A method of purifying lignin by subjecting a slurry comprising lignin to an electric field

Abstract

The present invention relates to a process for purifying, such as salt / ion depletion, and / or ash reduction,and / or sulphur removal, and / or free sugar depletion,and / or VOC depletion or fractionating,preferably by using dewatering, of a slurry comprising a lignin or lignin derivative or a combination thereof. A lignin or lignin derivative obtainable from said process and uses thereof are also disclosed.

Description

technical field [0001] The present invention relates to purification methods such as salt / ion depletion, and / or ash reduction, and / or desulfurization, and / or free sugars of a slurry comprising lignin or lignin derivatives or combinations thereof Consumption and / or VOC consumption, or fractionation, preferably by dehydration. Also disclosed are lignin or lignin derivatives obtainable from said method and uses thereof. Background technique [0002] Lignin from forest biomass or lignocellulosic material can be recovered and used as a valuable raw material for further conversion, modification, or used in the natural form obtained. The first problem is the removal of lignin from lignocellulosic materials. In pulp kraft, lignin can be removed from black liquor. The commercial LignoBoost method has been shown to be effective for producing purified lignin. However, the product still contains ash (inorganic compounds), ions, and organic materials, which can be detrimental to the ...

AI Technical Summary

Problems solved by technology

[0008] There is still the technical problem of removing ash and ions, and especially sulfur, from lignin obtained from black liquor processes or similar processes or side streams.

Although acidification and subsequent washing and dehydration steps are repeated in one or more sequences, it is not sufficient to effectively remove the last fraction of ash and ions, which is necessary to produce high quality purified lignin

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