Phase Behavior of Mixtures of Bitumen andn-Butane

The phase behavior of bitumen and n-butane mixtures was investigated at temperatures from 20 to 230 °C and pressures from 2 to 10 MPa. The measurements included saturation pressures, compositions at the onset of the second liquid phase, and the compositions and masses of the light n-butane-rich and heavy “pitch” phases in the liquid–liquid region. The phase compositions were measured in terms of the n-butane, maltenes, and C5-asphaltenes...