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Continuous process for preparation of dian

  • US 4,301,305 A
  • Filed: 12/28/1979
  • Issued: 11/17/1981
  • Est. Priority Date: 12/30/1978
  • Status: Expired due to Term
First Claim
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1. A method of preparing dian by condensation of phenol with acetone in the presence of acid ion-exchange catalyst of sulfonated copolymer of styrene and divinylbenzene, with multiple circulation of the reaction mixture through a catalyst bed, wherein said process is conducted in three stages, characterized in that said three stages of the process are performed in two reactors in two stationary catalyst beds, each of the beds having a height of 5-20 m, each of said beds being divided into an upper and bottom zone;

  • wherein said reaction mixture is circulated in particular stages of the process with a different linear velocity, said first stage of the process being conducted in the bed of the first reactor in turn in said bottom and then upper zone of the catalytic bed at a temperature of 80°

    -85°

    C., said second stage being carried out in the bottom zone of the catalytic bed of the second reactor at a temperature of 65°

    C. to 90°

    C., and the third stage of the process being conducted in the upper zone of the second reactor at a temperature of 70°

    to 95°

    C., wherein said linear velocity of flow of the reaction mixture through the bottom zones of the catalytic bed in both of the reactors is not greater than 10 m/h, and the linear velocity of flow of the reaction mixture through the upper zones of the catalyst bed in both of the reactors is not greater than 4 m/h.

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