Systems and methods for reducing the formation of impurities during 244bb dehydrochlorination to 1234yf
View Patent ↗The present disclosure provides various manufacturing processes for the production of 2,3,3,3-tetrafluoropropene (HFO-1234yf or 1234yf). Such methods may allow for the improved yields, more economical processes, and waste reduction in the production of 1234yf and subsequent processes.
1. A method of manufacturing 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprising:
providing a feed comprising 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and 1-chloro-3,3,3-trifluoropropane (HCFC-253fb);
removing the HCFC-253fb from the feed until the feed contains less than 200 ppm of the HCFC-253fb; and
dehydrochlorinating the HCFC-244bb in the feed to form a product stream containing HFO-1234yf.
2. The method of claim 1 , wherein the removing step comprises at least one of distillation, partial vaporization, partial condensing, or combinations thereof.
3. The method of claim 2 , wherein the removing step comprises continuous distillation.
4. The method of claim 1 , wherein the removing the HCFC-253fb from the feed is performed until the feed contains less than 100 ppm of the HCFC-253fb.
5. The method of claim 4 , wherein the removing the HCFC-253fb from the feed is performed until the feed contains less than 50 ppm of the HCFC-253fb.
6. A method of manufacturing 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprising:
providing a feed comprising 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb), HF, and 1-chloro-3,3,3-trifluoropropane (HCFC-253fb);
separating the HF and the HCFC-253fb; and
dehydrochlorinating the HCFC-244bb in the feed to form a product stream containing HFO-1234yf.
7. The method of claim 6 , wherein the separating step comprises distillation.
8. The method of claim 7 , wherein the distillation is multistage distillation.
9. The method of claim 7 , wherein at least a portion of the HCFC-253fb is separated by taking a side draw from a distillation column.
10. The method of claim 7 , wherein the distillation is continuous distillation.
11. The method of claim 6 , wherein the separating comprises at least one of decanting, centrifuging, liquid-liquid extraction, distilling, flash distilling, or combinations thereof.
12. The method of claim 6 , wherein the separating step comprises forming an azeotrope in a distillation column.
13. The method of claim 6 , further comprising, after dehydrochlorination, separating and recycling unreacted HCFC-244bb.
14. A method of manufacturing 2,3,3,3-tetrafluoropropene (HFO-1234yf) comprising:
providing a feed comprising 2-chloro-1,1,1,2-tetrafluoropropane (HCFC-244bb) and 1-chloro-3,3,3-trifluoropropane (HCFC-253fb);
dehydrochlorinating the HCFC-244bb in the feed to form a product stream containing HFO-1234yf; and
controlling the formation of vinyl chloride (1140), 3,3,3-trifluoropropene (HFO-1243zf), or combinations thereof at or below a predetermined threshold, wherein the controlling the formation 1140, HFO-1243zf, or combinations thereof includes removal of HCFC-253fb prior to the dehydrochlorinating step.
15. The method of claim 14 , wherein the predetermined threshold is about 300 ppm.
16. The method of claim 14 , wherein the removal of HCFC-253fb is performed until the feed has less than 200 ppm of HCFC-253fb.
17. The method of claim 14 , wherein the formation of vinyl chloride (1140) is controlled below 200 ppm.
18. The method of claim 14 , wherein the formation of 3,3,3-trifluoropropene (HFO-1243zf) is controlled below 200 ppm.
19. The method of claim 2 , wherein the distillation comprises removal of the HCFC-244bb from a side-draw.