Wax precipitation from North Sea crude oils. 3. Precipitation and dissolution of wax studied by differential scanning calorimetry

Abstract

Differential scanning calorimetry was used to study was precipitation from a series of North Sea crude oils by measuring glass transition temperatures, wax precipitation and dissolution temperatures (wax appearance and disappearance, respectively), and was precipitation and dissolution enthalpies in the temperature range from +70 to −140 o C. With respect to physical characteristics, the oils ranged from very light paraffinic condensates to heavy waxy crudes including biodegraded and asphaltenic oils. On the basis of glass transition temperatures, the oils could be sorted into groups that corresponded to their physical descriptions, whereas a similar grouping according to the precipitation or dissolution temperatures did not correspond to the physical characteristics