Gas Liberation Research Articles

A Model for Relative Permeabilities Under Gas Liberation or Condensate Precipitation in Porous Medium

We derive a model for relative permeabilities under two-phase flows in porous media, where the phases may partly mix with each other, and one of the phases may be immobile. Particular cases are the bubble formation in an oil reservoir when the pressure falls below the bubble point, or, similarly, condensation and droplet precipitation in a gas-condensate reservoir. The dependencies for the relative permeabilities on the saturation are derived based on a pore-level model of the porous medium, represented as a capillary network. Distribution of the bubbles or droplets in the network is computed with the application of a method similar to the fundamental statistical physics. Model formula for the conductivities of single capillaries, depending on the numbers of bubbles or droplets in them, is converted to the relative permeabilities of the whole lattice by application of the effective medium formalism. We establish universal correlations between the micro-characteristics of the porous medium, constituting our model, and the parameters in the Corey–Brooks dependencies for relative permeabilities: exponents and limiting saturations. In this way, it is also possible to extend the standard Corey–Brooks formula onto the saturation ranges where one of the phases is immobile. A comparison with the available experimental data indicates the good performance of the model. The experimental data may be fitted by variation of a single parameter, and the data from similar rocks have similar parameter values, which indicates the physical soundness of the model.

Aluminium Phosphide-Induced Expression of Covertly Present Brugada Pattern in Electrocardiogram: A Rare Case Report

Aluminum phosphide is a common suicidal agent in an agrarian country like India. Toxicity is mostly due to the liberation of phosphine gas, which non-competitively inhibits cytochrome oxidase in the mitochondria causing cell hypoxia. It can involve almost any organ in the body, but the most common is cardiovascular system. Various cardiovascular manifestations are hypotension, myocarditis, pericarditis, congestive heart failure, various ECG changes like myocardial infarction, conduction abnormalities, various arrhythmias, and very rarely unmasking of the Brugada pattern. Here we are presenting a case in which the patient developed unmasking of the Brugada pattern in ECG, and gradually he improved symptomatically and ECG wise with conservative treatment. As unmasking of the Brugada pattern in ECG can lead to life-threatening arrhythmias, one has to be cautious and keep this in mind while dealing with a case of aluminum phosphide poisoning.

Impact of in-situ gas liberation for enhanced oil recovery and CO2 storage in liquid-rich shale reservoirs

ABSTRACT Carbon dioxide injection in shale reservoirs can be beneficial for enhanced oil recovery and CO2 storage scenarios. CO2 mass transfer can be influenced strongly by the in-situ liberation of light oil components from live oil forming a distinct gas phase. This mechanism has been overlooked in the past for studying CO2 and oil interactions in tight formations. In this work, a series of analytical solutions and numerical simulations were developed to identify the effect on EOR by CO2 due to the liberation of a light hydrocarbon gas phase from live oil in shales. The analytical model demonstrated faster diffusion of CO2 in the two-phase system due to the presence of this gas phase. Using numerical approaches, laboratory-scale simulations indicated that in-situ gas formation can increase oil recovery by 35%. At the field-scale, an additional oil recovery of 9.8% could be attained. Also, the CO2 storage capacity of shale formations could be significantly enhanced due to capillary trapping of CO2 in the liberated gas. The results of this study could potentially be used to improve evaluations of the potential of CO2 EOR in shale reservoirs.

A COMPARATIVE STUDY ON SINGLE AND DOUBLE JOINTED CU-AL BIMETALLIC STRIPS USING FRICTION STIR SPOT WELDING PROCESS

Welding is one of the best and quick process to join metals. In modern times, we concern more about environmental hazards due to hazardous gases liberated during conventional welding processes. Fiction Stir welding is a simple process in which a solid metal joint is produced by the heat of friction. In a similar technique, we can make spot welds of similar or dissimilar metallic joints by using Friction Stir Spot Welding. Since there is an absence of any liberation of poisonous gases, this method is safe to the environment and user. In this study, we made a dissimilar lap joint of Copper and Aluminium strips using an H13 steel tool. The pin profile of the tool is based on the thickness of the plate/weld. Weld based process parameters such as tool rotational speed, Dwell time and plunge depth. A lap joint with a desirable overlapping length between friction weld spots is compared and analyzed for mechanical bonding strength for both single and double joints. The results show a considerable increase in tensile strength for double-jointed specimen compared to a single-joint.

COMPUTER MODELING OF COAL SEAM BLASTING

The authors discuss the mechanism of breaking coal by blasting with a view to optimizing this method of dynamic treatment of coal and improving drilling-and-basting performance. A combination model of high gassy coal is used to describe the connection between coal breaking by blasting and subsequent gas liberation. This model and the smoothed-particle hydrodynamics method are used to study evolution of damage zones and stress–strain behavior of coal in the neighborhood of a blasthole after explosion. The research findings help predict coal response to the dynamic impact.

Compositional effect on oxygen reduction reaction in Pr excess double perovskite Pr1+xBa1-xCo2O6-δ cathode materials

The kinetics of oxygen reduction reaction (ORR), being a prime requisite for electrode materials after the higher conductivity. Further, electrodes are observed to dissolute on reaction at triple phase boundary. However, the compositional effect on ORR is least understood. In order to inspect the ORR mechanism with substitution, a series of (1 + x) PrCoO3 − (1 − x) BaCoO3 (x = 0.2 to 1.0 with step of 0.2) compositions are prepared using conventional solid-state route method. The Rietveld refinement of X-ray diffractograms and specific heat curves confirms the formation of double phase comprising orthorhombic Pmmm phase corresponding to PrBaCo2O6-δ and Pnma phase corresponding to PrCoO3 for x = 0.2 to 0.8 with well connected and porous microstructure. The triple phase boundary reactions suggest the formation of Co(OH)3 along with H2 gas on reaction of these composite electrodes with H2O during electrochemical dissolution. However, chronoamperometric studies prove the suitability of x = 0.6 sample with higher ORR and liberation of H2 gas at room temperature.

Effectiveness of microwave processing approach and green blowing agents usage in foaming natural rubber

This study mainly concerns the role of foam heating process techniques and its impact on cellular micromorphology, density and gas liberation mechanism of natural rubber foam with distilled water as blowing agent. Three different modes of heating process techniques and varying amount of distilled water have been examined on the foam density and cellular morphology, having rather identical morphological formation, cell distribution and relatively reducing densities but significant cell wall thickness. It is deduced that the increase in the water loading substantially affects the decrease in the foam densities, cell uniformity and stability. However, the heating process techniques influence the cell distribution and stability more than the amount of water content loading. The combine microwave oven process technique has improved the process of moisture diffusion into the water-blown open cell natural rubber foam unlike the slower procedure of conventional heating technique. In addition, the natural rubber foam physical properties and microstructure is improved better than the conventional heating technique. In all the simultaneous combine microwave oven technique is the best among the evaluated technique from the experiment because of density increment, cell distribution, pores flaccidity and uniform cells.

Multi-criteria PSO-based optimal design of grid-connected hybrid renewable energy systems

ABSTRACT Human-induced climate change through the over liberation of greenhouse gases, resulting in devastating consequences to the environment, is a concern of considerable global significance which has fuelled the diversification to alternative renewable energy sources. The unpredictable nature of renewable resources is an impediment to developing renewable projects. More reliable, effective, and economically feasible renewable energy systems can be established by consolidating various renewable energy sources such as wind and solar into a hybrid system using batteries or back-up units like conventional energy generators or grids. The precise design of these systems is a critical step toward their effective deployment. An optimal sizing strategy was developed based on a heuristic particle swarm optimization (PSO) technique to determine the optimum number and configuration of PV panels, wind turbines, and battery units by minimizing the total system life-cycle cost while maximizing the reliability of the hybrid renewable energy system (HRES) in matching the electricity supply and demand. In addition, by constraining the amount of conventional electricity purchased from the grid, environmental concerns were also considered in the presented method. Various systems with different reliabilities and potential of reducing consumer’s CO2 emissions were designed and the behavior of the proposed method was comprehensively investigated. An HRES may reduce the annualized cost of energy and carbon footprint significantly.

Natural Gas Liberations around Production Wells at Russian Arctic Gas Fields

Gas samples from gas liberations around wellheads on two giant natural gas fields in West Siberia (Bovanenkovo and Yamburg) have been tested for their carbon isotopic and molecular compositions. Results have shown local, microbial genesis of gas and that its source is permafrost at both gas fields. Gas liberation is caused by permafrost rock massif thawing around working well. Gas liberations can appear at different distances from the casing inside the radius of thawing. Two gas samples taken from gas liberations at casing border have shown thermogenic origin, which was explained by deep gas leakage through the casing. Gas liberations from deep production horizons are few, and they concentrate around the casing. Permafrost gas liberations are numerous, and they are spread at different distances from the wellhead.

Boosting multiple photo-assisted and temperature controlled reactions with a single redox-switchable catalyst: Solvents as internal substrates and reducing agent

An alternative and economically viable process for the synthesis of β-aryl enals, enones and the aryl amines has been developed by partial oxidation of ethanol, isopropanol and N, N-dimethyl formamide (DMF). The formation of β-aryl enals, enones and the aryl amines was catalyzed by a mixed metal oxides layer of cobalt and chromium supported on halloysite nanotubes, designated as CoCr2O4-HNT. The CC and CN bond formation reactions were found to be influenced by temperature and the nature of base. The condensation of aldehyde with in situ generated acetaldehyde by ethanol oxidation forming β-aryl enals occurred selectively at 120 °C. The partial oxidation of isopropanol to acetone and its condensation with aldehydes forming β-aryl enones occurred at room temperature. Increase in temperature caused the liberation of hydrogen gas from isopropanol and allowed the reversible reduction of aldehydes to alcohols. Increase in temperature in isopropanol and increase in base concentration in ethanol causes the selective reduction of aldehydes to alcohols. Besides being active for the Claisen-Schmidt type of reactions and the aryl halides amination process, the synthesized catalyst was also found to be highly active for the photocatalytic oxidation of benzyl alcohols in absence of any external oxidizing agent. The positive holes (h+) generated at the Co(II) site as evident from EPR analysis was considered to be responsible for high photocatalytic activity of the material reducing the recombination rate of holes and electrons (e−). Density Functional Theory calculations were performed to understand the mechanism of ethanol oxidation to acetaldehyde.

Using non-combustion explosion in H2O/DMF to synthesize 3D Structure of ultrathin Bi nanofilm with high catalytic activity for p-nitrophenol reduction

The synthesis of inorganic micro-/nano-materials by dry combustion is somewhat dangerous since it is performed under high temperature. The ultrathin Bi nanofilms with 3D structures were synthesized using a safe approach of non-combustion explosion in H2O/DMF solution at room temperature and atmospheric pressure. The violent reaction between H2O2 and NH3 · H2O resulted in a non-combustion explosion due to the fast evolution of gases. Then under high temperature and high pressure during solvothermal process, the further slight explosion occurred where the oxygen-containing molecules of H2O2 and NO3− acted as oxidants, while the hydrogen-containing molecules of NaBH4, NH3 · H2O and DMF acted as reductants. The release of gases was accompanied with BiIII reduction by NaBH4. The 3D structure of ultrathin Bi nanofilms with many void spaces formed due to the explosive force and foams from the sharp liberation of gases. Such ultrathin Bi nanofilms with 3D structure exhibited outstanding catalytic activity for p-nitrophenol hydrogenation which is important to treat the environmental pollution from p-nitrophenol discharge. Within only several seconds p-nitrophenol hydrogenation was completed without delay. The non-combustion explosion exhibits potential applications for the synthesis of 3D ultrathin film materials as high efficient catalysts.

The Deceptive and Unwanted Gas Liberalization Process in Russia

This paper argues that this perception of the gas liberalization process in Russia is far too rosy. The analysis of the gas liberalization process in Russia demonstrates that there have been very few changes made in the legislative framework that would favor the opening of the market and the involvement of all independent gas players. We find that many of the gas “reforms” undertaken are still such that favor Gazprom and the Kremlin’s control over the sector. We find that the changes in market share are not an outcome of the gas liberalization process, and that many of the reforms (i.e., liberalization of the export market and more favorable regulatory conditions) only apply to two purportedly “independent” gas companies (Rosneft and Novatek) that are in reality owned by Russian President Vladimir Putin’s close circle of friends.

Gas Liberation in the High-Temperature Isothermal Holding of Coke Residues

The dynamics of nitrogen, hydrogen, and carbon-monoxide liberation in the isothermal holding of coke residues from G, Zh, KO, KS, and T coal at 1000°C is studied in experiments after heating at 10°C/min. The gas liberation in isothermal holding continues throughout the experiment (2 h). The rate of gas liberation declines exponentially in the course of holding. The rates of H2 and CO emission are related to the clinkering properties of the coal (the plastic-layer thickness) on the basis of a second-order polynomial; for the rate of nitrogen liberation, this relationship is linear. In isothermal holding, the mass loss of the coke residue may be 0.60–1.00% after 60 min and 0.85–1.38% after 120 min. The corresponding gas yields are 25–30 and 35–42 m3/t of coke. The gas consists of 76.8–93.0 vol % hydrogen, 1.9–11.7 vol % nitrogen, and 4.1–14.9 vol % carbon monoxide.

Natural Gas markets in the European Union: Testing Resilience

The liberalization and integration of natural gas markets in Europe have resulted in gas-to-gas competition on a European scale with closely related natural gas prices in the various markets. More recently, the European Union aims to become a resilient energy union which may call for additional policy measures. In this paper we discuss the need for such additional measures on top of the existing measures to liberalize and integrate markets. We test the hypothesis that the European natural gas market is resilient to adequately deal with external shocks by analyzing the five most dramatic supply disturbances in the European natural gas markets over the past decade. We find that the natural gas markets were able to trigger responses by market parties which prevented forced supply of gas to consumers in almost all cases. In one case, infrastructure bottlenecks prevented market players to adequately respond to a shock. Hence, we conclude that the best policy to create a resilient energy union is to further integrate European markets and to further remove barriers for market participants.

Combined lignin defunctionalisation and synthesis gas formation by acceptorless dehydrogenative decarbonylation

Iridium catalysed acceptorless dehydrogenative decarbonylation of organosolv lignin is exemplified for the combined lignin defunctionalisation and liberation of synthesis gas.

Formation of Common Electricity and Gas Markets in the EAEU: Market Models, Barriers and Solutions

The formation of common industrial markets of the Eurasian Economic Union (EAEU) in the energy sector is not just a task to fulfill the terms of the Treaty on the EAEU, but a necessary condition for expanding integration interaction between partner countries, a necessary resource platform for developing competitive potential in the industrial sector of the EAEU member countries and a factor for ensuring energy security The formation of common industrial markets of the Eurasian Economic Union (EAEU) in the energy sector is not just a task to fulfill the terms of the Treaty on the EAEU, but a necessary condition for expanding integration interaction between partner countries. It’s a necessary resource platform for developing competitive potential in the industrial sector of the EAEU member countries and a factor for ensuring energy security The authors examine in the article the world experience in applying various models for integrating energy markets, in particular electricity and gas, taking into account the specifics of the functioning of the sectoral national systems of the EAEU countries, their resource potential, the level of development of competition and monopolization, and the possibilities of transit of electricity and gas. The potential of creating and developing a common electricity market on the basis of the signed agreements in the EAEU was studied in the context of differences in the institutional and legal bases, the degree of development of competition in the national industrial electricity markets, and their liberalization levels. The revealed differences in the models of the national electricity markets of the EAEU countries cause a long transition period for the formation of a common market with a gradual decrease in the number of seizures in generation / production, transmission and ensuring the security of energy supply to countries. It is noted, that the coordinated model of the transition period does not contribute to the rapid obtaining of significant synergistic effects and the solution of energy redundancy problems. The need to develop a coordinated industrial policy of the EAEU countries to expand the use of resource potential and export of energy resources to third countries is noted. It requires an integrated approach to creating common markets, primarily electricity and gas. (можно дать одним предложением The need to develop a coordinated industrial policy of the EAEU countries to expand the use of resource potential and export of energy resources to third countries is noted, which requires an integrated approach to creating common markets, primarily electricity and gas., а можно оставить и так)The current level of the institutional and legal basis for the formation of the gas market does not allow to overcome the differences in the degree of liberalization of national gas markets, their monopolization and, accordingly, pricing, and determines the acceleration of integration rapprochement. The formation of common markets actualizes the format of exchange trading, the institutionalization of which on the electricity market is already provided for in the EAEU interstate agreements, and on the common gas market requires coordination and implementation of electronic trading mechanisms, drawing on Russian experience.

Hard alloy production by SHS compaction in an open die

The paper investigates the possibility of carrying out SHS for the Ti (81.5 wt.%) + B (18.5 wt.%) composition in the air followed by pressing combustion products in an open steel die with walls limiting their radial flow under tough heat dissipation conditions without the use of an intermediate loose medium of the heat insulator. Modes of reaction powder mixture preparation for synthesis were optimized. Such process characteristics as bulk density, compaction, elastic aftereffect were determined for initial powders and reaction mixtures, and the strength of compactions was estimated. It is shown that there is a relationship between the strength of charge compacts, combustion rate and changes in their volume after combustion in the air under intensive gas liberation during combustion. The optimal charge compact density was found equal to 0.75 corresponding to the maximum combustion rate without charge emissions with a minimum change in volume. As a result of the optimization, the possibility of effective and safe conduct synthesis process without the use of an intermediate loose medium of the heat insulator is shown. Hard-alloy plates with a diameter of 60 mm and a thickness of 11 mm were obtained in the open steel die under SHS compaction conditions. The structure of the resulting hard alloy is unique with a porosity of less than 0.5 %. It consists of titanium diboride (~60 wt.%) and titanium-based binder phase (~ 40 wt.%). Such a structure obtained as a result of accelerated cooling can be defined as nonequilibrium, since the main phase for the studied composition should be titanium monoboride (TiB) in accordance with the Ti–B state diagram. The microhardness of the fabricated hard alloy is HV = 18000 MPa.

Investigation of the Effect of Foaming Agent on the Fabrication of NiTi Foams Using the Self-Propagating, High-Temperature Synthesis Process

Fabrication of NiTi intermetallic foams using the self-propagating, high-temperature synthesis (SHS) process was investigated. Weighed amounts of powders taken from an equimolar mixture of Ni and Ti powders along with 0.5, 1, and 1.5 wt pct of different foaming agents were cold pressed to form cylindrical compacts 10 mm in diameter, 20 mm in height, and 7 to 8 g in weight. A novel, induction-assisted ignition method was used for indirect heating and igniting the compressed mixtures at one end. As a result of intensive exothermic reaction between Ni and Ti and decomposition of foaming agents and liberation of gases, highly porous products were obtained. Characterization of the products was carried out using X-ray diffraction (XRD) and a scanning electron microscope equipped with an energy-dispersive spectroscope (SEM-EDS). The main phase in the products was detected to be B2(NiTi) with minor amounts of NiTi2 as the secondary phase. Other undesirable phases, such as Ni4Ti3 and Ni3Ti, were not detected. The effect of type and percentage of foaming agent on the formation and distribution of pores within the products was studied. Final products with porosities up to ~ 80 vol pct were obtained by adding foaming agent. Under the conditions of this study, CaH2 proved to be the most effective foaming agent considering its ability to generate a uniform distribution of pores, while TiH2 was not considered favorable due to its decomposition at relatively low temperatures. In general, the addition of foaming agents in amounts higher than 1wt pct is not recommended; due to the endothermic nature of thermal decomposition reactions of foaming agents, excessive use of these agents can result in suppression of the exothermic reaction.

Droplet combustion of kerosene augmented by stabilized nanoaluminum/oxidizer composite mesoparticles

Inclusion of energetic and chemically active nanoparticles into liquid fuels and propellants is known to affect resultant combustion dynamics. Recently, the activity of such nanoparticle additives has been promoted using electrospray to preassemble said particles into nitrocellulose-bound mesoparticle (MP) clusters of either nanoaluminum (nAl) or oxygen-carrying nanoparticle primaries. In either case, stability in kerosene with TOPO surfactant and isolated droplet burning rates estimated in a free-droplet combustion experiment increase substantially with the MP additive architecture. Burning rates benefit from violent physical mixing of droplet systems which occurs when the carried nanoparticles are energetic and/or chemically active, causing gas generation, additive transport to the flame, energy or oxygen release, and further gas liberation accelerating the process. In this study, this same physical underlying mechanism is seen superimposed with the effects of another advantage of electrospray particle assembly: MP composition flexibility. By mixing nAl with oxide nanoparticles to form composite MPs, these novel additives for hydrocarbons are employed to modify kerosene and their effects are found to be dependent on the oxidizer chosen. Most notably, nAl/CuO MPs show evidence of interparticle thermite reaction in the droplet system yielding a cooperative benefit of the two constituents relative to either alone in MPs. Use of oxidizer co-additives and the MP architecture with nAl represents a flexible and promising method of overcoming low burning rates of hydrocarbons with high as-received nAl loadings and provides expansive means of tunability to tailor nanofuel properties.

Seismic loading of fault-controlled fluid seepage systems by great subduction earthquakes

Various types of fluid expulsion features (mud volcanoes, pockmarks, authigenic carbonate mounds and associated gas pipes, etc.) are often found above subduction zones, which have the highest seismic potential on Earth. Faults potentially control the liberation of deep-seated greenhouse gases into the feeder systems of seepage features located above subduction thrusts. These feeder systems could be stressed by large earthquakes, yet the mechanisms that can drive episodic mobilization of stored hydrocarbon gases remain poorly understood. Here I address the potential stress loading on fluid expulsion systems created by past earthquakes nucleated at both accretionary and erosive subduction margins. The most significant effects occur in the epicentral area where subduction earthquakes can produce normal stress changes as high as 20–100 bar, although these are generally restricted to relatively small regions. Coseismic normal stress changes and elastic strain relaxation upon a ruptured subduction thrust could increase crustal permeability by dilating fault-controlled conduits, and channelling fluids to the seafloor. Fluid pressure pulses released during subduction earthquakes can greatly contribute to the rupture of fluid pathways that have been brought closer to failure from coseismic static stress changes, although the inaccessible location of most submarine seepage systems has so far hampered probing these relationships.