Henry P. Scott *
,
Russell J. Hemley
,
Ho-kwang Mao
,
Dudley R. Herschbach
,
Laurence E. Fried ¶,
W. Michael Howard ¶,
and Sorin Bastea ||
*Department of Physics and Astronomy,
Indiana University, South Bend, IN 46634;
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
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.
J. F. Kenney, I. K.
Karpov, Ac. Ye. F. Shnyukov, V. A. Krayushkin, I. I. Chebanenko, V. P.
Klochko, (2001), Energia, 22/3, 18-23.
PDF version.
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.
J. F. Kenney, Ac. Ye. F.
Shnyukov, V. A. Krayushkin, I. K. Karpov, V. G. Kutcherov, I. N.
Plotnikova, (2001), Energia, 22/3, 26-34.
PDF version
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.
J. F. Kenney, V. G. Kutcherov,
N. A. Bendeliani, V. A. Alekseev, (2002), Proceedings of the National
Academy of Sciences (U.S.A.), 99/17, 10976-10981.
PDF version
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.
V.
G. Kutcherov, N. A. Bendeliani, V. A. Alekseev, J. F. Kenney, (2002),
Proceedings of the National Academy of Sciences of Russia, 387/6,
789-792.
PDF version
The Evolution of Multicomponent Systems at
High Pressures: IV. The Genesis of Optical Activity in High-density,
Abiotic Fluids.
J. F. Kenney, U. K. Deiters,
(2001), Physical Chemistry - Chemical Physics, 2,
3163-3174.
PDF version
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.
J. F. Kenney, (1999),
Physical Chemistry - Chemical Physics, 1, 3277-3285.
PDF version
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.[†]
The Evolution of Multi-component Systems at High Pressures: I. The
High-Pressure, Supercritical, Gas-Liquid Phase Transition.
J.
F. Kenney, Fluid Phase Equilibria, (1998), 148, 21-47.
PDF version.
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