METHOD OF SEPARING METHANOL GAS AND PRODUCTION OF POLYMER GRADE LOW CARBON ALKENE Russian patent published in 2011 - IPC C07C1/20 C07C11/04 C07C11/06 C07C7/04 C07C7/11 

FIELD: chemistry.

SUBSTANCE: method of separating cracking methanol gas and production of polymer grade low carbon alkene involves: (1) a compression step where cracking methanol gas enters a compression system with multi-step compression, where pressure of cracking methanol gas subjected to three-step or four-step compression reaches up to 1.1-2.5 MPaG; (2) a decontamination step in which cracking methanol gas compressed at step (1) is cleaned from impurities in a decontamination system to obtain refined cracking gas, where concentration of CO₂ in the methanol cracking gas treated at the decontamination step is less than 1 ppm and/or total content of alkyne is less than 5 ppm; (3) an adsorption and separation step where refined cracking gas obtained from step (2) successively enters the column for previous removal of ethylene, an ethylene absorber, a demethaniser and an ethylene dephlegmator to obtain a polymer grade ethylene product and a C₄ fraction and/or the same gas successively enters the column of the previous removal of ethylene, a de-ethaniser, a depropaniser and a propylene fractionation column to obtain a polymer grade propylene product and a C₅ product.

EFFECT: use of said method enables to obtain polymer grade low carbon cracking methanol gas.

14 cl, 1 ex, 2 tbl, 4 dwg