310 results found
Papadopoulos AI, Perdomo FA, Tzirakis F, et al., 2021, Molecular engineering of sustainable phase-change solvents: From digital design to scaling-up for CO2 capture, CHEMICAL ENGINEERING JOURNAL, Vol: 420, ISSN: 1385-8947
Ravipati S, Simoes Santos M, Economou I, et al., 2021, Monte Carlo molecular simulation study of carbon dioxide sequestration into dry and wet calcite pores containing methane, Energy and Fuels, Vol: 35, Pages: 11393-11402, ISSN: 0887-0624
We perform grand canonical Monte Carlo (GCMC) simulations to study the adsorption of carbon dioxide in a calcite slit pore. The injection of carbon dioxide is simulated by increasing the chemical potential of carbon dioxide, which allows for an investigation of adsorption under varying carbon dioxide loadings. The study is carried out for three different environments: an empty pore; a pore containing methane; and a pore containing methane with trace amounts of water. We systematically investigate the impact of the presence of these other fluids on carbon dioxide adsorption. We study the influence of carbon dioxide loading on fluid density in the pore and examine individual fluid-density profiles (in the direction normal to the fluid–solid interface). The order of fluid adsorption affinity to the surface is found to be water > carbon dioxide > methane. The interpretation of our results is informed by the examination of free-energy-averaged fluid–substrate potentials, which are computed independently from the simulations. Our observations suggest that ignoring the presence of water could lead to overestimation not only of methane availability but also of carbon dioxide storage capacity in pores, with important consequences in, for example, modeling carbon dioxide sequestration in calcite-rich reservoirs. Ultimately, it is hoped that the molecular-level insights from this study will aid the multiscale modeling of reservoir fluids in the context of enhanced oil recovery and carbon dioxide sequestration.
Febra SA, Bernet T, Mack C, et al., 2021, Extending the SAFT-gamma Mie approach to model benzoic acid, diphenylamine, and mefenamic acid: Solubility prediction and experimental measurement, Fluid Phase Equilibria, Vol: 540, Pages: 1-20, ISSN: 0378-3812
The prediction of the solubility of active pharmaceutical ingredients (APIs) is a significant challenge whichis of importance in pharmaceutical applications and solvent selection. Here, we extend the table of groupinteractions (3 like interactions, 47 unlike interactions) of the SAFT-γ Mie group-contribution equation ofstate to model the phase behaviour and solubility of mefenamic acid, a nonsteroidal anti-inflammatorydrug, in a range of solvents. In addition to mefenamic acid, we also consider its molecular synthons:benzoic acid and diphenylamine. New experimental solubility data are presented for the three moleculesin a range of solvents, and three new SAFT-γ Mie functional groups are defined (aCCOOH, aCNHaC andCH3CO) and characterised, together with their interactions with solvent groups. Literature data for thevapour pressure, single-phase density, saturation density, vapourisation enthalpy, bubble temperature,dew temperature, and bubble pressure are used to characterise the new group interactions. Solubilitydata are used to characterise the new group-group interactions only if there are no other experimentaldata available. The transferability and predictive accuracy of the new models are assessed by comparing the theoretical predictions with the experimental solubility data. Our comparison includes alcohols,ketones, and esters as families of solvents and mixed-solvent solubility predictions.
Watson OL, Jonuzaj S, McGinty J, et al., 2021, Computer Aided Design of Solvent Blends for Hybrid Cooling and Antisolvent Crystallization of Active Pharmaceutical Ingredients, ORGANIC PROCESS RESEARCH & DEVELOPMENT, Vol: 25, Pages: 1123-1142, ISSN: 1083-6160
Morgado P, Barras J, Galindo A, et al., 2021, Solubility of water in mixtures of (n-alkanes + n-perfluoroalkanes) and in n-perfluoroalkylalkanes: experimental and modeling with the SAFT-γ Mie group-contribution approach, Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, ISSN: 0026-8976
The solubility of water in liquid n-perfluorohexane and in an equimolar mixture of n-hexane + n-perfluorohexane is experimentally determined as a function of temperature. The solubility of water in the equimolar mixture is significantly higher than the average of the solubilities in the pure solvents suggesting, for the first time, that mixing hydrogenated and perfluorinated chains enhances the solubility of water. The solubility in the equimolar mixture of n-hexane + n-perfluorohexane is also determined theoretically with the SAFT-γ Mie group-contribution approach, allowing a direct quantitative estimate of how much the large deviations from ideality contribute to the solubility of water in the mixture. In addition, the SAFT-γ Mie approach is used to represent the solubility of water in a number of n-perfluoroalkylalkanes, covering a range of relative lengths of the hydrogenated and perfluorinated chains. The theory can be used to predict the relative extent of the solubility of water in the different solvents, in good agreement with the experimental data. This is accomplished by using a single parameter to describe the strong attractive interaction between water and the CH2CF2 group at the junction between the hydrogenated and perfluorinated segments, which is known to be responsible for the increased solubility of water in these substances.
Lindeboom T, Zhao B, Jackson G, et al., 2021, On the liquid demixing of water plus elastin-like polypeptide mixtures: bimodal re-entrant phase behaviour, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 23, Pages: 5936-5944, ISSN: 1463-9076
Jackson G, Perdomo Hurtado FA, Khalit SH, et al., 2021, Description of the thermodynamics and fluid-phase behaviour of aqueous solutions of linear, branched, and cyclic amines, AIChE Journal, Vol: 67, Pages: 1-19, ISSN: 0001-1541
The SAFT‐ɣ Mie group‐contribution equation of state is used to represent the fluid‐phase behaviour of aqueous solutions of a variety of linear, branched, and cyclic amines. New group interactions are developed in order to model the mixtures of interest, including the like and unlike interactions between alkyl primary, secondary, and tertiary amine groups (NH2, NH, N), cyclic secondary and tertiary amine groups (cNH, cN), and cyclohexylamine groups (cCHNH, cCHN) with water (H2O). The group‐interaction parameters are estimated from appropriate experimental thermodynamic data for pure amines and selected mixtures. By taking advantage of the group‐contribution nature of the method, one can describe the fluid‐phase behaviour of mixtures of molecules comprising those groups over broad ranges of temperature, pressure, and composition. A number of aqueous solutions of amines are studied including linear, branched aliphatic, and cyclic amines. Liquid‐liquid equilibria (LLE) bounded by lower critical solution temperatures (LCSTs) have been reported experimentally and are reproduced here with SAFT‐ɣ Mie approach. The main feature of the approach is the ability not only to represent accurately the experimental data employed in the parameter estimation, but also to predict the vapour‐liquid, liquid‐liquid, and vapor‐liquid‐liquid equilibria, and LCSTs with the same set of parameters. Pure compound and binary phase diagrams of diverse types of amines and their aqueous solutions are assessed in order to demonstrate the main features of the thermodynamic and fluid‐phase behaviour.
Lee YS, Galindo A, Jackson G, et al., 2021, An approach for simultaneous computer-aided solvent design and process design for CO<inf>2</inf> chemical absorption processes, Computer Aided Chemical Engineering, Pages: 167-172
In the field of Computer-Aided Molecular and Process Design (CAMPD), a variety of solution methods have been developed to handle the complexities associated with the non-convexity and non-linearity of molecular structure-property and process models. However, mostalgorithms are prone to failing to generate feasible solutions when the integrated solvent-process model renders a significant portion of the search space infeasible. In this work, we propose a solution approach for the integrated design of an optimal chemical absorption process in which tailored feasibility tests are incorporated into a process optimisation problem. The solution approach allows the exploration of a design space without unnecessary difficulties by recognising infeasibilities. The effectiveness of the approach is demonstrated on an aqueous amine solvent-based CO2 capture process.
Haslam AJ, Gonzalez-Perez A, Di Lecce S, et al., 2020, Expanding the Applications of the SAFT-gamma Mie Group-Contribution Equation of State: Prediction of Thermodynamic Properties and Phase Behavior of Mixtures, JOURNAL OF CHEMICAL AND ENGINEERING DATA, Vol: 65, Pages: 5862-5890, ISSN: 0021-9568
Morgado P, Barras J, Galindo A, et al., 2020, Modeling the Fluid-Phase Equilibria of Semifluorinated Alkanes and Mixtures of (n-Alkanes plus n-Perfluoroalkanes) with the SAFT-gamma Mie Group-Contribution Approach, JOURNAL OF CHEMICAL AND ENGINEERING DATA, Vol: 65, Pages: 5909-5919, ISSN: 0021-9568
Jackson G, 2020, OBITUARY Ian R. McDonald (1938-2020), Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, Vol: 118, Pages: 1-2, ISSN: 0026-8976
Kohns M, Lazarou G, Forte E, et al., 2020, Predictive models for the phase behaviour and solution properties of weak electrolytes: nitric, sulfuric and carbonic acid, Physical Chemistry Chemical Physics, Vol: 22, Pages: 15248-15269, ISSN: 1463-9076
The distribution of ionic species in electrolyte systems is important in many fields of science and engineering, ranging from the study of degradation mechanisms to the design of systems for electrochemical energy storage. Often, other phenomena closely related to the ionic speciation, such as ion pairing, clustering and hydrogen bonding, which are difficult to investigate experimentally, are also of interest. Here, we develop an accurate molecular approach, accounting for reactions as well as association and ion pairing, to deliver a predictive framework that helps validate experiment and guides future modelling of speciation phenomena of weak electrolytes. We extend the SAFT-VRE Mie equation of state [D. K. Eriksen et al., Mol. Phys., 2016, 114, 2724–2749] to study aqueous solutions of nitric, sulphuric and carbonic acid, considering complete and partially dissociated models. In order to incorporate the dissociation equilibria, correlations to experimental data for the relevant thermodynamic equilibrium constants of the dissociation reactions are taken from the literature and are imposed as a boundary condition in the calculations. The models for water, the hydronium ion, and carbon dioxide are treated as transferable and are taken from our previous work. Here we present new molecular models for nitric acid, and the nitrate, bisulfate, sulfate, and bicarbonate anions. The resulting framework is used to predict a range of phase behaviour and solution properties of the aqueous acids over wide ranges of concentration and temperature, including the degree of dissociation, as well as the activity coefficients of the ionic species, and the activity of water and osmotic coefficient, density, and vapour pressure of the solutions. The SAFT-VRE Mie models obtained in this manner provide a means of elucidating the mechanisms of association and ion pairing in the systems studied, complementing the experimental observations reported in the literature.
Bernet T, Mueller EA, Jackson G, 2020, A tensorial fundamental measure density functional theory for the description of adsorption in substrates of arbitrary three-dimensional geometry, JOURNAL OF CHEMICAL PHYSICS, Vol: 152, ISSN: 0021-9606
Blas FJ, Galindo A, Jackson G, 2020, Thermodynamics 2019 Conference-Punta Umbria, Costa de la Luz, Huelva, Spain, 26-28 June 2019, MOLECULAR PHYSICS, Vol: 118, ISSN: 0026-8976
Morgado P, Colaco B, Santos V, et al., 2020, Modelling the thermodynamic properties and fluid-phase equilibria ofn-perfluoroalkanes and their binary mixtures with the SAFT-gamma Mie group contribution equation of state, MOLECULAR PHYSICS, Vol: 118, ISSN: 0026-8976
Di Lecce S, Lazarou G, Khalit SH, et al., 2020, Modelling and prediction of the thermophysical properties of aqueous mixtures of choline geranate and geranic acid (CAGE) using SAFT-gamma Mie (vol 9, pg 38017, 2019), RSC ADVANCES, Vol: 10, Pages: 19463-19465
Lee L, Graham E, Galindo A, et al., 2020, A comparative study of multi-objective optimization methodologies for molecular and process design, Computers and Chemical Engineering, Vol: 136, ISSN: 0098-1354
The need to consider multiple objectives in molecular design, whether based on techno-economic, environmental or health and safety metrics is increasingly recognized. There is, however, limited understanding of the suitability of different multi-objective optimization algorithm for the solution of such design problems. In this work, we present a systematic comparison of the performance of five mixed-integer non-linear programming (MINLP) multi-objective optimization algorithms on the selection of computer-aided molecular design (CAMD) and computer-aided molecular and process design (CAMPD) problems. The five methods are designed to address the discrete and nonlinear nature of the problem, with the aim of generating an accurate approximation of the Pareto front. They include: a weighted sum approach without global search phases (SWS), a weighted sum approach with simulated annealing (SA), a weighted sum approach with multi level single linkage (MLSL), the sandwich algorithm with MLSL and the non dominated sorting genetic algorithm-II (NSGA-II). The algorithms are compared systematically in two steps. The effectiveness of the global search methods is evaluated with SWS, WSSA and WSML. WSML is found to be most effective and a comparative analysis of WSML, SDML and NSGA-II is then undertaken. As a test set of these optimization techniques, two of CAMD and one CAMPD problems of varying dimensionality are formulated as case studies. The results show that the sandwich algorithm with MLSL provides the most efficient generation of a diverse set of Pareto points, leading to the construction of an approximate Pareto front close to exact Pareto front.
Papadopoulos A, Shavalieva G, Papadokonstantakis S, et al., 2020, An approach for simultaneous computer-aided molecular design with holistic sustainability assessment: Application to phase-change CO2 capture solvents, COMPUTERS & CHEMICAL ENGINEERING, Vol: 135, ISSN: 0098-1354
Bowskill DHH, Tropp UE, Gopinath S, et al., 2020, Beyond a heuristic analysis: integration of process and working-fluid design for organic Rankine cycles, MOLECULAR SYSTEMS DESIGN & ENGINEERING, Vol: 5, Pages: 493-510, ISSN: 2058-9689
Wehbe M, Haslam A, Adjiman CS, et al., 2020, Predicting optimal salt forms for active pharmaceutical ingredients using the SAFT-y mie equation of state
Jonuzaj S, Watson OL, Ottoboni S, et al., 2020, Computer-aided Solvent Mixture Design for the Crystallisation and Isolation of Mefenamic Acid, Editors: Pierucci, Manenti, Bozzano, Manca, Publisher: ELSEVIER SCIENCE BV, Pages: 649-654
Ravipati S, Galindo A, Jackson G, et al., 2019, An investigation of free-energy-averaged (coarse-grained) potentials for fluid adsorption on heterogeneous solid surfaces, PHYSICAL CHEMISTRY CHEMICAL PHYSICS, Vol: 21, Pages: 25558-25568, ISSN: 1463-9076
Hall CK, Kofke DA, Galindo A, et al., 2019, Peter Cummings - a pillar in the field of statistical mechanics and molecular simulation FOREWORD, Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, Vol: 117, Pages: 3479-3483, ISSN: 0026-8976
Di Lecce S, Galindo A, Khalit SH, et al., 2019, Modelling and prediction of the thermophysical properties of aqueous mixtures of Choline Geranate and Geranic acid (CAGE) using SAFT-g Mie, RSC Advances: an international journal to further the chemical sciences, Vol: 9, Pages: 38017-38031, ISSN: 2046-2069
Deep eutectic solvents and room temperature ionic liquids are increasingly recognised as appro-priate materials for use as active pharmaceutical ingredients and formulation additives. Aque-ous mixtures of choline and geranate (CAGE), in particular, have been shown to offer promisingbiomedical properties but the understanding of the thermophysical behaviour of these mixturesremains limited. Here, we develop interaction potentials for use in the SAFT–γgroup–contributionapproach, to study the thermodynamic properties and phase behaviour of aqueous mixtures ofcholine geranate and geranic acid. The determination of the interaction parameters betweenchemical functional groups is carried out in a successive fashion, characterising each group basedon those previously developed. The parameters of the groups relevant to geranic acid are esti-mated using experimental phase–equilibrium data such as vapour pressure and saturated–liquiddensity of simple pure components (n–alkenes, branched alkenes and carboxylic acids) and thephase equilibrium data of mixtures (aqueous solutions of branched alkenes and of carboxylicacids). Geranate is represented by further incorporating the anionic carboxylate group, COO−,which is characterised using aqueous solution data of sodium carboxylate salts, assuming fulldissociation of the salt in water. Choline is described by incorporating the cationic quaternaryammonium group, N+, using data on choline choride solutions. The osmotic pressure of aque-ous mixtures of CAGE at several concentrations is predicted and compared to experimental dataobtained as part of our work to assess the accuracy of the modelling platform. The SAFT–γMieapproach is shown to be predictive, providing a good description of the measured data for a widerange of mixtures and properties. Furthermore, the new group interaction parameters neededto represent CAGE extend the set of functional group
Bowron DT, Fernandez-Alonso F, Jackson G, 2019, A tribute to Alan Soper - foreword by the editors FOREWORD, MOLECULAR PHYSICS, Vol: 117, Pages: 3195-3196, ISSN: 0026-8976
Febra SA, Aasen A, Adjiman CS, et al., 2019, Intramolecular bonding in a statistical associating fluid theory of ring aggregates, MOLECULAR PHYSICS, ISSN: 0026-8976
Campos-Villalobos G, Ravipati S, Haslam AJ, et al., 2019, Modelling adsorption using an augmented two-dimensional statistical associating fluid theory: 2D-SAFT-VR Mie, Molecular Physics: An International Journal at the Interface Between Chemistry and Physics, Vol: 117, Pages: 3770-3782, ISSN: 0026-8976
We present an extension of the SAFT-VR Mie approach to model adsorption of molecular fluids based on a two-dimensional (2D) approximation to describe the adsorbed fluid. Analytical results are provided for the first- and second-order perturbation terms of the free energy for the 2D system. The adsorption model is based on the assumption that the particle pair interactions in the adsorbed and bulk phases are described with the same Mie potential exponents λa and λr, in contrast with the square-well version of the 2D-SAFT-VR approach in which it is considered necessary to modify the attractive ranges of the SW interactions. This important difference between the two approaches leads to a reduction in the number of molecular parameters to be determined. In order to demonstrate the performance of the 2D-SAFT-VR Mie approach, we present results for the the modelling of carbon dioxide (CO2) and methane (CH4) adsorbed onto dry coal.
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