The present invention relates to a reactor (1000) configured to nitrate a stoichiometric excess of an aromatic compound (1) with nitric acid (2) in the presence of sulfuric acid (3) in a continuous process under adiabatic conditions, the reactor (1000) comprising a plurality of static dispersion elements (310) arranged in a spaced-apart relationship to form a plurality of reaction chambers (400) inside the reactor (1000), wherein at least one of the reaction chambers (400) has a largest cross-sectional area (420') that is larger than that of the in flow direction preceding reaction chamber (400), and at least two of the reaction chambers (400) have an internal volume that is larger than that of the in flow direction preceding reaction chamber (400). The present invention also relates to a production plant for producing a nitrated aromatic compound, comprising the reactor (1000) according to the invention, and to a continuous process for producing a nitrated aromatic compound, comprising adiabatically reacting an aromatic compound (1) with nitric acid (2) in the presence of sulfuric acid (3) in the reactor of the invention (1000) or in the production plant of the invention.
B01J 4/00 - Dispositifs d'alimentationDispositifs de commande d'alimentation ou d'évacuation
B01J 19/00 - Procédés chimiques, physiques ou physico-chimiques en généralAppareils appropriés
B01J 19/24 - Réacteurs fixes sans élément interne mobile
C07C 201/08 - Préparation de composés nitrés par substitution d'atomes d'hydrogène par des groupes nitro
C07C 205/06 - Composés contenant des groupes nitro liés à un squelette carboné ayant des groupes nitro liés à des atomes de carbone de cycles aromatiques à six chaînons
A fluid mixing device (10) for use in chemical reactions involving two or more immiscible fluid phases. It mixes the reactants and prevents phase separation, particularly in pipe bends. The device (10) for mixing fluids flowing through a pipe (16), comprises a plate (12) having a flowpath (14) therethrough and two or more tabs (20) extending from the plate into the flowpath at an angle (24) from the plane (22) of the plate. The tabs (20) are formed by first folds (32) in the plate, at least two of the tabs (20A) having a second fold (26) therein, the tabs and first and second folds being arranged to produce two counter-rotating vortices (30) in the fluids passing through the pipe. The device has a plane of symmetry (28) perpendicular to the plane (22) of the plate (12).
A nitration reactor (10) incorporating sections of downward flow for use in preparing nitrated organic compounds. It comprises a first vertically-oriented reactor section (12), a second vertically-oriented reactor section (14), a connecting section (16) between the two reactor sections, one or more inlets (20, 22) for introducing nitration reactants into the reactor, an outlet (24) for the removal of nitration reaction products, a vertically-downward flowpath (26) for the nitration reactants in one of the reactor sections or the connecting section, and operating conditions that produce a flow regime in the vertically-downward flowpath that is a dispersed flow regime or a bubbly flow regime. The invention overcomes the limitations of prior art nitration reactors of the type in which fluids flow largely in a vertically upward direction, with respect to hydrostatic demands and plant layout considerations.
A process for removing impurities from crude nitrated aromatic products obtained during the nitration of aromatic compounds. The nitrated aromatic products are purified by treatment with ammonia washing followed by caustic washing. The nitrophenolic-containing wash waters are treated to recover dissolved organics and ammonia, and the stripped ammonia-wash effluent is incinerated. Carbon dioxide, which can accumulate in the process, is purged to the caustic washer.
C07C 205/06 - Composés contenant des groupes nitro liés à un squelette carboné ayant des groupes nitro liés à des atomes de carbone de cycles aromatiques à six chaînons
C01C 1/10 - Séparation d'ammoniac de liqueurs ammoniacales, p. ex. de liqueurs contenant des gaz dissous
C07C 205/17 - Composés contenant des groupes nitro liés à un squelette carboné le squelette carboné étant substitué de plus par des groupes hydroxy ayant des groupes nitro liés à des atomes de carbone acycliques et des groupes hydroxy liés à des atomes de carbone de cycles aromatiques à six chaînons
C02F 1/20 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout par dégazage, c.-à-d. par libération des gaz dissous
C02F 1/34 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout au moyen d'oscillations mécaniques
C02F 101/34 - Composés organiques contenant de l'oxygène
C02F 101/38 - Composés organiques contenant de l'azote
C02F 103/36 - Nature de l'eau, des eaux résiduaires ou des eaux ou boues d'égout à traiter provenant de l'industrie chimique non prévue dans les groupes provenant de la fabrication de composés organiques
5.
METHOD OF PURIFYING NITRATED AROMATIC COMPOUNDS FROM A NITRATION PROCESS
A process for removing impurities from crude nitrated aromatic products obtained during the nitration of aromatic compounds. The nitrated aromatic products (1) are purified by treatment with ammonia washing (102) followed by caustic washing (104). The nitrophenolic-containing wash waters (4, 8) are treated to recover dissolved organics and ammonia, and the stripped ammonia-wash effluent (10) is incinerated. Carbon dioxide, which can accumulate in the process, is purged (12) to the caustic washer (104).
C07C 205/06 - Composés contenant des groupes nitro liés à un squelette carboné ayant des groupes nitro liés à des atomes de carbone de cycles aromatiques à six chaînons
C02F 1/72 - Traitement de l'eau, des eaux résiduaires ou des eaux d'égout par oxydation
6.
PROCESS FOR ADIABATIC PRODUCTION OF MONONITROTOLUENE
A process for continuous adiabatic nitration of toluene to mononitrotoluene (MNT). The process yields a product quality of MNT that is comparable to that obtained by isothermal production. The process uses excess toluene, with the reaction rate being controlled to maintain a residual of 0.003-0.102 wt% nitric acid in the spent acid and an orange to red color of the spent acid. Further process conditions include re- concentrated sulfuric acid at 83 to 99 degrees C. with a concentration of sulfuric acid from 66 to 70.5 wt%. This is mixed with nitric acid to generate a mixed acid with 1.0 to 3.8 wt% nitric acid and toluene is added at a rate of 1.1 to 1.71 moles toluene/mole nitric acid. The reactants are mixed in a reactor with an overall average mixing intensity of 5.8 to 19 W/kg of contained solution.
A process for continuous adiabatic nitration of toluene to mononitrotoluene (MNT). The process yields a product quality of MNT that is comparable to that obtained by isothermal production. The process uses excess toluene, with the reaction rate being controlled to maintain a residual of 0.003-0.102 wt % nitric acid in the spent acid and an orange to red color of the spent acid. Further process conditions include re-concentrated sulfuric acid at 83 to 99 degrees C. with a concentration of sulfuric acid from 66 to 70.5 wt %. This is mixed with nitric acid to generate a mixed acid with 1.0 to 3.8 wt % nitric acid and toluene is added at a rate of 1.1 to 1.71 moles toluene/mole nitric acid. The reactants are mixed in a reactor with an overall average mixing intensity of 5.8 to 19 W/kg of contained solution.
A method and apparatus for removing non-aromatic impurities from non-nitrated aromatic reactant in a nitration production process, in which process an aromatic reactant is nitrated (100) to produce a nitrated aromatic product using a molar excess of the aromatic reactant, and non-nitrated aromatic reactant is recovered (102) from the produced nitrated aromatic product and is recycled (104) for use in the nitration production process. A portion of the removed excess non-nitrated aromatic reactant is diverted (106) and subjected to nitration (108). The nitrated stream may be further processed by separating out the spent acids (110) and the non-aromatic impurities (116). These streams may be sent (114, 118) to a suitable location in the nitration production train.
A method and apparatus for removing non-aromatic impurities from non- nitrated aromatic reactant in a nitration production process, in which process an aromatic reactant is nitrated (100) to produce a nitrated aromatic product using a molar excess of the aromatic reactant, and non-nitrated aromatic reactant is recovered (102) from the produced nitrated aromatic product and is recycled (104) for use in the nitration production process. A portion of the removed excess non-nitrated aromatic reactant is diverted (106) and subjected to nitration (108). The nitrated stream may be further processed by separating out the spent acids (1 10) and the non-aromatic impurities (116). These streams may be sent (114, 118) to a suitable location in the nitration production train.
C07C 205/06 - Composés contenant des groupes nitro liés à un squelette carboné ayant des groupes nitro liés à des atomes de carbone de cycles aromatiques à six chaînons
A method of removing alkalinity and salt from a nitroaromatic product downstream of water washing to remove mineral acids and alkaline washing to remove salts of organic acids, comprises washing the product stream with an acidic aqueous solution, prior to the step of removing excess organic reactant, by steam stripping or distillation. Acid removed from the stripper or column is recycled back for use in the acidic washing. The acidic washing is done instead of the neutral washing step of the prior art. It removes residual salt and decreases the level of entrained colloidal water in the nitroaromatic product.
A process for treating wastewater containing nitro-hydroxy-aromatic compounds using oxidative sub-critical conditions. The wastewater to be treated is adjusted to contain excess hydroxide equivalent to greater than three moles of free hydroxide per mole of total nitro-hydroxy-aromatic compounds, and a sub-stoichiometric amount of an oxidant is supplied to the wastewater. The nitro-hydroxy-aromatic compounds may include nitro-phenol salts or nitro-cresol salts.
A method of safely vaporizing liquid chlorine containing high concentrations of nitrogen trichloride contaminant from a chloralkali plant. In a vertical plug-flow vaporizer having an upward flow direction, a stream of liquid chlorine containing nitrogen trichloride is received. A gas such as air, nitrogen or chlorine gas is introduced into the liquid stream upstream of the boiling zone of the vaporizer to induce a flow regime, for example annular flow or mist flow, that prevents a mass accumulation of nitrogen trichloride in the vaporizer. The liquid chlorine containing nitrogen trichloride is vaporized. The resulting gas stream may be processed to destroy the nitrogen trichloride and recycled to the chlorine production train.
An adiabatic process for making mononitrobenzene by the nitration of benzene which minimizes the formation of nitrophenols and dinitrobenzene by-products. The process uses a mixed acid having less than 3 wt % nitric acid, 55 to 80 wt % sulfuric acid, and water. The initial temperature of the mixed acid is in the range of 60 to 96° C. The nitration reaction is complete in about 300 seconds and produces less than 1,200 ppm nitrophenols and less than about 80 ppm dinitrobenzene. The reaction can be carried out in a plug-flow or a stirred pot reactor, or a combination of such reactors.
A method of safely vaporizing liquid chlorine containing high concentrations of nitrogen trichloride contaminant from a chloralkali plant. In a vertical plug-flow vaporizer having an upward flow direction, a stream of liquid chlorine containing nitrogen trichloride is received. A gas such as air, nitrogen or chlorine gas is introduced into the liquid stream upstream of the boiling zone of the vaporizer to induce a flow regime, for example annular flow or mist flow, that prevents a mass accumulation of nitrogen trichloride in the vaporizer. The liquid chlorine containing nitrogen trichloride is vaporized. The resulting gas stream may be processed to destroy the nitrogen trichloride and recycled to the chlorine production train.
A method of processing a stream of liquid chlorine containing nitrogen trichloride from a chloralkali plant. The liquid stream is received into a vaporizer in which it is evaporated 1O1 chlorine gas and nitrogen trichloride gas. The gas stream is processed by destroying the nitrogen trichloride gas, for example in a superheater or a catalytic bed. The processed gas stream is recycled to the chlorine production train of the chloralkali plant. The process avoids the use of organic solvents to decompose the nitrogen trichloride and the creation of a waste stream requiring further handling.
A method for making mononitrobenzene using a plug flow reactor train. Benzene, nitric acid and sulfuric acid are introduced into the reactor and produced mononitrobenzene is removed at an outlet end. All of the benzene and at least part of the sulfuric acid are introduced at the inlet end of the reactor. A first portion of the nitric acid is introduced by a first nitric acid feed into the inlet end and a second portion of the nitric acid is introduced at one or more additional feeds that are spaced between the inlet end and the outlet end. The method results in reduced formation of by-product dinitrobenzene, improving the reaction yield of mononitrobenzene while avoiding the need for a distillation step.
A method of removing alkalinity and salt from a nitroaromatic product downstream of water washing to remove mineral acids and alkaline washing to remove salts of organic acids, comprises washing the product stream with an acidic aqueous solution, prior to the step of removing excess organic reactant, by steam stripping or distillation. Acid removed from the stripper or column is recycled back for use in the acidic washing. The acidic washing is done instead of the neutral washing step of the prior art. It removes residual salt and decreases the level of entrained colloidal water in the nitroaromatic product.
C07C 205/06 - Composés contenant des groupes nitro liés à un squelette carboné ayant des groupes nitro liés à des atomes de carbone de cycles aromatiques à six chaînons
18.
SUB-CRITICAL PARTIAL OXIDATION FOR TREATMENT OF NITRATION WASTES
A process for treating wastewater containing nitro-hydroxy-aromatic compounds using oxidative sub-critical conditions. The wastewater to be treated is adjusted to contain excess hydroxide equivalent to greater than three moles of free hydroxide per mole of total nitro-hydroxy-aromatic compounds, and a sub-stoichiometric amount of an oxidant is supplied to the wastewater. The nitro-hydroxy-aromatic compounds may include nitro-phenol salts or nitro-cresol salts.
A method for making mononitrobenzene using a plug flow reactor train. Benzene, nitric acid and sulfuric acid are introduced into the reactor and produced mononitrobenzene is removed at an outlet end. All of the benzene and at least part of the sulfuric acid are introduced at the inlet end of the reactor. A first portion of the nitric acid is introduced by a first nitric acid feed into the inlet end and a second portion of the nitric acid is introduced at one or more additional feeds that are spaced between the inlet end and the outlet end. The method results in reduced formation of by-product dinitrobenzene, improving the reaction yield of mononitrobenzene while avoiding the need for a distillation step.
C07C 201/08 - Préparation de composés nitrés par substitution d'atomes d'hydrogène par des groupes nitro
B01J 19/24 - Réacteurs fixes sans élément interne mobile
C07C 205/06 - Composés contenant des groupes nitro liés à un squelette carboné ayant des groupes nitro liés à des atomes de carbone de cycles aromatiques à six chaînons
An adiabatic process for making mononitrobenzene by the nitration of benzene which minimizes the formation of nitrophenols and dinitrobenzene by-products. The process uses a mixed acid having less than 3 wt% nitric acid, 55 to 80 wt% sulfuric acid, and water. The initial temperature of the mixed acid is in the range of 60 to 96°C. The nitration reaction is complete in about 300 seconds and produces less than 1,200 ppm nitrophenols and less than about 80 ppm dinitrobenzene. The reaction can be carried out in a plug-flow or a stirred pot reactor, or a combination of such reactors.
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