Process for the delignification of lignocellulosic material by maintaining a concentration of carbon monoxide in the presence of oxygen and alkali
AssigneeMo och Domsjo Aktiebolag
InventorsAllan Geoffrey Jamieson, Hans Olof Samuelson, Leif Ake Smedman, Kent Ivar Sondell
Life of this patent
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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is maintained by withdrawing carbon monoxide and oxygen gas from the delignification, and separating and recycling withdrawn oxygen gas.
Claims37
A process for the delignification of lignocellulosic material which comprises carrying out the delignification with oxygen gas and alkali in the presence of a gas phase comprising oxygen gas and carbon monoxide wherein the carbon monoxide is in a concentration within the range from about 1% to about 12% by volume of the gas phase while maintaining the carbon monoxide concentration within said range by withdrawing carbon monoxide and oxygen gas from the delignification, and separating and recycling withdrawn oxygen gas.
Dependencies are inferred from the claim text.