Recovering mono-propylene glycol
AssigneeUpm-Kymmene Corporation
InventorIsko Kajanto
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Abstract
A method for recovering mono-propylene glycol from a mixture comprising bio-derived diols and an organic impurity is disclosed. The method may comprise: (ia) separating the organic impurity from mono-propylene glycol in a first distillation process, wherein the first distillation process is carried out at a temperature within the range of 140-200° C. and a pressure within the range of 0.3-1.0 bar; and (ii) recovering mono-propylene glycol. Further is disclosed mono-propylene glycol obtainable by the method.
Claims19
A method for recovering mono-propylene glycol from a mixture comprising bio-derived diols and an organic impurity, wherein the mixture comprises mono-propylene glycol in an amount of at least 50 weight-% of the total weight of the mixture, and wherein the method comprises:
- (ia) separating the organic impurity from mono-propylene glycol in a first distillation process, wherein the first distillation process is carried out at a temperature within the range of 140-200° C. and a pressure within the range of 0.3-1.0 bar;
- and
- (ib) separating diols that have a boiling point lower than the boiling point of mono-propylene glycol, from mono-propylene glycol in a second distillation process, wherein the second distillation process is carried out at a temperature within the range of 90-150° C. and a pressure within the range of 0.05-0.2 bar;
- (ii) recovering mono-propylene glycol.
Dependencies are inferred from the claim text.