The scaling equation proposed by Rassamdana et al. [H. Rassamdana, B. Dabir
, M. Nematy, M. Farhani, M. Sahimi, AIChE J. 42 (1996) 10-22; H. Rassamdana
, M. Sahimi, AIChE J. 42 (1996) 3318-3332.] is an attractive tool for model
ing asphaltene precipitation, as it is simple and the properties of complex
asphaltenes are not involved. fn this work, the universality gf exponents
Z and Z' in the scaling equation has been examined. The results show that Z
' can be taken as a universal constant (Z' = -2), while Z depends on oil co
mposition but is independent of the specific precipitant (n-alkane) used. F
or the oils studied, the optimum value of exponent Z is in the range of 0.1
0 less than or equal to Z less than or equal to 0.50. The predictive capabi
lity of the scaling equation has been checked by comparison with literature
precipitation data, and further extended to the prediction of the onset of
asphaltene deposition and asphaltene precipitation in the gas-injected cru
de oils. (C) 2000 Elsevier Science B.V. All rights reserved.