Abstract:
Ausfällungen von Nitrohydroxyaromat-Salzen aus den bei der Nitrierung von aromatischen Verbindungen nach alkalischer Wäsche anfallenden nitrierten Rohprodukten, z.B. Mononitrotoluolen, werden verhindert, indem man die nitrierten Rohprodukte in Kontakt mit einem sauren Ionentauscher bringt. Die nitrierten Rohprodukte sind vorzugsweise ausgewählt unter einem Zulauf zu einer Destillationskolonne, einem Sumpfumlauf einer Destillationskolonne und einem Zulauf zu einem Verdampfer.
Abstract:
The invention concerns a method for treating an aqueous solution derived from sluicing of crude mononitrated or dinitrated aromatic compounds obtained by nitration of the corresponding aromatic compounds, consisting in: (a) contacting said aqueous solution with said aromatic compound thereby obtaining an aqueous phase and an organic phase; (b) recycling said organic phase in the nitration process; (c) distilling said aqueous phase; (d) recycling the resulting concentrated acid solution, in the nitration process; (e) recycling or eliminating the recuperated water after distillation.
Abstract:
The present invention relates to novel itermediates of formula (1) wherein the wavy bond ( SIMILAR SIMILAR ) represents the racemate, the (R)-enantiomer or the (S)-enantiomer; and R is hydrogen, a carboxyl-protecting group or a cation of an addition salt; or solvate thereof; and to the use thereof in a process for the preparation of certain 3-fluoro oxindole derivatives.
Abstract:
A process is disclosed for removing a light organic compound from a liquid composition comprising said light organic compound in admixture with a nitroaromatic compound, said light organic compound having a partial vapor pressure in said composition that is greater than the partial vapor pressure of said nitroaromatic compound in said composition, said process comprising contacting said composition with steam or a gas to cause at least a portion of said light organic compound to pass out of said composition and into admixture with said steam or gas.
Abstract:
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).
Abstract:
The present invention provides a process for nitrating aromatic compounds without the need for a solid catalyst and/or any organic solvents and/or any other additives. A typical process includes combining or admixing a nitric acid and an anhydride compound under conditions sufficient to produce a reactive intermediate. The aromatic compound to be nitrated is then added to this reactive intermediate to produce a nitroaromatic compound. The nitroaromatic compound can be substituted with one or more, typically, one to three, and often one or two nitrate (-NO 2 ) groups.
Abstract:
A presente invenção diz respeito a um processo de extracção de ácidos minerais e ácidos orgânicos hidrofílicos de compostos aromáticos, nomeadamente nitroaromaticos, de preferência o Mononitrobenzeno Bruto (MNB), através de um processo de lavagem e refinamento destes. Esta invenção diz ainda respeito a um dispositivo/equipamento que compreende um conjunto de misturadores estáticos dispostos em série e/ou paralelo, seguidos de um separador líquido-líquido e seguido posteriormente por um coalescedor, e ainda, a reciclagem de parte da água ácida separada no coalescedor.
Abstract:
Proposed is a separation method in a toluene to dinitrotoluene process, wherein said method with a first process step comprising feeding a toluene comprising first stream (1) and a nitric acid comprising second stream (2) into a first reactor (R1), react- ing of the toluene comprising first stream (1) and the nitric acid comprising second stream (2) within the first reactor (R1) to a first reaction mixture (3), said first reaction mixture (3) comprising a first liquid/liquid mixed phase of an acid phase and an organic phase comprising mononitrotoluene, feeding the first reaction mixture (3) into a first separation device (S1), separating the first reaction mixture (3) within the first separa- tion device (S1) into a first forward stream (4) having a flow direction to a second process step and a first backward stream (5) having a flow direction back to the first reactor (R1), said method having a second process step comprising feeding the first forward stream (4) into a second reactor (R2), feeding a nitric acid comprising third stream (6) and a sulfuric acid comprising fourth stream (7) into the second reactor (R2), reacting of the first forward stream (4), the nitric acid comprising third stream (6) and the sulfuric acid comprising fourth stream (7) within the second reactor (R2) to a second reaction mix- ture (8), said second reaction mixture (8) comprising a second liquid/liquid mixed acid phase and an organic phase comprising mononitrotoluene and dinitrotoluene, feeding the second reaction mixture (8) into a second separation device (S2), separating the second reaction mixture (8) within the second separation device (S2) into a second forward stream (9) having a flow direction to a process output and a second backward stream (10) having a flow direction back to the first reactor (R1), wherein fine separating of at least one of the streams (4, 5, 9,10) after the first separa- tion step (S1) and/or the second separation step (S2) in a coalescer is carried out.
Abstract:
Gegenstand der Erfindung ist ein kontinuierliches Verfahren zur Herstellung von Nitrobenzol durch Nitrierung von Benzol mit Mischungen aus Schwefel- und Salpetersäure unter Einsatz eines stöchiometrischen Überschusses an Benzol, bei dem der Gehalt an aliphatischen organischen Verbindungen im Einsatzbenzol während der Anfahrzeit der Produktionsanlage stets kleiner als 1,5 Massen-%, bezogen auf die Gesamtmasse des Einsatzbenzols, gehalten wird. Dies wird erreicht, indem entweder während der Anfahrzeit das Einsatzbenzol aus rezykliertem nicht umgesetzten Benzol (Rückbenzol) und der Reaktion neu zugeführtem Benzol (Frischbenzol), abhängig von der Reinheit beider Ströme, in entsprechenden Mengenverhältnissen gemischt wird, oder indem während der Anfahrzeit auf die Rezyklierung nicht umgesetzten Benzols komplett verzichtet wird, das Einsatzbenzol also nur aus der Reaktion neu zugeführtem Benzol besteht.