The Evolution of Multicomponent Systems at High Pressures: VI. The Thermodynamic Stability of the Hydrogen-Carbon System: The Genesis of Hydrocarbons and the Origin of Petroleum

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. 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. Special high-pressure apparatus has been designed which permits investigations at pressures to 50 kbar and temperatures to 2000 K, 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 iron oxide, FeO, and marble, CaCO3, 99.9% pure and wet with triple-distilled water

Barriers to the wider implementation of biogas as a source of energy: A state-of-the-art review

Many countries have realised that biogas as a source of energy is an important component for sustainability transition. However, the total production volume of biogas is still relatively low. Such slow development raises a fundamental question—what are the current barriers hindering the wider uptake of biogas as a source of energy? In order to answer the question, a systematic state-of-the-art review of the barriers was conducted based on the Scopus database. The results of the review were summarised by country and were divided into two broad categories: developed and developing economies. Each group was analysed separately according to six types of barriers: (1) technical, (2) economic, (3) market, (4) institutional, (5) socio-cultural, and (6) environmental barriers. By analysing the barriers through different contexts, the most frequent and crucial constraints the biogas industry currently faces were identified and integrated into a systematic classification. In addition, possible solutions on how to overcome the most critical barriers were added.QC 20191106</p

Cost-efficient measurement of energy content of propanated biomethane

This paper presents a correlative method for the cost-efficient measurement of the energy content of propanated biomethane, which is relevant for injection into gas distribution grids. The gross calorific value and Wobbe index were predicted by the regression models from the measured set of physical properties of the gas sample, including speed of sound, sound attenuation parameter, and carbon dioxide concentration. The required properties can be measured using standard sensors and instruments; therefore, they enable in situ application of the method. The results of the experimental validation corroborated with the results of chromatographic analysis.QC 20210118</p

Cost-efficient measurement of energy content of propanated biomethane

This paper presents a correlative method for the cost-efficient measurement of the energy content of propanated biomethane, which is relevant for injection into gas distribution grids. The gross calorific value and Wobbe index were predicted by the regression models from the measured set of physical properties of the gas sample, including speed of sound, sound attenuation parameter, and carbon dioxide concentration. The required properties can be measured using standard sensors and instruments; therefore, they enable in situ application of the method. The results of the experimental validation corroborated with the results of chromatographic analysis.QC 20210118</p

Cost-efficient measurement of energy content of propanated biomethane

This paper presents a correlative method for the cost-efficient measurement of the energy content of propanated biomethane, which is relevant for injection into gas distribution grids. The gross calorific value and Wobbe index were predicted by the regression models from the measured set of physical properties of the gas sample, including speed of sound, sound attenuation parameter, and carbon dioxide concentration. The required properties can be measured using standard sensors and instruments; therefore, they enable in situ application of the method. The results of the experimental validation corroborated with the results of chromatographic analysis.QC 20210118</p

High-pressure chemistry of propane

This study is a comprehensive research of the propane's high-pressure and high-pressure high temperature behaviour using diamond-anvill cell technique combined with vibrational spectroscopy. As we have found, propane while being exposed to the high pressures (5-40 GPa) could exhibit three solid-solid phase transitions. With the applyimg of laser heating technique, propane could react with the formation of various hydrocarbon compounds and carbon. At temperatures less than 900 K and in the range of pressures from 3 to 22 GPa propane remains stable.QC 20200203</p

High-pressure chemistry of propane

This study is a comprehensive research of the propane's high-pressure and high-pressure high temperature behaviour using diamond-anvill cell technique combined with vibrational spectroscopy. As we have found, propane while being exposed to the high pressures (5-40 GPa) could exhibit three solid-solid phase transitions. With the applyimg of laser heating technique, propane could react with the formation of various hydrocarbon compounds and carbon. At temperatures less than 900 K and in the range of pressures from 3 to 22 GPa propane remains stable.QC 20200203</p

Raman Spectroscopy Study on Chemical Transformations of Propane at High Temperatures and High Pressures

This study is devoted to the detailed in situ Raman spectroscopy investigation of propane C3H8 in laserheated diamond anvil cells in the range of pressures from 3 to 22 GPa and temperatures from 900 to 3000 K. We show that propane, while being exposed to particular thermobaric conditions, could react, leading to the formation of hydrocarbons, both saturated and unsaturated as well as soot. Our results suggest that propane could be a precursor of heavy hydrocarbons and will produce more than just sooty material when subjected to extreme conditions. These results could clarify the issue of the presence of heavy hydrocarbons in the Earth’s upper mantle.QC 20200203</p