The present paper deals with the studies of crude oil composition, physicochemical characterisation of pour point depressants (PPD's) and waxes to know the specific & selective performance of PPD on crude for designing wax crystal modifier according to requirement.
The study reveals that the performance of PPD is closely governed by composition of crude in respect of nuclei present mainly asphaltene, type & amount of waxes and the amount of distillates. The study indicates that PPD can be made more effective by compounding waxy crudes with light distillate fractions and vice versa by the change in PPD composition, degree and extent of polymerization and creating environment suitable for co-crystallization.
The chain length of the alkyl ester chain should corresponds with the carbon number ranging C20-C24. It has been observed that polymers having Mow molecular weights do not affect the rheology. The melting point of PPD should match with the melting point of the waxes for limiting the growth of the crystals. C22 to C29 normal paraffins are predominant in GS-16-4 & Bombay High crude oil. The studies may be helpful for selection of PPD’s for high wax content crudes.