Processes utilizing solvent extraction
Embodiments of an invention disclosed herein relate to processes utilizing solvent extraction to remove nitrogen containing compounds and optionally other components from feedstreams of olefins and paraffins.
1. A process for removing nitriles and/or pyrroles from a feedstream, the process comprising the steps of:
(a) contacting at least one solvent with one or more adsorbents to remove contaminants of nitrogen and sulfur; and
(b) contacting at least one feedstream comprising olefins, paraffins, and at least one of a nitrile and/or a pyrrole with the at least one solvent produced in step (a) to remove at least a portion of the nitrile and/or the pyrrole from the at least one feedstream to produce at least one treated feedstream which comprises less than 0.1 ppm of nitrogen and a contaminated solvent;
(c) regenerating the contaminated solvent produced in step (b) by contacting the contaminated solvent with an inert gas to remove at least a portion of the nitrile and/or pyrrole to produce a regenerated solvent; and
(d) recycling at least a portion of the regenerated solvent produced in step (c) to step (a).
2. The process of claim 1 , wherein the at least one solvent is selected from the group consisting of at least one of alkyl/alkenyl/aryl carbonate, sulfolane, water, a glycol, and mixtures thereof.
3. The process of claim 1 , wherein the at least one solvent comprises a compound represented by the formula:
4. The process of claim 1 , wherein the at least one feedstream comprises one or more of C 3 -C 15 olefins, one or more paraffins having the same or different carbon number, and any isomer thereof.
5. The process of claim 1 , wherein the at least one feedstream has a liquid density (in accordance with ASTM D4052) at 15° C. of 0.89 kg/1 or less.
6. The process of claim 1 , wherein the at least one feedstream has a liquid density (in accordance with ASTM D4052) at 15° C. of 0.78 kg/1 or less.
7. The process of claim 1 , wherein the nitrile is selected from the group consisting of at least one of acetonitrile, propionitrile, and mixtures thereof.
8. The process of claim 1 , wherein the nitrile is propionitrile.
9. The process of claim 1 , wherein the process further comprises independently one or more hydrogenation steps and/or distillation steps of the at least one feedstream before or after the contacting of the at least one feedstream with the at least one solvent.
10. The process of claim 1 , wherein the process is performed in the temperature range from −25° C. to 75° C.
11. The process of claim 1 , wherein the process is performed in the temperature range from −15° C. to 50° C.
12. The process of claim 1 , wherein the process further comprises removing at least one of ammonia, amides, amines, pyridines, imides, cyanates, pyrrolidones, and mixtures thereof.
13. The process of claim 1 , wherein the process further comprises removing at least one of mercaptans, sulfides, and mixtures thereof.
14. The process of claim 1 , wherein the process occurs in a counter-current mode.
15. A process for the oligomerization of olefins, the process comprising the steps of:
(a) contacting at least one solvent with one or more adsorbents to remove contaminants of nitrogen and sulfur;
(b) contacting at least one feedstream comprising olefins, paraffins, and at least one of a nitrile and/or a pyrrole with the at least one solvent produced in step (a) to remove at least a portion of the nitrile and/or the pyrrole from the at least one feedstream to produce at least one treated feedstream which comprises less than 0.1 ppm of nitrogen and a contaminated solvent;
(c) regenerating the contaminated solvent produced in step (b) by contacting the contaminated solvent with an inert gas to remove at least a portion of the nitrile and/or pyrrole to produce a regenerated solvent;
(d) recycling at least a portion of the regenerated solvent produced in step (c) to step (a); and
(e) subsequently contacting the at least one treated feedstream with a catalyst under oligomerization conditions to produce oligomers.
16. The process of claim 15 , wherein the at least one feedstream comprises one or more of C 3 -C 15 olefins, one or more paraffins having the same or different carbon number, and any isomer thereof.
17. The process of claim 15 , wherein the catalyst is selected from the group consisting of at least one of molecular sieve catalysts, solid phosphoric acid catalysts (sPa), metal oxide catalysts, nickel-based homogeneous catalysts, and mixtures thereof.
18. The process of claim 15 , wherein the catalyst is a zeolite catalyst.
19. The process of claim 15 , wherein the at least one solvent is selected from the group consisting of at least one of an alkyl/alkenyl/aryl carbonate, sulfolane, water, a glycol, and mixtures thereof.
20. The process of claim 15 , wherein the adsorbent is selected from the group consisting of molecular sieves, activated carbons, silica gels, resins, and mixtures thereof.
21. The process of claim 15 , wherein the inert gas comprises helium, nitrogen or a mixture thereof.
22. The process of claim 15 , wherein the contaminated solvent is regenerated by stripping with hot nitrogen.
23. The process of claim 1 , wherein the adsorbent is selected from the group consisting of molecular sieves, activated carbons, silica gels, resins, and mixtures thereof.
24. The process of claim 1 , wherein the inert gas comprises helium, nitrogen or a mixture thereof.
25. The process of claim 1 , wherein the contaminated solvent is regenerated by stripping with hot nitrogen.