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Method for continuous countercurrent ogranosolv saccharification of comminuted lignocellulosic materials

  • US 4,941,944 A
  • Filed: 01/02/1990
  • Issued: 07/17/1990
  • Est. Priority Date: 07/13/1984
  • Status: Expired due to Fees
First Claim
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1. In a method for continuous organosolv treatment of a comminuted lignocellulose material containing naturally occurring water in a reaction vessel, wherein the lignocellulose material is contacted at elevated temperatures with a mixture of an organic solvent, water and a catalytic amount of an acid as a cooking liquor which facilitates the dissolution of the lignocellulose material, the improvement which comprises:

  • (a) introducing the lignocellulosic material into the vessel through a first inlet in countercurrent flow to the cooking liquor such that in a first zone of the vessel mainly lignin and hemicellulosic sugars are dissolved from the lignocellulosic material leaving a remaining cellulose and such that in a second zone of the vessel spaced from the first zone mainly oligomeric sugars are formed from the remaining cellulose;

    (b) introducing the cooking liquor through a second inlet into the second zone in the vessel in countercurrent flow to the lignocellulosic material at a first temperature T1 in the vessel and removing the cooling liquor in the first zone from a first outlet from the vessel at a temperature T2 lower than T1, wherein the water in the comminuted lignocellulosic material introduced into the first zone dilutes the cooking liquor and provides the temperature T1 for dissolution of the lignin and hemicelluloses in the first zone which are removed from the first zone through the first outlet; and

    (c) rapidly cooling the cooking liquor after removing the cooking liquor from the vessel wherein the lignin remains dissolved in the cooking liquor during the cooling.

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