Processing and purification of carbonaceous materials

Patent metadata

Field	Value
Publication number	US-12312476-B2
Application number	US-202017624420-A
Country	US
Kind code	B2
Filing date	Jul 8, 2020
Priority date	Jul 10, 2019
Publication date	May 27, 2025
Grant date	May 27, 2025

Abstract

The present invention relates to a process for the processing and/or purification of carbon black comprising the steps of: a) providing carbon black containing impurities b) providing an aqueous fluid comprising a nitrogen hydride c) providing an alkali metal hydroxide and/or an alkali metal d) contacting the mixture of step a), the fluid of step b) and the alkali metal hydroxide and/or alkali metal of step c) e) subjecting the composition obtained in step d) to an elevated temperature in the range of 80 to 240° C. and an elevated pressure in the range of 5 to 50 bar f) separating a carbonaceous solid from the composition obtained in step e). The present invention further relates to the use of a nitrogen hydride as a dispersing agent for producing and/or stabilizing an aqueous suspension.

First claim

The invention claimed is:

1. A process for processing and/or purifying carbonaceous solids comprising:
a) providing a mixture comprising a carbonaceous solid and at least one inorganic compound, wherein the carbonaceous solid comprises carbon black,
b) providing an aqueous fluid comprising a nitrogen hydride,
c) providing an alkali hydroxide and/or an alkali metal
d) contacting the mixture of step a), the fluid of step b) and the alkali metal hydroxide and/or alkali metal of step c)
e) subjecting the composition obtained in step d) to a reduced or increased temperature and/or to a reduced or increased pressure
f) separating a carbonaceous solid from the composition obtained in step e).

2. The process according to claim 1 , wherein the mixture of step a) comprises the carbonaceous solid in an amount of from 50 to 99 wt. % based on a total weight of the mixture.

3. The process according to claim 2 , wherein the mixture of step a) comprises the at least one inorganic compound in an amount of from 1 to 30 wt. %, based on the total weight of the mixture.

4. The process according to claim 1 ,
wherein the mixture of step a) is obtained by pyrolysis of scrap tyres.

5. The process according to claim 1 , wherein the fluid of step b) comprises a nitrogen hydride selected from the group consisting of ammonia, inorganic ammonium salts, primary or secondary organic amines and ammonium salts thereof, and mixtures thereof.

6. The process according to claim 5 , wherein the fluid comprises ammonia and/or ammonium hydroxide.

7. The process according to claim 1 , wherein the alkali hydroxide and/or alkali metal in step c) is provided in a molar ratio to the inorganic compounds of the mixture of step a) in the range of from 0.25:1 to 2:1, and/or
wherein the fluid in step b) is provided in an amount ranging from 2 L of fluid per 1 kg of the mixture of step a to 200 L of fluid per 1 kg of the mixture of step a).

8. The process according to claim 1 , wherein step e) is carried out stepwise under at least two different conditions of temperature and pressure.

9. The process according to claim 1 ,
wherein the separated carbonaceous solid of step f) is present together with inorganic compounds in an amount of from 0.001 to 5.0 wt. %, based on the total weight of the separated carbonaceous solid and the inorganic compounds.

10. The process according to claim 1 , comprising a step g) of treating and/or working-up an aqueous phase obtained in step f), comprising the following steps:
g1) separating the nitrogen hydride according to step b) and/or reaction products thereof, and
g2) separating one or more inorganic compounds according to step a) and/or reaction products thereof, and
g3) recovering the process water.

11. The process according to claim 10 , wherein step g1) comprises separating one or more ammonium salts, and
wherein step g2) comprises separating one or more sodium silicates from the composition obtained in step g1), and
wherein step g3) comprises recovering the process water from the composition obtained in step g2).

12. The process according to claim 1 , wherein the aqueous fluid of step b) has a concentration of nitrogen hydride in the range of 0.05 to 5 mol/L.

13. The process according to claim 1 , wherein the at least one inorganic compound of step a) comprises two or more inorganic compounds which are at least poorly water soluble.

14. The process according to claim 1 , wherein the pH of the composition in step e) is adjusted to a value of 9 to 13.

15. The process according to claim 1 , wherein an alkali hydroxide is provided in step c).

16. The process according to claim 1 , wherein the at least one inorganic compound is two or more inorganic compounds comprising zinc sulphide, zinc oxide, silicon dioxide, silicates, aluminum oxide, or mixtures thereof.

17. The process according to claim 1 , wherein the composition in step e) is subjected to an increased temperature and an increased pressure.

18. The process according to claim 17 , wherein the increased temperature is a temperature in a range of 80° C. to 240° C.

19. The process according to claim 17 , wherein the increased pressure is a pressure in a range of 5 to 50 bar.

20. A process for processing and/or purifying carbonaceous solids comprising:
a) providing a mixture comprising a carbonaceous solid and inorganic compounds, wherein the carbonaceous solid comprises carbon black, and the inorganic compounds comprise zinc sulphide, zinc oxide, silicon dioxide, silicates, aluminum oxide, or any mixture thereof;
b) providing an aqueous fluid comprising a nitrogen hydride, wherein the nitrogen hydride is selected from the group consisting of ammonia, ammonium hydroxide, ammonium halides, guanidine, guanidine derivatives, and ammonium salts thereof;
c) providing an alkali hydroxide;
d) contacting the mixture of step a), the fluid of step b) and the alkali metal hydroxide of step c);
e) subjecting the composition obtained in step d) to an increased temperature and an increased pressure; and
f) separating a carbonaceous solid from the composition obtained in step e).

Assignees

• Fraunhofer Ges Forschung

Inventors

• Kaiser Christian
• Thome Volker
• Seifert Severin
• Dittrich Sebastian

Classifications

• C09C1/487

  Separation; Recovery (quenching C09C1/50 - C09C1/54) · CPC title

• C09C1/482

  Preparation from used rubber products, e.g. tyres (recovery of plastics or other constituents of waste material containing plastics B29B17/00) · CPC title

• C01P2006/12

  Surface area · CPC title

• C01P2004/64

  Nanometer sized, i.e. from 1-100 nanometer · CPC title

• C01P2004/62

  Submicrometer sized, i.e. from 0.1-1 micrometer · CPC title