Methods for integrated separation of dienes

A method of processing pygas, the method comprising:

• separating the pygas to produce a C4-C5 stream comprising C4 and C5 hydrocarbons and a C6-C9+ stream comprising C6+ hydrocarbons;
• separating the C4-C5 stream to produce a C4 stream comprising C4 hydrocarbons and a C5 stream comprising C5 hydrocarbons;
• processing the C5 stream in a dimerization unit under reaction conditions sufficient to dimerize cyclopentadiene of the C5 stream and form a reactor product stream comprising C5 hydrocarbons and dicyclopentadiene;
• separating the reactor product stream to produce a top product stream comprising C5 hydrocarbons and a bottom product stream comprising dicyclopentadiene;
• separating the top product stream to produce a first product stream comprising isoprene, a second product stream comprising pentadiene, and a C5 raffinate comprising pentanes, pentenes, and/or piperlynes;
• processing the C5 raffinate in a first hydrogenation unit to hydrogenate the pentenes and/or piperlynes;
• processing the C4 stream in the first hydrogenation unit under reaction conditions sufficient to saturate unsaturated C4 hydrocarbons of the C4 stream;
• separating the C6-C9+ stream in a deheptanizer to produce a C6-C7 stream comprising C6 and C7 hydrocarbons and a C8-C9+ stream comprising C5 and C9+ hydrocarbons;
• processing the C6-C7 stream in a second hydrogenation unit under reaction conditions sufficient to produce benzene and toluene;
• separating the C8-C9+ stream in a deoctanizer to produce a C8 stream comprising C8 hydrocarbons and a C9+ stream comprising unhydrogenated C9+ hydrocarbons;
• and
• processing the C8 stream in a styrene separation unit to produce a xylene stream comprising primarily xylene and a styrene stream comprising primarily styrene.

A method of processing pygas, the method comprising:

• separating the pygas to produce a C4-C5 stream comprising C4 and C5 hydrocarbons and a C6-C9+ stream comprising C6+ hydrocarbons;
• separating the C4-C5 stream to produce a C4 stream comprising C4 hydrocarbons and a C5 stream comprising C5 hydrocarbons;
• processing the C5 stream in a dimerization unit under reaction conditions sufficient to dimerize cyclopentadiene of the C5 stream and form a reactor product stream comprising C5 hydrocarbons and dicyclopentadiene;
• separating the reactor product stream to produce a top product stream comprising C5 hydrocarbons and a bottom product stream comprising dicyclopentadiene;
• separating the top product stream to produce a first product stream comprising isoprene, a second product stream comprising pentadiene, and a C5 raffinate comprising pentanes, pentenes, and/or piperlynes;
• processing the C5 raffinate in a first hydrogenation unit to hydrogenate the pentenes and/or piperlynes;
• processing the C4 stream in the first hydrogenation unit under reaction conditions sufficient to saturate unsaturated C4 hydrocarbons of the C4 stream;
• processing the C6-C9+ stream in a second hydrogenation unit under reaction conditions sufficient to produce a hydrogenated C6-C9+ stream;
• separating the hydrogenated C6-C9+ stream to produce a purified C6-C9+ stream and a fuel gas stream;
• and
• separating the purified C6-C9+ stream in a deoctanizer to produce a hydrogenated C6-C8 stream comprising benzene, toluene, xylene, and ethylbenzene, a hydrogenated wash oil stream, and a hydrogenated fuel oil stream.