公开(公告)号：US20170291869A1

公开(公告)日：2017-10-12

申请号：US15514107

申请日：2015-09-29

申请人： Covestro Deutschland AG

发明人： Thomas KNAUF ,  Jürgen MÜNNIG ,  Wolfgang LORENZ ,  Bernd PENNEMANN

IPC分类号： C07C201/08 ,  C07C201/16 ,  B01D53/00

CPC分类号： C07C201/08 ,  B01D53/002 ,  B01D2257/7027 ,  C07C201/16 ,  C07C205/06

摘要： The invention relates to a method for producing dinitrotoluene, comprising the following steps: a) nitrating toluene with a mixture of nitric acid and sulfuric acid and subsequently separating a sulfuric-acid-containing aqueous phase that arises in the nitration, wherein a raw dinitrotoluene is obtained, b) washing the raw dinitrotoluene in a water wash with neutral and/or alkaline washing water, wherein a pre-cleaned dinitrotoluene, which contains at least water in addition to dinitrotoluene, is obtained after the washing water used in the last wash has been separated, and c) separating the water from the pre-cleaned dinitrotoluene, d) collecting the waste water from steps a), b), and/or c), e) optionally extracting the collected waste water from step d) with toluene and returning the thus obtained organic phase to step a), f) freeing the collected waste water from step d), or, if the optional step e) is performed, the extracted waste water from step e), of toluene in a toluene stripper, wherein a toluene-containing exhaust gas flow is obtained, g) feeding at least one exhaust gas flow from steps a), b), c), d), e), or f) into an exhaust gas condenser and removing the toluene contained in the at least one exhaust gas flow in said exhaust gas condenser, wherein the method comprises the following further step: h) feeding the exhaust gas flow arising in step g) after the condensing out of the toluene to a thermal exhaust air cleaning, wherein nitrogen is added to the exhaust gas flow to be fed to the exhaust gas condenser or to the exhaust gas flow leaving the exhaust gas condenser, wherein preferably a nitrogen concentration in the exhaust gas flow of at least 0.1 vol % is set, especially preferably of at least 0.5 vol %.

公开(公告)号：US20200061491A1

公开(公告)日：2020-02-27

申请号：US16467323

申请日：2017-12-04

申请人： COVESTRO DEUTSCHLAND AG

发明人： Bernd PENNEMANN ,  Jürgen BAUSA

IPC分类号： B01D3/24

摘要： The invention relates to a cascade tray suitable for use in a rectifying column and comprising openings in the weir-type cascade edge, to a rectifying column containing at least one cascade tray according to the invention, to a method for operating such a rectifying column, and to the use of a claimed rectifying column in the fractionation of specific substance mixtures.