Process for purifying renewable feedstock comprising fatty acids

Patent metadata

Field	Value
Publication number	US-11053452-B2
Application number	US-201916713247-A
Country	US
Kind code	B2
Filing date	Dec 13, 2019
Priority date	Dec 14, 2018
Publication date	Jul 6, 2021
Grant date	Jul 6, 2021

Abstract

The present invention relates to a process for purifying renewable feedstock comprising fatty acids, said process comprising the steps, where the renewable feedstock comprising fatty acids comprises at least one acid oil and at least another renewable feedstock, and it is treated with an aqueous medium, to obtain a mixture, and a first stream comprising water is separated from said mixture and a second stream comprising fatty acids is obtained as purified renewable feedstock.

First claim

The invention claimed is:

1. A process for purifying renewable feedstock comprising fatty acids, wherein said process comprises the steps, where the renewable feedstock comprising fatty acids comprises at least one acid oil and at least another renewable feedstock, and said renewable feedstock comprising fatty acids is treated with an aqueous medium, at the temperature from 140 to 195° C., under a pressure from 0.1 to 70 bar (abs), and where the ratio of the renewable feedstock comprising fatty acids to the aqueous medium is from 1:5 to 5:1, respectively, to obtain a mixture, and a first stream comprising water and a second stream comprising fatty acids are separated from said mixture, and the second stream is obtained as purified renewable feedstock, wherein the renewable feedstock comprising fatty acids comprises 20-95 wt % of acid oil or mixtures of acid oils.

2. The process according to claim 1 , wherein the purified renewable feedstock comprises not more than 50 mg/kg phosphorus, calculated as elemental phosphorus.

3. The process according to claim 1 , wherein the purified renewable feedstock comprises not more than 100 mg/kg of alkali metals, alkaline earth metals, metals of the groups VIIB and VIIIB of the Periodic table of elements, or combinations thereof, calculated as elemental metals.

4. The process according to claim 1 , wherein the first stream comprising water comprises not more than 10 000 mg/kg total organic carbon.

5. The process according to claim 1 , wherein the purified renewable feedstock comprises not more than 50 mg/kg phosphorus and not more than 100 mg/kg alkali metals, alkaline earth metals, metals of the groups VIIB and VIIIB of the Periodic table of elements, or combinations thereof, and the first stream comprising water comprises not more than 10 000 mg/kg total organic carbon.

6. The process according to claim 1 , wherein the aqueous medium comprises 0.01 to 3 wt % of an acid selected from sulphuric acid and C1-C10 organic acids, calculated based on the renewable feedstock comprising fatty acids.

7. The process according to claim 6 , wherein the C1-C10 organic acid is EDTA or C1-C6 organic acid selected from citric acid, formic acid, oxalic acid, acetic acid, butyric acid, valeric acid, caproic acid and propionic acid.

8. The process according to claim 6 , wherein the acid is sulphuric acid.

9. The process according to claim 1 , wherein the aqueous medium comprises water, mixtures of water and steam, or mixtures of streams comprising water or water and steam, with water soluble and/or water miscible organic compounds.

10. The process according to claim 1 , wherein the other renewable feedstock is selected from the group consisting of fatty acid distillates from physical refining of plant oils or animal fats, distillers corn oil from ethanol production, crude tall oil, waste cooking oils, lard, brown grease, trap grease, waste fats, low-grade oils, super critical water liquefaction oils, pyrolysis oils, plant oils, animal fats and any combination thereof.

11. The process according to claim 1 , wherein the other renewable feedstock comprises crude tall oil.

12. The process according to claim 1 , wherein the renewable feedstock comprising fatty acids comprises 5-80 wt % of another renewable feedstock or a combination thereof.

13. The process according to claim 1 , wherein the renewable feedstock comprising fatty acids comprises 30-95 wt % of acid oil or mixtures of acid oils and 5-70 wt % of crude tall oil.

14. The process according to claim 1 , wherein the aqueous medium comprises not more than 3 wt % of organic compounds.

15. The process according to claim 1 , wherein the temperature is from 140 to 190° C.

16. The process according to claim 1 , wherein the pressure is from 1 to 60 bar (abs).

17. The process according to claim 1 , wherein the residence time is from 10 min to 12 hours.

18. The process according to claim 1 , wherein the pH of the first stream is in the range from 0 to 6.5.

19. The process according to claim 1 , wherein the second stream is fractionated to obtain a gaseous fraction, a light liquid fraction and a heavy liquid fraction.

20. The process according to claim 1 , wherein at least part of the first stream is recirculated to the aqueous medium.

21. The process according to claim 1 , wherein the carbon yield is at least 98%.

22. The process according to claim 1 , wherein the purified renewable feedstock comprises not more than 10 mg/kg phosphorus, calculated as elemental phosphorus.

23. The process according to claim 1 , wherein the purified renewable feedstock comprises not more than 50 mg/kg of alkali metals, alkaline earth metals, metals of the groups VIIB and VIIIB of the Periodic table of elements, or combinations thereof, calculated as elemental metals.

24. The process according to claim 1 , wherein the aqueous medium comprises 0.01 to 3 wt % of organic compounds.

25. The process according to claim 1 , wherein the temperature is from 145 to 185° C.

26. The process according to claim 1 , wherein the residence time is from 15 min to 3 hours.

27. The process according to claim 1 , wherein the pH of the first stream is in the range from 0.1 to 4.

Assignees

• Upm Kymmene Corp

Inventors

• Gutierrez Andrea
• Björklöf Thomas

Classifications

• C11B3/00 Primary

  Refining fats or fatty oils · CPC title

• C11B13/00

  Recovery of fats, fatty oils or fatty acids from waste materials · CPC title

• C11B3/006 Primary

  by extraction · CPC title

• C11B13/005

  of residues of the fabrication of wood-cellulose (in particular tall-oil) · CPC title

• Y02P30/20

  using bio-feedstock · CPC title