Phase Behavior and Thermophysical Properties of Peace River Bitumen + Propane Mixtures from 303 K to 393 K

Abstract

Propane and mixtures including propane as a principal component are among the leading potential candidates for co-injection along with steam for improving the process and environmental efficiency of oil sands bitumen production processes. Phase diagrams and thermophysical property data enable technologies for the development and optimization of such processes. In this work, phase behavior, phase composition, and phase densities of propane + Peace River bitumen mixtures are reported in the temperature range 303 to 393 K at pressures ranging from 1 to 6 MPa. The phase behavior of this pseudobinary mixture can be categorized as Type III according to the van Konynenburg–Scott nomenclature. Pressure–temperature at fixed composition, and pressure–composition at fixed temperature phase diagrams, and pressure–temperature phase projections are presented, along with saturated compositions and densities of the coexisting bitumen-saturated propane liquid (L1) and propane-saturated bitumen liquid (L2) phases. Saturated L1 and L2 phases are both significantly less dense than liquid water phases at the same temperatures and pressures, and the volumes of mixing, particularly for the L1 phase, are large and negative. This data set provides a benchmark for process development and process design calculations for ongoing bitumen production and deasphalting applications.

The Phase Behavior of Heavy Oil and Propane Mixtures

“…Badamchi-Zadeh et al (2009a) and Jossy et al (2009) observed VL and LL boundaries for propane diluted bitumen but did not measure phase compositions. Dini et al (2016) also observed VL and LL regions and predicted a VLL boundary.…”

“…Both VL and LL regions were observed for mixtures of bitumen and propane (Badamchi-Zadeh et al, 2009a;Jossy et al, (2009); Nourozieh et al, 2015). Dini et al, (2016) also observed VL and LL regions and predicted a VLL boundary. They identified the two liquid phases as a solvent/maltene-rich and a bitumen-rich phase.…”

“…Whereas, Dini et al 2016 predicted the LL boundary at approximately 29 wt% propane as a straight vertical line (no pressure dependence). Nourozieh et al 2015 presented propane solubility data (VL boundary) for mixtures with an Athabasca bitumen that are also in agreement with the VL data presented in this thesis.…”

“…However, it is challenging to predict the performance of solvent-added recovery methods, particular solvent losses in the reservoir, partly because the phase behavior of mixtures of heavy oil and solvents is not well known. The introduction of a low molar mass solvent can lead to complex phase behavior such as the formation of vapor-liquid (VL), liquid-liquid (LL), VLL, and possibly VLLL (where the liquids are solvent-rich, bitumen-rich, asphaltene-rich phases) regions depending on the solvent type, content, temperature, and pressure (Mehrotra and Svrcek, 1988;Zou et al, 2007;Badamchi-Zahed et al, 2009a;Dini et al, 2016). The phase behavior of heavy oil and solvent mixtures is also a key factor for surface processes, such as deasphalting, and for flow assurance issues, such as asphaltene precipitation and further deposition.…”

“…The reported phase behavior of mixtures of bitumen and an n-alkane includes vapor-liquid (VL), liquid-liquid (LL), VLL, and possibly VLLL regions, depending on the solvent type, content, temperature, and pressure conditions (Mehrotra and Svrcek, 1988;Zou et al, 2007;Badamchi-Zahed et al, 2009a;Dini et al, 2016). The range of phase behavior encountered at typical process conditions depends strongly on the carbon number of the n-alkane.…”