Enthalpy of dissociation and hydration number of carbon dioxide hydrate from the Clapeyron equation

In this paper, the solubility of carbon dioxide (CO2) in water along the isobar of 400 bar is determined by computer simulations using the well-known TIP4P/Ice force field for water and the TraPPE model for CO2. In particular, the solubility of CO2 in water when in contact with the CO2 liquid phase and the solubility of CO2 in water when in contact with the hydrate have been determined. The solubility of CO2 in a liquid-liquid system decreases as the temperature increases. The solubility of CO2 in a hydrate-liquid system increases with temperature. The two curves intersect at a certain temperature that determines the dissociation temperature of the hydrate at 400bar (T3). We compare the predictions with T3 obtained using the direct coexistence technique in a previous work. The results of both methods agree, and we suggest 290(2)K as the value of T3 for this system using the same cutoff distance for dispersive interactions. We also propose a novel and alternative route to evaluate the change in chemical potential for the formation of hydrates along the isobar. The new approach is based on the use of the solubility curve of CO2 when the aqueous solution is in contact with the hydrate phase. It considers rigorously the non-ideality of the aqueous solution of CO2, providing reliable values for the driving force for nucleation of hydrates in good agreement with other thermodynamic routes used. It is shown that the driving force for hydrate nucleation at 400bar is larger for the methane hydrate than for the carbon dioxide hydrate when compared at the same supercooling. We have also analyzed and discussed the effect of the cutoff distance of dispersive interactions and the occupancy of CO2 on the driving force for nucleation of the hydrate.

The Lunnan Oilfield in the Tarim Basin is known for its abundant oil and gas resources. However, the marine clastic reservoir in this oilfield poses challenges due to its tightness and difficulty in development using conventional water drive methods. To improve the recovery rate, this study focuses on the application of carbon dioxide flooding after a water drive. Indoor experiments were conducted on the formation fluids of the Lunnan Oil Formation, specifically investigating gas injection expansion, thin tube, long core displacement, oil and gas phase permeability, and solubility. By injecting carbon dioxide under the current formation pressure, the study explores the impact of varying amounts of carbon dioxide on crude oil extraction capacity, high-pressure physical parameters of crude oil, and phase characteristics of formation fluids. Additionally, the maximum dissolution capacity of carbon dioxide in formation water is analyzed under different formation temperatures and pressures. The research findings indicate that the crude oil extracted from the Lunnan Oilfield exhibits specific characteristics such as low viscosity, low freezing point, low-medium sulfur content, high wax content, and medium colloid asphaltene. The measured density of carbon dioxide under the conditions of the oil group is 0.74 g/cm3, which closely matches the density of crude oil. Additionally, the viscosity of carbon dioxide is 0.0681 mPa·s, making it well-suited for carbon dioxide flooding. With an increase in the amount of injected carbon dioxide, the saturation pressure and gas-oil ratio of the crude oil also increase. As the pressure rises, carbon dioxide dissolves rapidly into the crude oil, resulting in a gradual increase in the gas-oil ratio, expansion coefficient, and saturation pressure. As the displacement pressure decreases, the degree of carbon dioxide displacement initially decreases slowly, followed by a rapid decrease. Moreover, an increase in the injection rate of carbon dioxide pore volume leads to a rapid initial improvement in oil-displacement efficiency, followed by a slower increase. Simultaneously, the gas-oil ratio exhibits a slow increase initially, followed by a rapid rise. Furthermore, as the displacement pressure increases, the solubility of carbon dioxide in water demonstrates a linear increase. These research findings provide valuable theoretical data to support the use of carbon dioxide flooding techniques for enhancing oil recovery.

The effect of pressure on diffusivity in binary or multicomponent systems such as gas−liquid or gas−solid systems has rarely been reported. The diffusivity of carbon dioxide in extruded gelatinized starch has been measured in this study at pressures of up to 117 bar (1700 psi). Such data are fundamentally not only useful in the understanding of the supercritical carbon dioxide (SC-CO2)/starch systems but also can be useful for the design and control of processes utilizing carbon dioxide injection or mixing in starch-based matrices. The methodology developed here was an improvement over a previously reported technique, enabling high-pressure data to be obtained. The diffusivity of carbon dioxide in the melt was found to be a strong function of pressure but not of moisture content in the range of 34.5−39% (w/w) studied. This diffusivity value decreased from 7.5 × 10-10 to 0.9 × 10-10 m2/s as pressure was increased from atmospheric to 115 bar. The low-pressure diffusivity value was only an order of magnitude lower than that reported for a carbon dioxide in water system and comparable to reported values of diffusivity of CO2 in softened polymers. These diffusivity values are also the same order of magnitude as the reported values of the diffusivity of water in starch, suggesting similar mechanisms of diffusion for carbon dioxide and water diffusivity in starch. The observed pressure dependency of the diffusivity may be due to the melt's high compressibility at these pressures. The solubility of carbon dioxide in the starch melt was proportional to the product of the solubility of carbon dioxide in water and the melt's moisture content.

New experimental solubility data for carbon dioxide in pure water and in aqueous solution containing sodium hydroxide in the temperature range (293.15 to 393.15) K and pressures up to 5 MPa are presented in this work. A new experimental apparatus based on an equilibrium cell with a constant volume allowing the measurement of carbon dioxide solubility is presented. The liquid phase composition at the thermodynamic equilibrium is determined by an analytical method (ion chromatography) and a static synthetic method. The CO2 + water system is used to validate the experimental apparatus; therefore data obtained are compared with literature data.

Effect of temperature and pressure on the solubility of carbon dioxide in water in the presence of gas hydrate

Enthalpy of dissociation and hydration number of methane hydrate from the Clapeyron equation

CO2 Capture via Crystalline Hydrogen-Bonded Bicarbonate Dimers

The solubility of carbon dioxide in cerebral cortical tissue from cats was determined in homogenates, acidified to pH < 4 (cf. van Slyke, Sendroy, Hastings and Neill, 1928). The homogenates, which were prepared from brains frozen in situ with liquid nitrogen, were equilibrated with pure carbon dioxide at 37.5° C. The carbon dioxide content of the homogenates was determined by the microdiffusion method of Conway (1950) and the resulting Kuenen coefficients (ml CO2/g and ml CO2/g of H2O) calculated. A linear relationship was found between solubility coefficient and tissue concentration in the homogenates. Extrapolation to undiluted tissue gave the coefficients 0.49 (ml CO2/g tissue) and 0.61 (ml CO2/g of H2O in the tissue) respectively. The solubility of carbon dioxide in the tissue followed Henry's law, which should indicate that no appreciable amount of carbon dioxide is adsorbed onto tissue constituents. Measurement of the solubility coefficient for carbon dioxide in cerebrospinal fluid at 37.5° C revealed that this coefficient came very close to that obtained in a 0.16 M NaCl solution. The solubility coefficient in water, originally determined to test the methods used, was in good agreement with two, but in less good agreement with the majority of the coefficients reported in the literature. An examination of the literature indicated a source of error in the determination of the latter values.

In the immiscible displacement of oil by carbon dioxide gas, the solubility and diffusivity of carbon dioxide are important factors that determine the efficiency of the process, because an increase in the carbon dioxide solubility and diffusivity into oil leads to an increase in oil recovery. It is shown by experimental studies that the solubility and diffusivity of carbon dioxide into oil are governed by the saturation pressure, reservoir temperature, composition of the oil and purity of the gas. The solubility and diffusivity of carbon dioxide into Aberfeldy heavy oil were measured, using impure carbon dioxide gas containing nitrogen as the main contaminant gas. It was noted that increasing the concentration of nitrogen in the carbon dioxide stream decreased the solubility and diffusivity of carbon dioxide in oil, consequently leading to a reduction in the swelling of the oil by carbon dioxide. Displacement experiments were also conducted to observe the effect of using impure carbon dioxide in place of pure carbon dioxide in the immiscible displacement WAG process. It was noted that the presence of nitrogen in carbon dioxide adversely affected oil recovery by the process and that increasing the nitrogen concentration up to 30 mole% could result in 10% loss in oil recovery. Introduction The solubility of carbon dioxide is the most important effect in the immiscible displacement of oil by carbon dioxide gas since it was found by Rojas(1) that among other mechanisms, an increase in the carbon dioxide solubility in oil leads to an increase in oil recovery. This is true because the solubility of carbon dioxide greatly reduces the viscosity of the oil and promotes the swelling of the oil. Viscosity reduction and swelling of the oil lower the water-oil mobility ratio, consequently leading to an increased oil recovery. Early work in 1926 by Beecher and Parkhurst(2) showed that carbon dioxide was more soluble on a molar basis in a 30.2 °API oil than air and natural gas. Svreck and Mehrota's data(3) for carbon dioxide, methane and nitrogen showed that and Mehrotra's data(3), carbon dioxide is the most soluble and nitrogen the least soluble in bitumen. The solubility of carbon dioxide in oil is governed by the saturation pressure, reservoir temperature, composition of the oil and purity of the gas. Miller and Jones(4) and Chung, Jones, and Nguyen(5) measured the solubility of carbon dioxide in Canyon and Wilmington heavy oils and found that the solubility of carbon dioxide in heavy crude oils increased with pressure but decreased with temperature and reduced API gravity. Briggs and Puttagunta(6) reported sets of data for carbon dioxide solubility in Aberfeldy oil and swelling of oil at 20.6 °C. Their data showed that both carbon dioxide solubility and oil swelling increased when pressure increased. Later, Sayegh and Sarbar(7) established that carbon dioxide is more soluble in oil at lower temperatures than at higher ones.

Results of the annual series of complex measurements of carbon dioxide, oxygen, and biogenic elements in the subglacial water in the littoral zone of the southern area of Lake Baikal, carried out from 2004 to 2016, are analyzed. It was found that the plankton photosynthetic activity significantly decreases the partial pressure of carbon dioxide in water (to 240–350 μatm) as compared to the partial pressure of CO2 in the atmosphere (about 385 μatm) by the end of ice cover season. Hence, the CO2 flux can be directed only from the atmosphere to the water surface during the ice breakup in the littoral zone of Southern Baikal.

The solubility of carbon dioxide in water is measured at 278.15–348.15 K and 0.1–1 MPa. The experimental data are compared with those obtained from equations of state such as van der Waals, Redlikh-Kwong, Soave- Redlikh-Kwong, Peng-Robinson coupled with two mixing rules van der Waals and Wong Sandler equations. Also, the solubility of carbon dioxide in water is modeled using the artificial neural network system and optimized with genetic algorithm method. The results show that the artificial neural network system can accurately predict the solubility of carbon dioxide in water than the other equations of state.

Effect of Nitrogen On the Solubility And Diffusivity of Carbon Dioxide Into Oil And Oil Recovery By the Immiscible WAG Process T.A. Nguyen; T.A. Nguyen Petroleum Recovery Institute Search for other works by this author on: This Site Google Scholar S.M. Farouq Ali S.M. Farouq Ali Petroleum Recovery Institute Search for other works by this author on: This Site Google Scholar Paper presented at the Annual Technical Meeting, Calgary, Alberta, June 1995. Paper Number: PETSOC-95-64 https://doi.org/10.2118/95-64 Published: June 06 1995 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Get Permissions Search Site Citation Nguyen, T.A., and S.M. Farouq Ali. "Effect of Nitrogen On the Solubility And Diffusivity of Carbon Dioxide Into Oil And Oil Recovery By the Immiscible WAG Process." Paper presented at the Annual Technical Meeting, Calgary, Alberta, June 1995. doi: https://doi.org/10.2118/95-64 Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex Search nav search search input Search input auto suggest search filter All ContentAll ProceedingsPetroleum Society of CanadaPETSOC Annual Technical Meeting Search Advanced Search AbstractIn the immiscible displacement of oil by carbon dioxide gas, the solution and diffusion of carbon dioxide are important factors that determine the efficiency of the process, since an increase in the carbon dioxide solubility and diffusivity into oil leads to an increase in oil recovery because the oil phase left behind contains more carbon dioxide and less oil. It is shown by experimental studies that the solubility and diffusivity of carbon dioxide into oil are governed by the saturation pressure, reservoir temperature I composition of the oil and purity of the gas. The solubility and diffusivity of carbon dioxide into Aberfeldy heavy oil were measured, using impure carbon dioxide gas containing nitrogen as the main ontaminant gas. It was noted that increasing the concentration of nitrogen in the carbon dioxide stream ecreased the solubility and. diffusivity of carbon dioxide into oil, consequently leading to a reduction in the swelling oil of by carbon dioxide.Displacement experiments were also conducted to observe the effect of using impure carbon dioxide in place of pure carbon dioxide in the immiscible displacement WAG process. It was noted that the presence of nitrogen in carbon dioxide adversely affected oil recovery by the process and that increasing the nitrogen concentration up to 30 mole% could result in 10% loss in oil recovery.IntroductionThe solubility of carbon dioxide is the most important effect in the immiscible displacement of oil by carbon dioxide gas since it is theorized that among other mechanisms, an increase in the carbon dioxide solubility in oil leads to an increase in oil recovery because the oil phase left behind contains more carbon dioxide and less oil.Early work in 1926 by Beecher and Parkhurst1 showed that carbon dioxide was more soluble on a molar basis in a 30.2 °API oil than air and natural gas. Svreck and Mehrotra's data2 also showed that, among the three gases: carbon dioxide methane, and nitrogen, carbon dioxide is the most soluble and nitrogen the least soluble in bitumen.The solubility of carbon dioxide in oil is governed by the saturation pressure, reservoir temperature, composition of the oil and purity of the gas. Miller and Jones3 and Chung, Jones, and Nguyen4 measured the solubility of carbon dioxide n Canyon and Wilmington heavy oils and found that the solubility of carbon dioxide in heavy crude oils increased with pressure but decreased with temperature and reduced API gravity. Later, Sayegh and Sarbar5 established that carbon dioxide is more soluble in oil at lower temperatures than at higher ones. Patton, Coats, and Spence6, Holm and Josendal7, and Chung et al4 showed that the solubility of carbon dioxide reduced with me presence of methane in oil since carbon dioxide had to displace methane before dissolving in oil Holm and Josendal7 also mentioned that carbon dioxide did not displace all of the methane when it came into contact with oil. Spivak and Chima noted that the solubility of pure carbon dioxide in oil was higher than that of a carbon dioxide-nitrogen mixture. Keywords: upstream oil & gas, dioxide, petroleum society, experiment, oil recovery, pvt measurement, carbon dioxide, carbon dioxide solubility, nitrogen, carbon dioride Subjects: Fluid Characterization, Improved and Enhanced Recovery, Phase behavior and PVT measurements This content is only available via PDF. 1995. Petroleum Society of Canada You can access this article if you purchase or spend a download.

Hydrate thermal dissociation behavior and dissociation enthalpies in methane-carbon dioxide swapping process

The classical view of the entities existing in a solution of carbon dioxide in water is that of dissolved carbon dioxide, hydrated carbon dioxide or carbonic acid, bicarbonate ion, hydronium ion, and carbonate ion, Estimates of the concentrations of all these species are available from a variety of types of measurements. Nuclear magnetic resonance studies on. the C13 isotope dissolved as carbon dioxide in water, deuterium oxide, and in sodium hydroxide solution of various concentrations have not given any results which would require the alteration of these views. Because of equipment limitations, carbonic acid has not been detected, but a maximum limit for its concentration has been set which is not inconsistent with the predictions of electrochemical data.Two most interesting questions remain unanswered by data thus far accumulated: Why is such a large proportion of the carbon dioxide in solution present in dissolved but not hydrated form; and Why is the reaction of hydration such a slow process?

Determination of diffusion coefficients of carbon dioxide in water between 268 and 473 K in a high-pressure capillary optical cell with in situ Raman spectroscopic measurements