Solubility of 2,5-Di-tert-butylhydroquinone and Process Design for Its Purification Using Crystallization

The solubility of 2,5-di-tert-butylhydroquinone (DTBHQ) in acetone, ethyl acetate, methanol, and the mixtures of ethanol and water was measured and correlated in the temperature range between 278.95 K and 346.15 K. It was found that the solubility in acetone increases more rapidly with increasing temperature than in other solvents. The data was correlated using the modified Apelblat, Buchowski-Ksiazczak λh, and Van’t Hoff equations, with a maximum relative average deviation of less than 2.74 %. The obtained thermodynamic models were used in designing a crystallization process and synthesizing a flowsheet for effective purification of crude DTBHQ from the byproduct of tertiary butylhydroquinone (TBHQ).