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 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: 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 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 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 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 invention relates to a process for preparing aromatic amines by catalytic hydrogenation of the corresponding nitro compounds, in particular for preparing toluenediamine by hydrogenation of dinitrotoluene, wherein hydrogenation catalysts in which a mixture of nickel, palladium and an additional element selected from the group consisting of cobalt, iron, vanadium, manganese, chromium, platinum, iridium, gold, bismuth, molybdenum, selenium, tellurium, tin and antimony is present as active component on a support are used.