Process for production of bisphenol A

A process of producing bisphenol A comprising:

• (A) a step of producing a phenolic solution containing bisphenol A by reacting phenol with acetone,
• (B) a crystallization step of cooling the obtained phenolic solution containing bisphenol A in a crystallization device and continuously forming a slurry containing adduct crystals comprising phenol and bisphenol A,
• (C) a solid-liquid separation step of separating the adduct crystals from the formed slurry,
• (D) a step of producing bisphenol A by removing phenol from the separated adduct crystals,
• wherein the crystallization step is performed 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, in which the phenolic solution containing bisphenol A is fed into one compartment in the crystallization device, the produced slurry of adduct crystals is sequentially transported into each compartment, and then the temperature of the slurry in the following stage is controlled 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, and
• wherein, in the crystallization step,
• (a) the fed solution of bisphenol A in phenol is cooled at 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 (% by weight) in the final crystallization stage prior to transporting the slurry into the solid-liquid separation step and is B (% by weight) in the crystallization stage in which crystals are first formed, the value of B/A is kept at 0.7 or less.