As the fact of depletion of the major fossil-fuel sources is gradually being unveiled on a worldwide scale, the exploration and exploitation of the earth's other natural fuels assume ever-increasing importance. Because of practically global availability of bitumens, asphalts, and tar sands, these natural deposits could offer a significant supplement to the waning oil and gas reserves. The interest which was generated by these potential fuels many years ago, however, was rather cursory and has not been followed by systematic scientific investigation and analysis. Although oil companies and some public concerns have invested heavily in the research on these potential fuels, the results of the investigations are not readily available. The small volume of published material on the subject tends to inhibit further the development of bitumens, asphalts and tar sands into viable fuels.
Guided by the purpose of focusing interest on these fuels, the editors invited a number of internationally known experts to summarize the current status of knowledge on origin and exploitation of bitumens, asphalts and tar sands. The editors hope that this book will be useful to the scientists and engineers who are already engaged in research in this field, as well as provide the impetus to others to devote themselves to the research on and development of these fuels. Regardless of its magnitude, any contribution to the encouragement of research work on these fuels, which may be stimulated by this book, would totally grafity the editors and contributors.
The editors wish to extend their gratitude to the contributors who worked hard to produce their chapters and, then, found the patience to wait out the span of time it has taken for the full realization of this book. The editors would also like to thank C.S. Wen, Michelle Hsi, Valerie Alexander, Mary A. Smith, and Keith Manasco for their efforts in the preparation of this manuscript.