Patent ID: 7238848

Claim:
A method for removing dimethyl ether together with propane from an olefin-containing stream synthesized from methanol, comprising: contacting methanol with a small pore molecular sieve catalyst to produce the olefin-containing stream; separating C 1 /C 2 hydrocarbons from C 3 + hydrocarbons in the olefin-containing stream; separating C 3 hydrocarbons along with the dimethyl ether from C 4 + hydrocarbons; sending the C 3 hydrocarbons containing the dimethyl ether to a C 3 splitter, comprising a first portion on top half of the C 3 splitter and a second portion on the bottom half of the C 3 splitter; removing propylene from the first portion of the C 3 splitter so that a propylene product stream containing at most only traces of dimethyl ether is obtained; and removing propane from the second portion of the C 3 splitter, wherein the dimethyl ether together with the propane is removed from the second portion of the C 3 splitter as one stream.