Process for purifying a mixture of diols
AssigneeNovamont S.p.A.
InventorMarco Cotti Comettini
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Abstract
The present invention relates to a process for the separation of 1,3 and 1,4-butanediol from a mixture thereof.
Claims17
A process for the separation of 1,3-butanediol having a purity of more than 99% by weight and 1,4-butanediol having a purity of more than 98% by weight from a mixture thereof comprising a preliminary step of mixing synthesis products containing 1,3-butanediol with synthesis product containing 1,4-butanediol and the further steps of
- (a) removing from said mixture, by one or more distillation operations,
- i. solvent
- ii. a heavy fraction
- iii. a light fraction
- iv. a fraction including 1,4-butanediol,
- wherein at least one of said fractions (iii) and (iv) comprises 1,3-butanediol;
- (b) subjecting at least one of said fractions (iii) and (iv) comprising 1,3-butanediol to further distillation;
- wherein the heavy fraction means compounds with a higher boiling point than 1,4-butanediol, and the light fraction means compounds with a lower boiling point than 1,3-butanediol.
A process for producing a polyester of the diacid-diol type which comprises reacting a 1,4-butanediol composition having a concentration of the 1,4-butanediol exceeding 98.0% by weight and including 1,3-butanediol in an amount of from 20 ppm to 20000 ppm as source of diol, wherein the polyester of the diacid-diol type comprises:
- (a) a dicarboxylic component comprising:
- (a1) 0-80% by moles, relative to the total dicarboxylic component, of units derived from at least one aromatic dicarboxylic acid, and
- (a2) 20-100% by moles, relative to the total dicarboxylic component, of units derived from at least one aliphatic dicarboxylic acid, and
- (b) a diol component comprising 1,4-butanediol.
A polyester of the diacid-diol type comprising:
- (a) a dicarboxylic component comprising:
- (a1) 0-80% by moles, relative to the total dicarboxylic component, of units derived from at least one aromatic dicarboxylic acid, and
- (a2) 20-100% in by moles, relative to the total dicarboxylic component, of units derived from at least one aliphatic dicarboxylic acid, and
- (b) a diol component comprising 1,4-butanediol, the said polyester comprising from 10 ppm to 10000 ppm of 1,3-BG.
Dependencies are inferred from the claim text.