EFFECT OF POLYACRYLATE-TYPE POUR POINT DE PRESSANTS ON CRUDE-OIL - INFLUENCE OF MOLECULAR-WEIGHT AND ITS DISTRIBUTION

The effect of pour-point depressants (PPD) of the polyalkylacrylate-ty pe on n-paraffin solutions (C-20-C-36) has been investigated with the help of pour-point measurements (Knauer automatic MC850). Dependent on the chain length of the n-paraffins several maxima in pour-point depr ession efficiency were found. The locations of these maxima are strong ly influenced by the molecular weight and m.w. distribution of the pol ymeres used as PPD. The solubility of the polymers in the solvent of p araffin solutions is another important factor determing the location o f the optimal efficiency. These factors (solubility, molecular weight and m.w.-distribution of the polymers) could be important for the effi ciency of the PPD in paraffinic crude oils as well. For crude oils the concentrations and distributions of the higher n-paraffins are additi onal parameters affecting the behaviour of the PPD. The optimum effect of the PPD for crude oils is to be expected for largely overlapping c ristallisation temperature-ranges of the polymers and the n-paraffins.