METHOD AND APPARATUS FOR EXTRACTING METHOXYPROPANOLS FROM WATER STREAM Russian patent published in 2024 - IPC C07C41/38 C07C43/13 B01D11/04 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method and apparatus for extracting 1-methoxy-2-propanol and 2-methoxy-1-propanol from a waste water stream. Method includes the following stages: a) extracting waste water stream (101) using extraction solvent stream (102) in countercurrent extraction column (1) at temperature of 20 to 60 °C, to obtain raffinate stream (103) and extract stream (104), b) heating extract stream (104) by passing it through heat exchanger (8) in heat consumption area of heat exchanger to produce heated extract stream, c) extractive distillation of the heated extract stream in an extractive distillation column (3) comprising an extraction solvent inlet (105) located above the heated extract stream inlet, to obtain a first stream of overhead product (106) enriched with water and a first stream of bottoms product (107) depleted of water compared to the heated extract stream, d) distillation of first stream of bottoms product (107) in distillation column for extraction of solvent (4) to obtain second stream of overhead product (108) containing 1-methoxy-2-propanol and 2-methoxy-1-propanol, and second stream of bottoms product (109) containing the extracted solvent for extraction, e) distilling second overhead stream (108) in a distillation column for separating isomers (5) to obtain a third overhead stream (110) containing 1-methoxy-2-propanol, and a third bottoms stream (111) containing 2-methoxy-1-propanol, f) cooling the second still product stream (109) by passing it through heat exchanger (8) in the heat exchanger heat input region to obtain an extracted solvent stream for extraction, and g) directing a portion of the extracted solvent stream for extraction to step a) for use as an extraction solvent stream (102) and a portion of the extracted solvent stream for extraction to step c) for use as extraction solvent (105).

EFFECT: reducing the content of organic impurities in the waste water stream without the need to heat this stream for distillation.

14 cl, 1 dwg, 5 tbl, 5 ex