Journal: Computers & Chemical Engineering

Abbreviation

Comput. Chem. Eng.

Publisher

Elsevier

Journal Volumes

ISSN

0098-1354
1873-4375

Description

Filters

Reset filters

Search Results

Publications 1 - 10 of 100
  • Integrated design of solvent–antisolvent mixtures and crystallization processes powered by machine learning
    Item type: Journal Article
    Bosetti, Luca; Winter, Benedikt; Lindfeld, Johanna; et al. (2025)
    Computers & Chemical Engineering
    Crystallization is a key separation technology in the chemical and pharmaceutical industries, offering high-purity products with relatively low energy consumption. However, the design of efficient antisolvent crystallization processes is inherently complex due to the interactions between solvent and antisolvent, as well as the selection of process conditions. Existing computer-aided molecule and process design (CAMPD) frameworks rely on group contribution or quantum-mechanical methods for thermophysical property predictions, which either limit the molecular design space or result in high computational costs. To overcome these challenges, we couple machine learning-based property predictions with a SMILES-based molecular design algorithm into a CAMPD framework (ML-CAMPD), enabling rapid and accurate solvent selection for crystallization. We demonstrate this ML-CAMPD framework through the case study of ibuprofen antisolvent crystallization, showing improvements in process efficiency. A screening study identified acetone-water as the most promising solvent–antisolvent pair. By applying the CAMPD framework to design new mixtures, we find solvent–antisolvent systems that outperformed acetone-water by 10% in energy efficiency. The proposed approach broadens the applicability of CAMPD frameworks and offers a powerful tool for designing efficient and sustainable crystallization processes.
  • Optimization-based approach for maximizing profitability of bioethanol supply chain in Brazil
    Item type: Journal Article
    Kostin, Andrei; Macowski, Diogo H.; Pietrobelli, Juliana M.T.A.; et al. (2018)
    Computers & Chemical Engineering
    In this work, a mathematical approach for optimizing and planning the Brazilian bioethanol supply chains (SC) is presented. The optimization problem has an MILP formulation, aiming to maximize the net present value (NPV) of the entire SC of the sugar and bioethanol sector in Brazil. The model takes into account seven different production technologies, two types of warehouses, three types of transportation modes and seven exportation options, whose data were obtained from Brazilian industrial practices. The model aims to propose the optimal configuration of a bioethanol network, that is, the locations of the production and storage facilities, their capacity of expansion policy, the technology selected for manufacturing and materials storage and the flows of all feedstock and final products involved in the bioethanol SC in Brazil. A comparison between the current situation of Brazilian bioethanol SC and the optimal configuration achieved by the proposed model is also included.
  • Multi-objective synthesis of energy systems: Efficient identification of design trade-offs
    Item type: Journal Article
    Hennen, Maike; Postels, Sarah; Voll, Philip; et al. (2017)
    Computers & Chemical Engineering
    The synthesis of energy systems usually has to consider several conflicting objectives leading to a large set of Pareto-optimal solutions with multiple trade-offs. From this large set of solutions, good compromise solutions have to be identified which is a complex and computationally demanding task. We therefore propose a method to reduce both the set of objectives and the solution space: First, the set of objectives is reduced by employing a method from the literature to determine the objectives best representing the design trade-offs. However, in practice, aggregated costs are the decisive criterion. Thus, in a second step, the solution space of the synthesis problem is restricted to an acceptable deviation from minimal aggregated costs. Thereby, only relevant solutions are obtained. The two steps significantly reduce the effort for multi-objective optimization focusing on the most relevant part of the solutions. The proposed method is applied to a real-world case study.
  • Design of low-carbon multi-energy systems in the SecMOD framework by combining MILP optimization and life-cycle assessment
    Item type: Journal Article
    Reinert, Christiane; Nolzen, Niklas; Frohmann, Julia; et al. (2023)
    Computers & Chemical Engineering
    Decarbonizing complex industrial energy systems is an important step to mitigate climate change. Designing the transition of such sector-coupled industrial energy systems to low-carbon designs is challenging since both cost-efficient operation and the reduction of environmental impacts over the whole life cycle need to be considered in the system design. Optimal system designs can be identified using software: Recently, the open-source framework SecMOD was introduced for the linear optimization of multi-energy system models, considering environmental impacts by fully integrating life-cycle assessment. In this work, we extend SecMOD to allow mixed-integer decisions that are vital to model industrial energy systems. Thereby, we provide the first open-source mixed-integer linear program framework with full integration of life-cycle assessment. We use SecMOD to investigate the benefits of a pumped-thermal energy storage system in a sector-coupled industrial energy system and identify trade-offs regarding the system design by comparing the economic and climate optimum.
  • Model compendium, data, and optimization benchmarks for sector-coupled energy systems
    Item type: Journal Article
    Sass, Susanne; Faulwasser, Timm; Hollermann, Dinah Elena; et al. (2020)
    Computers & Chemical Engineering
    Decarbonization and defossilization of energy supply as well as increasing decentralization of energy generation necessitate the development of efficient strategies for design and operation of sector-coupled energy systems. Today, design and operation of process and energy systems rely on powerful numerical methods, in particular, optimization methods. The development of such methods benefits from reproducible benchmarks including transparent model equations and complete input data sets. However, to the authors’ best knowledge and with respect to design and optimal control of sector-coupled energy systems, there is a lack of available benchmarks. Hence, this article provides a model compendium, exemplary realistic data sets, as well as two case studies (i.e., optimization benchmarks) for an industrial/research campus in an open-source description. The compendium includes stationary, quasi-stationary, and dynamic models for typical components as well as linearization schemes relevant for optimization of design, operation, and control of sector-coupled energy systems.
  • Identification of diffusive transport by means of an incremental approach
    Item type: Journal Article
    Bardow, André; Marquardt, Wolfgang (2004)
    Computers & Chemical Engineering
    Predictive models for diffusion in liquids contain still large uncertainties due to a lack of experimental data. Modern measurement techniques offer high-resolution concentration data but data analysis tools are usually designed for scarce data. A new incremental approach to model identification is therefore introduced and applied to the estimation of diffusion coefficients. The identification problem is split here in a sequence of inverse problems following the steps of model development. Thereby, model uncertainty and computational cost are minimized. The concentration dependence of binary diffusion coefficients can now be efficiently established from a single experiment. Furthermore, the robust estimation of the ternary diffusion matrix from a single data set is demonstrated.
  • Recent developments in the control of constrained hybrid systems
    Item type: Journal Article
    Morari, Manfred; Baric, Miroslav (2006)
    Computers & Chemical Engineering
  • A novel MILP-based objective reduction method for multi-objective optimization: Application to environmental problems
    Item type: Journal Article
    Guillén Gosálbez, Gonzalo (2011)
    Computers & Chemical Engineering
    Multi-objective optimization has recently emerged as a useful technique in sustainability analysis, as it can assist in the study of optimal trade-off solutions that balance several criteria. The main limitation of multi-objective optimization is that its computational burden grows in size with the number of objectives. This computational barrier is critical in environmental applications in which decision-makers seek to minimize simultaneously several environmental indicators of concern. With the aim to overcome this limitation, this paper introduces a systematic method for reducing the number of objectives in multi-objective optimization with emphasis on environmental problems. The approach presented relies on a novel mixed-integer linear programming formulation that minimizes the error of omitting objectives. We test the capabilities of this technique through two environmental problems of different nature in which we attempt to minimize a set of life cycle assessment impacts. Numerical examples demonstrate that certain environmental metrics tend to behave in a non-conflicting manner, which makes it possible to reduce the dimension of the problem without losing information. © 2011 Elsevier Ltd. All rights reserved
  • Software supporting optimal experimental design: A case study of binary diffusion using EFCOSS
    Item type: Journal Article
    Rasch, Arno; Bücker, Hans; Bardow, André (2009)
    Computers & Chemical Engineering
    Methods for optimal experimental design aim at minimizing uncertainty in parameter estimation problems. Despite their long tradition in applied mathematics and importance in practical applications, they are currently not widely used in computational science and engineering. To make the techniques of optimal experimental design more accessible to a broader community, we introduce a novel software environment called EFCOSS and demonstrate its ease of use and versatility in two case studies of binary diffusion experiments. Through the use of a component-based software architecture, integration of automatic differentiation technology and facilitated interfacing to optimization algorithms, EFCOSS minimizes the computational overhead for the user who can thus focus on model development and analysis itself. The presented case studies focus on diffusion experiments in liquids since these experiments are typically very demanding. The use of optimal experimental design techniques allows to reduce experimental time and effort significantly.
  • Algebraic surrogate-based flexibility analysis of process units with complicating process constraints
    Item type: Journal Article
    Forster, Tim; Vázquez, Daniel; Moreno-Palancas, Isabela Fons; et al. (2024)
    Computers & Chemical Engineering
    Flexibility analyses are widespread in chemical engineering to quantify allowed deviations from nominal conditions. Standard approaches to perform flexibility analysis can be hard to apply if process constraints are difficult to handle, as it happens in bioprocesses with dynamic constraints. Here, focusing on the computation of the traditional flexibility index in problems with complicating constraints, we apply symbolic regression to build algebraic expressions of the said complicating constraints, simplifying the flexibility analysis of complex process models by enabling the application of state-of-the-art deterministic solvers. Our approach is applied to ethanol production in fed-batch operation mode and a chromatographic process. The performance is assessed in terms of model building time, predictive accuracy of the model, and the time required to solve the flexibility formulations. Overall, our approach, which focuses on computing the original flexibility index proposed in the literature, provides an alternative way to analyse the flexibility of processes entailing complicating constraints.
Publications 1 - 10 of 100