Title:
METHOD OF SEPARATING DIMETHYL CARBONATE AND METHANOL
Document Type and Number:
WIPO Patent Application WO/2000/064853
Kind Code:
A2
Abstract:
This invention relates to a method of separating methanol and dimethyl carbonate in a distillation column through extractive distillation. The extractive distillation is conducted in the presence of an extractive distillation agent which modifies the azeotropic behavior of the dimethyl carbonate/methanol mixture. A vapor side stream is removed from the distillation column.
Inventors:
NISOLI ALBERTO
BOUWENS STEPHAN MATHYS
DOHERTY MICHAEL FRANCIS
MALONE MICHAEL FRANCIS
BOUWENS STEPHAN MATHYS
DOHERTY MICHAEL FRANCIS
MALONE MICHAEL FRANCIS
Application Number:
PCT/US2000/008934
Publication Date:
November 02, 2000
Filing Date:
April 04, 2000
Export Citation:
Assignee:
GEN ELECTRIC (US)
International Classes:
C07C31/04; C07C67/54; C07C29/84; C07C68/08; C07C69/96; (IPC1-7): C07C68/00
Foreign References:
| EP0581115A2 | 1994-02-02 | |||
| CN1212172A | 1999-03-31 | |||
| JP2000086592A | 2000-03-28 |
Other References:
PATENT ABSTRACTS OF JAPAN vol. 018, no. 222 (C-1193), 21 April 1994 (1994-04-21) & JP 06 016596 A (ASAHI CHEM IND CO LTD), 25 January 1994 (1994-01-25)
CHEMICAL ABSTRACTS, vol. 130, no. 1, 4 January 1999 (1999-01-04) Columbus, Ohio, US; abstract no. 5103y, HELIN PAN: "Separation of methanol-DMC azeotrope by extractive distillation" page 570; column 1; XP002901265 & HUADONG LIGONG DAXUE XUEBAO, vol. 24 424, no. 4, 1998, pages 389-392,
CHEMICAL ABSTRACTS, vol. 130, no. 1, 4 January 1999 (1999-01-04) Columbus, Ohio, US; abstract no. 5103y, HELIN PAN: "Separation of methanol-DMC azeotrope by extractive distillation" page 570; column 1; XP002901265 & HUADONG LIGONG DAXUE XUEBAO, vol. 24 424, no. 4, 1998, pages 389-392,
Attorney, Agent or Firm:
Snyder, Bernard (3135 Easton Turnpike W3C Fairfield, CT, US)
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Claims:
WHAT IS CLAIMED IS:
| 1. | A method of separating dimethyl carbonate and methanol from a mixture comprising dimethyl carbonate and methanol in a distillation column, the method comprising the steps of A) distilling a mixture comprising dimethyl carbonate and methanol in the presence of an extractive distillation agent selected from the group consisting of an aromatic hydroxy compound, an alkyl aryl ether, a dialkyl carbonate, an alkyl aryl carbonate, a diaryl carbonate, an alkylene carbonate and an alicyclic alcohol; and B) removing a side stream comprising primarily dimethyl carbonate from the distillation column. |
| 2. | The method of claim 1, wherein the side stream is below a point where a feed stream comprising the dimethyl carbonate and methanol enters the distillation column. |
| 3. | The method of claim 1, wherein the side stream is above a point where a feed stream comprising the dimethyl carbonate and methanol enters the distillation column. |
| 4. | The method of claim 1, wherein steps A) and B) are conducted simultaneously. |
| 5. | The method of claim 1, wherein the extractive distillation agent is anisole. |
| 6. | The method of claim 1, wherein the extractive distillation agent is phenol. |
| 7. | The method of claim 1, wherein the side stream is removed at a point in the column where the vapor mass fraction of dimethyl carbonate in the column is at or near a maximum. |
| 8. | A method for separating dimethyl carbonate and methanol from a mixture comprising dimethyl carbonate and methanol in a single distillation column comprising the steps of: A) feeding a dimethyl carbonate/methanol feed stream comprising dimethyl carbonate and methanol and a second stream comprising an extractive distillation agent into the distillation column, the dimethyl carbonate/methanol feed stream being fed into the extractive distillation column below the second stream, the extractive distillation agent selected from the group consisting of an aromatic hydroxy compound, an alkyl aryl ether, a dialkyl carbonate, an alkyl aryl carbonate, a diaryl carbonate, an alkylene carbonate and an alicyclic alcohol; B) distilling the dimethyl carbonate and methanol in the presence of the extractive distillation agent in the distillation column; and; C) removing an overhead product stream, a side product stream, and a bottom product stream from the distillation column, the overhead product stream comprising primarily methanol, the side product stream comprising primarily dimethyl carbonate and the bottom product stream comprising primarily the extractive distillation agent. |
| 9. | The method of claim 8, wherein the side product stream is removed at a point in the distillation column where the vapor mass fraction of the dimethyl carbonate in the column is at or near a maximum. |
| 10. | The method of claim 8, further comprising the step of recycling the bottom product stream to the second stream. |
| 11. | The method of claim 8, further comprising the step of feeding an entrainer makeup stream to the second stream. |
| 12. | The method of claim 8, wherein the extractive distillation agent is phenol. |
| 13. | The method of claim 8, wherein the extractive distillation agent is anisole. |
| 14. | The method of claim 8, wherein the mass ratio of the second stream to the dimethyl carbonate/methanol feed stream is from 0.1: 1 to 10: 1. |
| 15. | The method of claim 12, wherein the mass ratio of the second stream to the dimethyl carbonate/methanol feed stream is from 2: 1 to 4: 1. |
| 16. | The method of claim 13, wherein the mass ratio of the second stream to the dimethyl carbonate/methanol feed stream is from 0.5: 1 to 2: 1. |
| 17. | The method of claim 8, wherein the pressure in the rectification column is from 1 to 10 bar. |
| 18. | The method of claim 8, further comprising the step of feeding the side product stream comprising primarily dimethyl carbonate to a side rectification column having a distillation zone, distilling the dimethyl carbonate to remove impurities from the dimethyl carbonate, and removing from the side rectification column a product liquid stream comprising dimethyl carbonate having a purity greater than the side product stream. |
| 19. | The method of claim 8, wherein steps A) through C) are conducted simultaneously. |
| 20. | A method of separating dimethyl carbonate and methanol from a mixture comprising dimethyl carbonate and methanol in a distillation column, the method comprising the steps of A) distilling a mixture comprising dimethyl carbonate and methanol in the presence of an extractive distillation agent selected from the group consisting of phenol and anisole; and B) removing a side stream comprising primarily dimethyl carbonate from the distillation column. |
| 21. | A method for separating dimethyl carbonate and methanol from a mixture comprising dimethyl carbonate and methanol in a single distillation column comprising the steps of: A) feeding a dimethyl carbonate/methanol feed stream comprising dimethyl carbonate and methanol and a second stream comprising an extractive distillation agent into the distillation column, the dimethyl carbonate/methanol feed stream being fed into the extractive distillation column below the second stream, the extractive distillation agent selected from the group consisting of phenol and anisole; B) distilling the dimethyl carbonate and methanol in the presence of the extractive distillation agent in the distillation column; and; C) removing an overhead product stream, a side product stream, and a bottom product stream from the distillation column, the overhead product stream comprising primarily methanol, the side product stream comprising primarily dimethyl carbonate and the bottom product stream comprising primarily the extractive distillation agent. |
| 22. | The method of claim 21, further comprising the step of recycling the bottom product stream to the second stream. |
| 23. | A method for separating dimethyl carbonate and methanol from a mixture comprising dimethyl carbonate and methanol in a single distillation column comprising the steps of: A) feeding a dimethyl carbonate/methanol feed stream comprising dimethyl carbonate and methanol and a second stream comprising an extractive distillation agent into the distillation column, the first stream being fed into the extractive distillation column below the second stream, the extractive distillation agent is phenol; B) distilling the dimethyl carbonate and methanol in the presence of the extractive distillation agent in the distillation column; and; C) removing an overhead product stream, a side product stream, and a bottom product stream from the distillation column, the overhead product stream comprising primarily methanol, the side product stream comprising primarily dimethyl carbonate and the bottom product stream comprising primarily the extractive distillation agent. |
| 24. | The method of claim 23, further comprising the step of feeding the side product stream comprising primarily dimethyl carbonate to a side rectification column having a distillation zone, distilling the dimethyl carbonate to remove impurities from the dimethyl carbonate, and removing from the side rectification column a product liquid stream comprising dimethyl carbonate having a purity greater than the side product stream. |
| 25. | The method of claim 24, wherein the product liquid stream is pure. |
Description:
INTERNATIONALSEARCHREPORT r------------------) Intematio"'AppiicatlonNo PCT/U)00/08934 C.(Continuation)DOCUMENTSCONSIDEREDTOBERELEVANT CategoryCitation ofdocument,withindication,whereappropriate,oftherelevantpass
agesRelevant to claim No. ACHEMICALABSTRACTS,vol.130,no.1, 1 4January1999(1999-01-04) Columbus,Ohio,US; abstractno.5103y, HELINPAN:"Separation ofmethanol-DMC azeotropebyextractivedistillation" page570;column1; * XP002901265 abstract &HUADONGLIGONGDAXUEXUEBAO, vol.24424,no.4,1998,pages389-392, XCN1212172A(CHINAPETROCHEMICALCORP)1 31March1999(1999-03-31) thewholedocument -&CHEMICALABSTRACTS,vol.133,no.1, 3July2000(2000-07-03) Columbus,Ohio,US; abstractno.6148r, XIAOB:"Separating azeotropeofmethanol anddimethylcarbonatebyextractive distillation" page6149;column2; XP002901266 abstract P,XJP2000086592A(KOKAITOKKYOKOHO)1 28March2000(2000-03-28) thewholedocument -&CHEMICALABSTRACTS,vol.132,no.18, 1May2000(2000-05-01) Columbus,Ohio,US; abstractno.236813n, MIURAHETAL:"Energy-efficient purificationofcarbonatediestersby extractivedistillation,andapparatusfor theprocess" page682;column1; XP002901267 abstract INTERNATIONALSEARCHREPORT r-----------------) Intemational ApplicationNo Int lation on patent tamiy members pCT j U 00/08934 l PatentdocumentPublicationPatentfamily Publication citedinsearchreportdatemember(s)date JP06016596A25-01-1994NONE EP0581115A02-02-1994DE4224770A03-02-1994 DE59302580D20-06-1996 ES2086834T01-07-1996 JP6157423A03-06-1994 CN1212172A31-03-1999NONE JP2000086592A28-03-2000NONE