The spontaneous genesis of hydrocarbons that comprise natural petroleum have been analyzed by chemical thermodynamic-stability theory. The constraints imposed on 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 and by using the technique of the factored partition function of the simplified perturbed hard-chain theory. The chemical potentials and the respective thermodynamic Affinity have been calculated for typical components of the H-C system over a range of pressures between 1 and 100 kbar (1 kbar ؍ 100 MPa) 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 Ϸ30 kbar, excepting only the lightest, methane. The pressure of 30 kbar corresponds to depths of Ϸ100 km. For experimental verification of the predictions of the theoretical analysis, a special high-pressure apparatus has been designed that permits investigations at pressures to 50 kbar and temperatures to 1,500°C and also allows rapid cooling while maintaining high pressures. The high-pressure genesis of petroleum hydrocarbons has been demonstrated using only the reagents solid iron oxide, FeO, and marble, CaCO 3, 99.9% pure and wet with tripledistilled water. N atural petroleum is a hydrogen-carbon (H-C) system, in distinctly nonequilibrium states, composed of mixtures of highly reduced hydrocarbon molecules, all of very high chemical potential and 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, regrettably has 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 the...
