METHOD AND APPARATUS FOR EXTRACTING BISPHENOL A Russian patent published in 2011 - IPC C07C39/16 C07C37/84 C07C37/20 B01D9/02 

FIELD: chemistry.

SUBSTANCE: present invention relates to a method of extracting bisphenol A, involving: (A) a condensation reaction step on which excess amount of phenol reacts with acetone in the presence of an acid catalyst; (B) a concentration step on which the reaction mixture obtained at step (A) is concentrated; (C) a step for crystallising and separating liquid and solid, on which the reaction mixture concentrated at step (B) is cooled such that the adduct of bisphenol A and phenol crystallises and separated into an adduct and a mother solution; (D) an isomerisation step on which all the mother solution obtained at step (C) is treated with an isomerisation catalyst and isomerised; (E) an extraction step on which the adduct of bisphenol A and phenol is extracted from the isomerised liquid obtained at step (D); (F) a step for decomposing the adduct on which phenol is removed from the adduct of bisphenol A and phenol obtained at step (C) to obtain molten bisphenol A; and (G) a granulation step on which molten bisphenol A is granulated into product granules. The method of extracting the adduct of bisphenol A and phenol at step (E) involves 1) crystallisation of the adduct of bisphenol A and phenol in the presence of phenol while feeding liquid isomerised at step (D) into a crystalliser, having an outer jacket and fitted with a scrubber for scraping precipitate on its inner wall when cooling water passes through the outer jacket so as to cool the inside of the crystalliser; 2) scraping adduct deposited on the inner wall of the crystalliser; 3) filtering and washing the adduct suspension on a periodic-type filter, having a washing function and serving as a solid/liquid separator and 4) circulation of the adduct obtained at step (B) and/or step (C). Present invention also relates to apparatus for extracting the adduct of bisphenol A and phenol from isomerised liquid at step (E) of the disclosed method.

EFFECT: high efficiency of the method of extracting bisphenol A.

3 cl, 3 ex