Method of removing volatile compounds from a lignin-containing material, use of a distillation method, and a lignin-containing material

Patent metadata

Field	Value
Publication number	US-12479876-B2
Application number	US-202017786003-A
Country	US
Kind code	B2
Filing date	Dec 18, 2020
Priority date	Dec 20, 2019
Publication date	Nov 25, 2025
Grant date	Nov 25, 2025

Abstract

According to an example aspect of the present invention, there is provided a method of removing volatile compounds from a lignin-containing material, the method comprising: providing a material comprising lignin and volatile compounds; treating the material by a distillation method in order to vaporize at least a part of the volatile compounds.

First claim

The invention claimed is:

1 . A method of removing volatile compounds from a lignin-containing material, the method comprising:
providing the lignin-containing material comprising lignin and the volatile compounds; treating the material by a distillation method in order to vaporize at least a part of the volatile compounds, wherein said treating step comprises steam stripping the lignin-containing material at a pressure not larger than 1.5 bar.

2 . The method according to claim 1 , wherein said treating comprises exposing the lignin-containing material to steam in order to vaporize at least a part of the volatile compounds.

3 . The method according to claim 2 , wherein, before exposure to the steam, said lignin-containing material comprises at least 100 mg/kg guaiacol of the dry matter of the lignin-containing material.

4 . The method according to claim 2 , wherein, before exposure to the steam, said lignin-containing material comprises at least 1000 mg/kg guaiacol of the dry matter of the lignin-containing material.

5 . The method according to claim 1 , wherein the volatile compounds comprise volatile odorous compounds.

6 . The method according to claim 1 , wherein the lignin-containing material is in the form of an aqueous suspension.

7 . The method according to claim 1 , wherein said volatile compounds comprise sulphides and/or guaiacol.

8 . The method according to claim 1 , wherein the lignin-containing material originates from a pulp production process and comprises lignin that has been precipitated from black liquor.

9 . The method according to claim 1 , wherein the lignin-containing material originates from a pulp production process and comprises lignin that has been precipitated from black liquor and thereafter acid washed.

10 . The method according to claim 1 , wherein the volatile compounds comprise volatile odorous compounds, and wherein the treating comprises exposing the lignin-containing material to steam at a temperature from 50 to 120° C. to vaporize at least a part of the volatile odorous compounds.

11 . The method according to claim 1 , further comprising:
before or during the treating step, forming an aqueous suspension or a moist paste of said lignin-containing material.

12 . The method according to claim 1 , wherein the volatile compounds comprise volatile odorous compounds, and wherein the method further comprises:
after or during the treating step, condensing the vaporized odorous compounds.

13 . The method according to claim 1 , wherein the lignin-containing material originates from a pulp production process.

14 . The method according to claim 1 , wherein the volatile compounds comprise sulphides, and wherein the sulphides are selected from the group consisting of dimethyl sulphide, dimethyl disulphide, dimethyl trisulphide, and combinations thereof.

15 . The method according to claim 1 , wherein the volatile compounds comprise guaiacol.

16 . The method according to claim 1 , wherein the method is carried out as a continuous process.

17 . The method according to claim 1 , wherein the treated lignin-containing material comprises less than 50 mg/kg of guaiacol of the dry matter dry matter of the lignin-containing material.

18 . The method according to claim 1 , wherein the treated lignin-containing material comprises less than 1 mg/kg of guaiacol of the dry matter of the lignin-containing material.

Assignees

• Andritz Oy

Inventors

• Poukka Outi
• Salmenkivi Katja
• Pehu-Lehtonen Lauri
• Sjögård Pauliina
• Tamminen Tarja
• Liitiä Tiina
• Ohra-Aho Taina

Classifications

• D21C11/08

  Deodorisation {; Elimination of malodorous compounds, e.g. sulfur compounds such as hydrogen sulfide or mercaptans, from gas streams (oxidation of liquors D21C11/0057; post-combustion of gases D21C11/127)} · CPC title

• D21C11/0007 Primary

  Recovery of by-products, i.e. compounds other than those necessary for pulping, for multiple uses or not otherwise provided for (volatile compounds obtained by decomposition of spent liquors in order to regenerate them D21C11/125; compounds obtained by fractionating the liquors in order to regenerate them D21C11/0042) · CPC title

• B01D5/006

  with evaporation or distillation · CPC title

• B01D3/38

  Steam distillation · CPC title

• B01D3/14

  Fractional distillation {or use of a fractionation or rectification column} · CPC title