Scientific Abstracts on Peak Oil Issues |
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Generation of methane in the Earth's mantle: In situ high pressure-temperature measurements of carbonate reduction
*Department of Physics and Astronomy,
Indiana University, South Bend, IN 46634; Contributed by Russell J. Hemley, August 12, 2004 We present in situ observations of hydrocarbon formation via carbonate reduction at upper mantle pressures and temperatures. Methane was formed from FeO, CaCO3-calcite, and water at pressures between 5 and 11 GPa and temperatures ranging from 500°C to 1,500°C. The results are shown to be consistent with multiphase thermodynamic calculations based on the statistical mechanics of soft particle mixtures. The study demonstrates the existence of abiogenic pathways for the formation of hydrocarbons in the Earth's interior and suggests that the hydrocarbon budget of the bulk Earth may be larger than conventionally assumed. The Constraints of the Laws of Thermodynamics upon
the Evolution of Hydrocarbons: The Prohibition of Hydrocarbon Genesis at
Low Pressures. This first article dealing with the general subject of the modern Russian-Ukrainian theory of abyssal, abiotic petroleum origins does not itself involve specifically that body of knowledge. This article discusses the reasons which led physicists, chemists, thermodynamicists, and chemical, mechanical, and petroleum engineers to reject, already by the last quarter of the nineteenth century, the hypothesis that highly-reduced hydrocarbon molecules of high chemical potentials might somehow evolve spontaneously from highly-oxidized biological molecules of low chemical potentials, and reviews briefly the fundamental scientific reasons for the failure of the 18th-century hypothesis1 of a biological origin of petroleum. A fundamental attribute of modern Russian petroleum science is that it conforms to the general, fundamental laws of physics and chemistry. Although such constraint may seem an obvious requisite for any scientific assertion, the 18th-century hypothesis that petroleum might somehow evolve spontaneously from biological detritus in the near-surface depths of the Earth stands, contrarily, in glaring violation of the most fundamental, and irrevocable, laws of nature: the second law of thermodynamics. The second law of thermodynamics is a statement of irreversibility, and is an acknowledgement that spontaneous physical processes “go only one way.” Such property of the natural world is commonly and inevitably experienced in day-to-day life. Such common, irreversible phenomena as heat flow, diffusion, and chemical reactions are constantly observed. When any two bodies at different temperatures are placed in contact, and no other action is taken upon them, heat flows from the hotter body to the colder, until such time as their respective temperatures become equal throughout their volumes; at which time the flow of heat ceases; and the process never reverses, so as to return the initially hotter body to any temperature higher (and the initially colder body, lower) than the final equilibrium temperature. Similarly, when two miscible fluids are placed in the same volume (such as a drop of cream in a coffee cup), and no other action is taken upon them, each fluid diffuses throughout the other, until such time as their respective densities become equally uniform throughout the volume; at which time the diffusive flow ceases; and the process never reverses, so as to return either fluid to any local density higher than the final equilibrium one. Likewise for chemical processes, when any two chemical species capable of reacting (reagents) are placed in contact, and no other action is taken upon them, chemical reaction proceeds, until such time as the reagents have reached their equilibrium chemical state; at which time the reaction ceases; and the process never reverses, so as to return the chemical products to the state of the initial reagents. The scientific principle which subsumes all of these intuitively obvious processes is the second law of thermodynamics. When the second law of thermodynamics is expressed in its mathematical (and general) form, it may be used directly to predict whether any hypothesized chemical reaction will proceed, at any temperature or pressure. Dismissal of Claims of a Biological Connection for Natural Petroleum. Introduction. With recognition that the laws of thermodynamics prohibit spontaneous evolution of liquid hydrocarbons in the regime of temperature and pressure characteristic of the crust of the Earth, one should not expect there to exist legitimate scientific evidence that might suggest that such could occur. Indeed, and correctly, there exists no such evidence. Nonetheless, and surprisingly, there continue to be often promulgated diverse claims purporting to constitute “evidence” that natural petroleum somehow evolves (miraculously) from biological matter. In this short article, such claims are briefly subjected to scientific scrutiny, demonstrated to be without merit, and dismissed. The claims which purport to argue for some connection between natural petroleum and biological matter fall into roughly two classes: the “look-like/come-from” claims; and the “similar(recondite)-properties/come-from” claims. The “look-like/come-from” claims apply a line of unreason exactly as designated: Such argue that, because certain molecules found in natural petroleum “look like” certain other molecules found in biological systems, then the former must “come-from” the latter. Such notion is, of course, equivalent to asserting that elephant tusks evolve because those animals must eat piano keys. In some instances, the “look-like/come-from” claims assert that certain molecules found in natural petroleum actually are biological molecules, and evolve only in biological systems. These molecules have often been given the spurious name “biomarkers.” The scientific correction must be stated unequivocally: There have never been observed any specifically biological molecules in natural petroleum, except as contaminants. Petroleum is an excellent solvent for carbon compounds; and, in the sedimentary strata from which petroleum is often produced, natural petroleum takes into solution much carbon material, including biological detritus. However, such contaminants are unrelated to the petroleum solvent. The claims about “biomarkers” have been thoroughly discredited by observations of those molecules in the interiors of ancient, abiotic meteorites, and also in many cases by laboratory synthesis under imposed conditions mimicking the natural environment. In the discussion below, the claims put forth about porphyrin and isoprenoid molecules are addressed particularly, because many “look-like/come-from” claims have been put forth for those compounds. The “similar (recondite)-properties/come-from” claims involve diverse, odd phenomena with which persons not working directly in a scientific profession would be unfamiliar. These include the “odd-even abundance imbalance” claims, the “carbon isotope” claims, and the “optical-activity” claims. The first, the “odd-even abundance imbalance” claims, are demonstrated to be utterly unrelated to any biological property. The second, “carbon isotope” claims, are shown to depend upon measurement of an obscure property of carbon fluids which cannot reliably be considered a measure of origin. The third, the “optical-activity” claims, deserve particular note; for the observations of optical activity in natural petroleum have been trumpeted loudly for years as a “proof” of some “biological origin” of petroleum. Those claims have been thoroughly discredited decades ago by observation of optical activity in the petroleum material extracted from the interiors of carbonaceous meteorites. More significantly, recent analysis, which has resolved the previously-outstanding problem of the genesis of optical activity in abiotic fluids, has established that the phenomenon of optical activity is an inevitable thermodynamic consequence of the phase stability of multi-component fluids at high pressures. Thereby, the observation of optical activity in natural petroleum is entirely consistent with the results of the thermodynamic analysis of the stability of the hydrogen-carbon [H-C] system, which establish that hydrocarbon molecules heavier than methane, and particularly liquid hydrocarbons, evolve spontaneously only at high pressures, comparable to those necessary for diamond formation. There are two subjects which are particularly relevant for destroying the diverse, spurious claims concerning a putative connection of petroleum and biological matter: the investigations of the carbon material from carbonaceous meteorites; and the reaction products of the Fischer-Tropsch process. Because of their importance, a brief discussion of both is in order. The Evolution of Multi-component Systems at High Pressures: VI. The
Thermodynamic Stability of the Hydrogen-Carbon System: The Genesis of
Hydrocarbons and the Origin of Petroleum. Abstract: The spontaneous genesis of hydrocarbons which comprise natural petroleum have been analyzed by chemical thermodynamic stability theory. The constraints imposed upon chemical evolution by the second law of thermodynamics are briefly reviewed; and the effective prohibition of transformation, in the regime of temperatures and pressures characteristic of the near-surface crust of the Earth, of biological molecules into hydrocarbon molecules heavier than methane is recognized. For the theoretical analysis of this phenomenon, a general, first-principles equation of state has been developed by extending scaled particle theory (SPT) and by using the technique of the factored partition function of the Simplified Perturbed Hard Chain Theory (SPHCT). The chemical potentials, and the respective thermodynamic Affinity, have been calculated for typical components of the hydrogen-carbon (H-C) system over a range pressures between 1-100 kbar, and at temperatures consistent with those of the depths of the Earth at such pressures. The theoretical analyses establish that the normal alkanes, the homologous hydrocarbon group of lowest chemical potential, evolve only at pressures greater than approximately thirty kbar, excepting only the lightest, methane. The pressure of thirty kbar corresponds to depths of approximately 100 km. For experimental verification of the predictions of the theoretical analysis, special high-pressure apparatus has been designed which permits investigations at pressures to 50 kbar and temperatures to 1500°C, and which also allows rapid cooling while maintaining high pressures. The high-pressure genesis of petroleum hydrocarbons has been demonstrated using only the solid reagents solid iron oxide, FeO, and marble, CaCO3, 99.9% pure, wet with triple-distilled water. Natural petroleum is a hydrogen-carbon [H-C] system, in distinctly non-equilibrium states, composed of mixtures of highly reduced, hydrocarbon molecules, all of very high chemical potential, most in the liquid phase. As such, the phenomenon of the terrestrial existence of natural petroleum in the near-surface crust of the Earth has presented several challenges, most of which have remained unresolved until recently. The primary scientific problem of petroleum has been the existence and genesis of the individual hydrocarbon molecules themselves: how, and under what thermodynamic conditions, can such highly-reduced molecules of high chemical potential evolve. The scientific problem of the genesis of hydrocarbons of natural petroleum, and consequentially of the origin of natural petroleum deposits, has regrettably been one too much neglected by competent physicists and chemists; the subject has been obscured by diverse, unscientific hypotheses, typically connected with the rococo hypothesis(1) that highly-reduced hydrocarbon molecules of high chemical potentials might somehow evolve from highly-oxidized biotic molecules of low chemical potential. The scientific problem of the spontaneous evolution of the hydrocarbon molecules comprising natural petroleum is one of chemical thermodynamic stability theory. This problem does not involve the properties of rocks where petroleum might be found, nor of microorganisms observed in crude oil. This paper is organized into five parts. The first section reviews briefly the formalism of modern thermodynamic stability theory, the theoretical framework for the analysis of the genesis of hydrocarbons and the H-C system, - as similarly for any system. The second section examines, applying the constraints of thermodynamics, the notion that hydrocarbons might evolve spontaneously from biological molecules. Here are described the spectra of chemical potentials of hydrocarbon molecules, particularly the naturally-occurring ones present in petroleum. Interpretation of the significance of the relative differences between the chemical potentials of the hydrocarbon system and those of biological molecules, applying the dictates of thermodynamic stability theory, disposes of any hypothesis of an origin for hydrocarbon molecules from biological matter, excepting only the lightest, methane. In the third section is described a first-principles, statistical mechanical formalism, developed from an extended representation of scaled particle theory appropriate for mixtures of aspherical, hard-body molecules, combined with a mean-field representation of the long-range, attractive component of the intermolecular potential. In the fourth section, the thermodynamic Affinity developed using this formalism establishes that the hydrocarbon molecules peculiar to natural petroleum are high-pressure polymorphs of the H-C system, similarly as diamond and lonsdalite are to graphite for the elemental carbon system, and evolve only in thermodynamic regimes of pressures greater than 25-50 kbar. The fifth section reports the experimental results obtained using equipment specially-designed to test the predictions of the previous sections. Application of pressures to 50 kbar and temperatures to 1500°C upon solid (and obviously abiotic) CaCO3 and FeO, wet with triple-distilled water, all in the absence of any initial hydrocarbon or biotic molecules, evolves the suite of petroleum fluids: methane, ethane, propane, butane, pentane, hexane, branched isomers of those compounds, and the lightest of the n-alkene series. The synthesis of hydrocarbons from abiotic reagents
at pressures to 5 Gpa. The Evolution of Multicomponent Systems at
High Pressures: IV. The Genesis of Optical Activity in High-density,
Abiotic Fluids. Abstract: The spontaneous genesis of hydrocarbons which comprise natural petroleum have been analyzed by chemical thermodynamic stability theory. The constraints imposed upon chemical evolution by the second law of thermodynamics are briefly reviewed; and the effective prohibition of transformation, in the regime of temperatures and pressures characteristic of the near-surface crust of the Earth, of biological molecules into hydrocarbon molecules heavier than methane is recognized. For the theoretical analysis of this phenomenon, a general, first-principles equation of state has been developed by extending scaled particle theory (SPT) and by using the technique of the factored partition function of the Simplified Perturbed Hard Chain Theory (SPHCT). The chemical potentials, and the respective thermodynamic Affinity, have been calculated for typical components of the hydrogen-carbon (H-C) system over a range pressures between 1-100 kbar, and at temperatures consistent with those of the depths of the Earth at such pressures. The theoretical analyses establish that the normal alkanes, the homologous hydrocarbon group of lowest chemical potential, evolve only at pressures greater than approximately thirty kbar, excepting only the lightest, methane. The pressure of thirty kbar corresponds to depths of approximately 100 km. For experimental verification of the predictions of the theoretical analysis, special high-pressure apparatus has been designed which permits investigations at pressures to 50 kbar and temperatures to 1500°C, and which also allows rapid cooling while maintaining high pressures. The high-pressure genesis of petroleum hydrocarbons has been demonstrated using only the solid reagents solid iron oxide, FeO, and marble, CaCO3, 99.9% pure, wet with triple-distilled water. Natural petroleum is a hydrogen-carbon [H-C] system, in distinctly non-equilibrium states, composed of mixtures of highly reduced, hydrocarbon molecules, all of very high chemical potential, most in the liquid phase. As such, the phenomenon of the terrestrial existence of natural petroleum in the near-surface crust of the Earth has presented several challenges, most of which have remained unresolved until recently. The primary scientific problem of petroleum has been the existence and genesis of the individual hydrocarbon molecules themselves: how, and under what thermodynamic conditions, can such highly-reduced molecules of high chemical potential evolve. The scientific problem of the genesis of hydrocarbons of natural petroleum, and consequentially of the origin of natural petroleum deposits, has regrettably been one too much neglected by competent physicists and chemists; the subject has been obscured by diverse, unscientific hypotheses, typically connected with the rococo hypothesis(1) that highly-reduced hydrocarbon molecules of high chemical potentials might somehow evolve from highly-oxidized biotic molecules of low chemical potential. The scientific problem of the spontaneous evolution of the hydrocarbon molecules comprising natural petroleum is one of chemical thermodynamic stability theory. This problem does not involve the properties of rocks where petroleum might be found, nor of microorganisms observed in crude oil. This paper is organized into five parts. The first section reviews briefly the formalism of modern thermodynamic stability theory, the theoretical framework for the analysis of the genesis of hydrocarbons and the H-C system, - as similarly for any system. The second section examines, applying the constraints of thermodynamics, the notion that hydrocarbons might evolve spontaneously from biological molecules. Here are described the spectra of chemical potentials of hydrocarbon molecules, particularly the naturally-occurring ones present in petroleum. Interpretation of the significance of the relative differences between the chemical potentials of the hydrocarbon system and those of biological molecules, applying the dictates of thermodynamic stability theory, disposes of any hypothesis of an origin for hydrocarbon molecules from biological matter, excepting only the lightest, methane. In the third section is described a first-principles, statistical mechanical formalism, developed from an extended representation of scaled particle theory appropriate for mixtures of aspherical, hard-body molecules, combined with a mean-field representation of the long-range, attractive component of the intermolecular potential. In the fourth section, the thermodynamic Affinity developed using this formalism establishes that the hydrocarbon molecules peculiar to natural petroleum are high-pressure polymorphs of the H-C system, similarly as diamond and lonsdalite are to graphite for the elemental carbon system, and evolve only in thermodynamic regimes of pressures greater than 25-50 kbar. The fifth section reports the experimental results obtained using equipment specially-designed to test the predictions of the previous sections. Application of pressures to 50 kbar and temperatures to 1500°C upon solid (and obviously abiotic) CaCO3 and FeO, wet with triple-distilled water, all in the absence of any initial hydrocarbon or biotic molecules, evolves the suite of petroleum fluids: methane, ethane, propane, butane, pentane, hexane, branched isomers of those compounds, and the lightest of the n-alkene series. The Evolution of Multi-component Systems at High Pressures: II. The
Alder-Wainwright, High-Density, Gas-Solid Phase Transition of the
Hard-Sphere Fluid. Abstract: The
thermodynamic stability of the hard-sphere gas has been examined, using
the formalism of scaled particle theory [SPT], and by applying explicitly
the conditions of stability required by both the second and third laws of
thermodynamics. The temperature and volume limits to the validity of SPT
have also been examined. It is demonstrated that scaled particle theory
predicts absolute limits to the stability of the fluid phase of the
hard-sphere system, at all temperatures within its range of validity.
Because scaled particle theory describes fluids equally well as dilute
gases or dense liquids, the limits set upon the system stability by SPT
must represent limits for the existence of the fluid phase and transition
to the solid. The reduced density at the stability limits determined by
SPT is shown to agree exactly with those of that estimated for the
Alder-Wainwright, supercritical, high-density gas-solid phase transition
in a hard-sphere system, at a specific temperature, and closely over a
range of more than 1,000K. The temperature dependence of the gas-solid
phase stability limits has been examined over the range 0.01K-10,000K. It
is further shown that SPT describes correctly the variation of the entropy
of a hard-core fluid at low temperatures, requiring its entropy to vanish
as T → 0
by undergoing a gas-solid phase transition at finite temperature and all
pressures.[†] Peak
Oil Introduction: a Lesson in UN-learning Exploration-Development of Dnieper-Donets
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Geophysical Laboratory,
Carnegie Institution of Washington, 5251 Broad Branch Road NW, Washington,
DC 20015; 
Department of
Chemistry and Chemical Biology, Harvard University, Cambridge, MA 02138;
and ¶Chemistry and Materials Science Directorate and ||Physics
and Advanced Technologies Directorate, Lawrence Livermore National
Laboratory, Livermore, CA 94550
