Patents by Inventor Leif Ake Smedman

Leif Ake Smedman 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).

  • Process for the delignification of lignocellulosic material by maintaining a concentration of carbon monoxide in the presence of oxygen and alkali
    Patent number: 4050981
    Abstract: Process for improving the selectivity of delignification of lignocellulosic material in the presence of oxygen gas and alkali by maintaining a carbon monoxide content in the gas phase within the range from about 1% to about 12% by volume. The carbon monoxide concentration is maintained by withdrawing carbon monoxide and oxygen gas from the delignification, and separating and recycling withdrawn oxygen gas.
    Type: Grant
    Filed: June 11, 1975
    Date of Patent: September 27, 1977
    Assignee: Mo och Domsjo Aktiebolag
    Inventors: Allan Geoffrey Jamieson, Hans Olof Samuelson, Leif Ake Smedman, Kent Ivar Sondell
  • Pulping of lignocellulosic material with oxygen in two stages at increasing pH
    Patent number: 3944463
    Abstract: A process is provided for producing cellulose pulp of high brightness, which comprises pulping lignocellulosic material such as wood with oxygen under superatmospheric pressure in two stages, in the first at a pH within the range from about 6 to about 9, and in the second at a more alkaline pH of at least about 10.
    Type: Grant
    Filed: December 12, 1973
    Date of Patent: March 16, 1976
    Assignee: Mo och Domsjo Aktiebolag
    Inventors: Hans Olof Samuelson, Leif Ake Smedman, Erik Olof Sture Hagglund