Patent ID: 7867379

Claim:
A process for producing a product stream from a steam cracked hydrocarbon feed stream comprising: a) thermally cracking a hydrocarbon feed stream in the presence of steam in an ethylene steam cracker furnace at a temperature of at least 1382° F. (750° C.) to produce a cracked product stream; b) cooling the cracked product stream to a temperature below 1382° F. (750° C.); c) fractionating the cracked product stream to produce at least a first fractionated product stream and a second fractionated product stream, wherein the second fractionated product stream has a higher final boiling point than the first fractionated product stream and the second fractionated product stream has a final boiling point greater than 1000° F. (538° C.); d) inputting the second fractionated product stream into a membrane system wherein the second fractionated product stream contacts a first side of at least a first membrane; e) passing a portion of the second fractionated product stream from the first side of the first membrane, through the first membrane, to a second side of the first membrane; f) retrieving at least a first permeate stream from the second side of the first membrane; and g) retrieving at least a first retentate stream from the first side of the first membrane; wherein the first permeate stream has a Micro Carbon Residue wt % that is at least 25% lower than the Micro Carbon Residue wt % of the second fractionated product stream.