CO2 Fluid Research Articles

Modelling of Transient CO2/Water Flow in Wellbore considering Multiple Mass and Heat Transfer

A transient fully coupled model is proposed to investigate the two-phase flow of CO2 and water-based fluid in a wellbore, considering the complex mass and heat transfer in different flow patterns and dynamic coupling between the wellbore and reservoir. Based on mass conservation, momentum, and energy balance, the model employs a state-of-the-art equation of state and transport models to analyze the variations of multiphase flow behaviors and CO2 properties in a wellbore. Applied in the scenario of a drilled gas kick, the proposed model is used to simulate the processes of gas migration and two-phase flow in the wellbore. The results indicate that the CO2 solubility increases gradually with the increment of depth, the trend of which shows an abrupt change in 500-1000 m due to the phase transition of CO2. During kick development, the fronts of free gas and dissolved gas increase almost linearly with time. Through a comparison of CO2 and CH4 kicks, gas dissolution is found to significantly suppress the development process of CO2 kick. The error in kick prediction can reach 42% if the effect of gas dissolution is neglected. However, it can be neglected for CH4 kick.

Structural improvement and thermodynamic optimization of a novel supercritical CO2 cycle driven by hot dry rock for power generation

Due to the higher thermal extraction rate, injection capacity and fluidity of supercritical CO2, supercritical CO2 as the circulating working fluid in the enhanced geothermal systemfor thermal utilization of hot dry rock resources will achieve higher energy efficiency. In view of the low power generation efficiency of the supercritical CO2 cycle and the decrease in the mass flow rate of the CO2 fluid in the cycle caused by dissolution and precipitation of CO2 fluid in rocks and minerals in fractures, a novel supercritical CO2 cycle with CO2 pressurization process is proposed. Based on the conventional supercritical CO2 cycle and CO2 pressurization process, the cycle configuration is optimized to improve the generation performance and reduce the power consumption. The optimization rate which compared to the conventional supercritical CO2 cycle and CO2 pressurization processis selected as the evaluation index to prove the improvement of the cycle performance after the improvement, and the main thermodynamic parameters that affect the cycle performance are optimized. The results show that the reduction of the condensation temperature in the supercritical CO2 cycle, the liquefaction pressureand cooling temperature in the CO2 pressurization process, will all lead to the improvement of the cycleoperation performance. Under the best operating conditions, the optimization rates of the proposed supercritical CO2 cycle and CO2 pressurization process are 19.8% and 4.3%, respectively.

Application of bulk fluid volatile chemistry to exploration for metasedimentary rock-hosted orogenic gold deposits: An example from the Meguma terrane, Nova Scotia, Canada

Disseminated gold (Au) deposits hosted in metasedimentary rocks present unique exploration challenges because the Au is generally very fine-grained or refractory, and not vein-hosted. Exploration programs in such settings rely on extensive lithogeochemical surveys, lesser structural analysis, and little emphasis on ore-fluid geochemistry. The Moose River anticline (MRA) in the Lower Paleozoic Meguma terrane (Nova Scotia, Canada) hosts several high-tonnage (~10–20 Mt), low-grade (≤1–4 g/t Au) Au deposits comprised of disseminated ± quartz vein-hosted mineralization in metamudstones. Here, the Touquoy deposit hosted in the MRA is used to evaluate a new approach to geochemical exploration by examining if the volatile chemistry of host rocks preserves a signature related to Au mineralization, using a gas chromatographic (GC) technique that analyzes bulk volatiles released from crushed rock. Since GC is a bulk analytical technique, (i.e., multiple generations of fluid inclusion volatiles yielding a mixed analytical volume), the volatile composition of fluid inclusions were also investigated in-situ using laser Raman microspectroscopy to reconcile bulk analyses with the composition and abundance of different inclusion types. Inclusions in quartz pressure shadows associated with porphyroblasts host N2 ± CH4-dominant vapor phases and represent wall rock-equilibrated fluids. In comparison, fluid inclusion vapor phases in quartz veinlets crosscutting the metamudstones are more complex in composition and show a continuum between CO2-dominant and N2 ± CH4-dominant compositions; the former is interpreted as the fluid responsible for Au mineralization in the Meguma terrane (e.g., H2O-CO2 ± CH4 ± N2 fluids). GC shows statistically significant differences in the compostion of the bulk volatiles released from crushed metamudstones from the Touquoy deposit (n = 21) and barren (n = 24) settings. Whereas the former commonly contain detectable CO2 (50% of samples; LoQ(CO2) ~ 10−10 mol/g), only ~4% of metamudstones from barren settings along the MRA contain CO2, yielding a t-test p-value of 0.0103 between the two sample populations. Whereas the more frequent detection of CO2 in mineralized samples is related to increasing carbonate alteration proximal to Au mineralization, no correlation is observed between bulk CO2 abundance and Au grade. Additionally, anomalous differences in abundances of released C3 (t-test p-value = 0.043) and C4 (t-test p-value = 0.03) hydrocarbons (HC) are recognized between the two populations (LoQ(HC) ca. 10−13 to 10−12 mol/g), with Touquoy metamudstones having higher Σ(C3)/CH4 and Σ(C4)/CH4 ratios compared to barren equivalents. The compositional differences suggest that more aqueous-carbonic fluids infiltrated metamudstone units where locally favorable physical and/or chemical conditions were present, resulting in increased Au endowment. The relative increase in fluid flux, and thus Au grade, resulted in more trapped CO2 (i.e., resulting from more trapped inclusions and/or greater CO2 fluid component) and modification to hydrocarbon signatures through homologation and/or degradation reactions. Rigorous sample preparation ensures these compositional differences are related to paleofluids and not contamination.Tentatively, the results suggest that the bulk analysis of volatiles released from fluid inclusions in metamudstones may be a useful vectoring tool for disseminated Au mineralization in Meguma-type gold systems and similar environments (e.g., Carlin-type). This technique may be appropriately scaled to complement exploration drilling programs and may be more sensitive in determining ore proximity than often ambiguous pathfinder elements.

Quantitative evaluation of geological fluid evolution and accumulated mechanism: in case of tight sandstone gas field in central Sichuan Basin

Tight gas exploration plays an important part in China’s unconventional energy strategy. The tight gas reservoirs in the Jurassic Shaximiao Formation in the Qiulin and Jinhua Gas Fields of central Sichuan Basin are characterized by shallow burial depths and large reserves. The evolution of the fluid phases is a key element in understanding the accumulation of hydrocarbons in tight gas reservoirs. This study investigates the fluid accumulation mechanisms and the indicators of reservoir properties preservation and degradation in a tight gas reservoir. Based on petrographic observations and micro-Raman spectroscopy, pure CH4 inclusions, pure CO2 inclusions, hybrid CH4–CO2 gas inclusions, and N2-rich gas inclusions were studied in quartz grains. The pressure–volume–temperature–composition properties (PVT-x) of the CH4 and CO2 bearing inclusions were determined using quantitative Raman analysis and thermodynamic models, while the density of pure CO2 inclusions was calculated based on the separation of Fermi diad. Two stages of CO2 fluid accumulation were observed: primary CO2 inclusions, characterized by higher densities (0.874–1.020 g/cm3) and higher homogenization temperatures (> 210 °C) and secondary CO2 inclusions, characterized by lower densities (0.514–0.715 g/cm3) and lower homogenization temperatures: ~ 180–200 °C). CO2 inclusions with abnormally high homogenization temperatures are thought to be the result of deep hydrothermal fluid activity. The pore fluid pressure (44.0–58.5 MPa) calculated from the Raman shift of C–H symmetric stretching (v1) band of methane inclusions is key to understanding the development of overpressure. PT entrapment conditions and simulation of burial history can be used to constrain the timing of paleo-fluid emplacement. Methane accumulated in the late Cretaceous (~ 75–65 Ma), close to the maximum burial depth during the early stages of the Himalayan tectonic event while maximum overpressure occurred at ~ 70 Ma, just before uplift. Later, hydrocarbon gas migrated through the faults and gradually displaced the early emplaced CO2 in the reservoirs accompanied by a continuous decrease in overpressure during and after the Himalayan event, which has led to a decrease in the reservoir sealing capabilities. The continuous release of overpressure to present-day conditions indicates that the tectonic movement after the Himalayan period has led to a decline in reservoir conditions and sealing properties.

Moisture‐Resistant and Mechanically Strong Polyimide‐Polymethylsilsesquioxane Hybrid Aerogels with Tunable Microstructure

AbstractMoisture‐resistant and mechanically strong polyimide (PI)‐polymethylsilsesquioxane hybrid aerogels with doubly cross‐linked structures are synthesized through sol–gel technology and supercritical CO2 fluid drying. By using bis(trimethoxysilylpropyl) amine as a cross‐linker, the end‐capped polyamide acid derived from biphenyl‐3,3′,4,4′‐tetracarboxylic dianhydride and 4,4′‐oxydianiline is cross‐linked with a silica network using methyltrimethoxysilane as the silica source precursor. The resultant hybrid aerogels show low density (0.12–0.15 g cm−3), low thermal conductivity (0.032–0.049 W m−1 K−1), high hydrophobicity (125–140°) and good thermal stability (above 435 °C) with tunable microstructure. With the increase of silica sol volume, the microstructure of hybrid aerogels transforms from fibrous network to hierarchical microstructure. Aerogels with high content of silica sol exhibit good moisture resistance, high Young's modulus (Max. 19.6 MPa), and high specific modulus (Max. 131 kN m kg−1), which are attributed to their unique hierarchical microstructure with a sheet skeleton. These hybrid aerogels are promising in the fields of thermal insulation, aerospace applications and so on.

A multi-dimensional parametric study of variability in multi-phase flow dynamics during geologic CO2 sequestration accelerated with machine learning

Successful geologic CO2 storage projects depend on numerical simulations to predict reservoir performance during site selection, injection verification, and post-injection monitoring phases of the project. These numerical simulations solve non-linear sets of coupled partial differential equations, while accounting for multi-phase fluid dynamics on the basis of constitutive equations that are embedded into the solution scheme. As a consequence, individual simulations often require tens to hundreds of hours to complete on high-performance computing clusters. Moreover, laboratory experiments reveal that parametric functions for capillary pressure and relative permeability exhibit substantial variability, even within the same rock type. This combination of computational expense and wide-ranging parametric variability means that there remains substantial uncertainty in the behavior of multi-phase CO2-water systems, particularly in the context of feedbacks between relative permeability and capillary pressure. To bridge this knowledge gap, we develop a novel workflow that utilizes physics-based numerical simulation to train an artificial neural network (ANN) emulator for interrogating the multivariate parameter space that governs both capillary pressure and relative permeability. With this approach, the ANN is trained to emulate both fluid pressure distribution and CO2 saturation, which are then interrogated quantitatively to generate parametric response surface mappings with high-fidelity resolution. Results from this study initially show that capillary entry pressure is the dominant control on both CO2 plume geometry and fluid pressure propagation when considering the combined effects of capillary pressure and relative permeability, particularly when phase interference is low and residual CO2 saturation is high. Moreover, the ANN emulator provides tremendous computational speed-up by computing 2691 individual simulations in several minutes; whereas, the same simulation ensemble would have required ~3 years of simulation time using only physics-based simulation methods (25,000 times speed up).

Performance Enhancement and Bending Restoration for Flexible Amorphous Indium Gallium Zinc Oxide Thin-Film Transistors by Low-Temperature Supercritical Dehydration Treatment.

For high-performance and high-lifetime flexible and wearable electronic applications, a low-temperature posttreatment method is highly expected to enhance the device performance and repair the defects induced by the low-temperature fabrication process intrinsically. Particularly, if the method can repair the traces induced by the multiple cycles of bending or deforming, it would overcome current fatal obstacles and provide a vital solution to the rapid development of flexible electronics. In this work, we propose a method to apply low-temperature supercritical CO2 fluid with a dehydration function to improve or even restore the performance of flexible amorphous indium gallium zinc oxide (a-IGZO) thin-film transistors (TFTs). After the treatment, the a-IGZO TFT exhibits 3 times improvement drivability up to 0.24 μA/μm, a smaller subthreshold swing of 0.18 V dec-1, a smaller Vth of 0.25 V, and a larger Ion/Ioff ratio of 3.8 × 107. Additionally, the posttreated a-IGZO TFTs possess relatively good uniformity and reproducibility with an on-current standard deviation of 0.047 μA/μm, and the performance of the a-IGZO TFT after the treatment remains almost unchanged even after bending 2500 times at a bending radius of 5 mm. These characteristics are attributed to the improved quality of the channel and gate dielectric. It is worth noting that when this is applied to a flexible TFT-driven organic light-emitting diode lighting system, this treatment method can restore the performance of not only the TFT but also the lighting system, even after the system has been bent more than 600 times and has failed. To date, this is the first time that the bending-track erasing function of the supercritical fluid for flexible systems has been reported, which has the potential to prolong the lifetime of flexible electronics.

Role of CO2 in the evolution of Kimberlite Magma: Experimental constraints at 5.5 GPa and 1200–1450 °C

According to the existing models of kimberlite origin, free exsolution CO2 may be an important agent in the evolution of primary kimberlite magma and initiation of crack propagation. We study the reaction of garnet lherzolite with carbonatitic melt rich in molecular CO2 and H2O in experiments at 5.5 GPa and 1200–1450 °C. The experimental results show that carbonation of olivine with formation of orthopyroxene and magnesite can buffer the contents of molecular CO2 in the melt, which impedes immediate separation of CO2 fluid from melt equilibrated with the peridotite source. The solubility of molecular CO2 in the melt decreases from 20 -25 wt% at 4.5–6.8 wt% SiO2 typical of carbonatite to below 7–12 wt% in more silicic melts with 26–32 wt% SiO2. Interaction of garnet lherzolite with carbonatitic melt (at a weight proportion of 2:1) in the presence of 2–3 wt% H2O and 17–24 wt% of total CO2 at 1200–1450 °C yields low-SiO2 (<10 wt%) alkali‑carbonated melts, which shows multiphase saturation with magnesite-bearing garnet harzburgite. Thus, carbonatitic melts rich in volatiles can originate in a harzburgite source at moderate temperatures common to continental lithospheric mantle (CLM). Excessive volatiles may be present in carbonatitic melts not equilibrated with the peridotitic source due to the formation of metasomatic reaction zones.Having separated from the source, carbonatitic magma enriched in molecular CO2 and H2O can rapidly become more silicic (>25 wt% SiO2) by dissolution and carbonation of entrapped peridotite. Furthermore, interaction of garnet lherzolite with carbonatitic melt rich in K, CO2, and H2O at 1350 °C produces immiscible carbonate-silicate and K-rich silicate melts. Quenched silicate melt develops globules of foam-like vesicular glass. Differentiation of immiscible melts early during their ascent may equalize the compositions of kimberlite magmas generated in different CLM sources. The fluid phase can release explosively from ascending magma at lower pressures as a result of SiO2 increase which reduces the solubility of CO2 and due to the decarbonation reaction of magnesite and orthopyroxene.

Corrosion simulation via coupling computational fluid dynamics and NORSOK CO2 corrosion rate prediction model for an outlet header piping of an air-cooled heat exchanger

In this study CO2 corrosion of outlet header pipe of an air-cooled heat exchanger in a natural gas dehydration unit of a gas refinery was investigated by simulation via coupling computational fluid dynamics and NORSOK M-506 CO2 corrosion prediction model. The Euler-Euler approach incorporated with k–ε model for the fluid turbulence was employed to simulate gas-liquid two-phase flow. The simulation results were utilized as the inputs of NORSOK CO2 corrosion prediction model to calculate CO2 corrosion rate. Fluid streamlines, velocity, viscosity, density and temperature profiles and also the distribution of gas and liquid phases through the investigated outlet header pipe were calculated and a three-dimensional corrosion rate map was presented. The results showed that there is a good agreement between the data obtained by corrosion simulation and field observation. It was found here that coupling computational fluid dynamics and CO2 corrosion prediction models can successfully predict regional corrosion rates and determine locations susceptible to CO2 corrosion.

Interlaboratory Application of Raman CO2 Densimeter Equations: Experimental Procedure and Statistical Analysis Using Bootstrapped Confidence Intervals.

Raman spectroscopy has been used extensively to calculate CO2 fluid density in many geological environments, based on the measurement of the Fermi diad split (Δ; cm-1) in the CO2 spectrum. While recent research has allowed the calibration of several Raman CO2 densimeters, there is a limit to the interlaboratory application of published equations. These calculate two classes of density values for the same measured Δ, with a deviation of 0.09 ± 0.02 g/cm3 on average. To elucidate the influence of experimental parameters on the calibration of Raman CO2 densimeters, we propose a bottom-up approach beginning with the calibration of a new equation, to evaluate a possible instrument-dependent variability induced by experimental conditions. Then, we develop bootstrapped confidence intervals for density estimate of existing equations to move the statistical analysis from a sample-specific to a population level. We find that Raman densimeter equations calibrated based on spectra acquired with similar spectral resolution calculate CO2 density values lying within standard errors of equations and are suitable for the interlaboratory application. The statistical analysis confirms that equations calibrated at similar spectral resolution calculate CO2 densities equivalent at 95% confidence, and each Raman densimeter does have a limit of applicability, statistically defined by a minimum Δ value, below which the error in calculated CO2 densities is too high.

Preparation of graphene/PMMA composites with assistance of ultrasonic wave under supercritical CO2 conditions

The two-dimensional material graphene has many excellent physicochemical properties such as large specific surface area, high electron migration rate, good chemical properties, good thermal conductivity, high elastic modulus and mechanical strength that make it very valuable for theoretical research and application in the preparation of graphene/polymer composites. In this paper, the effects of ultrasonic intensity and reaction time on the molecular weight and yield of PMMA under supercritical CO2 conditions were investigated. It was found that there are threshold and optimal values of ultrasonic intensity for initiating the reaction in supercritical CO2 system. The threshold value is 150 W/cm2 and the optimal ultrasonic intensity value is 225 W/cm2. There is also an optimal value of ultrasonic initiation time for ultrasonic initiation polymerization. Combining the reaction yield and the molecular weight of the product, 2 h of ultrasonic initiation is a suitable initiation reaction time. Based on the synthesis of PMMA by ultrasonic excitation, the preparation of Graphene/PMMA composites by ultrasound assistance was also investigated. The TG and DTG characterization of PMMA and complex materials prepared by ultrasonic excitation showed that the radicals generated by ultrasonic excitation were uniformly distributed and did not generate unsaturated double bonded polymers. The electrical conductivity of the Graphene/PMMA composites prepared by ultrasonic excitation at a graphene content of 1 wt% increased to 1.13 × 10-1 S/cm, which is better than that of the Graphene/PMMA prepared by in situ polymerization. This may be attributed to the ultrasound-assisted supercritical CO2 fluid action that resulted in a more uniform distribution of Graphene mixed with PMMA in the prepared composites. Therefore, it is of important practical significance for the preparation of Graphene/PMMA composites by ultrasound-induced polymerization.

Supercritical carbon dioxide extraction of plant phytochemicals for biological and environmental applications – A review

Recently, supercritical fluid CO2 extraction (SFE) has emerged as a promising and pervasive technology over conventional extraction techniques for various applications, especially for bioactive compounds extraction and environmental pollutants removal. In this context, temperature and pressure regulate the solvent density and thereby effects the yield, selectivity, and biological/therapeutic properties of the extracted components. However, the nature of plant matrices primarily determines the extraction mechanism based on either density or vapor pressure. The present review aims to cover the recent research and developments of SFE technique in the extraction of bioactive plant phytochemicals with high antioxidant, antibacterial, antimalarial, and anti-inflammatory activities, influencing parameters, process conditions, the investigations for improving the yield and selectivity. In another portion of this review focuses on the ecotoxicology and toxic metal recovery applications. Nonpolar properties of Sc-CO2 create strong solvent strength via distinct intermolecular interaction forces with micro-pollutants and toxic metal complexes. This results in efficient removal of these contaminants and makes SFE technology as a superior alternative for conventional solvent-based treatment methods. Moreover, a compelling assessment on the therapeutic, functional, and solvent properties of SFE is rarely focused, and hence this review would add significant value to the SFE based research studies. Furthermore, we mention the limitations and potential of future perspectives related to SFE applications.

Application of New Supercritical Extraction Technology in Extraction and Separation of Effective Components of Traditional Chinese Medicine

Supercritical CO2 extraction technology uses supercritical CO2 fluid as extractant to extract and separate effective components from plants from liquid or solid. At present, CO2 is widely used in supercritical fluid, with a critical temperature of 31.265 °C and a critical pressure of 7.18 MPa. The critical conditions are easy to reach. In supercritical state, the density of CO2 fluid is very sensitive to the changes of temperature and pressure, The widely used separation technologies can be divided into two types: membrane separation and traditional separation. The traditional separation methods can be divided into steam distillation, sublimation, cold soaking, precipitation, percolation, decocting method and Soxhlet extraction, etc. These separation methods have certain limitations. In this paper, SFE technology is combined with modern analytical techniques, such as gas chromatography, high performance liquid chromatography, thin layer chromatography, gas chromatography-mass spectrometry, liquid chromatography-mass spectrometry, etc., so that the component analysis can be carried out more efficiently and quickly. Because of the above advantages, SFE is especially beneficial to the extraction of effective components in traditional Chinese medicine and its preparations.

Measurement of CO2 diffusion coefficients in both bulk liquids and carven filling porous media of fractured-vuggy carbonate reservoirs at 50 MPa and 393 K.

Diffusion coefficients are necessary to describe the mass transfer and adsorption rate of CO2 in formation fluids. However, data is scarcely reported for actual reservoir conditions of high pressure and temperature, which are normal in most scenarios of the CO2-enhanced oil recovery process in China's fractured-vuggy reservoirs and carbon storage process. Accordingly, this work employed the pressure decay method (PD) and relevant mathematical models to determine the CO2 diffusion coefficient in both liquids and cavern filling porous media at 50 MPa and 393 K. The effects of the type of reservoir fluids, the properties of carven filling porous media, and water saturation on CO2 diffusion coefficients were investigated. Results in bulk reservoir liquids showed that the CO2 diffusion coefficient in the oil sample was 4.1243 × 10−8 m2 s−1, much higher than those in the pure alkane phase, pure water and brine sample from reservoirs. Results of CO2 diffusion in carven filling porous media saturated with oil demonstrated a significant dependence on properties such as porosity and permeability, and a correlation in the CO2 diffusion coefficients between the bulk oil phase and cavern filling porous media in the form of touristy was documented. CO2 diffusion in the fractured cavern porous media was much higher than that without fracture. An increase in water saturation reduced CO2 diffusion coefficients in the carven filling porous medium studied, herein. Thus, the CO2 diffusion coefficient is essentially related to the type of liquid and properties of the filling media.

Vessel Blowdown of CO &lt;sub&gt;2&lt;/sub&gt;-Rich Fluids: Experiments and Simulations

In carbon capture and storage projects using CO2 ship transport from capture to injection sites, CO2 leakage can occur at onshore storage vessels or in the ship vessels. In order to quantify the consequences of CO2 leaks, that may lead to dry ice formation, process tools suitable for CO2-rich fluids are needed. Sophisticated thermodynamic models that take into account solid CO2 formation are required to simulate depressurization of vessels containing pure CO2 or CO2-rich fluids. The tuning and validation of these complex models require reliable experimental measurements. However, for the time being, very few and poorly documented experimental data exist in the literature. The main objectives of the CARDICE (CARbon Dioxide ICE) Joint Industry Project were to perform CO2 blowdown experiments and to use the experimental data to benchmark and improve the VessFire process software. Blowdown experiments were carried out by Ineris. The set-up consisted of a 2 m3 spherical vessel that can handle high pressure (200 bara) and low temperature (-60°C). The first set of tests considered gas releases of pure methane and methane/carbon dioxide mixtures, from high pressure and ambient temperature. A second set of tests consisted of pure CO2 releases at vapour/liquid equilibrium, with initial temperatures varying from -20°C down to -40°C, and corresponding saturation pressures of 20 down to 10 bara. All the tests were conducted successfully with acceptable measurements and without any safety issue. These pilot scale tests are unique and provide very valuable data for assessing process software tools & models. VessFire, developed by Petrell, is a hybrid 0D-3D tool based on fluid dynamics modelling and a finite-element method for the heat transfer within the walls. Vessfire can handle non-equilibrium thermodynamics of vapour, liquid and solid phases, including the phase changes. With the help of the test results, it was possible to evaluate the performance of Vessfire and identify its strengths and weaknesses for modelling of blowdown operations. Vessfire is considered as a potential tool that can be used for design and simulation of blowdown of single CO2 vessels.

Features of Mineral Crystallization at Different Stages of the Magmatism Evolution of the Gorely Volcano (Kamchatka): Data on Melt and Fluid Inclusions

Abstract ––Studies of melt and fluid inclusions and minerals as well as computational modeling (based on the data on the composition of melt inclusions, clinopyroxenes, and amphiboles) gave an insight into the physicochemical parameters of magmatic systems during the evolution of the precaldera Pra-Gorely Volcano and during the subsequent formation of rock complexes of the Young Gorely Volcano. The estimated temperatures of crystallization of olivine, clinopyroxene, and plagioclase phenocrysts (1115–1260 °С) and amphibole (740–890 °С) are in agreement with the earlier published data on the magmatism of the Gorely Volcano. Computational modeling based on the compositions and homogenization temperatures of melt inclusions showed that the established depth interval of mineral crystallization (21.0–1.5 km) with pressures of 7.0–0.5 kbar can be divided into two ranges, 21–15 km and 9.0–1.5 km. Both the Pra-Gorely and Young Gorely volcanoes have magma chambers in these depth ranges. The Pra-Gorely Volcano is characterized by higher temperatures of mineral crystallization (1240–1190 °С) as compared with the Young Gorely Volcano (1190–1125 °С). The presence of primary fluid inclusions with low-density CO2 and of syngenetic primary melt inclusions in plagioclase of the Pra-Gorely Volcano indicates that the mineral crystallized from a heterophase melt. At the same time, the cores of plagioclase phenocrysts formed from a homogeneous melt. A drastic drop in pressure led to the phase separation of magma throughout the magma column (upper and lower chambers) and to the growth of zones saturated with CO2 fluid inclusions in the plagioclase crystals formed from a two-phase melt. The subsequent closure of the system and the disappearance of CO2 phase resulted in the growth of plagioclase from a homogeneous melt.

Design of 10 kW Low Temperature Power Cycle Using Amine— CO2 Fluid

Our thermodynamic study indicated that low temperature power cycle using amine-CO2 fluid can obtain the performance equal to or higher than that of the current organic Rankine cycle. We designed a 10 kW test equipment. We set high temperature heat source is hot water at the temperature of 90°C and the flow rate of 8,200kg/h, which is a coolant from a gas engine. The heat and mass balance of the equipment was calculated thermodynamically. The result showed the power of 10.5kW and the system efficiency of 7.3 per cent at the the amine – CO2 fluid flow rate of 1,000kg/h, and the turbine expansion ratio of 4.8. The preliminary estimation shows as follows. The diameter and rotational speed of the turbine blade are 0.115m and 54,400min-1, respectively. The number, width, and length of the recuperator plates are 20, 117mm, and 835mm, respectively. The height and cross sectional area of the absorption bed are 0.35m and 0.027m2, respectively.

Effect of Cyclotrichium niveum Essential Oil on Rumen Microbial Fermentation and in vitro Digestibility of Barley

The digestibility of feed in ruminants and the volatile fatty acids (VFA) resulting from digestion directly affect animal performance. It has long been studied on the use of essential oils as an alternative to antibiotics to ensure optimum conditions for the rumen environment. Cyclotrichium niveum (mountain mint) essential oil is rich in antimicrobial agents. In this study different doses (0, 50, 100 and 150 mg/L of culture fluid) of Cyclotrichium niveum essential oil was incubated 24 hours with barley in diluted ruminal fluid takes from fistulated cows fed with a 40:60 concentrate:forage diet in order to assess the effects on rumen microbial fermentation and in vitro true digestibility of barley. True digestibility of barley was determined in ANKOM Daisy Incubator. All doses of Cyclotrichium niveum significantly (P&amp;lt;0.001) decreased the in vitro dry matter (DM), organic matter (OM), neutral detergent fiber (NDF) digestibility of barley. Cyclotrichium niveum essential oil negatively affected end-products of rumen fermentation; the value of the measured rumen volatile fatty acids (VFA: acetate, propionate, butyrate, isobutyric acid, valerate and isovalerate) significantly decreased compared to the control group (P&amp;lt;0.001). Carbon dioxide and methane gases created as a result of incubation in rumen fluid were calculated using volatile fatty acid values formed in rumen fluid. The addition of Cyclotrichium niveum essential oil significantly reduces the CO2 in rumen fluid (P&amp;lt;0.001). Methane (CH4) gas from rumen fluid was significantly decreased in treatment groups compared the control group (P &amp;lt;0.001) While end-products of rumen fermentation parameters significantly decreased with all doses of Cyclotrichium niveum essential oil, rumen pH has increased (P&amp;lt;0.05). The results show that when the Cyclotrichium niveum essential oil incubated with barley significantly inhibited the rumen microbial activity and overall fermentation process of rumen.

Novel energy station by natural fluid CO 2

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Nature of ore-forming fluids in the Mehdiabad world-class sub-seafloor replacement SEDEX-type Zn-Pb-Ba-(Cu-Ag) deposit, Iran; constraints from geochemistry, fluid inclusions, and O-C-Sr isotopes

Abstract The Mehdiabad deposit is the largest accumulation of siliciclastic-carbonate hosted zinc in the world, with a total resource of 394 Mt, grading 4.2% Zn, 1.6% Pb, and 36 g/t Ag. In this study, trace element, fluid inclusions studies, and O-C-Sr isotopic analyses were carried out on the host rock and related sulfide ores in the Mehdiabad deposit, aiming to reveal the nature of ore-forming fluids. The average REE contents of the ore samples are higher than those of the host rock samples. The Cd values of sphalerite in the ores range from 0.11 to 0.63 wt%, which suggested that the Mehdiabad Zn-Pb-Ba-(Cu-Ag) mineralization was formed in a sedimentary-exhalative environment. Investigation of the fluid inclusions reveals relatively moderate temperature (105–261 °C) with scattered salinity (0.03–19.44 wt% NaCl eq.). This finding suggests that hydrothermal brine fluid mixing with seawater could be the primary mechanism that prompted ore formation. The host limestones have δ13CPDB values ranging from +1.9 to +2.2‰, and δ18OSMOW values from +1.7 to +2.7‰. Hydrothermal dolomites have δ13CPDB values from +10.6 to +11.2‰, and δ18OSMOW values from +13.4 to +15.0‰. These O-C isotopic studies suggest that CO2 in the hydrothermal fluids mainly originated from marine carbonate rocks. In the Mehdiabad deposit, δ18O values of all barite samples vary within a narrow range from 7.0 to 10.8‰, which roughly fall within that of the Early Cretaceous seawater. Sr isotope data for barite in the Mehdiabad deposit is more radiogenic than Lower Cretaceous seawater. This suggests that radiogenic Sr in the hydrothermal barites mainly originated from fluid-rock reactions involving radiogenic clastic minerals derived from Sangestan strata underlying the Taft Formation.