Method for preparing high-purity dicyclopentadiene

Abstract

The invention discloses a method for preparing high-purity dicyclopentadiene (DCPD). The method comprises the steps of adding a diluting agent into crude dicyclopentadiene serving as a raw material during depolymerization, mixing dicyclopentadiene with the diluting agent in a ratio of 0.5-5, and then putting the mixture into a depolymerization rectifying tower, wherein at a normal pressure, the depolymerization temperature is 160-200 DEG C, the reflux ratio is 0.5-5, and the depolymerization time is 1-3 hours; obtaining high-purity cyclopentadiene (CPD) from the top of the tower, putting the cyclopentadiene into a tubular reactor to finally obtain dicyclopentadiene of which the purity is more than 99%, wherein the reaction temperature is 40-120 DEG C, the reaction pressure is 0.1-1.5MPa, and the residence time is 4-10 hours. The method disclosed by the invention has obvious beneficial effects, can reduce polymerization reaction of the crude dicyclopentadiene during depolymerization, and can improve the yield of the dicyclopentadiene; meanwhile, the diluting agent can ensure that impurities including isopropenyl norbornene and the like can be depolymerized, and the purity of dicyclopentadiene is improved, so that the method is particularly suitable for preparing high-purity dicyclopentadiene from the raw material of crude dicyclopentadiene which is obtained through pyrolysis C5 thermal dimerization separation.

Description

technical field [0001] The invention discloses a method for preparing high-purity dicyclopentadiene, in particular to a method for preparing high-purity dicyclopentadiene from crude dicyclopentadiene through depolymerization and dimerization. By adding a diluent in the depolymerization process of the dicyclopentadiene, the degree of depolymerization of the dicyclopentadiene is improved and aggregation of polymers in the depolymerization process is avoided. Background technique [0002] Dicyclopentadiene (DCPD) is an important fine chemical raw material, which can be used to synthesize alicyclic petroleum resins for the preparation of adhesives, ink coatings, etc., and its copolymer with ethylene propylene can be used as an epoxy resin modifier, and Copolymerization of phenols to produce rubber, plastic antioxidants, spices, high boiling point solvents, etc. [0003] The dicyclopentadiene product obtained by separating cyclopentadiene (CPD) in the by-product C5 fraction of p...

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Problems solved by technology

[0006] Chinese patent CN1334262 discloses a method for preparing high-purity cyclopentadiene and the necessary special equipment. This method can avoid the use of solvents, but there is a problem of low degree of depolymerization, and the yield of cyclopentadiene is low

CN1781887 discloses a low-temperature dicyclopentadiene production process, which catalyzes the depolymerization of dicyclopentadiene at a lower temperature. This process requires the use of catalysts, and the process is relatively complicated

CN102060649A discloses a method for preparing high-purity dicyclopentadiene, using a high-temperature carrier, in which dicyclopentadiene is depolymerized, but polymers are aggregated in it, which is easy to coke, and the device cannot run for a long time in industrial applications

[0007] Due to the long residence time of liquid phase depolymerization, the raw material crude dicyclopentadiene is easy to polymerize during the depolymerization process, resulting in low yield during the depolymerization process, and accumulation of coking of polymers in the depolymerization kettle.

At the same time, in the prior art, the degree of depolymerization of dicyclopentadiene, the yield of dicyclopentadiene, the purity of dicyclopentadiene and the continuity of the production process cannot be taken into account in the process of preparing high-purity dicyclopentadiene

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