Abstract: The present invention relates to silica-based heterogeneous zinc compounds which are suitable as catalysts in the reaction of amines with dialkyl carbonates to produce carbamates. The catalysts have the formula [SiO2]—CH2—CHR—X—COOZn[Y], wherein [SiO2] represents a silica carrier selected from the group consisting of ordered mesoporous silica and irregular amorphous narrow pore silica, R represents a moiety selected from the group consisting of hydrogen, —CH3, and —CH2CH3, preferably hydrogen, X is an aliphatic chain of 2 to 11 carbon atoms that optionally comprises ether moieties and [Y] represents a mono anion. The invention is also directed towards a method for the preparation of the aforementioned compounds and towards method for the alkoxycarbonylation of amines.

Abstract: The industrial scale preparation of isocyanates gives rise to distillation bottom streams that are in need of further workup. These distillation bottom streams still also contain, as well as a distillation residue consisting of compounds that can be evaporated without decomposition only with great difficulty if at all (also referred to as residue for short), proportions of the desired target product (i.e. isocyanate to be prepared). The present invention relates to a process that enables recovery, in an efficient manner, of this proportion of isocyanate to be prepared in a distillation bottom stream which is obtained in the workup of the crude liquid process product which contains the isocyanate to be prepared and is formed in an isocyanate preparation process. More particularly, the present invention relates to a drying step in which the isocyanate to be prepared is recovered to form a solid material that has been largely to completely freed of this isocyanate.

Abstract: The present invention relates to silica-based heterogeneous zinc compounds which are suitable as catalysts in the reaction of amines with dialkyl carbonates to produce carbamates. The catalysts have the formula [SiO2]—CH2—CHR—X—COOZn[Y], wherein [SiO2] represents a silica carrier selected from the group consisting of ordered mesoporous silica and irregular amorphous narrow pore silica, R represents a moiety selected from the group consisting of hydrogen, —CH3, and —CH2CH3, preferably hydrogen, X is an aliphatic chain of 2 to 11 carbon atoms that optionally comprises ether moieties and [Y] represents a mono anion. The invention is also directed towards a method for the preparation of the aforementioned compounds and towards method for the alkoxycarbonylation of amines.

Abstract: The industrial scale preparation of isocyanates gives rise to distillation bottom streams that are in need of further workup. These distillation bottom streams still also contain, as well as a distillation residue consisting of compounds that can be evaporated without decomposition only with great difficulty if at all (also referred to as residue for short), proportions of the desired target product (i.e. isocyanate to be prepared). The present invention relates to a process that enables recovery, in an efficient manner, of this proportion of isocyanate to be prepared in a distillation bottom stream which is obtained in the workup of the crude liquid process product which contains the isocyanate to be prepared and is formed in an isocyanate preparation process. More particularly, the present invention relates to a drying step in which the isocyanate to be prepared is recovered to form a solid material that has been largely to completely freed of this isocyanate.

Abstract: Processes for the production of chlorine from a gas containing hydrogen chloride and carbon monoxide, which comprise the catalysed oxidation of the carbon monoxide as well as optionally further oxidizable constituents, with oxygen to form carbon dioxide in an upstream reactor under adiabatic conditions.

Abstract: Crude aniline is produced by hydrogenating nitrobenzene in the presence of a catalyst. This crude aniline is then purified by means of a single-step or multi-step distillation process in which aqueous alkali metal hydroxide solution is added to the crude aniline prior to distillation and/or during distillation of the crude aniline.

Abstract: Compounds containing phenolic hydroxy groups are removed from a gas stream which contains at least one aromatic amine generated during the gas-phase hydrogenation reaction of the corresponding nitroaromatic compounds with hydrogen, by adsorption on a basic solid.

Abstract: The present invention provides a catalyst containing titanium in bonded form, non-crystalline silicon dioxide and at least one crystalline silicate phase which has a zeolite structure, wherein the non-crystalline silicon dioxide is applied to at least one of the crystalline silicate phases which have a zeolite structure and wherein at least one of the crystalline silicate phases which have a zeolite structure contains silicon-carbon bonds with which non-hydrolytically separable organic groups R are bonded to silicon. Furthermore, the present invention provides a process for preparing this catalyst and a process for producing an epoxide from a compound which contains a carbon-carbon double bond (preferably from propene) comprising reacting the compound which contains a carbon-carbon double bond with hydrogen peroxide in the presence of the catalyst according to the invention.

Abstract: Di- and polyamines of the diphenylmethane series are produced by a) converting nitrobenzene and methanol in the presence of a catalyst to aniline, formaldehyde and carbon monoxide, and then b) converting the aniline and formaldehyde produced in step a) in the presence of an acid catalyst to di- and polyamines of the diphenylmethane series, and c) converting the carbon monoxide produced in step a) with chlorine to phosgene.

Abstract: Compounds containing phenolic hydroxy groups are removed from a gas stream which contains at least one aromatic amine generated during the gas-phase hydrogenation reaction of the corresponding nitroaromatic compounds with hydrogen, by adsorption on a basic solid.

Abstract: The present invention provides a catalyst containing titanium in bonded form, non-crystalline silicon dioxide and at least one crystalline silicate phase which has a zeolite structure, wherein the non-crystalline silicon dioxide is applied to at least one of the crystalline silicate phases which have a zeolite structure and wherein at least one of the crystalline silicate phases which have a zeolite structure contains silicon-carbon bonds with which non-hydrolytically separable organic groups R are bonded to silicon. Furthermore, the present invention provides a process for preparing this catalyst and a process for producing an epoxide from a compound which contains a carbon-carbon double bond (preferably from propene) comprising reacting the compound which contains a carbon-carbon double bond with hydrogen peroxide in the presence of the catalyst according to the invention.

Abstract: A process for the coupled production of chlorine and isocyanates in which the sulfuric acid used for both processes is combined after use, concentrated together and returned to one or both processes.

Abstract: Crude aniline is produced by hydrogenating nitrobenzene in the presence of a catalyst. The crude aniline is then extracted with aqueous alkali metal hydroxide solution under conditions such that the aqueous phase is the lower phase during separation of the aqueous and organic phases.

Abstract: The present invention provides a catalyst containing titanium in bonded form, non-crystalline silicon dioxide and at least one crystalline silicate phase which has a zeolite structure, wherein the non-crystalline silicon dioxide is applied to at least one of the crystalline silicate phases which have a zeolite structure and wherein at least one of the crystalline silicate phases which have a zeolite structure contains silicon-carbon bonds with which non-hydrolytically separable organic groups R are bonded to silicon. Furthermore, the present invention provides a process for preparing this catalyst and a process for producing an epoxide from a compound which contains a carbon-carbon double bond (preferably from propene) comprising reacting the compound which contains a carbon-carbon double bond with hydrogen peroxide in the presence of the catalyst according to the invention.

Abstract: Crude aniline is produced by hydrogenating nitrobenzene in the presence of a catalyst. This crude aniline is then purified by means of a single-step or multi-step distillation process in which aqueous alkali metal hydroxide solution is added to the crude aniline prior to distillation and/or during distillation of the crude aniline.

Abstract: Di- and polyamines of the diphenylmethane series are produced by a) converting nitrobenzene and methanol in the presence of a catalyst to aniline, formaldehyde and carbon monoxide, and then b) converting the aniline and formaldehyde produced in step a) in the presence of an acid catalyst to di- and polyamines of the diphenylmethane series, and c) converting the carbon monoxide produced in step a) with chlorine to phosgene.

Abstract: Diamines and polyamines of the diphenylmethane series are produced by a) converting nitrobenzene and methanol simultaneously to aniline and formaldehyde in the presence of a catalyst, and b) converting the aniline and formaldehyde prepared in step a) to diamines and polyamines of the diphenylmethane series in the presence of an acidic catalyst. The diamines and polyamines produced by this process are particularly useful for the production of diisocyanates and polyisocyanates of the diphenylmethane series.

Abstract: The present invention provides a catalyst containing titanium in bonded form, non-crystalline silicon dioxide and at least one crystalline silicate phase which has a zeolite structure, wherein the non-crystalline silicon dioxide is applied to at least one of the crystalline silicate phases which have a zeolite structure and wherein at least one of the crystalline silicate phases which have a zeolite structure contains silicon-carbon bonds with which non-hydrolytically separable organic groups R are bonded to silicon. Furthermore, the present invention provides a process for preparing this catalyst and a process for producing an epoxide from a compound which contains a carbon-carbon double bond (preferably from propene) comprising reacting the compound which contains a carbon-carbon double bond with hydrogen peroxide in the presence of the catalyst according to the invention.

Abstract: The present invention provides hydro-oxidation catalysts for the oxidation of hydrocarbons, containing an organic-inorganic hybrid material as well as gold particles and/or silver particles, a process for the production thereof, and the use thereof as a catalyst.

Abstract: The present invention provides hydro-oxidation catalysts for the oxidation of hydrocarbons, containing an organic-inorganic hybrid material as well as gold particles and/or silver particles, a process for the production thereof, and the use thereof as a catalyst.