Abstract: The invention relates to a process for producing a particulate, Si-bonded fluidized-bed catalyst having improved abrasion resistance, which comprises the steps I. provision of an aqueous suspension comprising zeolite particles, II. addition of a silicone resin mixture comprising one or more hydrolyzable silicone resin precondensates and mixing of the aqueous suspension and the silicone resin mixture, III. spray drying of the mixture obtained from step II, with the mixture being homogenized before spray drying, and IV. calcination of the spray-dried fluidized-bed catalyst obtained from step III, and an Si-bonded fluidized-bed catalyst which can be produced by this process and also its use for the nonoxidative dehydroaromatization of C1-C4-aliphatics.

Abstract: The invention relates to a process for producing a particulate, Si-bonded fluidized-bed catalyst having improved abrasion resistance, which comprises the steps I. provision of an aqueous suspension comprising zeolite particles, II. addition of a silicone resin mixture comprising one or more hydrolyzable silicone resin precondensates and mixing of the aqueous suspension and the silicone resin mixture, III. spray drying of the mixture obtained from step II, with the mixture being homogenized before spray drying, and IV. calcination of the spray-dried fluidized-bed catalyst obtained from step III, and an Si-bonded fluidized-bed catalyst which can be produced by this process and also its use for the nonoxidative dehydroaromatization of C1-C4-aliphatics.

Abstract: The invention relates to a process for producing a particulate, Si-bonded fluidized-bed catalyst having improved abrasion resistance, which comprises the steps I. provision of an aqueous suspension comprising zeolite particles, II. addition of a silicone resin mixture comprising one or more hydrolyzable silicone resin precondensates and mixing of the aqueous suspension and the silicone resin mixture, III. spray drying of the mixture obtained from step II, with the mixture being homogenized before spray drying, and IV. calcination of the spray-dried fluidized-bed catalyst obtained from step III, and an Si-bonded fluidized-bed catalyst which can be produced by this process and also its use for the nonoxidative dehydroaromatization of C1-C4-aliphatics.

Abstract: The present invention relates to a process for producing a supported tin-comprising catalyst, wherein a solution (S) comprising tin nitrate and at least one complexing agent is applied to the support, where the solution (S) does not comprise any solid or has a solids content of not more than 0.5% by weight based on the total amount of dissolved components.

Abstract: A process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, forming a fluid, amine-comprising reaction mixture in a reactor, wherein chromatographic analysis of the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Abstract: The present invention relates to a process for nonoxidatively dehydroaromatizing a reactant stream comprising C1-C4-aliphatics, comprising the steps of I. feeding reactant stream E into a reaction zone 1, converting reactant stream E under nonoxidative conditions in the presence of a particulate catalyst to a product stream P comprising aromatic hydrocarbons and discharging product stream P from reaction zone 1, II. transferring the catalyst with reduced activity as a result of deposited coke into a reaction zone 2, III. at least partly regenerating the catalyst with supply of a hydrogen-comprising gas stream H in a reaction zone 2, at least some of the coke deposited being converted to methane to form a methane-comprising gas stream M which is fed at least partly to reaction zone 1, IV. discharging the catalyst from reaction zone 2 and V.

Abstract: The present invention relates to a catalyst for dehydroaromatizing C1-C4-aliphatics, said catalyst being obtainable by twice treating a zeolite from the group of MFI and MWW with NH4-containing mixtures, in each case with subsequent drying and calcination. The catalyst comprises molybdenum and, if appropriate, as further elements, Cu, Ni, Fe, Co, Mn, Cr, Nb, Ta, Zr, V, Zn and/or Ga. The present invention further provides a process for dehydroaromatizing a mixture comprising C1-C4-aliphatics by conversion in the presence of the catalyst.

Abstract: The invention relates to a process for the electrochemical separation of hydrogen from a hydrogen-comprising reaction mixture R by means of a gastight membrane-electrode assembly comprising at least one selectively proton-conducting membrane and at least one electrode catalyst on each side of the membrane, where at least part of the hydrogen present in the reaction mixture R is oxidized to protons over the anode catalyst on the retentate side of the membrane and the protons are, after passing through the membrane to the permeate side, I reduced to hydrogen over the cathode catalyst and/or II reacted with oxygen over the cathode catalyst to form water, with the oxygen originating from an oxygen-comprising stream O which is brought into contact with the permeate side of the membrane, and also a reactor equipped with at least one membrane-electrode assembly.

Abstract: A process for preparing tolylenediamine by hydrogenating dinitrotoluene with hydrogen in the presence of a suspended catalyst in a vertically upright reactor (1), at the upper end of which is arranged a motive jet nozzle (2) through which the reaction mixture drawn off from the reactor bottom, via an external loop, is sprayed into the upper region of the reactor (1) and then flows into a central inserted tube (4) which is arranged in the longitudinal direction of the reactor, flows through the latter from the top downward and flows upward again outside the inserted tube (4) in an internal loop motion, with a heat exchanger (6) in the interior of the reactor (1), through which cooling water flows, and absorbs some of the heat of reaction as it does so, with a feed for the dinitrotoluene at the upper end of the reactor (1) and a feed for the hydrogen at the lower end of the reactor (1), and wherein, in addition to the heat exchanger (6) arranged in the interior of the reactor (1), a further heat exchanger (W

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: The present invention relates to a process for converting aliphatic hydrocarbons having 1 to 4 carbon atoms to aromatic hydrocarbons in the presence of a catalyst under nonoxidative conditions, wherein at least some of the hydrogen formed in the conversion electrochemically removed is by means of a gas-tight membrane-electrode assembly.

Abstract: The invention relates to a process for converting aliphatic hydrocarbons having from 1 to 4 carbon atoms into aromatic hydrocarbons, which comprises the steps: a) reaction of a feed stream E comprising at least one aliphatic hydrocarbon having from 1 to 4 carbon atoms in the presence of a catalyst under nonoxidative conditions to give a product stream P comprising aromatic hydrocarbons and hydrogen and b) electrochemical removal of at least part of the hydrogen formed in the reaction from the product stream P by means of a gastight membrane-electrode assembly comprising at least one selectively proton-conducting membrane and at least one electrode catalyst on each side of the membrane, where at least part of the hydrogen is oxidized to protons over the anode catalyst on the retentate side of the membrane and the protons are, after passing through the membrane on the permeate side, reacted with oxygen to form water over the cathode catalyst, with the oxygen originating from an oxygen-comprising stream O whi

Abstract: The present invention relates to a process for nonoxidative dehydroaromatization of aliphatic hydrocarbons by converting a reactant stream comprising aliphatic hydrocarbons in the presence of a catalyst which comprises at least one metallosilicate as a support, at least one element selected from the group of Mo, W and Re as an active component and at least one further transition metal which is not a noble metal as a dopant, wherein the catalyst is regenerated regularly with hydrogen under nonoxidative conditions. The further transition metal used is preferably Fe, Ni, Cu and Co.

Abstract: The present invention relates to a process for converting aliphatic hydrocarbons having 1 to 4 carbon atoms to aromatic hydrocarbons, comprising the steps of: a) converting a reactant stream E which comprises at least one aliphatic hydrocarbon having 1 to 4 carbon atoms in the presence of a catalyst under nonoxidative conditions to a product stream P comprising aromatic hydrocarbons and hydrogen, and b) electrochemically removing at least some of the hydrogen formed in the conversion from the product stream P by means of a gas-tight membrane-electrode assembly which has at least one selectively proton-conducting membrane and, on each side of the membrane, at least one electrode catalyst, at least some of the hydrogen being oxidized to protons over the anode catalyst on the retentate side of the membrane, and the protons, after passing through the membrane, on the permeate side over the cathode catalyst, are partly, in b1) reduced to hydrogen with application of a voltage, and partly, in b2) reacted with oxy

Abstract: A process for preparing aromatic amines by hydrogenation of nitroaromatics in the presence of catalysts, forming a fluid, amine-comprising reaction mixture in a reactor, wherein chromatographic analysis of the reaction mixture is carried out to determine the concentration of nitro and nitroso compounds in the reaction mixture.

Abstract: The invention relates to a process for producing a particulate, Si-bonded fluidized-bed catalyst having improved abrasion resistance, which comprises the steps I. provision of an aqueous suspension comprising zeolite particles, II. addition of a silicone resin mixture comprising one or more hydrolyzable silicone resin precondensates and mixing of the aqueous suspension and the silicone resin mixture, III. spray drying of the mixture obtained from step II, with the mixture being homogenized before spray drying, and IV. calcination of the spray-dried fluidized-bed catalyst obtained from step III, and an Si-bonded fluidized-bed catalyst which can be produced by this process and also its use for the nonoxidative dehydroaromatization of C1-C4-aliphatics.

Abstract: The present invention relates to a process for nonoxidatively dehydroaromatizing a reactant stream comprising C1-C4-aliphatics, comprising the steps of I. feeding reactant stream E into a reaction zone 1, converting reactant stream E under nonoxidative conditions in the presence of a particulate catalyst to a product stream P comprising aromatic hydrocarbons and discharging product stream P from reaction zone 1, II. transferring the catalyst with reduced activity as a result of deposited coke into a reaction zone 2, III. at least partly regenerating the catalyst with supply of a hydrogen-comprising gas stream H in a reaction zone 2, at least some of the coke deposited being converted to methane to form a methane-comprising gas stream M which is fed at least partly to reaction zone 1, IV. discharging the catalyst from reaction zone 2 and V.

Abstract: The present invention relates to a process for carrying out endothermic, heterogeneously catalyzed reactions in which the reaction of the starting materials is carried out in the presence of a mixture of inert heat transfer particles and catalyst particles, where the catalyst particles are regenerated in a nonoxidative atmosphere at regular intervals and the heat of reaction required is introduced by separating off the inert heat transfer particles, heating the heat transfer particles in a heating zone and recirculating the heated heat transfer particles to the reaction zone. The process of the invention is particularly suitable for the nonoxidative dehydroaromatization of C1-C4-aliphatics in the presence of zeolite-comprising catalysts.

Abstract: The invention relates to a process for the electrochemical separation of hydrogen from a hydrogen-comprising reaction mixture R by means of a gastight membrane-electrode assembly comprising at least one selectively proton-conducting membrane and at least one electrode catalyst on each side of the membrane, where at least part of the hydrogen present in the reaction mixture R is oxidized to protons over the anode catalyst on the retentate side of the membrane and the protons are, after passing through the membrane to the permeate side, I reduced to hydrogen over the cathode catalyst and/or II reacted with oxygen over the cathode catalyst to form water, with the oxygen originating from an oxygen-comprising stream O which is brought into contact with the permeate side of the membrane, and also a reactor equipped with at least one membrane-electrode assembly.

Abstract: The present invention relates to a process for converting aliphatic hydrocarbons having 1 to 4 carbon atoms to aromatic hydrocarbons in the presence of a catalyst under nonoxidative conditions, wherein at least some of the hydrogen formed in the conversion electrochemically removed is by means of a gas-tight membrane-electrode assembly.