PURIFICATION OF ADDUCT CRYSTALS BY A MELT COLUMN PURIFIER

摘要

A new concept of melt crystallization operation has been introduced with the intentional formation of adducts, i.e. mixtures of a product component and an adduct former. In a column, a slurry containing adduct crystals was fed, and the crystal particles were sweated when they settled down to the bottom end where they were melted (resolved) to form a reflux liquid stream containing the two components. A few test operations have been conducted with the ternary system of phenol - 2,2- bis(p-hydroxyphenyl)propane (BPA) - its isomer containing some impurities. With this ternary system the adduct crystals were successfully separated and purified from the third component of the isomer. The achieved purity was high enough compared with other conventional separation methods and was analyzed in terms of the separation factor. The operation of the proposed adduct crystal column was found to be very stable.