Hot water extraction of bitumen from Utah tar sands

The dramatic projections for the energy market in the next few years have forced applied researchers and process designers to consider energy sources other than petroleum; such as tar sands, oil shale and coal. Physically tar sands consist of sand grains surrounded by a bituminous film (Figure 1). This bituminous coating, if properly separated from the sands, may certainly be used as feedstock for the production of fuels and petrochemicals. Utah has 51 deposits of tar sands containing an estimated 25 billion barrels of bitumen in place, which is about 95% of the total mapped resources in the United States(1). Although the extent of Utah tar sands, which amounts to approximately 900 billion barrels, Utah deposits do represent an appreciable potential when compared to the United States crude oil imports of 1.3 billion barrels during the same year. In spite of its significance, extraction and processing technology of Utah tar sands has not yet been developed. Since noticeable differences in the chemical and physical properties between Canadian and Utah bitumens have been observed, the technology acquired over the last fifty years in Canada can not be applied to Utah tar sands directly; rather, a detailed investigation on Utah tar sands is required. Currently, at the University of Utah, an ambitious research program on Utah tar sands is being conducted in order to obtain basic information concerning products characterization and process development. Different aspects of interest such as mining, extraction, upgrading and characterization of the products are being studied. The purpose of this paper is to summarize some of the advancements in the hot water extraction of bitumen from Utah tar sands and the characterization of this bitumen, specifically its viscosity.