Abstract: A method of producing Stress Activated Pyrolytic Carbon-Carbon NanoTube (SAPC-CNT) fibers is disclosed. The fibers are a composite consisting of a tubular core of pristine graphite planes that include carbon nanotubes (CNTs) surrounded by semi-graphitic carbon material that includes Stress Activated Pyrolytic Carbon (SAPC), the SAPC being characterized by wavy graphite planes ranging from 0.1 nm to 1 nm and oriented parallel to the axis of each fiber, the semi-graphitic carbon material also being characterized by an inclusion of 4 to 10 atomic percent of nitrogen heteroatoms, the nitrogen heteroatoms including an above 60% of quaternary and pyridinic nitrogen groups.

Abstract: The invention relates to a process for preparing a catalyst, which comprises: mixing a copper salt containing solution with a silicate salt containing composition resulting in a precipitated solid; and subjecting the precipitated solid to a temperature in the range of from 150 to 500° C. Further, the invention relates to a copper containing catalyst obtainable by said process. Still further, the invention relates to a hydrogenation process wherein such copper containing catalyst is used, more in particular a process wherein methyl phenyl ketone is hydrogenated into methyl phenyl carbinol.

Abstract: This invention discloses the process for hydrogenation of aromatic polycarboxylic acids or derivatives thereof, hydrogenation of aromatic polycarboxylic acids or derivatives thereof can be achieved in the present of the catalyst, which consist at least one metal of the eighth transition group of the Periodic Table as the active metal while group IIA and group IVA elements are included as the catalyst support.

Abstract: Described herein are processes for converting a biomass starting material (such as lignocellulosic materials) into a low oxygen containing, stable liquid intermediate that can be refined to make liquid hydrocarbon fuels. More specifically, the process can be a catalytic biomass pyrolysis process wherein an oxygen removing catalyst is employed in the reactor while the biomass is subjected to pyrolysis conditions. The stream exiting the pyrolysis reactor comprises bio-oil having a low oxygen content, and such stream may be subjected to further steps, such as separation and/or condensation to isolate the bio-oil.

Abstract: A process has been developed for preparing 2-methoxymethyl-1,4-benzenediamine (IV-a), other compounds of formula (IV), and the salts thereof, all of which may be used as primary intermediates in compositions for dyeing keratin fibers.

Abstract: A process for preparing alkylated p-phenylenediamine having the steps of reacting aniline and nitrobenzene in presence of a complex base catalyst to obtain 4-aminodiphenylamine intermediates, hydrogenating the 4-aminodiphenylamine intermediates to 4-aminodiphenylamine in presence of a hydrogenation catalyst, and reductively alkylating the 4-aminodiphenylamine to alkylated p-phenylenediamine.

Abstract: A process has been developed for preparing 2-methoxymethyl-1,4-benzenediamine (IV-a), other compounds of formula (IV), and the salts thereof, all of which may be used as primary intermediates in compositions for dyeing keratin fibers.

Abstract: The present invention relates to a method of producing aromatic amines by hydrogenation of aromatic nitro compounds. This method comprises the steps: A) making a reactor containing a hydrogenation catalyst available; B) supplying aromatic nitro compounds and hydrogen to the reactor and contacting them with a hydrogenation catalyst, with at least the hydrogen which is supplied to the reactor is by means of a compressor and the compressor contains an operating fluid which at least partially contacts the hydrogen; and C) regenerating the hydrogenation catalyst by heating and contacting it with oxygen. After step C), steps D1) and/or D2) are carried out. Step D1) removes at least some of any fluids that are present in the reactor and/or in parts of the installation which are fluidically connected to the reactor downstream, with the fluids having been at least partially present in the reactor and/or in these parts of the installation during C).

Abstract: The present invention relates to a process for the purification of aniline which originates from gas phase hydrogenations. In this process, only a minimum proportion of the aniline has to be evaporated and condensed again. The process is highly efficient in removing compounds which have phenolic hydroxyl groups and results in minimal losses of aniline. This process also reduces the unwanted coupling mechanisms in the division of the overall crude product in the fraction condensation into individual substreams and the subsequent workup of these.

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 continuous process for preparing at least one aromatic amine by hydrogenation of at least one nitroaromatic by means of hydrogen, where a liquid phase comprising at least the aromatic amine and a gas phase comprising at least hydrogen are present, in the presence of a catalyst suspended in the liquid phase at a temperature of from 50 to 250° C. and a pressure of from 5 to 50 bar, wherein the pressure in the reactor is kept essentially constant by continuous adaptation of the amount of hydrogen fed to the reactor, the total amount of hydrogen fed to the reactor is monitored and the introduction of the at least one nitroaromatic is interrupted if the hydrogen uptake in the reactor is not at least 50 mol % of the amount of hydrogen required for stoichiometric reaction of the at least one nitroaromatic to form the at least one aromatic amine.

Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of corresponding nitroaromatics by means of hydrogen, and also an apparatus suitable for this purpose. In particular, the invention relates to a process for preparing toluenediamine (TDA) by hydrogenation of dinitrotoluene (DNT).

Abstract: Systems and methods for producing aromatic amines and removing phenol therefrom are provided. The method can include hydrogenating one or more aromatic nitro compounds to produce a reaction product comprising one or more aromatic amines, water, and phenol. The method can also include contacting the reaction product with one or more ion exchange materials to produce an aromatic amine product that contains less phenol than the reaction product. The one or more ion exchange materials can be solid, semi-solid, or a combination thereof.

Abstract: The present invention relates to an apparatus of the loop Venturi reactor type for the continuous reaction of liquids with gases, in particular for hydrogenations, oxidations or acetylations, e.g. for the preparation of toluenediamine by hydrogenation of dinitrotoluene, and a process for the continuous reaction of liquid reactants with gaseous reactants in the apparatus. Here, the cooling medium surrounds the tubes of the heat exchanger of the apparatus of the invention whereas the reaction takes place in the tubes.

Abstract: The invention relates to a process for obtaining at least one aromatic amine from a liquid mixture comprising water and the at least one aromatic amine by extracting with at least one nitroaromatic in an extraction column (1) to form an essentially water- comprising raffinate stream and an extract stream comprising the at least one nitroaromatic and the aromatic amine. The extraction column (1) is divided by a dividing wall (3) into two regions (5, 7), and, in the case of an amount of liquid for separation which is less than a minimum cross sectional loading of the entire extraction column (1), the liquid mixture to be separated is fed only to one of the regions (5, 7) of the extraction column (1) divided by the dividing wall (3). The invention further relates to a process for preparing an aromatic amine and to an apparatus for separating a liquid mixture comprising water and at least one aromatic amine by extracting with at least one nitroaromatic, comprising an extraction column (1).

Abstract: A process for obtaining pure aniline contains catalytically hydrogenating nitrobenzene, to obtain a reaction mixture, separating the reaction mixture into a gas phase containing hydrogen and a liquid phase, liquid/liquid phase separating the liquid phase to obtain an aqueous phase and also crude aniline containing water as an organic phase, distillatively pre-purifying the crude aniline by removing the water via an overhead stream of a first distillation column to obtain a first bottom stream, feeding the first bottom stream as a feed stream to a pure column from which a pure aniline stream is taken off at the top and a second bottom stream containing high boilers is taken off, and passing the second bottom stream to incineration, by pumping the second bottom stream through heated pipelines and by adding methanol, ethanol, propanol, and/or acetone to the second bottom stream.

Abstract: According to the present invention, a chemical installation is provided. The chemical installation comprises A first unit for providing a first aqueous waste stream comprising nitrobenzene; At least a second unit for providing a second aqueous waste stream comprising aniline. The chemical installation comprises an aniline cleaning apparatus for removing nitrobenzene from aniline, and further comprising a stripping column for stripping aniline from an aqueous stream. The first and second aqueous waste stream are provided to the stripping column, stripping aniline and nitrobenzene from the first and the aqueous waste stream, and the stripped aniline and nitrobenzene is provided to the aniline cleaning apparatus.

Abstract: The invention relates to a process for purifying aniline produced by gas-phase hydrogenation of nitrobenzene, by fractional condensation of the crude reaction product obtained in gaseous form so that at least two liquid process products, a partial condensate (PK) and a total condensate (TK), are obtained, wherein the condensation leading to the formation of PK is carried out at higher temperature than the temperature leading to the formation of TK, a product stream originating from PK and a product stream originating from TK are each passed separately from one another into a distillation column consisting of at least one stripping section and at least one rectifying section, wherein the product stream originating from PK is introduced into the lower section of the distillation column between the lowermost stripping section and the section which follows, and the product stream originating from TK is introduced into the top of the distillation column above the uppermost rectifying section, and the desired purif

Abstract: The invention relates to a catalyst and to a process for hydrogenating organic compounds. In particular, the invention is directed to a process and catalyst for hydrogenating organic compounds with hydrogen. The organic compounds are subjected to hydrogenation in the presence of a catalyst comprising nitrogen-doped carbon nanotubes as a catalytically active component, wherein the proportion of nitrogen in the nanotubes is in the range of from about 0.05 to 20 wt. %.

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: In a chemical reactor for heterogeneously catalysed reaction of a fluid, comprising a holding device for catalyst particles and/or inert particles (80, 100) through which the fluid flows, the side of the holding device lying upstream when viewed in the direction of flow of the fluid comprises knitted wire mesh fabric (50), and the average clear mesh width of the knitted wire fabric (50) is smaller than the average particle size x50.3 of the particles (80, 100). The invention furthermore relates to a process for reaction of a fluid, wherein the reaction is carried out in a reactor according to the invention in the presence of heterogeneous catalyst particles (80) and the catalyst particles (80) are arranged in the holding device for catalyst particles (80). The invention also provides the use of knitted wire mesh fabric (50) as a holding device for catalyst particles and/or inert particles (80, 100) in chemical reactors.

Abstract: The present invention relates to a continuous process for preparing at least one aromatic amine by hydrogenation of at least one nitroaromatic by means of hydrogen, where a liquid phase comprising at least the aromatic amine and a gas phase comprising at least hydrogen are present, in the presence of a catalyst suspended in the liquid phase at a temperature of from 50 to 250° C. and a pressure of from 5 to 50 bar, wherein the pressure in the reactor is kept essentially constant by continuous adaptation of the amount of hydrogen fed to the reactor, the total amount of hydrogen fed to the reactor is monitored and the introduction of the at least one nitroaromatic is interrupted if the hydrogen uptake in the reactor is not at least 50 mol % of the amount of hydrogen required for stoichiometric reaction of the at least one nitroaromatic to form the at least one aromatic amine.

Abstract: The present invention relates to a continuous process for the production of nitrobenzene by nitration of benzene with nitric acid or mixtures of nitric acid and sulfuric acid to give a crude nitrobenzene, washing of the crude nitrobenzene by means of at least one of each of an acid, alkaline and neutral washing, there being obtained a pre-purified nitrobenzene which, as well as containing nitrobenzene, at least contains also low boilers, optionally middle boilers as well as high boilers and salts, wherein the pre-purified nitrobenzene is purified further by separating off low boilers in a distillation apparatus by evaporation of the low boilers, and separation of nitrobenzene from the resulting further purified nitrobenzene in a distillation apparatus by partial evaporation of nitrobenzene, wherein pure nitrobenzene is removed from the distillation apparatus in gaseous form and is subsequently condensed, and wherein the non-evaporated portion of the further purified nitrobenzene is fed back into the washing a

Abstract: An object is to provide a process for providing hydrogen or heavy hydrogens conveniently without the necessity of large-scale equipment and a process capable of performing hydrogenation (protiation, deuteration or tritiation) reaction conveniently without the use of an expensive reagent and a special catalyst. The production process includes a process for producing hydrogen or heavy hydrogens, containing subjecting water or heavy water to mechanochemical reaction in the presence of a catalyst metal, and a process for producing a hydrogenated (protiated, deuterated or tritiated) organic compound, containing subjecting an organic compound and water or heavy water to mechanochemical reaction in the presence of a catalyst metal.

Abstract: The present invention relates to a process for restoring the activity of spent catalysts for the hydrogenation of aromatic nitro compounds, in which a regeneration comprising at least a first burning off stage, a first washing stage, a second burning off stage and a second washing stage is carried out at periodic intervals.

Abstract: The invention relates to a method for producing 2,5-diaminotoluene by catalytic hydrogenation in an aprotic-non-polar solvent or in a mixture made of two or more aprotic-nonpolar solvents with hydrogen in the presence of a catalyst or a mixture of two or more catalysts. The invention further relates to crystalline 2,5-diaminotoluene having characteristic crystal modification. As compared to conventional forms of administration common in industry, this is characterised in that it is largely insensitive to air oxidation.

Abstract: A solid base catalyst having a carrier, an organic base, and an inorganic base. Both of the organic base and inorganic base are loaded on the carrier. The solid base catalyst is especially suitable for the synthesis of 4-Aminodiphenylamine (4-ADPA).

Abstract: A process for hydrogenating an aromatic nitro compound according to the invention comprises providing a hydrogen gas stream and a liquid aromatic nitro compound stream; providing a fixed bed catalytic reactor having an inflow side and an outflow side; feeding to the inflow side, the hydrogen gas stream and the liquid aromatic nitro compound stream; converting the hydrogen gas and the aromatic nitro compound into an aromatic amine, thereby providing a reactor effluent comprising the aromatic amine and water; evacuating the reactor effluent from the reactor at the outflow side of the reactor; wherein an inert solvent or water is fed to the inflow side of the reactor at a molar ratio of moles inert solvent or water to moles hydrogen is more than 1.

Abstract: A complex base catalyst comprising tetraalkyl ammonium hydroxide and tetraalkyl ammonium salt for the condensation reaction of aniline and nitrobenzene.

Abstract: To provide a hydrogenation catalyst which does not contain chromium oxide, unlike conventional copper/chromium oxide catalysts, and therefore does not cause any environmental contamination or health hazard, and which shows an activity, selectivity and durability at equivalent or higher levels to or than those of conventional copper/chromium oxide catalysts. A hydrogenation catalyst which comprises, as the main components, (1) copper and (2) at least one member selected from the group consisting of silicon oxide, calcium oxide and calcium silicate, wherein the content of the copper is from 20 to 60 wt % based on the entire amount of the hydrogenation catalyst, and in the calcium silicate, the molar ratio of calcium oxide (CaO) to silicon oxide (SiO2) is less than 1.

Abstract: The invention relates to a process for preparing aromatic amines by hydrogenation of corresponding nitroaromatics by means of hydrogen, and also an apparatus suitable for this purpose. In particular, the invention relates to a process for preparing toluenediamine (TDA) by hydrogenation of dinitrotoluene (DNT).

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 production method for 4,4?-bis(alkylamino)diphenylamine, and more specifically relates to a method in which 4,4?-dinitrodiphenylamine (4,4?-DNDPA) is produced by reacting urea with nitrobenzene in the presence of a polar organic solvent and a base catalyst, and then the 4,4?-bis(alkylamino)diphenylamine (4,4?-BAADA) is produced by subjecting the 4,4?-DNDPA and a ketone to hydrogenation in the presence of a hydrogenation catalyst.

Abstract: Systems and methods for producing aromatic amines and removing phenol therefrom are provided. The method can include hydrogenating one or more aromatic nitro compounds to produce a reaction product comprising one or more aromatic amines, water, and phenol. The method can also include contacting the reaction product with one or more ion exchange materials to produce an aromatic amine product that contains less phenol than the reaction product. The one or more ion exchange materials can be solid, semi-solid, or a combination thereof.

Abstract: The invention relates to a process for obtaining at least one aromatic amine from a liquid mixture comprising water and the at least one aromatic amine by extracting with at least one nitroaromatic in an extraction column (1) to form an essentially water-comprising raffinate stream and an extract stream comprising the at least one nitroaromatic and the aromatic amine. The extraction column (1) is divided by a dividing wall (3) into two regions (5, 7), and, in the case of an amount of liquid for separation which is less than a minimum cross sectional loading of the entire extraction column (1), the liquid mixture to be separated is fed only to one of the regions (5, 7) of the extraction column (1) divided by the dividing wall (3). The invention further relates to a process for preparing an aromatic amine and to an apparatus for separating a liquid mixture comprising water and at least one aromatic amine by extracting with at least one nitroaromatic, comprising an extraction column (1).

Abstract: The invention relates to a process for preparing aromatic amines by catalytically hydrogenating the corresponding aromatic nitro compound, which comprises using a copper catalyst with a support comprising SiO2, the SiO2 having been prepared by wet grinding and subsequent spray drying.

Abstract: Aromatic amines are produced by catalytic hydrogenation of aromatic nitro compounds. The reaction mixture generated by this hydrogenation is then worked up by distillation in a manner which makes it possible to substantially free the amine of water with increased energy efficiency. Water free of amine and low boilers and the low boiling materials are also obtained.

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 process for preparing nitrobenzene derivatives and aniline derivatives, which are of significance as intermediates for fungicidally active alkylanilides.

Abstract: The invention relates to a catalyst and a process for hydrogenating organic compounds.

Abstract: Aromatic amines produced by hydrogenation of the corresponding nitroaromatic compounds are purified in a specified manner. In the purification procedure, the particular amine is initially mixed with an aqueous solution of a base. The organic and aqueous phases are then separated by adding excess water.

Abstract: The catalytic mixture resulting of a metal powder catalyst with a solid material (referred to here as a reaction-aid) that has good filtering properties, does not interfere with the reaction, does not interfere with recycling the catalyst back into the reaction, does not interfere with the refining and recovery of the metal from the catalyst after it is spent, and will not become separated from the catalyst during the preparation of this catalytic mixture, the chemical reaction or the separation of this catalytic mixture from the reaction medium, whereas the ratio of the reaction aid to the catalyst ranges from 0.05 to 20 on a weight basis. A preferred metal powder catalyst is acetylene black supported precious metal. Preferred reaction aids are sibunit powder or activated carbon. The catalytic mixture can be used for the catalytic transformation of compounds, such as the hydrogenation of olefins, or the hydrogenation of nitro compounds.

Abstract: A process for the industrial production of 2-amino-2-[2-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]ethyl]-1,3-propanediol hydrochloride (Compound I), an effective immunosuppressant. The process for producing 2-amino-2-[2-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]ethyl]-1,3-propanediol hydrochloride or a hydrate thereof includes the steps of reacting 4-(3-benzyloxyphenylthio)-2-chlorobenzaldehyde with ethyl diethylphosphonoacetate in a solvent in the presence of a base to form ethyl 3-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]acrylate; reducing the resulting ethyl 3-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]acrylate, followed by mesylation, iodination and nitration, to form 1-benzyloxy-3-[3-chloro-4-(3-nitropropyl)phenylthio]benzene; forming 2-[2-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]ethyl]-2-nitro-1,3-propanediol using a formaldehyde solution; and reducing the resulting 2-[2-[4-(3-benzyloxyphenylthio)-2-chlorophenyl]ethyl]-2-nitro-1,3-propanediol to form the desired product.

Abstract: The present invention relates to a magnetic separation apparatus for continuous separating and recovering magnetic solid particles from a solid-liquid mixture. The apparatus includes at least one magnetic separation unit and each unit includes: an outer cylindrical vessel having a material inlet, a first outlet, and a second outlet; an inner cylindrical vessel, at least part of which extends along the axis inside the first cylindrical vessel without contacting with the inner surface of the outer cylindrical vessel; and a magnet, rendering the bottom of the inner cylindrical vessel magnetism during the first period and making the part of the surface lose its magnetism during a second period. When the solid-liquid mixture flows through the magnetic surface of the inner cylindrical vessel in the passage, the magnetic solids are absorbed and separated from the mixture.

Abstract: Nitro-compounds are hydrogenated with an activated Ni catalyst that has an average particle size (APS) less than 25 ?m and is doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Pt, Cu, Ag, Au and Bi via its/their addition to the alloy before activation and/or doped with one or more elements from the list of Mg, Ce, Ti, V, Nb, Cr, W, Mn, Re, Fe, Ru, Co, Rh, Ir, Ni, Cu, Ag, Au and Bi by their adsorption onto the surface of the activated catalyst.

Abstract: A method for producing aniline or toluenediamine is disclosed which comprises forming a dispersion comprising hydrogen gas bubbles dispersed in a liquid medium comprising either nitrobenzene or dinitrotoluene, wherein the hydrogen gas bubbles have a mean diameter less than 1 micron; and subjecting the dispersion to hydrogenation reaction promoting conditions comprising pressure less than about 600 kPa and temperature less than about 200° C., whereby at least a portion of the nitrobenzene or dinitrotoluene is hydrogenated to form aniline or toluenediamine, respectively. A system for carrying out the method is also disclosed.

Abstract: A process for preparing aromatic amines by catalytic hydrogenation of the corresponding nitro compound in a fluidized-bed reactor, in which a gaseous reaction mixture comprising the nitro compound and hydrogen flows from the bottom upward through a heterogeneous particulate catalyst forming a fluidized bed, wherein the fluidized bed is provided with internals which divide the fluidized bed into a plurality of cells arranged horizontally in the fluidized-bed reactor and a plurality of cells arranged vertically in the fluidized-bed reactor, with the cells having cell walls which are permeable to gas and have openings which ensure an exchange number of the heterogeneous, particulate catalyst in the vertical direction in the range from 1 to 100 liters/hour per liter of reactor volume, is proposed.

Abstract: The invention pertains to an improved apparatus comprised of a monolith catalytic reactor having an inlet and an outlet and a static mixer having an inlet and an outlet thereto with the outlet of said static mixer in communication with the inlet of said monolith catalytic reactor. The invention also pertains to an improvement in a process for effecting a reaction in the monolith catalytic reactor wherein a reactant gas and reactant liquid are introduced to the inlet to the monolith catalytic reactor, reacted and, then, the reaction product passed through the outlet of the monolith catalytic reactor.

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.