Johannes Schilling


Last Name

Schilling

First Name

Johannes

ORCID

0000-0001-8013-5439

Organisational unit

09696 - Bardow, André / Bardow, André

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2015 - 2019302020 - 202579
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Publications 1 - 10 of 109
  • Feeding Brightway with data – Automated data extraction from chemical process simulations into LCA software
    Item type: Other Conference Item
    Spiekermann, Lukas; Sewani, Hitesh; Lochmann, Sebastian; et al. (2025)
    Mitigating climate change requires the development of new chemical processes (Shukla et al., 2022). Confirming their climate benefits requires life cycle assessment (LCA). Still, in practice, LCAs of chemical processes are often conducted by manually extracting data from process simulation software and transferring it to LCA tools (Köck et al., 2023). This manual approach is time-consuming, susceptible to human error (Azzaro-Pantel et al., 2022), and may overlook process flows that appear negligible but can substantially affect the environmental impacts (Rosental et al., 2020). Here, we present the tool ALCHEMIA (Automated Life Cycle extraction from cHEMical process models Into Assessments) that addresses these challenges by automatically connecting chemical process simulations with the Brightway environment (Mutel, 2017). A graphical user interface facilitates mapping process streams to life cycle inventories, while data handling is performed in the background. We demonstrate the tool based on bio-based and CO2-based process studies available in the literature. These studies are implemented in several flow sheeting software packages, including Aspen Plus, Aspen HYSYS, and AVEVA Process Simulation. We show the rapid generation of LCA results based on existing process simulation studies and highlight the importance of holistic LCA to account for all relevant streams. Overall, ALCHEMIA streamlines data handling in LCA of chemical process simulations by unlocking automated data transfer to the LCA software environment Brightway.
  • ORC on tour: Integrated design of dynamic ORC processes and working fluids for waste-heat recovery from heavy-duty vehicles
    Item type: Conference Paper
    Tillmanns, Dominik; Petzschmann, Jonas; Schilling, Johannes; et al. (2019)
    Computer Aided Chemical Engineering ~ 29th European Symposium on Computer Aided Process Engineering
    Organic Rankine Cycles (ORC) convert low temperature heat into power. To maximize conversion efficiency, both ORC process and working fluid have to be tailored to the specific application. Common solution approaches for the resulting integrated design of ORC process and working fluid are limited to steady-state applications. However, for applications in dynamic settings, steady-state design approaches can lead to suboptimal solutions due to the neglect of the dynamic behavior. In this work, we present an approach for the integrated design of ORC process and working fluid considering the dynamics. The approach is based on the Continuous-Molecular Targeting–Computer-aided Molecular Design (CoMT-CAMD) framework. Herein, the physically based Perturbed-Chain Statistical Associating Fluid Theory (PC-SAFT) is used as thermodynamic model. To capture the ORC behavior under dynamic conditions, dynamic models for the ORC equipment are integrated into the process model. The result is an optimal control problem (OCP) yielding an optimal working fluid and the corresponding optimal process control for a given dynamic input. This so-called dynamic CoMT-CAMD approach is applied to an ORC for waste-heat recovery on a heavy-duty vehicle. Whereas steady-state design approaches fail, the presented approach identifies the optimal working fluid and the corresponding optimal control of the ORC process. © 2019 Elsevier B.V.
  • Integrated design of ORC process and working fluid using PC-SAFT and Modelica
    Item type: Conference Paper
    Tillmanns, Dominik; Gertig, Christoph; Schilling, Johannes; et al. (2017)
    Energy Procedia ~ 4th International Seminar on ORC Power Systems
    Organic Rankine Cycles (ORC) use low-temperature heat to generate electrical power. To use the full potential of a heat source, the ORC has to be tailored to the specific application. Tailoring a cycle means an integrated design of both process and working fluid. This integrated design leads to complex mixed-integer nonlinear program (MINLP) optimization problems. To avoid this complexity, working fluid candidates are commonly preselected using heuristic guidelines; subsequently, the process is optimized for the set of preselected working fluids. However, the preselection can fail, leading to suboptimal solutions. An approach for integrated design of ORC process and working fluid is the Continuous-Molecular Targeting–Computer-aided Molecular Design (CoMT-CAMD) approach. CoMT-CAMD employs the physically-based Perturbed-chain Statistical Associating Fluid Theory (PC-SAFT) equation of state as thermodynamic model of the working fluid. In PC-SAFT, each working fluid is described by a set of pure component parameters. In a first step, the so-called CoMT step, the discrete pure component parameters are relaxed resulting in a hypothetical optimal working fluid and the corresponding optimal process. In a second step, real working fluids with similar properties are identified using Computer-aided Molecular Design and a second-order Taylor approximation of the objective function around the hypothetical optimum. So far, the process models in CoMT-CAMD were implemented in a procedural programming language, which hinders the reusability, the use for more complex processes and dynamic simulations. In this work, we integrate CoMT-CAMD into the object-oriented modelling language Modelica. For this purpose, Modelica is directly linked to PC-SAFT. Thereby, already existing model libraries for Modelica can be used to model the ORC process. The resulting design approach is applied to the integrated design of an ORC process and working fluid for a geothermal power station.
  • Exploiting machine-learning thermodynamics for process design of the polyurethane waste recycling
    Item type: Other Conference Item
    Bosetti, Luca; Winter, Benedikt Alexander; Lindfeld, Johanna; et al. (2023)
  • One-stage approach for the integrated design of ORC processes and working fluid using PC-SAFT
    Item type: Conference Paper
    Schilling, Johannes; Lampe, Matthias; Groß, Joachim; et al. (2016)
    Computer Aided Chemical Engineering ~ 26th European Symposium on Computer Aided Process Engineering
    Organic Rankine Cycles (ORC) can transform low-temperature heat into electrical power. To ensure optimal use of a heat source, process and working fluid need to be tailored to the specific application. We present a one-stage approach for the integrated design of ORC process and working fluid, which identifies the optimal working fluid and the corresponding optimal process in a single optimization problem. For this purpose, a process model is combined with a modern thermodynamic model of the working fluid. The process model is based on equilibrium thermodynamics. The perturbed-chain statistical associating fluid theory (PC-SAFT) is used as physically-based thermodynamic model of the working fluid. The fluid model is extended by a group-contribution method based on PC-SAFT to enable Computer-aided molecular design (CAMD) of novel working fluids within the optimization. The full model enables the integrated design of process and working fluid. The optimization is an MINLP problem depending on two kinds of design variables: continuous process variables and integer variables representing the molecular structure of the working fluid. The one-stage approach is exemplified in a case study for a subcritical ORC process. The approach is shown to efficiently identify the optimal working fluid and the corresponding optimal process parameters. Integer cuts are employed to generate a ranked list of candidates.
  • Molecule design beyond group counts - Integrated design of processes and molecule superstructures
    Item type: Other Conference Item
    Rehner, Philipp; Schilling, Johannes; Bardow, André (2023)
    33rd European Symposium on Computer Aided Process Engineering (ESCAPE33). Extended Abstracts
  • Integrating environmental impacts into the screening of metal-organic frameworks for carbon capture
    Item type: Other Conference Item
    Schilling, Johannes; Sanchez-Fernandez, Eva; Charalambous, Charithea; et al. (2023)
    33rd European Symposium on Computer Aided Process Engineering (ESCAPE33). Extended Abstracts
  • It’s a match: Systematische Suche nach Ko-Lösungsmitteln für die chemische Absorption
    Item type: Conference Poster
    Rueben, Lisa; Schricker, Hendrik; Rehner, Philipp; et al. (2023)
    Die Auswahl des richtigen Lösungsmittels entscheidet über den Erfolg der chemischen Absorption zur CO2-Abtrennung. Ein zusätzliches Ko-Lösungsmittel eröffnet Effizienzpotenziale, gleichzeitig erschwert der größere Gestaltungsspielraum die Lösungsmittelauswahl. Zur zielgerichteten Auswahl von Lösungsmitteln wurden daher systematische Methoden entwickelt, die Prozessmodelle mit prädiktiven thermo-dynamischen Modellen kombinieren [1]. Bisher standen hierbei nicht-geladene Systeme im Vordergrund. Die chemische Absorption führt aber in der Regel zu Elektrolytlösungen und erfordert daher thermodynamische Modelle, die den Einfluss der Ionen berücksichtigen. Eine Möglichkeit hierzu sind Elektrolyt-Zustandsgleichungen, wie beispielsweise die electrolyte PC-SAFT Zustandsgleichung (ePC-SAFT) [2]. Das ePC-SAFT-Modell beschreibt Gleichgewichtseigenschaften von Elektrolytlösungen mit hoher Güte [3], sodass es aussichtsreich erscheint, auf dieser Basis nach Lösungsmitteln zu suchen. In dieser Arbeit präsentieren wir ein Framework für die Auswahl von Ko-Lösungsmitteln für die chemische Absorption. Das Framework kombiniert ein rigoroses Gleichgewichtsmodell des chemischen Absorptionsprozesses mit ePC-SAFT als thermodynamischem Modell. Neben dem Screening von Ko-Lösungsmitteln optimiert das Framework gleichzeitig die Prozessbedingungen. Für eine Fallstudie zur Gaswäsche screenen wir potenzielle physikalische Ko-Lösungsmittel, die die Betriebskosten pro kg abgetrennten Sauergas bei optimalen Prozessbedingungen minimieren. Dabei identifizieren wir eine Rangfolge der am besten geeigneten Ko-Lösungsmittel. Alle Kandidaten reduzieren die Betriebskosten im Vergleich zu einem Szenario ohne Ko-Lösungsmittel deutlich. Das entwickelte Framework ermöglicht somit die Auswahl effizienter Ko-Lösungsmittel in Anwendun-gen mit Elektrolytmischungen, sodass die Prozess-Performance optimiert wird. [1] Borhani und Wang, Renewable Sustainable Energy Rev., 2019, 114, 109299. [2] Bülow et al., Ind. Eng. Chem. Res., 2021, 60, 17, 6327-6336. [3] Bülow et al., Fluid Phase Equilib., 2021, 535, 112967.
  • Co-solvent selection for chemical absorption based on electrolyte PC-SAFT
    Item type: Conference Poster
    Rueben, Lisa; Schricker, Hendrik; Rehner, Philipp; et al. (2023)
  • Integrated design of ORC process and working fluid for transient waste-heat recovery from heavy-duty vehicles
    Item type: Conference Paper
    Schilling, Johannes; Eichler, Katharina; Pischinger, Stefan; et al. (2018)
    Computer Aided Chemical Engineering ~ 13th International Symposium on Process Systems Engineering (PSE 2018)
    Organic Rankine Cycles (ORC) transform low- and medium-temperature heat into mechanical power. One promising application of ORCs is the recovery of exhaust gas heat from heavy-duty vehicles. To utilize the full potential of the transient exhaust gas heat, both, the ORC process and working fluid have to be designed. To integrate the working fluid design into the process design, we developed the so-called 1-stage CoMT-CAMD approach, which allows us to identify the optimal combination of ORC process and working fluid. However, 1-stage CoMT-CAMD is limited to steady-state heat input preventing the consideration of the transient exhaust gas behavior. In this work, we propose an iterative algorithm combining 1-stage CoMT-CAMD with time-series aggregation to tackle the challenge of transient exhaust gas behavior, so-called time-resolved 1-stage CoMT-CAMD. By using time-series aggregation, the transient exhaust gas behavior can be represented with sufficient accuracy by a few time steps serving as quasi-steady-state input for 1-stage CoMT-CAMD. The presented algorithm efficiently identifies the optimal working fluid and ORC process while capturing the transient exhaust gas behavior.
Publications 1 - 10 of 109