Claims
- 1. A process for the production of dialkyl carbonates comprising the steps of:(a) feeding urea and a primary alcohol to a reaction zone; (b) feeding a complex compound represented by R2Sn(OCH3)2·χL, wherein R=CnH2n+1, n=1 to 12, χ=1 or 2, and L is oxygen atom containing organic complexing agent; and (c) concurrently in said reaction zone (i) reacting a portion of the primary alcohol and urea in the presence of said organotin compound and said high boiling electron donor atom containing solvent to produce dialkyl carbonate; (ii) removing the dialkyl carbonate and ammonia from said reaction zone as vapor and (iii) contacting said vapor from step (c)(ii) with DEOX under conditions of extractive distillation to selectively extract dialkyl carbonate.
- 2. The process according to claim 1 wherein ammonia and a portion of said alcohol are removed from said reaction zone as vapor and withdrawn along with said dialkyl carbonate as overheads.
- 3. The process according to claim 2 wherein said overheads are partially condensed to separate said ammonia as a vapor from said dialkyl carbonate and said alcohol as a liquid.
- 4. The process according to claim 1 wherein said R2Sn(OCH3)2 is dibutyltin dimethoxide.
- 5. The process according to claim 1 wherein said R2Sn(OCH3)2 compound comprises dibutyltin dimethoxide.
- 6. The process according to claim 1 wherein L comprises triethylene glycol dimethyl ether.
- 7. The process according to claim 1 wherein said R2Sn(OCH3)2 comprises dibutyltin dimethoxide and L comprises triethylene glycol dimethyl ether.
- 8. The process according to claim 1 wherein said R2Sn(OCH3)2 comprises dibutyltin dimethoxide and L comprises diethylene glycol dimethyl ether.
- 9. The process according to claim 1 wherein said primary alcohol comprises methanol and said dialkyl carbonate comprises dimethyl carbonate.
- 10. A process for recovering DMC from mixtures comprising contacting a DMC containing stream with DEOX under conditions of extractive distillation to selectively extract DMC into said DEOX.
- 11. The process according to claim 10 wherein said DMC containing stream contains methanol.
- 12. The process according to claim 10 wherein said DMC containing stream has previously been treated to remove NH3 by fractionation.
- 13. The process according to claim 10 wherein said DMC containing stream is vapor phage.
Parent Case Info
This application claims benefit of U.S. Provisional No. 60/212,061 filed Jun. 12, 2000.
US Referenced Citations (6)
Foreign Referenced Citations (1)
Number |
Date |
Country |
0 742 198 |
Nov 1996 |
EP |
Provisional Applications (1)
|
Number |
Date |
Country |
|
60/212061 |
Jun 2000 |
US |