Publications
178 results found
Vasileiadis M, Adjiman CS, Pantelides CC, 2013, Ab initio prediction of crystal structure and the effects of temperature on the relative stability of enantiotropic polymorphs, Pages: 460-461
Avaullee L, Adjiman CS, Calado F, et al., 2012, Gsaft: Application of the SAFT-γ mie group contribution EoS in the Oil/Gas Industry - From academic research to industrial deployment, AIChE 2012 - 2012 AIChE Annual Meeting, Conference Proceedings
SAFT-γ Mie is a new equation of state recently developed by the Molecular Systems Engineering group at Imperial College London. It is an advanced group-contribution form of the SAFT equation of state making use of the Mie potential for a more accurate and flexible description of the dispersive/repulsive interactions between segments. One of its key characteristics is the accurate description of vapour/liquid phase equilibria, including the region of the critical point, as well as the second-derivative thermodynamic properties such as the thermal expansivity, isothermal compressibility, heat capacity, Joule-Thomson coefficient, and speed of sound. In 2009, Process Systems Enterprise (PSE) acquired the exclusive intellectual property rights associated with SAFT-γ Mie and related work, for the purpose of incorporating these developments within its gSAFT advanced thermodynamics technology for process modelling. In late 2010, TOTAL, PSE and Imperial College embarked on a joint project aimed at exploring in detail the applicability, benefits and limitations of this technology on a wide range of mixtures of interest to the oil & gas industry. The current phase of the project is primarily focused on mixtures of hydrocarbons (alkanes and aromatics), carbon dioxide, water and methanol. The main output is a single, consistent set of group parameters capable of accurately describing the behaviour of these generic mixtures within the SAFT-γ Mie framework. Starting with a brief overview of the SAFT-γ Mie equation of state, this paper primarily focuses on the systematic methodology employed in developing the corresponding like and unlike group parameters. This comprises a sequence of steps including the choice of representative components and mixtures, the definition of an appropriate set of groups required to describe them, the collection of the necessary experimental data, a streamlined set of software tools and workflows employed for the accurate, ef
Vasileiadis M, Kazantsev AV, Karamertzanis PG, et al., 2012, The polymorphs of ROY: application of a systematic crystal structure prediction technique, ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE CRYSTAL ENGINEERING AND MATERIALS, Vol: 68, Pages: 677-685
- Author Web Link
- Cite
- Citations: 59
Bardwell DA, Adjiman CS, Arnautova YA, et al., 2011, Towards crystal structure prediction of complex organic compounds - a report on the fifth blind test, ACTA CRYSTALLOGRAPHICA SECTION B-STRUCTURAL SCIENCE CRYSTAL ENGINEERING AND MATERIALS, Vol: 67, Pages: 535-551
- Author Web Link
- Cite
- Citations: 340
Kazantsev AV, Karamertzanis PG, Adjiman CS, et al., 2011, Successful prediction of a model pharmaceutical in the fifth blind test of crystal structure prediction, INTERNATIONAL JOURNAL OF PHARMACEUTICS, Vol: 418, Pages: 168-178, ISSN: 0378-5173
- Author Web Link
- Cite
- Citations: 101
Kazantsev AV, Karamertzanis PG, Pantelides CC, et al., 2011, CrystalOptimizer: An Efficient Algorithm for Lattice Energy Minimization of Organic Crystals Using Isolated-Molecule Quantum Mechanical Calculations, Process Systems Engineering, Pages: 1-42, ISBN: 9783527316953
- Cite
- Citations: 7
Kazantsev AV, Karamertzanis PG, Adjiman CS, et al., 2011, Efficient Handling of Molecular Flexibility in Lattice Energy Minimization of Organic Crystals, JOURNAL OF CHEMICAL THEORY AND COMPUTATION, Vol: 7, Pages: 1998-2016, ISSN: 1549-9618
- Author Web Link
- Cite
- Citations: 105
Vasileiadis M, Kazantsev AV, Karamertzanis PG, et al., 2011, The polymorphs of ROY: Application of crystal structure prediction techniques, Pages: 856-857
Kazantsev AV, Karamertzanis PG, Pantelides CC, et al., 2010, <i>Ab Initio</i> Crystal Structure Prediction for Flexible Molecules, 20th European Symposium on Computer Aided Process Engineering (ESCAPE), Publisher: ELSEVIER SCIENCE BV, Pages: 817-822, ISSN: 1570-7946
- Author Web Link
- Cite
- Citations: 3
Urban Z, Cheng YS, Pantelides CC, 2009, High-fidelity modelling and detailed design of PEM fuel cell stacks, Conference Proceedings - 2009 AIChE Annual Meeting, 09AIChE
The optimal design of PEM fuel cell stacks is a particularly challenging task. On one hand, it is important to model in detail the numerous complex coupled phenomena that take place within each layer, including both the fluid mechanics in the fuel and air channels, and the electrochemical reactions and the multicomponent mass and heat diffusion within the electrolyte membrane. On the other hand, it is necessary to represent with reasonable accuracy stacks which involve tens or even hundreds of such layers. Moreover, determining optimal designs requires the examination of a large number of alternatives. Overall, the combination of these three factors leads to a formidable computational problem. We present a hybrid modelling technique that combines Computational Fluid Dynamic (CFD) models of flow channel hydrodynamics with first-principles physical and chemistry models that have been validated against laboratory data. This fully-coupled approach has numerous advantages over either "pure" CFD or "pure" first-principles models; examples include the ability to predict very accurately the temperature profiles and current density across the anode-electrolyte-cathode assembly. In principle, the above hybrid approach is applicable both to individual cell assemblies and to entire stacks. However, the computational load becomes extremely high for stacks involving large numbers of layers. This is a problem that also occurs with "pure" CFD models of the stack. The problem is, to some extent, alleviated by the availability of highly parallelised CFD codes. However, the simulation of stacks involving more than a few tens of layers remains problematic, and this is even more so when these simulations need to be repeated many times for the purposes of stack optimisation. In view of the above, this paper presents novel and powerful hybrid modelling technology that enables multiple parallel processing of CFD and first-principles models in the context of la
Kucherenko S, Rodriguez-Fernandez M, Pantelides C, et al., 2009, Monte Carlo evaluation of derivative-based global sensitivity measures, 5th International Conference on Sensitivity Analysis of Model Output (SAMO 2007), Publisher: ELSEVIER SCI LTD, Pages: 1135-1148, ISSN: 0951-8320
- Author Web Link
- Cite
- Citations: 191
Karamertzanis PG, Kazantsev AV, Issa N, et al., 2009, Can the Formation of Pharmaceutical Cocrystals Be Computationally Predicted? 2. Crystal Structure Prediction, JOURNAL OF CHEMICAL THEORY AND COMPUTATION, Vol: 5, Pages: 1432-1448, ISSN: 1549-9618
- Author Web Link
- Cite
- Citations: 114
Gao G-Y, Wang M, Pantelides CC, et al., 2009, Mathematical Modeling and Optimal Operation of Industrial Tubular Reactor for Naphtha Cracking, 10th International Symposium on Process Systems Engineering, Publisher: ELSEVIER SCIENCE BV, Pages: 501-506, ISSN: 1570-7946
- Author Web Link
- Cite
- Citations: 12
Karamertzanis PG, Kazantsev AV, Issa N, et al., 2008, Modeling and prediction of the crystal structure of pharmaceutical Co-crystals, AIChE Annual Meeting, Conference Proceedings
- Cite
- Citations: 2
Kazantsev AV, Karamertzanis PG, Adjiman CS, et al., 2008, Computational prediction of effects of pressure on organic crystal structure, AIChE Annual Meeting, Conference Proceedings
Kazantsev AV, Karamertzanis PG, Adjiman CS, et al., 2008, A computationally efficient algorithm for accurate local energy minimization of crystal structures containing flexible molecules, AIChE Annual Meeting, Conference Proceedings
Pantelides CC, 2008, Model-based innovations in process development and design, AIChE Annual Meeting, Conference Proceedings
Luna-Ortiz E, Lawrence P, Pantelides CC, et al., 2008, Optimal flow assurance policies for hydrate prevention in deep-water gas production systems, AIChE Annual Meeting, Conference Proceedings
Luna-Ortiz E, Lawrence P, Pantelides CC, et al., 2008, An integrated framework for model-based flow assurance in deep-water oil and gas production, 18th European Symposium on Computer Aided Process Engineering (ESCAPE-18), Publisher: ELSEVIER SCIENCE BV, Pages: 787-792, ISSN: 1570-7946
- Author Web Link
- Cite
- Citations: 2
Neumann J, Pantelides CC, 2008, Consistency on domain boundaries for linear PDAE systems, SIAM JOURNAL ON SCIENTIFIC COMPUTING, Vol: 30, Pages: 916-936, ISSN: 1064-8275
- Author Web Link
- Cite
- Citations: 3
Kakalis NMP, Pantelides CC, 2007, Polydispersity-based homotopy/continuation for phase equilibria of polydisperse polymer systems, FLUID PHASE EQUILIBRIA, Vol: 253, Pages: 88-97, ISSN: 0378-3812
- Author Web Link
- Cite
- Citations: 3
Karamertzanis PG, Pantelides CC, 2007, <i>Ab initio</i> crystal structure prediction.: II.: Flexible molecules, 3rd International Conference on Foundations of Molecular Modeling and Simulation (FOMMS), Publisher: TAYLOR & FRANCIS LTD, Pages: 273-291, ISSN: 0026-8976
- Author Web Link
- Cite
- Citations: 98
Rodriguez-Fernandez M, Kucherenko S, Pantelides C, et al., 2007, Optimal experimental design based on global sensitivity analysis, 17th European Symposium on Computer Aided Process Engineering (ESCAPE-17), Publisher: ELSEVIER SCIENCE BV, Pages: 63-68, ISSN: 1570-7946
- Author Web Link
- Cite
- Citations: 21
Lawrence PS, Pantelides CC, 2006, Dynamic modelling of hydrate formation and its inhibition in oil and gas production wells and pipelines, CHISA 2006 - 17th International Congress of Chemical and Process Engineering
Formation of hydrates in oil and gas wells and pipelines may cause blockages which pose a serious challenge to stable production operation and safety of wells. Hydrates are ice-like crystals comprising cage-like crystalline structure formed by water and stabilized by the presence of "guest" molecules within the lattice cavities. Typically the guest molecules are light gases and hydrocarbons that are present in the process stream. Several methods have been employed in industry to eliminate or slow down the formation of hydrates. One approach is to eliminate the elements necessary for hydrate formation: the presence of hydrate-forming guest molecules, the presence of water, high pressure or low temperature. Alternatively, thermodynamic prevention methods involve the injection of an inhibitor to the well and this thermodynamically destabilizes hydrates and lowers the hydrate-formation temperature. Methanol is often used in significant quantities as an inhibitor and often a crude rule of thumb approach is adopted to estimate the quantity to be added. In this work, we have developed a detailed dynamic model to study the circumstances under which hydrates are formed in wells and pipes. A drift flux model (i.e. a homogeneous model that allows slip between phase) of three phase flow in wells has been developed. The model incorporates the van der Waals-Platteeuw description of the equilibrium between the hydrate and fluid phases, and can predict the dynamic appearance and disappearance of the hydrate phase. The model is also capable of predicting the impact of inhibitors on the elimination of hydrates. The above model has been implemented in gPROMS®, an equation based model development environment. The paper demonstrates the use of the model for the identification of the optimal inhibitor dosing schedule that needs to be followed to prevent hydrate formation.
Liberti L, Pantelides CC, 2006, An exact reformulation algorithm for large nonconvex NLPs involving bilinear terms, JOURNAL OF GLOBAL OPTIMIZATION, Vol: 36, Pages: 161-189, ISSN: 0925-5001
- Author Web Link
- Cite
- Citations: 89
Kakalis NMP, Kakhu AI, Pantelides CC, 2006, Efficient solution of the association term equations in the statistical associating fluid theory equation of state, INDUSTRIAL & ENGINEERING CHEMISTRY RESEARCH, Vol: 45, Pages: 6056-6062, ISSN: 0888-5885
- Author Web Link
- Cite
- Citations: 16
Gerogiorgis DI, Georgiadis M, Bowen G, et al., 2006, Dynamic Oil and Gas Production Optimization via Explicit Reservoir Simulation, Joint Conference Event of the 9th Symposium on Process Systems Engineering (PSE 2006)/16th European Symposium on Computer Aided Process Engineering (ESCAPE-16), Publisher: ELSEVIER SCIENCE BV, Pages: 179-184, ISSN: 1570-7946
- Author Web Link
- Cite
- Citations: 10
Blanco Gutierrez RF, Pantelides CC, Adjiman CS, 2006, Risk analysis and robust design under technological uncertainty, Joint Conference Event of the 9th Symposium on Process Systems Engineering (PSE 2006)/16th European Symposium on Computer Aided Process Engineering (ESCAPE-16), Publisher: ELSEVIER SCIENCE BV, Pages: 191-196, ISSN: 1570-7946
Technological innovation in process design often leads to increased technological risk arising from incomplete knowledge. We propose a systematic approach to manage this risk using mathematical models that are sufficiently detailed to quantify risk. Global sensitivity analysis is used to determine the complete probability distributions for the key performance indicators of the process, thereby allowing informed decisions to be taken regarding the acceptability of the risk inherent in a given design. It also produces global sensitivity indices which allow the identification of the critical uncertain parameters on which additional R&D needs to be focused if the risk is deemed to be unacceptably high. If the risk is acceptable, then scenario-based approximation is used to handle the residual uncertainty in the critical parameters. Issues regarding the robust and efficient solution of problems involving large numbers of scenarios based on nonlinear models with thousands of variables are considered. The methodology is demonstrated via a case study concerning the design of a catalytic tubular reactor.
Pantelides CC, 2005, Model-based innovation in the process industries, 7th World Congress of Chemical Engineering, GLASGOW2005, incorporating the 5th European Congress of Chemical Engineering
The emergence of hybrid models combining conventional equipment models with computational fluid dynamics descriptions has led to an unprecedented degree of predictive accuracy for diverse equipment such as multitubular fixed-bed catalytic reactors, polymerization reactors, crystallizers, and fuel cells. These developments have allowed the design of equipment with tighter control on product quality, while reducing design margins and improving profitability. In the area of process operations, the maturing of technologies such as dynamic optimization have significantly improved design optimal operating procedures by removing the need for trial-and-error approaches. Benefits have already been demonstrated in important areas such as optimal policies for grade switching in polymerization reactors, and optimal recipes in batch reactors and separators. Over the past few years, the off-line/on-line boundary has been breaking down, with detailed "design-quality" models have broke down, making the transition to on-line applications ranging from data reconciliation to model-based decision support, real-time optimization, and model predictive control. This has brought substantial benefits in terms both of the quality of the on-line solutions and of the cost of their deployment. This is an abstract of a paper presented at the 7th World Congress of Chemical Engineering (Glasgow, Scotland 7/10-14/2005).
Kakalis NMP, Pantelides CC, 2005, Efficient modelling of phase equilibria of polydisperse polymer systems using the saft equation of state, AIChE Annual Meeting, Conference Proceedings
Accurate prediction of the phase equilibria of polymers and polymer mixtures requires thermodynamic models which are able to deal with large size differences between molecules and strong deviations from ideal behaviour over wide ranges of operating conditions. One such advanced model is the SAFT (Statistical Associating Fluid Theory) equation of state which has proven particularly successful in predicting the thermodynamic behaviour of non-spherical molecules like polymers. Most practical polymers are polydisperse, with their molecular weight (and possibly other quantities) being distributed over a wide range of values. The corresponding thermodynamic behaviour and properties depend continuously on their molecular weight distribution. A standard approach is to assume a mathematical form for the distribution and then to discretise it into a certain number of pseudo-components. This often leads to problems relating to the efficient handling of large number of pseudo-components, especially in view of the fact that advanced equations of state such as SAFT are already highly nonlinear. We present a methodology for phase equilibrium calculations of polydisperse polymers. Given a polymer characterized by a set of measurable quantities, an optimization-based algorithm is first used to determine an accurate and computationally efficient discrete representation of the molecular weight distribution. The phase equilibrium problem for the polydisperse system is then solved via a homotopy/continuation algorithm making use of a physical continuation parameter. Starting from the corresponding monodisperse system, the homotopy continuously deforms the system to the desired polydisperse representation, while satisfying certain constraints throughout its path. The algorithm is applied to several vapour-liquid and liquid-liquid equilibria problems, and is shown to be accurate and reliable, avoiding turning points, bifurcations or stiffness irrespective of the number of pseudo-component
This data is extracted from the Web of Science and reproduced under a licence from Thomson Reuters. You may not copy or re-distribute this data in whole or in part without the written consent of the Science business of Thomson Reuters.