RETURNING SOLVENT TO CYCLE FROM HEAVY HYDROCARBON REMOVAL COLUMN Russian patent published in 2019 - IPC C07C7/05 C07C7/11 C07C5/327 C07C5/333 

FIELD: chemistry.

SUBSTANCE: disclosed is a method of extracting a solvent, involving: passing a stream of butane into a dehydrogenation unit to form a first process stream containing olefins; contacting a first process stream with an aromatic solvent stream in a contact cooler to form an olefin stream and a second process stream containing a solvent; flow of olefins is passed into separating unit with refrigerating chamber to separate flow of light gases from condensed flow containing C₄ and C₅₊ hydrocarbons; passing the condensed stream containing C₄ and C₅₊ hydrocarbons, to a selective hydrogenation unit to form a stream with a low content of acetylenes; passing a condensed stream with a reduced content of acetylenes to a column for removing heavy compounds to form an upper stream of heavy hydrocarbons containing olefins and a lower stream of heavy compounds containing C₅₊ hydrocarbons and extracted solvent; and part of lower flow of heavy compounds is passed into contact cooler.

EFFECT: technical result is to ensure significant reduction of processing costs, reduce consumption and losses of components subjected to separation in form of wastes.

10 cl, 3 ex, 1 dwg