Gas hydrates have significant applications in the areas of natural gas storage, desalination and gas separation. Knowledge of the thermodynamic conditions associated with hydrate formation is critical to their synthesis. Presently, we use machine learning (ML) to train and evaluate the performance of three algorithms on an experimental database (>1800 data points) to predict hydrate dissociation temperatures

Isobaric vapor-liquid equilibrium data were measured for the two binary systems of 2-methyl-1-pentanol + 2,3-butanediol and 3-methyl-1-butanol + 2,3-butanediol using a modified Othmer still VLE apparatus at 40, 60, 80 and 101 kPa. The standard uncertainty of the pressure and temperature was 0.13 kPa and 0.1 K, respectively. To assess the thermodynamic consistency of the experimental data, Herington

A general one-parameter friction theory model based on the recently developed cubic-plus-chain equation of state (Sisco and Abutaqiya et al., Industrial & Engineering Chemistry Research, 2019, 58, 7341) is proposed to describe the viscosity behavior of n-alkanes. The model is considered a one-parameter model because it only requires one characteristic critical viscosity per compound to predict viscosity

An experimental study of solid-liquid equilibrium of binary and ternary mixtures of ethyl laurate and ethyl palmitate, two ethyl esters frequently found in biodiesel, and decylbenzene, a representative aromatic compound present in conventional diesel, was carried out using differential scanning calorimetry (DSC). Such a study is of interest due to concerns about the economic and environmental sustainability

Entropy convergence is the experimental observation that the hydration entropies of families of non-polar solutes cross one another and converge at a distinct temperature above the boiling point of water. Entropy convergence has subsequently received significant theoretical and molecular simulation interest to interpret its molecular origin. Classic scaled particle theory has enjoyed success in describing

The partitioning behavior of norfloxacin (more hydrophilic) and sodium diclofenac (more hydrophobic) was studied considering the use of aqueous two-phase systems (ATPSs) based in copolymers and dextran. For this research, the phase behavior of systems composed of water, a copolymer (Pluronic PE6400, Pluronic L35, Pluronic PE6800, PEG-ran-PPG monobutyl ether and PEG-ran-PPG) and dextran (Mw=40000 and

Costa Tsonopoulos was a thermodynamicist with great contributions in applied thermodynamics but also a passion and dedication in using thermodynamics in industrial practice. He is well-known for his widely used methods for estimating the second virial coefficients, but his interests and developments are much wider. They include, among others, experimental measurements for water-hydrocarbons phase equilibrium

Fugacity coefficients of twelve polar or aromatic species at infinite dilution in water (H2S, benzene C6H6, toluene C7H8, methanethiol CH3SH, SO2, HCN, acetone (CH3)2CO, NH3, methylamine CH3NH2, methanol CH3OH, ethanol C2H5OH and phenol C6H5OH) have been evaluated from ambient conditions (298 K, 0.1 MPa) to high temperatures (up to 2000 K) and water densities (up to 1500 kg m–3). The approach is based

A central issue in the equation of state (EoS) development is to describe accurately fluid density and thus other thermodynamic properties based on it. This study attempts to investigate the density modeling of high-pressure mixtures, particularly related to reservoir fluids, by cubic and non-cubic EoS. A large density database of binary mixtures related to petroleum fluids was established and used

Chemical equilibrium constants for the methanol from CO/H2 reaction calculated from literature thermodynamic parameters are too high as compared to experimental results. Therefore, both the entropy value and the enthalpy of formation value of methanol were reviewed. A rigorous analysis of the association behaviour of methanol vapour confirms that dimers and cyclic tetramers play an important role,

Acid gas injection containing H2S is one strategy for managing atmospheric sulfur emissions where sulfur recovery may not be feasible or economical in some locations. Apart from its toxicity and corrosivity in wet environments, H2S forms a high temperature hydrate in the presence of water, which can cause issues such as plugging of transport pipelines or injection wellheads. Before transportation to

Ionic liquids (ILs) have good designability and promising prospect of application. By changing different cations or anions, ILs possessing better and specific properties can be synthesized. In this paper, molecular dynamics (MD) simulation is applied to study ILs with the anion of 2,5,8,11-tetraoxatridecan-13-oate (TOTO), which are named as TOTO-based ILs. Attention is mainly paid to the effect of

Accurate fluid phase equilibria modeling of carbon dioxide-methanol binary system is essential for numerous industrial applications. Prior modeling studies were limited in scope in terms of temperature and pressure ranges. In this study, the phase equilibria behavior of the binary system is modeled with cubic equations-of-state (EoS) including Peng–Robinson (PR) and Soave–Redlich–Kwong with various

In this work a new approach to the cross-association of non-self-associating (NSA) oxygenates with carbonyl oxygens within polar PC-SAFT is developed. Aldehydes, esters and ketones fall into this class of NSA molecules. The challenge in developing such an approach is that predictability of phase behavior of NSA species with alcohols is desired, while at the same time, there is the requirement that

The water content of gas is of importance in a wide variety of areas such as oil and gas, carbon capture and storage, medical, nuclear, food and hydrogen cells. In cases where pressurised gas is being used or transported in pipelines (i.e. natural gas, carbon dioxide, compressed air....) the main reason is that changes in temperature or pressure of gas with fixed water content may result in water condensing

The modeling of the density, viscosity and electrical conductivity of aqueous solutions saturated with boric acid, in the presence of sodium sulfate or lithium sulfate, are presented. The salt concentrations range studied were from (0 to 3.3242) mol•kg−1 for sodium sulfate and from (0 to 2.9336) mol•kg−1 for lithium sulfate at temperatures from (293.15 to 313.15) K and at 1 atm pressure. A model for

The existing equation of states (EOSs) cannot well reconcile the calculation accuracy and the computational cost for reproducing liquid volumes of water. In this study, we propose a series of improved volume translated Soave-Redlich-Kwong (VT-SRK) EOSs to achieve more accurate volumetric calculation for water with little additional computational cost. The overall average absolute percentage deviation

We present a multi-level delumping method suitable for thermal enhanced oil recovery processes. At low pressures, the temperature variable is the most critical factor impacting the displacement process through viscosity reduction and evaporation/condensation effects. Hydrocarbon components are vaporized under high temperatures, move downstream in the gas phase and condense back to the liquid phase

Cyclodextrins (CDs) are widely used in drug delivery, catalysis, food and separation processes. In this work, a comprehensive simulation study on the diffusion of the native α-, β- and γ-CDs in aqueous solutions is carried out using Molecular Dynamics simulations. The effect of the system size on the computed self-diffusivity is investigated and it is found that the required correction can be as much

In this work, density- and temperature-dependent effective diameters from two different thermodynamic perturbation theories (TPTs) are presented. The first theory is well-known Barker and Henderson's TPT, and the second one is based on the pioneering work by Rowlinson but applied to steeply repulsive potentials by Heyes. Three intermolecular potentials- generalized Lennard-Jones (GLJ), inverse power

Carbon dioxide hydrate was formed in aqueous suspensions of cellulose nanocrystals (CNC) and the induction time and rate of hydrate crystal growth was compared to data obtained when CO2 hydrate was formed in pure water (blank). CNC concentrations of 0.13, 0.5 and 0.75 wt % were employed to determine whether CNC could reduce the induction time and enhance hydrate growth rate as it has been reported

In this communication, effective cage radii of dodecahedral (D) cages in semiclathrate hydrates are investigated based on van der Waals and Platteeuw model. According to recent findings in semiclathrate hydrate structures, D cages in semiclathrate hydrates have anisotropic shapes which provide unique gas capacity and selectivity under mild temperature and pressure conditions. Since applications of

CO2 capturing is an industrial tool in worldwide sustainable development to reduce the greenhouse effect. In this study, the new experimental vapor-liquid equilibrium (VLE) data for CO2 solubility in the mixtures of physical and chemical solvents were investigated. The carbon dioxide solubility measurements were carried out using a quasi-static method through the DMSO (10 wt.%) +H2O and sulfolane (20

We derive a simple procedure for solving systems of linear equations arising from the linearization of the VTN-phase stability problem. Using the structure of the Hessian matrix, the solution is obtained by sequential usage of the Sherman-Morrison formula. The great advantage of the method is that the system of equation can be solved without even assembling the system. The performance and the speed-up

In a recent article entitled “Solubility Parameter of Carbon Dioxide–an Enigma” [1], Marcus reported the literature values for the solubility parameter of liquid carbon dioxide (CO2) at 298 K with discrepancies as large as 200%. An analogous article on ionic liquids has also been published [2], entitled: “Chameleonic Behavior of Ionic Liquids and Its Impact on the Estimation of Solubility Parameter”

In this study, the isothermal binary vapour-liquid equilibrium (VLE) data for the butan-1-ol + butane-1,4-diol/butane-2,3-diol system was measured and modelled, for use in the design and rating of separation processes. P-T-x-y equilibrium measurements were performed at four temperatures from approximately 353–388 K. A dynamic-analytical apparatus was utilized to perform the measurements at sub-atmospheric

We provide high-pressure experimental phase equilibrium data for systems containing mixtures formed by CO2 and mixtures of n-alkanes (n-C10H22/n-C20H42, n-C10H22/n-C24H50, n-C10H22/n-C20H42/n-C24H50) with CO2 weight fractions of 55%, 65% and 75%, temperature ranging from 273 K to 363 K and pressures up to 55 MPa. The measured equilibrium data include vapor-liquid (VL), solid-liquid (SL), and solid-liquid-vapor

The polynomial PM, integrated quadratic-linear IQLM and factorial analytic FAM solvation models are studied with the aim of estimating and optimizing the quaternary liquid-liquid equilibria. The reliability of existing models is analyzed with respect to three extraction factors by examining three literature quaternary systems, and the general ranking approximates the order PM > FAM > IQLM. A robust

In this work, thermal and mutual diffusivity of n-heptane (n-C7H16) with dissolved carbon dioxide (CO2) were simultaneously measured using dynamic light scattering (DLS) method from 298 to 473 K and saturation pressure up to 5.5 MPa. For this purpose, the DLS setup as well as temperature and pressure system were improved. Two hydrodynamic modes in connection with the statistical fluctuations of entropy

In this study, three different equations of state (EoS) for the ammonia/water mixture are compared with experimental data in order to find the EoS which best reproduces the measured data in the temperature range −30°C≤ϑ≤200°C and pressure range 1bar≤p≤30bar for absorption systems; the deviations among each other are to be pointed out. It is shown that the EoS of Tillner-Roth and Friend [1] shows the

The entropy of organics is a fundamental and crucial thermodynamic quantity. In this work, a unified quantitative structure-property relationship (QSPR) model was proposed to predict the standard absolute entropy for 15 kinds of organic compounds in three phase states based on the norm index concept. Three phase states of the standard absolute entropy of organics, namely, the solid state (So(s)), liquid

The phase behavior of binary mixtures of carbon dioxide (CO2) and hydrofluoroethers (HFEs) has been studied. In particular, experimental vapor-liquid equilibrium (VLE) data for CO2 + 1,1,1,2,3,3-hexafluoro-3-(2,2,2-trifluoroethoxy)propane (HFE-449mec-f) and 1-ethoxy-1,1,2,2,3,3,4,4,4-nonafluorobutane (HFE-7200) at temperatures of 303.15, 313.15, and 323.15 K are reported. The VLE data were measured

Enthalpy (heat) of fusion of cyclic and acyclic hydrocarbons can determine molecular packing in crystals, which can be useful in correcting thermochemical data to a standard state when combined with other thermodynamic properties. An improved model is derived from a core correlation for reliable prediction of their enthalpy of fusion. The reported data are 286 for deriving and testing the new models

In this work, to obtain optimal process conditions in a CO2 capturing plant, novel equipment modifications are made to achieve the desired product specification in the small and large pilot plants with low and high pressures. For this purpose, results from two different CO2 capturing pilot plants are compared at different process variables, using the different concentration of aqueous MEA (25, 28,

Computer simulation is a powerful tool in technical, economic, and environmental assessments of processes. Some commercial simulators are available with a friendly environment and an extensive database. For some compounds, primarily biocompounds, gaps still exist in terms of their properties. In this case, predictive models are necessary, but their results are not always reliable. Hence, thermodynamic

Aqueous biphasic systems containing water-miscible ionic liquids (ILs) and inorganic salt are considered as an effective media for liquid-liquid extraction of bioactive materials. One of the important advantages of ILs is the possibility for a modification of their chemical structure and, as a result, their properties, i.e. their multifunctionality. Among the modified ILs, the amino acid ILs (AAILs)

The present study aims to implement an electrolyte EoS developed in our previous work [A. Raeispour Shirazi, M. N. Lotfollahi, Fluid Phase Equilib., 502 (2019) 112289] to model the vapor-liquid equilibria (VLE) of CO2 solubility in aqueous N-methyldiethanolamine (MDEA) solution (CO2+MDEA+H2O ternary mixture) as well as H2O+MDEA+CO2-CH4 quaternary mixture. The proposed electrolyte PC-SAFT+MSA+Born equation

This comment addresses several points regarding data interpretation in a recent paper in the Journal, which results in an inaccurate interpretation of experimental data on CO2 diffusion in water. The experimental data were interpreted by Fick’s law of diffusion, while the existence of convection was disregarded.

Cubic equations of state have thus far yielded poor predictions of the thermodynamic properties of quantum fluids such as hydrogen, helium and deuterium at low temperatures. Furthermore, the shape of the optimal α functions of helium and hydrogen have been shown to not decay monotonically as for other fluids. In this work, we derive temperature-dependent quantum corrections for the covolume parameter

The Redlich-Kister (RK) three-coefficient expansion for gE is investigated geometrically and its global phase diagram is presented. The azeotropy and stability conditions yield surfaces (envelopes) in the three-dimensional azeotropy space and stability space respectively, whose axes represent variables determined from Henry's constants, pure substance vapor pressures and the highest-order RK coefficient