Method for producing C9 hydrogenated resin by reusing thermally polymerized liquid resin

A method for producing a C9 hydrogenated resin by reusing a thermally polymerized liquid resin, comprising:

• 1) preheating a polymerization reaction material by a feed heat exchanger, and then subjecting a resulting preheated polymerization reaction material to polymerization in a polymerization reactor group, wherein a heat source of the feed heat exchanger is a polymerization liquid obtained after the polymerization;
• 2) transferring the polymerization liquid that has released heat in the feed heat exchanger to a flash evaporation system (11), and performing flash evaporation, wherein a top of the flash evaporation system (11) is connected to a vacuum pump (18) through a first vacuum pipeline to provide a negative pressure for the flash evaporation system (11);
• 3) transferring unpolymerized C9 and a liquid resin that are evaporated from the flash evaporation system (11) to a refining tower (9), and performing refining;
• and subjecting a thermally polymerized resin obtained from a bottom of the flash evaporation system (11) to hydrogenation to synthesize a hydrogenated resin;
• and
• 4) using a refined liquid resin obtained from a bottom of the refining tower (9) as a vacuum mother liquor of the vacuum pump (18) and then returning the refined liquid resin to a feed pipeline in front of the feed heat exchanger group or the polymerization reactor group, and making the refined liquid resin to participate in the polymerization, wherein a top of the refining tower (9) is connected to the vacuum pump (18) through a second vacuum pipeline to provide a negative pressure for the refining tower (9).