Abstract: The present invention relates to a process for preparing cyclohexane by isomerizing a hydrocarbon mixture (HM1) comprising methylcyclopentane (MCP) in the presence of a catalyst. The catalyst is preferably an acidic ionic liquid. The starting material used is a stream (S1) which originates from a steamcracking process. The hydrocarbon mixture (HM1) obtained from this stream (S1) in an apparatus for aromatics removal has a reduced aromatics content compared to stream (S1), and (HM1) may optionally also be (virtually) free of aromatics. Depending on the type and amount of the aromatics remaining in the hydrocarbon mixture (HM1), especially in the case that benzene is present, the isomerization may additionally be preceded by performance of a hydrogenation of (HM1). In addition, depending on the presence of other components of (HM1), further purification steps may optionally be performed prior to or after the isomerization or hydrogenation.

Abstract: The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method has the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.

Abstract: The present invention relates to a process for the catalytic aldol condensation of aldehydes, in particular for preparing ?,?-unsaturated aldehydes, in a multiphase reactor.

Abstract: The present invention relates to a process for the catalytic aldol condensation of aldehydes, in particular for preparing ?,?-unsaturated aldehydes, in a multiphase reactor.

Abstract: The present invention relates to a process for preparing cyclohexane by isomerizing a hydrocarbon mixture (HM1) comprising methylcyclopentane (MCP) in the presence of a catalyst. The catalyst is preferably an acidic ionic liquid. The starting material used is a stream (S1) which originates from a steamcracking process. The hydrocarbon mixture (HM1) obtained from this stream (S1) in an apparatus for aromatics removal has a reduced aromatics content compared to stream (S1), and (HM1) may optionally also be (virtually) free of aromatics. Depending on the type and amount of the aromatics remaining in the hydrocarbon mixture (HM1), especially in the case that benzene is present, the isomerization may additionally be preceded by performance of a hydrogenation of (HM1). In addition, depending on the presence of other components of (HM1), further purification steps may optionally be performed prior to or after the isomerization or hydrogenation.

Abstract: The invention relates to a process for the oxidation of organic compounds by means of oxygen, in which, in a first step, the organic compound and at least part of the oxygen required for the oxidation are introduced into a first reaction zone which is operated isothermally and with backmixing and, in a second step, the reaction mixture from the first reaction zone is introduced into a second reaction zone which is operated adiabatically. The invention further relates to a reactor for carrying out the process, which comprises at least one isothermal reaction zone (3, 5) and an adiabatic reaction zone (7) which are arranged in a reactor shell (8), with each isothermal reaction zone (3, 5) being configured in the form of a jet loop reactor and the adiabatic reaction zone (7) being configured as a bubble column.

Abstract: The invention relates to a process for oxidizing at least one organic substance with oxygen, which comprises the following steps: (a) adding the at least one organic substance as a liquid and an oxygenous gas stream to a first reaction stage to form a reaction mixture, at least some of the oxygen reacting with the organic compound to form a reaction product, (b) adding the reaction mixture from the first reaction stage to an adiabatically operated reaction stage in which the unconverted organic substance reacts further at least partly to give the product. The invention further relates to an apparatus for performing the process.

Abstract: A process for isomerizing a saturated, branched and cyclic hydrocarbon, in which a tertiary carbon atom of the hydrocarbon is converted to a secondary carbon atom in the course of isomerization, by performing the isomerization in the presence of a superacidic ionic liquid comprising an organic cation and an inorganic anion, where the anion is a superacidic aluminum trichloride-Lewis base adduct, and of a copper(II) compound.

Abstract: The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.

Abstract: The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following steps a) catalytic hydrogenation of neral and/or geranial to give citronellal, b) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c) purification of isopulegol by crystallization and d) catalytic hydrogenation of isopulegol to give menthol.

Abstract: The invention relates to a process for the continuous preparation of toluenediamine by liquid-phase hydrogenation of dinitrotoluene by means of hydrogen in the presence of a suspended, nickel-comprising catalyst in a reactor with a product isolation unit downstream of the reactor to give a product output from the reactor comprising a liquid phase comprising toluenediamine and dinitrotoluene, in which the nickel-comprising catalyst is suspended, wherein the concentration of dinitrotoluene in the liquid phase of the product output from the reactor in the region between the reactor and the downstream product isolation unit is set to a value in the range from 1 to 200 ppm by weight, based on the total weight of the liquid phase of the product output from the reactor.

Abstract: A process for isomerizing a saturated hydrocarbon, by performing the isomerization in the presence of a superacidic ionic liquid comprising an organic cation and an inorganic anion, where the anion is a superacidic aluminum trichloride-Lewis base adduct, and of an olefin.

Abstract: The invention relates to a process for oxidizing at least one organic substance with oxygen, which comprises the following steps: (a) adding the at least one organic substance as a liquid and an oxygenous gas stream to a first reaction stage to form a reaction mixture, at least some of the oxygen reacting with the organic compound to form a reaction product, (b) adding the reaction mixture from the first reaction stage to an adiabatically operated reaction stage in which the unconverted organic substance reacts further at least partly to give the product. The invention further relates to an apparatus for performing the process.

Abstract: A process for isomerizing a saturated, branched and cyclic hydrocarbon, in which a tertiary carbon atom of the hydrocarbon is converted to a secondary carbon atom in the course of isomerization, by performing the isomerization in the presence of a superacidic ionic liquid comprising an organic cation and an inorganic anion, where the anion is a superacidic aluminum trichloride-Lewis base adduct, and of a copper(II) compound.

Abstract: The present invention relates to a process for the industrial preparation of a diamine starting from a corresponding alkenyl nitrile comprising at least one C—C double bond, which comprises the steps (a) reaction of the alkenyl nitrile with a corresponding monoamine in a first reactor so that the monoamine adds exothermically onto the at least one double bond to form an aminoalkyl nitrile, with the monoamine and water being charged initially and the alkenyl nitrile being fed in; (b) evaporation of unreacted alkenyl nitrile and monoamine to increase the concentration of the aminoalkyl nitrile product in the bottoms of the first reactor; (c) transfer of the aminoalkyl nitrile bottom product from step (b) to a second reactor; (d) batchwise catalytic hydrogenation of the aminoalkyl nitrile transferred in step (c) to the diamine in the second reactor, with each batch being obtained by initially charging a catalyst suitable for the hydrogenation of nitriles to amines and also water, the desired diamine and a bas

Abstract: The invention relates to a process for the oxidation of organic compounds by means of oxygen, in which, in a first step, the organic compound and at least part of the oxygen required for the oxidation are introduced into a first reaction zone which is operated isothermally and with backmixing and, in a second step, the reaction mixture from the first reaction zone is introduced into a second reaction zone which is operated adiabatically. The invention further relates to a reactor for carrying out the process, which comprises at least one isothermal reaction zone (3, 5) and an adiabatic reaction zone (7) which are arranged in a reactor shell (8), with each isothermal reaction zone (3, 5) being configured in the form of a jet loop reactor and the adiabatic reaction zone (7) being configured as a bubble column.

Abstract: The present invention relates to a particularly economic overall method for producing menthol, specifically for producing optically active, essentially enantiomerically and diastereomerically pure L-menthol and racemic menthol, starting from the starting material citral which is available inexpensively on an industrial scale. The method comprises the following steps a.1) catalytic hydrogenation of neral and/or geranial to give citronellal, b.1) cyclization of citronellal to isopulegol in the presence of an acidic catalyst, c.1) purification of isopulegol by crystallization and d.1) catalytic hydrogenation of isopulegol to give menthol.

Abstract: The present invention relates to a process for the industrial preparation of a diamine starting from a corresponding alkenyl nitrile comprising at least one C—C double bond, which comprises the steps (a) reaction of the alkenyl nitrile with a corresponding monoamine in a first reactor so that the monoamine adds exothermically onto the at least one double bond to form an aminoalkyl nitrile, with the monoamine and water being charged initially and the alkenyl nitrile being fed in; (b) evaporation of unreacted alkenyl nitrile and monoamine to increase the concentration of the aminoalkyl nitrile product in the bottoms of the first reactor; (c) transfer of the aminoalkyl nitrile bottom product from step (b) to a second reactor; (d) batchwise catalytic hydrogenation of the aminoalkyl nitrile transferred in step (c) to the diamine in the second reactor, with each batch being obtained by initially charging a catalyst suitable for the hydrogenation of nitriles to amines and also water, the desired diamine and a base,

Abstract: The present invention relates to a process for the industrial preparation of a diamine starting from a corresponding alkenyl nitrile comprising at least one C—C double bond, which comprises the steps (a) reaction of the alkenyl nitrile with a corresponding monoamine in a first reactor so that the monoamine adds exothermically onto the at least one double bond to form an aminoalkyl nitrile, with the monoamine and water being charged initially and the alkenyl nitrile being fed in; (b) evaporation of unreacted alkenyl nitrile and monoamine to increase the concentration of the aminoalkyl nitrile product in the bottoms of the first reactor; (c) transfer of the aminoalkyl nitrile bottom product from step (b) to a second reactor; (d) batchwise catalytic hydrogenation of the aminoalkyl nitrile transferred in step (c) to the diamine in the second reactor, with each batch being obtained by initially charging a catalyst suitable for the hydrogenation of nitriles to amines and also water, the desired diamine and a bas

Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, in which a fluid reaction mixture which comprises amines and from which the catalysts are separated off is formed in a reactor. After the catalysts have been separated off, a measurement of the absorption of UV/VIS radiation by the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.