The study of the phase behavior of the binary system hydrogen sulfide (H2S)-propylene (C3H6) is necessary for the optimization of gas sweetening processes and petrochemical streams. This study presents new isothermal vapor-liquid equilibrium (VLE) measurements for this system at 278.21, 298.12, 323.06, and 348.13 K, at pressures up to 5.8 MPa. The data were obtained using a precise static-analytic method with two magnetic capillary samplers (ROLSI(R)) for phase analysis by gas chromatography. The measurement uncertainties are u(T)= 0.02 K for temperature, u(P)= 0.0009 MPa for pressure, and u(x,y) = 0.001 for molar compositions. To model this data, a phi-phi approach utilizing the translated consistent Peng-Robinson (tc-PR) equation of state was used. For the liquid phase, we compared the classical van der Waals mixing rules against the Wong-Sandler mixing rules coupled with the NRTL model. Subsequently, a multiparametric equation of state was utilized to extend the analysis. After optimizing the parameters of each model by fitting them to experimental data, the final models accurately describe the phase behavior of the system. Their reliability and suitability for industrial process design and simulation are thereby demonstrated.

The phase behavior of the hydrogen sulfide (H2S) - benzene (C6H6) binary system is critical for optimizing gas sweetening, aromatic solvent recovery, and high-pressure reservoir in the petroleum industry, while ensuring environmental compliance. This study presents new isothermal vapor-liquid equilibrium (VLE) measurements for the H2S - C6H6 system at 278.21 K, 298.36 K, 323.38 K, and 343.39 K, covering pressures up to 4.5 MPa. The experimental data were obtained using a static-analytic method with two magnetic capillary samplers (ROLSI (R)), enabling precise sampling and analysis of both liquid and vapor phases via gas chromatography. The measurements have uncertainties of u(T, k = 2)= 0.02 K for temperature, u(P, k = 2)= 0.0008 MPa for pressure, and u(z) = 0.006 for molar compositions. The VLE data were modeled using the Peng-Robinson equation of state with classical van der Waals mixing rules and an alternative approach combining modified Huron-Vidal mixing rules with the NRTL model for the liquid phase. In addition, the predictive PPR78 and PSRK models were evaluated against the experimental dataset. With optimized binary interaction parameters, all models reproduced the measured data with acceptable deviations, effectively capturing the strongly non-ideal behavior of the H2S-C6H6 system. These results extend the experimental database for H2S-C6H6 mixtures, validate robust EOSbased and predictive modeling frameworks, and provide a reliable foundation for industrial process design, simulation, and optimization.

To study the effects of temperature as well as molecular interaction of a fluid system on the thermophysical properties of 2-propanol and n-Decane binary mixture, the density (rho), dynamic viscosity (eta), speed of sound (u), and refractive index (nD) of pure 2-propanol and n-Decane, along with their binary mixtures, were experimentally measured across the entire compositional range at temperatures from 283.15 to 343.15 K and atmospheric pressure. These experimental measurements helped in the evaluation of various thermophysical properties, such as excess molar volume (vE), coefficient of thermal expansion (alpha E), and isentropic compressibility I kappa sE). The experimental dynamic viscosity (eta) and density (rho) data were used to evaluate kinematic viscosity (v) and Gibbs free energy (Delta G) of flow with an equation based on Eyring's absolute state theory, and their corresponding excess properties. The excess properties of the binary mixtures were correlated using a Redlich-Kister type polynomial equation via the least-squares regression method, with fitting parameters determined for the binary system. Moreover, the Prigogine-Flory-Patterson theory (PFP) was utilized to identify the primary molecular interactions contributing to the excess molar volume at 293.15, 308.15, and 323.15 K for the binary mixtures. Additionally, the capability of the Eyring-NRTL model was tested to predict the viscosity as well as vapor-liquid equilibrium (VLE) of the binary system, and the correlated model results agreed with literature data.

The removal of CO2 and H2S from a gas by absorption with an aqueous alkanolamine solution is an energy-intensive process. The addition of a physical cosolvent might lower the regeneration energy but also affects the thermodynamics and kinetics of acid gas absorption. In this work, we study the impact on the thermodynamics and kinetics of CO2 and H2S absorption of the addition of 1,3-dimethyl-2-imidazolidinone (DMI) to the aqueous 2-(2-diethylaminoethoxy)ethanol (DEAE-EO) solvent. A comparison is made with the impact of DMI on an aqueous methyldiethanolamine (MDEA) solvent. In all cases, DMI reduced the solubility and the absorption rate of the acid gases. DMI also reduced the initial kinetic H2S/CO2 selectivity, although this effect seems much more pronounced in aqueous MDEA than in aqueous DEAE-EO. The equilibrium thermodynamic H2S/CO2 selectivity is higher in the presence of DMI.

In this study, we present new experimental data of vapor - liquid equilibrium for the binary system difluoromethane (R32) + 1,3,3,3-tetrafluoropropene (R1234ze(E)), measured at 273.14 and 363.32 K and at pressure ranging from 0.1568 to 4.3553 MPa. A " static -analytic " -type apparatus is used to do the measurements, with sampling of the equilibrium phases via capillary sampler (ROLSI (R)). We used three different models to correlate the data: 1) the Peng - Robinson cubic equation of state combined with the NRTL excess free energy model and Wong -Sandler mixing rules, 2) Helmholtz energy model like the one incorporated in REFPROP 10.0 software and 3) Predictive PPR78 model for which the new group parameter of R32 was adjusted. All of the three models show a very good agreement with the experimental data except for temperature higher that R32 critical temperature.

A complete study of thermophysical properties concerning the 2-(2-Diethylaminoethoxy)ethanol (DEAE-EO) + water binary system is realized. Density, speed of sound, dynamic and kinematic viscosities and refractive index measurements have been performed at atmospheric pressure, using a vibrating tube densitometer, a falling ball viscosimeter, and a refractometer, for pure DEAE-EO, pure water, and for aqueous solutions of DEAE-EO, from 278.15 to 323.15 K. The thermal expansion was calculated from density data. Excess Gibbs energy of flow and the corresponding excess entropy of flow were also calculated considering dynamic viscosity and density data. Excess molar properties (volume, isobaric expansion coefficient, Gibbs energy of flow and square of refractive index) were calculated and the Redlich-Kister equations were applied to correlate the data. Thermophysical properties of aqueous DEAE-EO (50 mol%) and Methyldiethanolamine (MDEA) (50 mol%) solutions were compared for their application in absorption of acid gasses.

Abstract Most carbon dioxide (CO2) storage schemes rely on storing CO2 in its supercritical state, free from impurities (SNC-Lavalin Inc., 2004). The X field reservoir model, like many other existing reservoir models, assumes pure CO2 injection for its numerical simulation of CO2 storage. However, one of the gas sample analyses from the X field revealed the presence of trace amounts of hydrogen sulfide (H2S,) ranging from 500 to 1000 ppm. Given the limitations of the separation technology, there is a potential scenario where CO2 might be co-injected with H2S for storage. Understanding the impact of this H2S within the injected CO2 stream is crucial for ensuring the success of Carbon Capture and Storage (CCS) operations (Basava-Reddi et al., 2014; Wang et al., 2011). There is a possibility of CO2 being co-injected with this H2S for storage. The effect of the contaminant in the injected CO2 stream needs to be accessed to ensure the success of the CCS operation. The alterations in the base CO2 solubility can ultimately influence storage integrity and capacity (Ahmad et al., 2023). While abundant solubility data for CO2 in water or brine exist in the literature (A Chapoy et al., 2004; Valtz et al., 2004; Ahmadi & Chapoy, 2018), limited data are available for this ternary CO2- H2S-Brine system. Therefore, the need to quantify the impact of H2S impurities on CO2 solubility is evident. In this context, extensive laboratory experiments were undertaken to address these uncertainties and further refine the X field dynamic model for enhanced accuracy.

Isothermal vapor-liquid equilibria (VLE) for eight binary systems involving R1233zd(E) [R1233zd(E) + n-butane, R1233zd(E) + CO2, R1233zd(E) + HCl, R1233zd(E) + R134a, R1233zd(E) + R152a, R1233zd(E) + R245fa], and R1233xf (R1233xf + R134a, R1233xf + R152a, R1233xf + R245fa) were measured at temperatures from 263 to 353 K. The experiments were conducted by means of a static analytic apparatus with phase analysis via gas chromatography, with the resulting maximum expanded uncertainties of 0.2 K for temperatures, 10 kPa for pressure, and 0.04 for vapor and liquid mole fractions. The main advantage of the equipment is that vapor and liquid samples were taken from vapor and liquid phase by two capillary samplers (ROLSI (R)). The Peng-Robinson equation of state and a modified Patel-Teja equation of state were both considered to represent the experimental data. If possible, comparison between the new experimental data and prediction with REFPROP 10.0 software were realized.

A complete study of thermophysical properties concerning the 1,3-dimethyl-2-imidazolidinone (DMI) + water binary system is realized. Density, speed of sound, dynamic viscosities, and refractive index measurements have been performed at atmospheric pressure, using a vibrating tube densitometer, a falling ball viscosimeter, and a refractometer for pure DMI, pure water, and for aqueous solutions of DMI, from 278.15 to 323.15 K. The thermal expansion was calculated from density data. Excess Gibbs energy of flow and the corresponding excess entropy of flow were also calculated considering dynamic viscosity and density data. Excess molar properties (volume, thermal expansion, Gibbs energy of flow, and square of refractive index) were calculated, and the Redlich-Kister equations were applied to correlate the data. The analysis of the behavior of the excess properties allows us to identify the most relevant molecular interaction in mixtures rich in DMI and in mixtures rich in water. Our results show that DMI can be classified as a liquid structure maker and that molecules of water are certainly inserted in the DMI network at finite dilution.

In the current energy transition context, underground storage of carbon dioxide (CO2) in salt caverns and aquifers has emerged as a promising solution for the Power-to-Gas process complications. However, mass exchange between the CO2 and the aqueous phase present in the storage site remains a major problem. This paper addresses the question of the kinetics of this mass exchange by performing both experimental and numerical investigations. A series of experiments under storage conditions were carried out in a PVT (Pressure–Volume–Temperature) cell, exposing a volume of CO2 to pure water or brine at low and high pressure values ranging between 10 and 16.8 MPa and at constant temperatures of 30 and 40 °C. In order to interpret the obtained experimental results and to characterize the transient mass exchange, two modeling approaches were developed: a simplified one based on pure diffusion, and a second combining pure diffusion with density-driven natural convection. Both modeling approaches have proven accurate in predicting the kinetics of CO2 dissolution. The scope of this study is limited to the laboratory scale but it can be used to quantify the CO2 dissolution on the storage site scale.

In the treatment of many fuel gases such as biogas, natural gas, syngas, and so on, tertiary alkanolamines play an important role in the selective removal of H2S with respect to CO2. The selectivity might be required for various reasons: to respect more stringent H2S specifications, to optimize the performance of the Claus unit, to lower the cost of CO2 capture, and so on. The H2S/CO2 selectivity is mainly kinetic and, to a lesser extent, thermodynamic. A novel experimental setup has been put in place to measure the time evolution of the simultaneous absorption of H2S and CO2. The results of an extensive experimental campaign with 18 different aqueous tertiary alkanolamine solvents (13 mol % amine, 87 mol % H2O) are presented. Although the absorption of H2S is expected to be a very fast proton transfer, a significant variation in H2S absorption rates and thus in selectivity is observed. This could not only be explained by the pKa or the viscosity of the amines. Therefore, an accurate quantitative molecular simulations-based kinetic model is developed and validated. The study allowed us to better understand the molecular origin of selectivity, as well as to identify amines with a higher selectivity than aqueous MDEA (MethylDiEthanolAmine), the standard industrial selective solvent.

Understanding the dissolution kinetics of CO2 in brine is important for efficient management of cycled CO2 in underground salt caverns. The kinetics is strongly influenced by natural convection, which is caused by density changes related to the concentration of dissolved gas as well as thermal changes driven by CO2 cycling and the effects of the geothermal gradient. Based on a novel non-dimensional model that couples cavern thermodynamics with the dissolution mechanisms, this study investigates how the natural convection related to mass and thermal changes impacts dissolution kinetics. The numerical model is validated using laboratory measurements, and thereupon upscaled to typical dimensions of a salt cavern. Although our simulations show that the total dissolved mass is relatively minor compared to the initial stored mass/cycled mass, it is nevertheless important to quantify other loss phenomena, particularly gas permeation into the host rock salt. The developed model can also be adapted easily to study the kinetics of dissolution of other gases, such as hydrogen and methane.

The chemical absorption of CO2 and H2S in aqueous tertiary amines is a well-known acid-base reaction. Kinetic and vapor-liquid equilibrium experiments show that the addition of an amide such as HMPA, which is known to be a strong liquid structure maker, significantly inhibits the acid-base reactions. The impact is more pronounced for CO2 than for H2S absorption. Despite the presence of water in the solvent, the absorption becomes almost physical. Due to hydrogen bonding and the hydrophobic effect, each amide molecule is involved in a cluster containing several water molecules, thus rendering the water molecules less available to participate in the reaction and to solvate HS- and HCO3- ions. This effect is absent when ethylene glycol, a weak structure maker, is added, even in large quantities. This study demonstrates the importance of solvent structure in the study of chemical reactions. State-of-the-art molecular dynamics simulations of the water-HMPA system could not reproduce the strongly negative excess volume of the mixture. This illustrates the need for more accurate force fields to simulate the structuring effect and their impact on chemical reactions.

Carbon dioxide capture transportation and storage is one of the technologies that can be employed to reduce CO2 emissions from power plants. Unfortunately, in the post combustion capture process, CO2 is not pure and contains impurities like SO2, NOx, N-2, O-2 and Ar for example. In this paper, VapourLiquid-Equilibrium (VLE) of a binary system composed of CO2 and N2O4/NO2 have been investigated. The equipment used is based on the "static-synthetic" method with a variable cell to determine the bubble pressure or saturated pressure of the system. The setup was used to obtain bubble point data at four isotherms (253.43, 273.43, 293.43, 303.43) K and pressures up to 7.3 MPa. The accuracies of the measured temperature and pressure were estimated to be 0.03 K and 0.12 kPa, respectively. The Peng-Robinson equation of state (PR78 EoS) is used to represent the isothermal P, x data. (C) 2022 Elsevier Ltd. All rights reserved.

The heat transfer capacity of air conditioning outside units is inextricably related to fins and airflow distribution, and research on the combination of the two is lacking. To analyze the fins and fin-and-tube heat exchanger, three-dimensional numerical models of the fins and flow field of the outdoor unit are created in this paper. On the one hand, the heat transfer and fluid flow characteristics of the fins are quantitatively evaluated and analyzed. On the other hand, the resistance coefficients of the porous media are numerically fitted to study the uniformity of the air velocity distribution on the surface of the heat exchanger. Two indexes, the total integrated heat capacity and JF-factor, are applied to evaluate the performance of the fins and fin-and-tube heat exchanger on the overall and specific levels, respectively. The results indicate that slit fins perform better than wave fins at heat transfer, whereas plain fins perform the worst. However, improved heat transfer performance results in increased pressure drop, which has a two-sided effect. It causes both a decrease in air volume flow rate and an increase in air distribution uniformity. Comparing the comprehensive performance of different fins, JF-factors of slit fins and wave fins are on average 20.95% and 14.36% higher than plain fins. In terms of overall performance, slit fins and wave fins have higher integrated heat exchange capacities than plain fins by 18.0% and 9.33%, respectively.

Carbon capture and storage technologies are projected to increasingly contribute to cleaner energy transitions by significantly reducing CO 2 emissions from fossil fuel-driven power and industrial plants. The industry standard technology for CO 2 capture is chemical absorption with aqueous alkanolamines, which are often being mixed with an activator, piperazine, to increase the overall CO 2 absorption rate. Inefficiency of the process due to the parasitic energy required for thermal regeneration of the solvent drives the search for new tertiary amines with better kinetics. Improving the efficiency of experimental screening using computational tools is challenging due to the complex nature of chemical absorption. We have developed a novel computational approach that combines kinetic experiments, molecular simulations and machine learning for the in silico screening of hundreds of prospective candidates and identify a class of tertiary amines that absorbs CO 2 faster than a typical commercial solvent when mixed with piperazine, which was confirmed experimentally.

Molecular simulations and chemoinformatics are used quite extensively to identify new adsorbents for CO2. The use of those digital tools is far less common in the search for new solvents (absorption) to capture CO2. This is primarily related to the complexity of the absorption process, mainly due to its reactive nature. This paper highlights and builds on several recent significant advances in computer-aided experimental developments in the field of absorption. First, we focus on physical solvents. We previously developed and experimentally validated a machine-learning tool to predict the absorption capacity of CO2 as well as its selectivity with respect to other gases (H2, N2, CO, H2, and H2S). In this paper we investigate whether multi-task learning (MTL), a technique that aims to improve machine learning efficacy by simultaneously modelling several properties, can improve the model performances. The accuracy of both models, with and without MTL, is, however, comparable. Second, we study the impact of the addition of a physical co-solvent to an aqueous amine solvent on the CO2 absorption rate. Physical co-solvents with a specific value lower than water are expected to reduce the solvent regeneration energy. A recently developed and validated molecular simulations-based tool to predict CO2 absorption rates in aqueous tertiary amines is applied to solvents of aqueous tertiary amines with physical co-solvents. A comparison with new experimental data is made. Both the model and the experimental data predict a lower CO2 absorption rate in the presence of most physical co-solvents studied.

Isothermal vapour-liquid equilibrium (VLE) for four binary systems involving R1234yf (R1234yf + R134a, R1234yf + R152a, R1234yf + R1233zd(E) and R1234yf + R1233xf) were measured at temperatures from 278.15 to 348.15 K. The experiments were conducted by means of a "static- analytic" apparatus with phase analysis via gas chromatography, with resulting uncertainties of 0.6 K for temperature, 8 kPa for pressure and a maximum of 0.007 for vapour and liquid mole fractions. The main advantage of the equipment is that vapour and liquid samples are taken from vapour and liquid phases by two capillary samplers (ROLSI (R)). The Peng Robinson Equation of State is considered to represent the experimental data. If possible, comparison between the new experimental data and prediction with REFPROP 10.0 software are realized.