Publications
254 results found
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 and Development, Vol: 25, Pages: 1123-1142, ISSN: 1083-6160
Choosing a solvent and an antisolvent for a new crystallization process is challenging due to the sheer number of possible solvent mixtures and the impact of solvent composition and crystallization temperature on process performance. To facilitate this choice, we present a general computer aided mixture/blend design (CAMbD) formulation for the design of optimal solvent mixtures for the crystallization of pharmaceutical products. The proposed methodology enables the simultaneous identification of the optimal process temperature, solvent, antisolvent, and composition of solvent mixture. The SAFT-γ Mie group-contribution approach is used in the design of crystallization solvents; based on an equilibrium model, both the crystal yield and solvent consumption are considered. The design formulation is implemented in gPROMS and applied to the crystallization of lovastatin and ibuprofen, where a hybrid approach combining cooling and antisolvent crystallization is compared to each method alone. For lovastatin, the use of a hybrid approach leads to an increase in crystal yield compared to antisolvent crystallization or cooling crystallization. Furthermore, it is seen that using less volatile but powerful crystallization solvents at lower temperatures can lead to better performance. When considering ibuprofen, the hybrid and antisolvent crystallization techniques provide a similar performance, but the use of solvent mixtures throughout the crystallization is critical in maximizing crystal yields and minimizing solvent consumption. We show that our more general approach to rational design of solvent blends brings significant benefits for the design of crystallization processes in pharmaceutical and chemical manufacturing.
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
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- Citations: 2
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 (<i>n</i>-Alkanes plus <i>n</i>-Perfluoroalkanes) with the SAFT-γ Mie Group-Contribution Approach, JOURNAL OF CHEMICAL AND ENGINEERING DATA, Vol: 65, Pages: 5909-5919, ISSN: 0021-9568
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- Citations: 4
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.
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
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- Citations: 1
Di Lecce S, Lazarou G, Khalit SH, et al., 2020, Correction: Modelling and prediction of the thermophysical properties of aqueous mixtures of choline geranate and geranic acid (CAGE) using SAFT-γ Mie, RSC Advances: an international journal to further the chemical sciences, Vol: 10, Pages: 19463-19465, ISSN: 2046-2069
Correction for ‘Modelling and prediction of the thermophysical properties of aqueous mixtures of choline geranate and geranic acid (CAGE) using SAFT-γ Mie’ by Silvia Di Lecce et al., RSC Adv., 2019, 9, 38017–38031. DOI: 10.1039/C9RA07057E
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
Galindo A, Trusler JPM, 2020, Preface, Fluid Phase Equilibria, Vol: 503, ISSN: 0378-3812
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
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- Citations: 4
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
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
Borhani T, Garcia-Munoz S, Luciani C, et al., 2019, Hybrid QSPR models for the prediction of the free energy of solvation of organic solute/solvent pairs, Physical Chemistry Chemical Physics, Vol: 21, Pages: 13706-13720, ISSN: 1463-9076
Due to the importance of the Gibbs free energy of solvation in understanding many physicochemical phenomena, including lipophilicity, phase equilibria and liquid-phase reaction equilibrium and kinetics, there is a need for predictive models that can be applied across large sets of solvents and solutes. In this paper, we propose two quantitative structure property relationships (QSPRs) to predict the Gibbs free energy of solvation, developed using partial least squares (PLS) and multivariate linear regression (MLR) methods for 295 solutes in 210 solvents with total number of data points of 1777. Unlike other QSPR models, the proposed models are not restricted to a specific solvent or solute. Furthermore, while most QSPR models include either experimental or quantum mechanical descriptors, the proposed models combine both, using experimental descriptors to represent the solvent and quantum mechanical descriptors to represent the solute. Up to twelve experimental descriptors and nine quantum mechanical descriptors are considered in the proposed models. Extensive internal and external validation is undertaken to assess model accuracy s in predicting the Gibbs free energy of solvation for a large number of solute/solvent pairs. The best MLR model, which includes three solute descriptors and two solvent properties, yields a coefficient of determination (R2) of 0.88 and a root mean squared error (RMSE) of 0.59 kcal/mol for the training set. The best PLS model includes six latent variables, and has a R2 value of 0.91 and a RMSE of 0.52 kcal/mol. The proposed models are compared to selected results based on continuum solvation quantum chemistry calculations. They enable the fast prediction of the Gibbs free energy of solvation of a wide range of solutes in different solvents.
Wehbe M, Adjiman C, Jackson G, et al., 2019, Prediction of the solubility of active pharmaceutical ingredients under varying conditions of ph and temperature using the saft-? mie equation of state
Kazepidis P, Papadopoulos AI, Seferlis P, et al., 2019, Optimal design of post combustion CO<sub>2</sub> capture processes based on phase-change solvents, Editors: Kiss, Zondervan, Lakerveld, Ozkan, Publisher: ELSEVIER SCIENCE BV, Pages: 463-468, ISBN: 978-0-12-819939-8
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- Citations: 7
Lee YS, Graham E, Jackson G, et al., 2019, A comparison of the performance of multi-objective optimization methodologies for solvent design, Editors: Kiss, Zondervan, Lakerveld, Ozkan, Publisher: ELSEVIER SCIENCE BV, Pages: 37-42, ISBN: 978-0-12-819939-8
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- Citations: 5
Watson OL, Galindo A, Jackson G, et al., 2019, Computer-aided Design of Solvent Blends for the Cooling and Anti-solvent Crystallisation of Ibuprofen, Editors: Kiss, Zondervan, Lakerveld, Ozkan, Publisher: ELSEVIER SCIENCE BV, Pages: 949-954, ISBN: 978-0-12-819939-8
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- Citations: 10
Evans R, Galindo A, Jackson G, et al., 2018, Daan Frenkel - An entropic career, Molecular Physics, Vol: 116, Pages: 2737-2741, ISSN: 0026-8976
Galindo A, Rahman S, Lobanova O, et al., 2018, SAFT‑γ force field for the simulation of molecular fluids. 5. Hetero Group coarse-grained models of linear alkanes and the importance of intramolecular interactions, Journal of Physical Chemistry B, Vol: 122, Pages: 9161-9177, ISSN: 1520-5207
The SAFT-γ Mie group-contribution equation of state [Papaioannou J. Chem. Phys. 2014, 140, 054107] is used to develop a transferable coarse-grained (CG) force-field suitable for the molecular simulation of linear alkanes. A heterogroup model is fashioned at the resolution of three carbon atoms per bead in which different Mie (generalized Lennard-Jones) interactions are used to characterize the terminal (CH3–CH2–CH2−) and middle (−CH2–CH2–CH2−) beads. The force field is developed by combining the SAFT-γ CG top-down approach [Avendaño J. Phys. Chem. B 2011, 115, 11154], using experimental phase-equilibrium data for n-alkanes ranging from n-nonane to n-pentadecane to parametrize the intermolecular (nonbonded) bead–bead interactions, with a bottom-up approach relying on simulations based on the higher resolution TraPPE united-atom (UA) model [Martin; , Siepmann J. Phys. Chem. B 1998, 102, 2569] to establish the intramolecular (bonded) interactions. The transferability of the SAFT-γ CG model is assessed from a detailed examination of the properties of linear alkanes ranging from n-hexane (n-C6H14) to n-octadecane (n-C18H38), including an additional evaluation of the reliability of the description for longer chains such as n-hexacontane (n-C60H122) and a prototypical linear polyethylene of moderate molecular weight (n-C900H1802). A variety of structural, thermodynamic, and transport properties are examined, including the pair distribution functions, vapor–liquid equilibria, interfacial tension, viscosity, and diffusivity. Particular focus is placed on the impact of incorporating intramolecular interactions on the accuracy, transferability, and representability of the CG model. The novel SAFT-γ CG force field is shown to provide a reliable description of the thermophysical properties of the n-alkanes, in most cases at a level comparable to the that obtained with higher resolution models.
Ravipati S, Aymard B, Kalliadasis S, et al., 2018, On the equilibrium contact angle of sessile liquid drops from molecular dynamics, Journal of Chemical Physics, Vol: 148, ISSN: 0021-9606
We present a new methodology to estimate the contact angles of sessile drops from molec-ular simulations, by using the Gaussian convolution method of Willard and Chandler (J.Phys. Chem. B, Vol. 114, 1954-1958, 2010) to calculate the coarse-grained density fromatomic coordinates. The iso-density contour with average coarse-grained density valueequal to half of the bulk liquid density is identified as the average liquid-vapor (LV) inter-face. Angles between the unit normal vectors to the average LV interface and unit normalvector to the solid surface, as a function of the distance normal to the solid surface, arecalculated. The cosines of these angles are extrapolated to the three-phase contact line toestimate the sessile drop contact angle. The proposed methodology, which is relativelyeasy to implement, is systematically applied to three systems: (i) a Lennard-Jones (LJ)drop on a featureless LJ9-3surface; (ii) an SPC/E water drop on a featureless LJ9-3sur-face; and (iii) an SPC/E water drop on a graphite surface. The sessile drop contact anglesestimated with our methodology for the first two systems, are shown to be in good agree-ment with the angles predicted from Young’s equation. The interfacial tensions requiredfor this equation are computed by employing the test-area perturbation method for the cor-responding planar interfaces. Our findings suggest that the widely adopted spherical-capapproximation should be used with caution, as it could take a long time for a sessile dropto relax to a spherical shape, of the order of100ns, especially for water molecules initiatedin a lattice configuration on a solid surface. But even though a water drop can take a longtime to reach the spherical shape, we find that the contact angle is well established muchfaster and the drop evolves towards the spherical shape following a constant-contact-anglerelaxation dynamics. Making use of this observation, our methodology allows a good es-timation of the sessile drop
Bui M, Adjiman CS, Bardow A, et al., 2018, Carbon capture and storage (CCS): the way forward, Energy and Environmental Science, Vol: 11, Pages: 1062-1176, ISSN: 1754-5692
Carbon capture and storage (CCS) is broadly recognised as having the potential to play a key role in meeting climate change targets, delivering low carbon heat and power, decarbonising industry and, more recently, its ability to facilitate the net removal of CO2 from the atmosphere. However, despite this broad consensus and its technical maturity, CCS has not yet been deployed on a scale commensurate with the ambitions articulated a decade ago. Thus, in this paper we review the current state-of-the-art of CO2 capture, transport, utilisation and storage from a multi-scale perspective, moving from the global to molecular scales. In light of the COP21 commitments to limit warming to less than 2 °C, we extend the remit of this study to include the key negative emissions technologies (NETs) of bioenergy with CCS (BECCS), and direct air capture (DAC). Cognisant of the non-technical barriers to deploying CCS, we reflect on recent experience from the UK's CCS commercialisation programme and consider the commercial and political barriers to the large-scale deployment of CCS. In all areas, we focus on identifying and clearly articulating the key research challenges that could usefully be addressed in the coming decade.
Grant E, Pan Y, Richardson J, et al., 2018, Multi-Objective Computer-Aided Solvent Design for Selectivity and Rate in Reactions, Computer Aided Chemical Engineering, Pages: 2437-2442
A hybrid empirical computer-aided methodology to design the solvent for a reaction, incorporating both selectivity and rate, is presented. A small initial set of diverse solvents is used, for which experimental, in situ kinetic data are obtained. A surrogate model is utilized to correlate the reaction kinetics with solvent properties and a computer-aided molecular design (CAMD) multi-objective optimization problem is then formulated to identify solvents with improved performance compared with the initial solvent set. This methodology is applied to an SNAr reaction of 2,4-difluoroacetophenone with pyrrolidine, which demonstrates an interesting effect of solvent on both the selectivity of the ortho-:para-substitution ratio and the overall rate of the reaction. A set of Pareto optimal solutions is identified, highlighting the trade-off between reaction rate and selectivity.
Jackson G, dufal S, Lafitte T, et al., 2018, Corrigendum: The A in SAFT: developing the contribution of association to the Helmholtz free energy within a Wertheim TPT1 treatment of generic Mie fluids, Molecular Physics, Vol: 116, Pages: 283-285, ISSN: 0026-8976
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