MODELLING OF WAX CRYSTALLIZATION IN SOLVENT DEWAXING SCRAPED SURFACE EXCHANGERS AND CHILLERS

The wax removal process using scraped surface exchangers and chillers in a solvent
dewaxing unit is the most common industrial technology for the production of
lubricant oils. The proper thermal design and control of the dewaxing process in these
chilling machines is essential for a high quality product. The quality of the desired
product is based on the control of the cooling rate and the wax crystallization process.
Therefore, an appropriate mathematical model is required to simulate the dewaxing
process for such complex wax-oil-solvent mixtures. A successful mathematical model
requires a good estimation of the waxy oil-solvent properties, heat transfer
characteristics, and wax crystal formation processes. To the best knowledge of the
researchers, such coupling model for real solvent dewaxing unit does not presented in
the literatures so far. In the present work, a reliable estimation model which
comprised experimental and theoretical tools was developed.