Intensification and improvement of petrolatum deoiling process by using pure n-alkanes as non-polar modifiers

Abstract

In order to intensify and improve the deoiling process, Alexandria crude petrolatum was subjected to one-stage fractional crystallization (deoiling process) using butyl acetate and methyl isobutyl ketone solvents at different solvent feed ratios of dilution ranging from 2:1 to 8:1 at fixed washing solvent ratio of 2:1 and ambient fractionating temperature of 20°C to produce micro-crystalline waxes. Non-polar modifiers such as individual pure n-alkanes with an even number of carbon atoms such as C20H42, C22H46 and C24H50 were added to the petrolatum deoiling solvent mixture in the percentages ranging from 0.05 to 1wt.% based on the feed to intensify petrolatum deoiling. Two tools of analysis such as XRD and SEM, beside the physical characteristics, were used to compare the crystal size and to observe the surface, shape and holes between crystals of the hard waxes separated without and with modifiers. Data revealed that, microcrystalline waxes with high quality are produced by using butyl acetate solvent at dilution and washing solvent ratios of 8:1 and 2:1 by weight, respectively with the addition of 1wt.% of a non-polar modifier; C20–24n-alkanes. The results are the increase of the filtration rate, growth of crystal size with more holes between the large crystals and improvement in the physical characteristics of the separated wax.