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

Abstract

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 to 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 h, and Van't Hoff equations, with the maximum relative average deviation less than 2.74 %. The obtained thermodynamic models were used in designing a crystallisation process and synthesizing a flowsheet for effective purification of crude DTBHQ from the by-product of tertiary butylhydroquinone (TBHQ).

Solubility in Different Solvents, Crystal Polymorph and Morphology, and Optimization of Crystallization Process of AIBN

“…Therefore, the growth of crystals from the solutions should be exothermic. 10 The experiments were performed in a 50 mL double-jacketed glass crystallizer, and the temperature was controlled using a JULABO refrigerated and heating circulator. The jacketed glass crystallizer was constantly stirred, and the experimental design is shown in Table 9.…”

“…The enthalpy of AIBN dissolution in all the solvents was positive, which indicated the dissolution of AIBN in all the solvents was endothermic. Therefore, the growth of crystals from the solutions should be exothermic Table lists the RAD values obtained with the different correlation models.…”

“…The Van’t Hoff model is also widely used to model the relationships between the mole fraction solubility, temperature, enthalpy of dissolution, and entropy of dissolution: , where x A is the mole fraction solubility, T is the absolute temperature, R is the gas constant, and ΔH and ΔS represent the enthalpy of dissolution and entropy of dissolution, respectively. ΔH and ΔS are assumed to be independent of the temperature within a certain temperature range.…”

Measurement and Correlation of the Solubility for Camptothecine in Different Organic Solvents

“…It is essential to choose a proper solvent in the process of crystallization for it has important influence on the purity, form, crystal morphology, and so on. Moreover, the solubility data is an important factor to obtain the optimization of crystallization processes . However, in our knowledge, no experimental study concerning the solubility of camptothecine in the system of chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed solvents.…”

“…Moreover, the solubility data is an important factor to obtain the optimization of crystallization processes. 3 However, in our knowledge, no experimental study concerning the solubility of camptothecine in the system of chloroform, methanol, ethanol, and {chloroform + (methanol or ethanol)} mixed solvents. In this work, solubility data were experimentally determined at atmospheric pressure over the temperature range of 276.13−326.59 K by using a gravimetric method.…”