Claims
- 1. A process for purifying dimethyl carbonate which comprises:
- (a) (1) continuously feeding a crude reaction mixture 1 which is a mixture mainly comprising dimethyl carbonate and methanol to a first column can A, and
- (2) simultaneously and continuously feeding a solution of dimethyl oxalate to the first column can A from the bottom of a second column can B wherein said dimethyl oxalate is added in an amount of 0.3 or more in terms of a mole fraction;
- (b) refluxing the mixture by heating the bottom of the first column to effect continuous distillation, removing methanol from the top of the first column as a first column distilled solution 3,
- (c) feeding a first column can solution 2 at the bottom thereof which is a mixture of dimethyl carbonate and dimethyl oxalate to the second column can B,
- (d) refluxing the mixture of dimethyl carbonate and dimethyl oxalate to effect continuous distillation, removing dimethyl carbonate from the top of the second column as a second column distilled solution 5, and
- (e) returning a second column can solution 4 at the bottom thereof which is dimethyl oxalate as a distillation residue to the first column can A.
- 2. The process according to claim 1, wherein dimethyl oxalate is added in an amount of 0.5 or more in terms of a mole fraction.
- 3. The process according to claim 1, wherein distillation is carried out under normal pressure.
- 4. The process according to claim 1, wherein said dimethyl carbonate is prepared by the method of using a nitrite.
Priority Claims (1)
Number |
Date |
Country |
Kind |
2-053148 |
Feb 1991 |
JPX |
|
Parent Case Info
This is a continuation of application Ser. No. 07/837,881, filed Feb. 20, 1992, pending.
US Referenced Citations (2)
Number |
Name |
Date |
Kind |
4467109 |
Tahara et al. |
Aug 1984 |
|
4663477 |
Crandall et al. |
May 1987 |
|
Continuations (1)
|
Number |
Date |
Country |
Parent |
837881 |
Feb 1992 |
|