Investigation of Oiling out phenomenon in different Industrial relevant processes


  • Salman R Naqvi


Oiling out, cooling crystallization


Oiling out is a wanted effect during the cooling crystallization of complex molecules from solution: upon cooling, crystallization is preceded by the formation of a second liquid phase (Oiling out) which disturbs the crystallization process and often deteriorates the product properties. On the basis of the crystallization of 4,4' dihydroxydiphenylsulfone (DHDPS) from water/acetone, water/1-propanol and water/ethanol mixtures, respectively. This study proved the dependence of the oiling-out behavior on the solvent system. Attempts were made to model the oiling-out phenomenon using a thermodynamic equation of state here: (Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT)). Applying this model, an oiling-out behavior of the ternary system DHDPS/water/ethanol could be predicted qualitatively. Exchanging the water/acetone, water/1-propanol solvent mixtures by a mixture of water and ethanol led to a prevention of oiling out. This could be predicted by the calculations using PC-SAFT, as well as confirmed experimentally.




How to Cite

Naqvi, S. R. (2011). Investigation of Oiling out phenomenon in different Industrial relevant processes. Journal of the Pakistan Institute of Chemical Engineers, 38(1), 55–62. Retrieved from