METHOD OF SEPARATING ETHYLENE OF POLYMERISATION PURITY FROM CATALYTIC CRACKING GASES Russian patent published in 2013 - IPC C07C11/04 C07C7/04 C07C7/11 C10G5/04 

FIELD: chemistry.

SUBSTANCE: after preliminary purification and compressing, gas is fed into an absorption-stripping column, in the top part of which light hydrocarbons are absorbed by an absorbent and in the bottom part of which the methane-hydrogen fraction is stripped, the bottom product of the absorption-stripping column is separated in a de-ethaniser into an ethane-ethylene fraction and a heavier fraction which is then fed into a depropaniser; in the depropaniser, a propane-propylene fraction and a heavier butane-butylene fraction are separated, the butane-butylene fraction is used as the absorbent in the absorption-stripping column and the ethane-ethylene fraction from the de-ethaniser is fed into an ethylene separating column, the bottom product of which is ethane, after which ethylene is fed into a fine purification unit to obtain ethylene of polymerisation purity, or the ethane-ethylene fraction from the de-ethaniser is fed into a unit for separating the ethane-ethylene fraction of the operating ethylene apparatus. The system is cooled using a propylene cooling cycle, as well as reverse ethane streams from the ethylene separating column and the methane-hydrogen fraction from the absorption-stripping column.

EFFECT: use of the present invention enables to obtain ethylene of polymerisation purity on a separate apparatus from a gas previously used as fuel.

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