Athabasca tar sands

Athabasca tar sands Naturally occurring mixtures of bitumen and sand found in Northern Alberta. 

Synthetic Fuel. Solvent extraction has many appHcations in synthetic fuel technology such as the extraction of the Athabasca tar sands (qv) and Irish peat using / -pentane [109-66-0] (238) and a process for treating coal (qv) using a solvent under hydrogen (qv) (239). In the latter case, coal reacts with a minimum amount of hydrogen so that the solvent extracts valuable feedstock components before the soHd residue is burned. Solvent extraction is used in coal Hquefaction processes (240) and synthetic fuel refining (see Coal conversion processes Fuels, synthetic). 

In addition to the significant consumption of coal and lignite, petroleum, and natural gas, several countries utilize modest quantities of alternative fossil fuels. Canada obtains some of its energy from the Athabasca tar sands development (the Great Canadian Oil Sands Project). Oil shale is burned at... 

Perhaps the biggest contribution that technological advancement in petroleum production will make is bringing large volumes of unconventional petroleum resources, eg, heavy oil and tar sands, into a viable economic realm by lowering the unit cost of production. Compared to the inventory of conventional petroleum reserves and undiscovered resources, the physical inventories of such unconventional petroleum resources are extremely large for example, the Athabasca tar sands in Alberta, Canada, are estimated to contain 360 x 10 m (2250 x 10 bbl) of in-place petroleum (19). This volume is equivalent to the total inventory, ie, the combined cumulative production, reserves, and undiscovered resources, of world conventional cmde petroleum. In... 

The Alberta (Athabasca) tar sand deposits are located in the northeast part of that Canadian province (Fig. 4). These are the only mineable tar sand deposits undergoing large-scale commercial exploitation as of this writing (ca 1997). 

Recovery methods are based either on mining combined with some further processing or operation on the oil sands m situ (Fig. 6). The mining methods are appHcable to shallow deposits, characterized by an overburden ratio (ie, overburden depth-to-thickness of tar sand deposit) of ca 1.0. Because Athabasca tar sands have a maximum thickness of ca 90 m and average ca 45 m, there are indications that no more than 10% of the in-place deposit is mineable within 1990s concepts of the economics and technology of open-pit mining. 

These are found in crude petroleum including bitumen in the Athabasca tar sands of Northern Alberta. They contain a complex mixture of saturated polycyclic live- and six-membered cycloalkanes with alkane and alkanoic acid substituents. Attention has been directed to the degradation of both commercially available products, and those that are produced during bitumen extraction. Although the former were degradable (Clemente et al. 2004), the higher molecular mass components of the latter were much more recalcitrant (Scott et al. 2005). 

Bowman, C. W. Molecular and Interfacial Properties of Athabasca Tar Sands, Proceedings of the Seventh World Petroleum Congress", Elsevier Publishing Company New York, 1967, 3, p 583. 

A paper contributed by J. E. Desnoyers, R. Beaudoin, C. Roux, and C. Perron described the use of microemulsions as a possible tool for the extraction of oil from tar sands. Using a technique called flow microcalorimetry recently developed at the University of Sherbrooke, these researchers studied the structure and stability of organic microphases in aqueous media. These microphases can be stabilized by surfactants and can dissolve large quantities of oil. In a similar vein, D. F. Gerson, J. E. Zajic, and M. D. Ouchi (University of Western Ontario) described the extraction of bitumen from Athabasca tar sands by a combined solvent-aqueous-surfactant system. 

The Relation of Surfactant Properties to the Extraction of Bitumen from Athabasca Tar Sand by a Solvent-Aqueous-Surfactant Process... 

The most important step in any aqueous extraction scheme is facilitation of the transfer of mineral particles from the bituminous matrix to the aqueous phase (Fig. 1). This process appears to be more favorable in the Athabasca tar sands than in other tar sands due to a postulated, but unobserved, film of absorbed water present on the mineral particles. The transfer process may be visualized in 2 stages 1) the transition from complete immersion in the bulk bituminous phase to partial contact with both phases, and 2) the transition from partial contact with both phases to complete immersion in the aqueous phase (Fig. la,b). 

The paddle mill was used to study the effect of surfactant type on a solvent-aqueous-surfactant extraction scheme for the recovery of bitumen from Athabasca tar sand. n the experiments of Figures 4,5 and 6, bitumen recovered from the surface phases was measured as a function of the mole fraction of ethylene oxide in the surfactant and as a function of the extraction step in which the surfactant was added. The results are reported as the % of the total bitumen present in the surface fraction. The amount of surfactant used was that required to give a final aqueous concentration of 0.02% (w/v), but in different sets of experiments the surfactant was added at various stages in the process. 

Adhesion Tensions and Tar Sand Extraction with Tween Surfactants. Mea-surement of the adhesion tension (t) allows the determination of the wettability of a given solid by a given liquid or surfactant solution. Measurements of adhesion tension between both bitumen or clay surfaces and various surfactant solutions is thus highly relevant to a study of the effects of surfactants in the separation of bitumen from Athabasca tar sand. 

A sample of raw bitumen recovered from Athabasca tar sands and provided by Sun Oil Co. was analyzed without further upgrading. Three distillate cuts of shale oil obtained from The Oil Shale Corp. were also analyzed without further upgrading. 

Ozone (6% in oxygen) was passed for two days through a loosely packed vertical column of Athabasca tar sand and the column eluted... 

Panzer t al. (5) extracted Athabasca tar sand in two steps, the first with compressed n-pentane (Tc = 570 K, Pc = 3.37 MPa) and the second with compressed benzene (Tc = 563 K, Pc = 4.92 MPa). At 533-563 K and 2.0-7.7 MPa, n-pentane extracted 95% of the maltenes and asphaltenes from the tar sand, whereas at atmospheric pressure only 75% was extracted. Further extraction with benzene at 633 K and 2.0 MPa removed the remaining higher molecular weight asphaltenes. This indicates that the chemical nature of the dense gas is important in some applications. 

Product properties from Athabasca tar sand bitumen feedstock ... 

The LC-Fining process has been applied to desulfurization of bitumen extracted from the Athabasca tar sands (Bishop, 1990). In one reported instance, a low-solids bitumen and a high-solids bitumen were employed as feedstocks whereupon good conversion of the bitumen to lower-sulfur products was noted... 

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