Abstract: The present invention relates to a method for increasing the reactivity of lignin, wherein the method comprises the following steps: a) forming, under heating at a temperature of 30-70° C., an aqueous dispersion comprising alkali and lignin, wherein the alkali comprises a hydroxide of an alkali metal; and b) heating the dispersion formed in step a) at a temperature of 50-95° C. for producing alkalated lignin.

Abstract: The present invention relates to a method for increasing the reactivity of lignin, wherein the method comprises the following steps: a) forming, under heating at a temperature of 30-70° C., an aqueous dispersion comprising alkali and lignin, wherein the alkali comprises a hydroxide of an alkali metal; and b) heating the dispersion formed in step a) at a temperature of 50-95° C. for producing alkalated lignin.

Abstract: The present invention relates to a method for increasing the reactivity of lignin, wherein the method comprises the following steps: a) forming, under heating at a temperature of 30-70° C., an aqueous dispersion comprising alkali and lignin, wherein the alkali comprises a hydroxide of an alkali metal; and b) heating the dispersion formed in step a) at a temperature of 50-95° C. for producing alkalated lignin.

Abstract: The present invention relates to a method for producing a binder composition, wherein the method comprises the following steps: (i) forming an aqueous composition comprising reactant components including lignin molecules of 11-60 lignin units, lignin molecules of 1-10 lignin units, polymerizable substance and crosslinking agent in the presence of a catalyst; and (ii) cooking the composition at a temperature of 60-95° C. for polymerizing the reactant components until a binder composition with a predetermined viscosity value is formed.

Abstract: The invention relates to a method for recovering low molecular weight lignin from a filtrate, wherein the low molecular weight lignin includes lignin molecules having a molecular weight of 3000 g/mol or lower, wherein the filtrate is obtained from a process where lignin is precipitated from black liquor and the formed precipitate is separated therefrom by filtration resulting in the filtrate including low molecular weight lignin being formed, and wherein the method includes the following steps: a) adjusting the pH of the filtrate to a value of 3-4 for precipitating lignin in the filtrate; b) separating the precipitated lignin from the filtrate; c) reslurrying the separated lignin until the dry solids content of the slurry is 25-40 weight-% and adjusting the pH of the slurry to a value of 2-3; d) washing the slurry; and e) separating the lignin from the slurry.

Abstract: The present invention relates to a method for producing a binder composition, wherein the method comprises the following steps: (i) forming an aqueous composition comprising reactant components including lignin molecules of 11-60 lignin units, lignin molecules of 1-10 lignin units, polymerizable substance and crosslinking agent in the presence of a catalyst; and(ii) cooking the composition at a temperature of 60-95 ° C. for polymerizing the reactant components until a binder composition with a predetermined viscosity value is formed.

Abstract: The present invention relates to a method for producing lignin esterified with at least one fatty acid, wherein the method includes the following steps: (i) reacting acetylated lignin with at least one fatty acid under the influence of heating and distilling at least part of the acetic acid formed during the reaction away from the reaction mixture, wherein per each mole of acetyl groups present in the lignin an excess molar amount of at least one fatty acid is used; and (ii) recovering lignin esterified with at least one fatty acid formed in step (i).

Abstract: The invention relates to a method for recovering low molecular weight lignin from a filtrate, wherein the low molecular weight lignin includes lignin molecules having a molecular weight of 3000 g/mol or lower, wherein the filtrate is obtained from a process where lignin is precipitated from black liquor and the formed precipitate is separated therefrom by filtration resulting in the filtrate including low molecular weight lignin being formed, and wherein the method includes the following steps: a) adjusting the pH of the filtrate to a value of 3-4 for precipitating lignin in the filtrate; b) separating the precipitated lignin from the filtrate; c) reslurrying the separated lignin until the dry solids content of the slurry is 25-40 weight-% and adjusting the pH of the slurry to a value of 2-3; d) washing the slurry; and e) separating the lignin from the slurry.