METHOD FOR SEPARATION BY ABSORPTION OF PYROLYSIS GAS PRODUCED FROM LOWER OLEFIN HYDROCARBONS Russian patent published in 2016 - IPC C07C7/04 C07C7/11 C07C11/02 

FIELD: oil and gas industry.

SUBSTANCE: invention is referred to method for separation by absorption of pyrolysis gas produced from lower olefin hydrocarbons, wherein primary and secondary absorbing agents are supplied to demethaniser in order to separate by absorption raw material of demethaniser by conunterflow contacting at moderate temperature and pressure, at that the above raw material is supplied to the medium or lower part of demethaniser, the above primary absorbing agent is supplied only to the medium part of demethaniser or to the medium and lower part of demethaniser simultaneously, the above secondary absorbing agent is supplied only to the upper part of demethaniser. At that the above primary absorbing agent and secondary absorbing agent are supplied to demethaniser with ratio of total flow rate of the first agent to the second one in the range from 10 to 1.05, thus obtaining top fraction containing mainly hydrogen and methane, and bottom fraction containing mainly absorbents and fraction C2+, at that the primary absorbing agent represents in essence mixed up fraction Cn or Cn+, the secondary absorbing agent represents in essence Cn' fraction of alkane or mixed up fraction Cn' or Cn'+, at that n and n' are equal to 3, 4 or 5 independently provided that when secondary absorbing agent represents mixed up fraction n' is not equal to 3.

EFFECT: usage of this invention allows increase in output of target products and reduction in power consumption during separation and treatment of pyrolysis gas.

21 cl, 5 ex, 10 tbl, 6 dwg