Removal of solubilized metals from Fischer-Tropsch products
The present disclosure is directed to a method and system of removing solubilized metals from a Fischer-Tropsch (FT) reactor product. The FT reactor product is contacted with a chelating agent to form metal complexes. The FT reactor product containing metal complexes are subjected to centrifugal separation to form a heavy phase and a light phase containing less than 500 wppb solubilized metals.
1. A method of removing solubilized metals from a Fischer-Tropsch (FT) reactor product, comprising:
contacting the FT reactor product with a chelating agent solution to form metal complex(es); and
subjecting the FT product containing the metal complex(es) to centrifugal separation to form a heavy phase and a light phase containing less than 500 wppb solubilized metals;
wherein
the chelating agent solution comprises a chelating agent and a solvent; and
the solvent comprises a glycol, an alcohol, or combinations thereof.
2. The method of claim 1 wherein the light phase is contacted with adsorbent media and/or filtration aids and filtered through a pressure leaf filter to provide a treated FT product.
3. The method of claim 2 wherein the treated FT product contains less than 300 wppb solubilized metals.
4. The method of claim 2 wherein
the FT reactor product comprises carboxylic acids; and
the method removes at least 30% of the carboxylic acids in providing the treated FT product.
5. The method of claim 4 wherein the method removes at least 60% of the carboxylic acids in providing the treated FT product.
6. The method of claim 2 further comprising either fractionating the treated FT product into fuel cuts without hydroprocessing, or hydroprocessing the treated FT product or fractions thereof.
7. The method of claim 6 wherein the hydroprocessing step saturates olefins.
8. The method of claim 6 wherein the hydroprocessing step isomerizes paraffins.
9. The method of claim 1 wherein the chelating agent comprises citric acid.
10. The method of claim 1 wherein the centrifugal separation is conducted in a stacked disc centrifuge.
11. The method of claim 1 wherein additional water is provided for the centrifugal separation step.
12. The method of claim 1 wherein the solubilized metals comprise cobalt or iron.
13. The method of claim 12 wherein the solubilized metals additionally comprise titanium or lanthanum.
14. The method of claim 1 wherein the contacting comprises high-shear mixing.
15. The method of claim 1 wherein the contacting comprises static mixing.
16. The method of claim 1 wherein the chelating agent comprises sodium tripolyphosphate, hydroxyethylenephosphoric acid, ethylene diamine tetraacetic acid, acetylacetone, tartaric acid, citric acid, oxalic acid, diethylenetriamine, triethanolamine, or combinations of any two or more thereof.
17. A method of removing solubilized metals from a Fischer-Tropsch (FT) reactor product, comprising:
contacting the FT reactor product with a chelating agent solution to form metal complex(es); and
contacting the FT product containing the metal complex(es) with absorbent and/or adsorbent media and/or filtration aids and filtering to provide a treated FT product containing less than 500 wppb solubilized metals;
wherein
the chelating agent solution comprises a chelating agent and a solvent; and
the solvent comprises a glycol, an alcohol, or combinations thereof.
18. The method of claim 17 wherein the chelating agent comprises citric acid.
19. The method of claim 17 wherein the treated FT product contains less than 300 wppb solubilized metals.
20. The method of claim 17 wherein
the FT reactor product comprises carboxylic acids; and
the method removes at least 30% of the carboxylic acids in providing the treated FT product.
21. The method of claim 20 wherein the method removes at least 60% of the carboxylic acids in providing the treated FT product.
22. The method of claim 17 further comprising either fractionating the treated FT product into fuel cuts without hydroprocessing, or hydroprocessing the treated FT product or fractions thereof.
23. The method of claim 22 wherein the hydroprocessing step saturates olefins.
24. The method of claim 22 wherein the hydroprocessing step isomerizes paraffins.
25. The method of claim 17 wherein the solubilized metals comprise cobalt or iron.
26. The method of claim 25 wherein the solubilized metals additionally comprise titanium or lanthanum.
27. A method comprising:
contacting a Fischer-Tropsch (FT) reactor product with a chelating agent solution to form metal complex(es); and
subjecting the FT product containing the metal complex(es) to centrifugal separation to form a heavy phase and a light phase;
wherein
the chelating agent solution comprises a chelating agent and a solvent;
the concentration of the chelating agent in the chelating agent solution is about 35 wt % to about 75 wt %; and
the solvent comprises a glycol, an alcohol, or combinations thereof.
28. The method of claim 27 wherein the chelating agent comprises citric acid.