Patent ID: 9145346
Filing Date: 2015-09-29
Classification: C07C

Abstract:
1. A process for the crystallization from a mixture comprising cis-2,2,4,4-tetramethylcyclobutanediol and trans-2,2,4,4-tetramethylcyclobutanediol dissolved in a solvent, the process comprising: (a) crystallizing at least a portion of 2,2,4,4-tetramethylcyclobutanediol in a crystallization zone operated at a temperature such that the concentration of 2,2,4,4-tetramethylcyclobutanediol in the crystallization zone is above the saturated concentration of 2,2,4,4-tetramethylcyclobutanediol to form a slurry comprising crystallized 2,2,4,4-tetramethylcyclobutanediol and the solvent; (b) transferring the slurry to a solid-liquid separation zone, (c) separating the slurry into a mother liquor stream comprising the solvent and dissolved 2,2,4,4-tetramethylcyclobutanediol and into a wet cake stream comprising at least a portion of the crystallized 2,2,4,4-tetramethylcyclobutanediol; wherein the solvent comprises an alkyl acetate, an alkyl propionate, an alkyl carbonate, an alkyl alcohol, an aromatic hydrocarbon, an alkyl ketone, an alkyl glycol, a blend of (1) an alkyl hydrocarbon and (2) an alkyl ester, or water or mixtures thereof.