PROPYLENE OXIDE PURIFICATION METHOD Russian patent published in 2021 - IPC C07D301/32 C07D303/04 

FIELD: chemical or physical processes.

SUBSTANCE: present invention relates to a method of purifying propylene oxide, comprising: (i) providing a stream of S0 containing propylene oxide, acetonitrile, water and an organic compound, containing a carbonyl group -C(=O)-, wherein said organic compound containing a carbonyl group -C(=O)- contains one or more of acetone and propionaldehyde; (ii) separating propylene oxide from stream S0 through distillation, comprising (ii.1) exposing stream S0 to distillation conditions in a first distillation unit, to obtain gaseous upper stream S1c, which is enriched with propylene oxide, compared to stream S0, liquid bottom stream S1a, which is enriched with acetonitrile and water, compared to flow S0, and side stream S1b, containing propylene oxide, which is enriched with carbonyl compound, compared to flow S0; (ii.2) reacting a carbonyl compound, contained in lateral stream S1b, with organic compound containing amino group -NH2, to obtain reaction product of organic compound containing carbonyl group, and an organic compound containing an amino group; (ii.3) separating propylene oxide from the reaction product of the organic compound containing a carbonyl group and an organic compound, containing an amino group, in a second distillation unit, to obtain gaseous upper stream S3a, which is enriched with propylene oxide, and a liquid lower stream S3b, which is enriched in reaction product of organic compound containing carbonyl group, and organic compound containing amino group; (ii.4) introducing an upper stream S3a, which is enriched with propylene oxide, into first distillation unit.

EFFECT: disclosed method enables to avoid accumulation of reagents and reaction products of carbonyl compounds with reagents of trapping in recycle flow of acetonitrile solvent.

21 cl, 3 tbl, 6 ex, 3 dwg