Patents by Inventor Wolfgang Dohmen

Wolfgang Dohmen has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).

  • Patent number: 9284255
    Abstract: The invention relates to an adiabatic process for producing nitrobenzene by nitrating benzene with sulphuric acid mixtures and nitric acid mixtures using a stoichiometric excess of benzene and reusing non-reacted benzene, the content of the aliphatic organic compounds in the feed benzene being limited, by the targeted evacuation of aliphatic organic compounds to at least one step in the process, to a content of less than 1.5 mass-%, in relation to the total amount of feed benzene.
    Type: Grant
    Filed: July 23, 2013
    Date of Patent: March 15, 2016
    Assignee: Bayer MaterialScience AG
    Inventors: Thomas Knauf, Alexandre Racoes, Wolfgang Dohmen, Antoni Mairata
  • Publication number: 20150175521
    Abstract: The invention relates to an adiabatic process for producing nitrobenzene by nitrating benzene with sulphuric acid mixtures and nitric acid mixtures using a stoichiometric excess of benzene and reusing non-reacted benzene, the content of the aliphatic organic compounds in the feed benzene being limited, by the targeted evacuation of aliphatic organic compounds to at least one step in the process, to a content of less than 1.5 mass-%, in relation to the total amount of feed benzene.
    Type: Application
    Filed: July 23, 2013
    Publication date: June 25, 2015
    Inventors: Thomas Knauf, Alexandre Racoes, Wolfgang Dohmen, Antoni Mairata
  • Patent number: 7763759
    Abstract: The invention relates to a continuous process for the manufacture of nitrobenzene. This process comprises the nitration of benzene with nitrating acid that contains at least 3.0 wt. % of nitric acid and at least 67.0 wt. % of sulfuric acid, in a reaction space in which the start temperature of the reaction is above 100.0° C. but below 102.0° C. In addition, this process requires that the benzene and the nitrating acid are dispersed in one another several times.
    Type: Grant
    Filed: September 21, 2009
    Date of Patent: July 27, 2010
    Assignee: Bayer MaterialScience AG
    Inventors: Thomas Knauf, Alexandre Racoes, Wolfgang Dohmen, Andreas Rausch
  • Publication number: 20100076230
    Abstract: The invention relates to a continuous process for the manufacture of nitrobenzene. This process comprises the nitration of benzene with nitrating acid that contains at least 3.0 wt. % of nitric acid and at least 67.0 wt. % of sulfuric acid, in a reaction space in which the start temperature of the reaction is above 100.0° C. but below 102.0° C. In addition, this process requires that the benzene and the nitrating acid are dispersed in one another several times.
    Type: Application
    Filed: September 21, 2009
    Publication date: March 25, 2010
    Inventors: Thomas Knauf, Alexandre Racoes, Wolfgang Dohmen, Andreas Rausch
  • Patent number: 7344650
    Abstract: Alkaline waste waters formed in the washing of crude nitrobenzene which has been prepared by the adiabatic nitration of benzene with nitrating acid, washed in an acidic washing process, and then washed in an alkaline washing process are treated. The alkaline waste water being treated generally contains benzene in a concentration of from about 100 to about 3000 ppm and nitrobenzene in a concentration of from about 1000 to about 10,000 ppm. In the process of the present invention, undissolved benzene and/or nitrobenzene are separated from the alkaline waste water, residual benzene and/or nitrobenzene is/are then optionally stripped out of the alkaline waste water, and the alkaline waste water from which benzene and/or nitrobenzene has been removed is heated to a temperature of from 150 to 500° C. under excess pressure with the exclusion of oxygen.
    Type: Grant
    Filed: April 7, 2005
    Date of Patent: March 18, 2008
    Assignee: Bayer MaterialScience AG
    Inventors: Thomas Knauf, Franz-Ulrich Von Gehlen, Wolfgang Dohmen, Jörg Schmiedler
  • Publication number: 20050224424
    Abstract: Alkaline waste waters formed in the washing of crude nitrobenzene which has been prepared by the adiabatic nitration of benzene with nitrating acid, washed in an acidic washing process, and then washed in an alkaline washing process are treated. The alkaline waste water being treated generally contains benzene in a concentration of from about 100 to about 3000 ppm and nitrobenzene in a concentration of from about 1000 to about 10,000 ppm. In the process of the present invention, undissolved benzene and/or nitrobenzene are separated from the alkaline waste water, residual benzene and/or nitrobenzene is/are then optionally stripped out of the alkaline waste water, and the alkaline waste water from which benzene and/or nitrobenzene has been removed is heated to a temperature of from 150 to 500° C. under excess pressure with the exclusion of oxygen.
    Type: Application
    Filed: April 7, 2005
    Publication date: October 13, 2005
    Inventors: Thomas Knauf, Franz-Ulrich Von Gehlen, Wolfgang Dohmen, Jorg Schmiedler