US 12,441,849 B2
Method for producing a crosslinked lignin with a highly specified surface area, crosslinked lignin, and technical rubber articles or tires comprising crosslinked lignin
Geertje Dautzenberg, Potsdam (DE); Jacob Podschun, Berlin (DE); and Tobias Wittmann, Berlin (DE)
Assigned to Suncoal Industries GmbH, Ludwigsfelde (DE)
Appl. No. 18/004,745
Filed by Suncoal Industries GmbH, Ludwigsfelde (DE)
PCT Filed Jul. 9, 2021, PCT No. PCT/DE2021/100602
§ 371(c)(1), (2) Date Jan. 9, 2023,
PCT Pub. No. WO2022/008008, PCT Pub. Date Jan. 13, 2022.
Claims priority of application No. 102020208683.4 (DE), filed on Jul. 10, 2020; and application No. 102021100142.0 (DE), filed on Jan. 7, 2021.
Prior Publication US 2023/0192966 A1, Jun. 22, 2023
Int. Cl. C08L 97/00 (2006.01); C08H 7/00 (2011.01); C08J 3/14 (2006.01); C08L 21/00 (2006.01); B60C 1/00 (2006.01)
CPC C08H 6/00 (2013.01) [C08L 97/005 (2013.01); B60C 1/00 (2013.01)] 28 Claims
 
1. A method for producing a cross-linked lignin in particulate form, wherein the method comprises the following steps:
(a) providing a black liquor with a dry matter content of 5 to 50% by weight,
(b) producing a liquid that contains lignin and at least one cross-linking agent and/or one precursor of the cross-linking agent and having the following properties:
a dry matter content of 5-25% by weight,
an ash content relative to the dry mass of 10-45% by weight,
a pH value of more than 6.5 and less than 10,
an electrical conductivity of more than 15 mS/cm to 400 mS/cm,
from the black liquor, wherein the production of the liquid comprises:
(i) mixing the black liquor with an acid and/or an acidic gas in order to lower the pH value, and
(ii) mixing the black liquor or a product derived therefrom with the at least one cross-linking agent and/or the precursor of the cross-linking agent, and
(iii) optionally adding a liquid in order to reduce the dry matter content,
(c) hydrothermal treatment of the liquid produced in step b) that contains lignin and at least one cross-linking agent and/or one precursor of the cross-linking agent at a temperature in a range from 150° C. to 270° C. with formation of cross-linked lignin particles in the liquid, and
(d) separating the liquid from the cross-linked lignin particles formed in step (c), and
(e) washing the separated cross-linked lignin particles with a washing medium.