| 摘要 |
An object of present invention is to provide a process of producing bisphenol A, and more particularly a process of producing bisphenol A having high purity and an excellent hue. <??>In the present invention, in a crystallization step to form the slurry containing adduct crystals, (a) a fed solution of bisphenol A in phenol is cooled at the temperatures of at least two steps to form a slurry containing adduct crystals, (b) at least two crystallization stages having different cooling temperatures are provided, and (c) when the solid fraction of the slurry is A Ä% by weightÜ in the final crystallization stage prior to transporting the slurry into the solid-liquid separation step and the solid fraction of the slurry is B Ä% by weightÜ in the crystallization stage in which crystals are first formed, the value of B/A is kept 0.7 or less, and the process of the present invention comprises, by using a multi-chamber type crystallization device having its inside divided into 3 or more compartments by partitions with at least one of the compartments equipped with a cooler, feeding the phenolic solution containing bisphenol A into one compartment of a crystallization device, sequentially transporting the produced slurry of adduct crystals to each compartment and controlling the temperature of the slurry in the following stage to be lower than that in the previous stage to gradually cool the slurry containing adduct crystals in at least one set of two serial compartments. |
