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US 10,894,866 B2Granted
Method for activating and precipitating lignin
AssigneeTeknologian tutkimuskeskus VTT Oy
InventorsHanne Wikberg, Taina Ohra-Aho, Juha Leppävuori, Tiina Liitiä
Life of this patent
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Abstract
According to an example aspect of the present invention, there is provided a method of producing reactive lignin from an alkaline lignin containing stream, such as black liquor, e.g. kraft lignin, by using thermal treatment with temperatures between 200 and 250° C. for simultaneous activation (for example by demethylation and/or demethoxylation) and precipitation of the lignin.
Claims13
A method for activating and recovering lignin from an alkaline lignin-containing feedstock by a thermal treatment, the method comprising:
- simultaneously activating and precipitating the lignin in the feedstock by a thermal treatment being carried out on the feedstock having a dry matter content of between 10 and 40 wt-% and a pH of 10-12, without added demethylation and demethoxylation enhancing agents, and at a self-generated pressure, by applying temperature between 200 and 220° C. and a retention time between 1 and 7 hours to the feedstock, wherein the pH, temperature, and retention time are selected along with the self-generated pressure to provide simultaneous demethylation and demethoxylation of the lignin.
Dependencies are inferred from the claim text.