to be transported, with an inert gas is arranged in the transport pipe (1) upstream from the shut-off device (2) in the transport direction, the inert gas being provided in the pressure accumulator (4) under an excess pressure and in an amount relative to the container (3) to be filled which are designed so that, in the case of a drop in the pressure in the transport pipe (1), the inert gas ensures a positive pressure difference in the transport pipe (1) to the container (3) over a period which is at least as long as the reaction

Abstract: A method for reliably avoiding backflow in the transport of a liquid under pressure via a transport pipe (1), in which a shut-off device (2) with differential pressure switching is arranged, into a container (3) which is under pressure and which comprises the liquid to be transported and/or another liquid is proposed, wherein a pressure accumulator (4) which is filled with the liquid to be transported up to a certain level and above the liquid level, in direct contact with the liquid to be transported, with an inert gas is arranged in the transport pipe (1) upstream from the shut-off device (2) in the transport direction, the inert gas being provided in the pressure accumulator (4) under an excess pressure and in an amount relative to the container (3) to be filled which are designed so that, in the case of a drop in the pressure in the transport pipe (1), the inert gas ensures a positive pressure difference in the transport pipe (1) to the container (3) over a period which is at least as long as the reaction

Abstract: The present invention provides a process for preparing 1,6-hexanediol from a carboxylic acid mixture which comprises adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols and is obtained as a by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or oxygen-containing gases and by water extraction of the reaction mixture, by esterification of the acids and hydrogenation, in which a) the mono- and dicarboxylic acids present in the aqueous dicarboxylic acid mixture are reacted with a low molecular weight alcohol to give the corresponding carboxylic esters, b) the resulting esterification mixture is freed of excess alcohol and low boilers in a first distillation stage, c) a separation of the bottom product is carried out in a second distillation stage into an ester fraction substantially free of 1,4-cyclohexanediols and a fraction comprising at least the majority of the 1,4-cyclohexanediols, d) the ester fraction substantially free of 1,4-cyclohexanediols is

Abstract: The present invention provides a process for preparing 1,6-hexanediol from a carboxylic acid mixture which comprises adipic acid, 6-hydroxycaproic acid and small amounts of 1,4-cyclohexanediols and is obtained as a by-product in the oxidation of cyclohexane to cyclohexanone/cyclohexanol with oxygen or oxygen-containing gases and by water extraction of the reaction mixture, by esterification of the acids and hydrogenation, in which a) the mono- and dicarboxylic acids present in the aqueous dicarboxylic acid mixture are reacted with a low molecular weight alcohol to give the corresponding carboxylic esters, b) the resulting esterification mixture is freed of excess alcohol and low boilers in a first distillation stage, c) a separation of the bottom product is carried out in a second distillation stage into an ester fraction substantially free of 1,4-cyclohexanediols and a fraction comprising at least the majority of the 1,4-cyclohexanediols, d) the ester fraction substantially free of 1,4-cyclohexanediols is ca

Abstract: A process for the purification of a substantially liquid effluent containing aldehydes and unconverted olefins coming from a hydroformylation reactor following low-pressure hydroformylation of C.sub.2 -C.sub.20 olefins or olefin mixtures containing different isomers of the respective olefins, said hydroformylation being catalyzed by means of a phosphorous rhodium catalyst homogeneously dissolved in the reaction medium and carried out at a temperature of from 50.degree. to 150.degree. C. and a pressure of from 2 to 30 bar.