Method and an apparatus for washing a crude lignin, a soluble carbohydrate containing fraction, a solid fraction and their use
AssigneeUpm-Kymmene Corporation
InventorsSami Turunen, Juha Tamper
Life of this patent
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Abstract
The invention relates to a method and an apparatus for washing a crude lignin slurry (5) formed from plant based raw material, wherein the method comprises separating a soluble carbohydrate containing fraction (10) from the crude lignin slurry (5) by using displacement washing in at least one solid-liquid separation stage (6) so that the crude lignin slurry is prepressed, washed and pressed, and recovering a solid fraction (11) and the soluble carbohydrate containing fraction (10). Further, the invention relates to the soluble carbohydrate containing fraction and the solid fraction, and their uses.
Claims11
A method for washing a composition that is formed from plant-based raw material including cellulose, hemicellulose, and lignin, the method comprising:
- forming the composition by at least a steam-explosion step and a hydrolysis step on the plant-based raw material, the composition including solid lignin and a soluble carbohydrate-containing fraction;
- filtering the soluble carbohydrate-containing fraction from the solid lignin in the composition to form a cake that includes the solid lignin so as to recover a portion of the soluble carbohydrate-containing fraction;
- and
- by use of a filter press, conducting a displacement washing process to recover an additional portion of the soluble carbohydrate-containing fraction from the cake, the displacement washing process comprising:
- prepressing the cake in the presence of pressure between 4 and 10 bar;
- flowing a washing liquid through the cake;
- and
- after the flowing, pressing the cake in the presence of pressure between 7 and 16 bar.
Dependencies are inferred from the claim text.