Jan Seiler

Last Name

Seiler

First Name

Jan

ORCID

0000-0002-8461-7993

Organisational unit

01159 - Lehre Maschinenbau und Verfahrenstechnik

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Publications 1 - 10 of 61

Integrating CO2 Electrolyzers in Electrochemical Plants: Heat Integration, Techno-Economic Analysis, and Life Cycle Assessment of the Production of 1-Butene from CO2
Spiekermann, Lukas; Lee, Mi Gyoung; Wicks, Joshua; et al. (2024)
2024 AIChE Annual Meeting Proceedings
Efforts to mitigate climate change have increased interest in utilizing CO2 as a sustainable feedstock within the chemical industry [1]. Recent progress in electrochemical CO2 reduction, facilitated using renewable electricity sources, presents a promising avenue for synthesizing valuable C2+ chemicals [2]. While the initial focus has been on the development of electrolyzers, recent research has broadened to include process design and downstream separation techniques [3]. However, the question remains how to integrate feedback from process design back into electrolyzer development. This work introduces a feedback loop from process design to electrolyzer development. The loop combines process modeling, heat integration, techno-economic analysis, and life cycle assessment. The resulting workflow is demonstrated for the CO2 electroreduction to ethylene and subsequent dimerization to 1-butene [4]. From the analysis, we derive development targets for CO2 electrolyzers. We assess the significance of cell voltage and Faradaic efficiency, highlighting that single-pass conversion minimally impacts overall process feasibility. Moreover, we emphasize the benefits of integrating electrolyzers with downstream and upstream units. In summary, we combine electrolyzer development and process systems engineering perspectives by bridging the scales from electrolyzers to integrated processes with economic and sustainability objectives. This study illustrates the integration of a process-oriented approach into technology advancement for an electrified chemical industry.
Waste Heat to Power: Full-Cycle Analysis of a Thermally Regenerative Flow Battery
Engelpracht, Mirko; Kohrn, Markus; Tillmanns, Dominik; et al. (2022)
Energy Technology
Large amounts of waste heat, below 120 °C, are released globally by industry. To convert this low-temperature waste heat to power, thermally regenerative flow batteries (TRFBs) have recently been studied. Most analyses focus on either the discharging or the regeneration phase. However, both phases have to be considered to holistically assess the performance of the flow battery. Therefore, a dynamic, open-access, full-cycle model of a Cu–NH3 TRFB is developed in Modelica and validated with data from the literature. Based on the validated model, a trade-off between power density and efficiency is shown that depends only on the discharging strategy of the flow battery. For a sensible heat source with an inlet temperature of 120 °C and heat transfer at a thermodynamic mean temperature of about 90 °C, the power density reaches 38 W m^(−2) over a complete cycle, and the efficiency reaches 20% of Carnot efficiency. In a benchmarking study, the power production of the flow battery is shown to already achieve 34% of a fully optimized organic Rankine cycle. Thus, TRFBs require further optimization to become a competitive technology for power production and energy storage from low-temperature waste heat.
Automating Life Cycle Assessment from Chemical Process Simulations
Spiekermann, Lukas; Sewani, Hitesh; Lochmann, Sebastian; et al. (2024)
Advancing sustainability requires knowledge on the environmental impacts of chemicals. For this purpose, life cycle assessment is the preferred method, but usually carried out by manually extracting data from process simulation software and transferring data to life cycle assessment software. This process is very labor-intensive and error-prone. Here, we bridge the gap between process simulation and life cycle assessment by automated data extraction from process simulators to life cycle assessment software. Our tool currently links the process simulators Aspen Plus, Aspen HYSYS, and AVEVA Process Simulation to the open-source tools Brightway/Activity Browser for life cycle assessment. The tool is exemplified using openly available case studies and simulation files for bio-based and CO2-based processes. Simulation studies can be combined to, e.g., integrated CO2 capture and utilization chains within life cycle assessment software. Our tool directly integrates process simulations results into life cycle inventory databases with easy workflows and could thereby enable the generation of more life cycle assessments of chemical processes.
How to produce 1-butene from CO2 electroreduction? Targets from techno-economic analysis and life cycle assessment
Spiekermann, Lukas; Lee, Mi Gyoung; Wicks, Joshua; et al. (2024)
Capillary-assisted evaporation of water from finned tubes: Impacts of dynamics and experimental setups
Seiler, Jan; Volmer, Rahel; Krakau, Dennis; et al. (2021)
Capillary-assisted thin-film evaporation has attracted increased attention recently to efficiently evaporate the natural refrigerant water at low pressures. Although capillary-assisted evaporators have been studied in many publications, it remained unclear if published results can be compared. Respective measurements are often conducted under different conditions in terms of setup, procedure and evaluation, and potentially important factors are not specified or disregarded. In this work, we compare experimental setups and procedures. Experiments with finned copper tubes are conducted at RWTH Aachen and Fraunhofer ISE. A set of requirements is identified to ensure good agreement of the overall heat transfer coefficients. Major requirements are the specification of the heat exchanger’s surface properties, analysis of measurement uncertainty, well-specified input conditions, and control of non-condensable gases (NCG). Furthermore, dynamic experiments with continuously decreasing filling levels prove to be well-suited to quickly assess the heat transfer at all filling levels in a single experiment. Thus, this work identifies approaches for fast, reproducible and comparable characterization of capillary-assisted evaporation.
Upgrading Waste Heat from 90 to 110 degrees C: The Potential of Adsorption Heat Transformation
Engelpracht, Mirko; Gibelhaus, Andrej; Seiler, Jan; et al. (2021)
Energy Technology
Low-grade heat is abundantly available below 100 degrees C, whereas industry mainly needs heat above 100 degrees C. Thus, the industry cannot directly utilize low-grade heat to save primary energy and emissions. Low-grade heat can be utilized by adsorption heat transformers (AdHTs); however, closed AdHTs to upgrade heat above 100 degrees C are only investigated by idealized steady-state analyses, which indicate the maximal theoretical performance. For evaluating the performance achievable in practice, this work studies a closed AdHT in a one-bed configuration using dynamic simulation. For the working pair AQSOA-Z02/H2O, the performance is optimized via the design of the adsorber heat exchanger and the control of the AdHT cycle. When heat is upgraded from 90 to 110 degrees C, releasing waste heat at 35 degrees C, the maximum exergetic coefficient of performance (COPexergetic) is 0.64, and the maximum specific heating power (SHP) is 590 W kg(-1). The maximum SHP can increase by 35% when releasing waste heat at 25 degrees C. Both performance indicators strongly depend on design, control, and the available temperature of the waste heat. Overall, AdHTs with optimized design and control are promising to utilize low-grade waste heat.
Heat and Mass Transfer Kinetics of MOF-Coatingsfrom Al-fumarate and CAU-10(Al)-H from IR-LTJ experiments: The Impact of Characteristic Times
Henninger, Matthias Roland Wolfgang; Gilges, Markus; Rustam, Lina; et al. (2020)
ISHPC 2021 Proceedings: Online Pre-Conference 2020
The metal-organic frameworks (MOFs) Al-fumarate and aluminum-isophthalate CAU-10 (CAU = Christian Albrechts University Kiel) are considered for water-based adsorption chillers because of their excellent cyclic stability and high water uptake. However, water uptake captures only the equilibrium behavior, while process performance depends strongly on kinetics. In this work, we, therefore, determine characteristic time constants for water ad- and desorption on Al-fumarate and CAU-10. The MOF coatings are studied by small-scale Infrared Large-Temperature-Jump (IR-LTJ) experiments. Commercially available granular silica gels serve as benchmark. We show that the performance expected from the characteristic time constants depends strongly on the chosen characteristic time as well as the chosen reference in the heat exchanger: For area-specific mean power, silica gel performs best for small time constants, CAU-10 and silica gel both perform best for intermediate time constants, and Al-fumarate performs best for large time constants for the temperature triple 10/30/80 °C. For volume-specific mean powers, silica gels are outperformed by both MOF-coatings with the best results for CAU-10 at intermediate time constants. The results highlight the potential of MOF coatings for adsorption chillers
Optimal design of adsorption chillers based on a validated dynamic object-oriented model
Lanzerath, Franz; Bau, Uwe; Seiler, Jan; et al. (2015)
Science and Technology for the Built Environment ~ 2014 International Sorption Heat Pump Conference
The design of adsorption chillers is usually based on experience and high experimental effort. Experimental effort can be reduced by using dynamic models. In the present study, a dynamic model is validated with a modular adsorption chiller test bed and then used to optimize design and process parameters to gain maximum cooling power. The modularity of the test bed enables the exchange of single components without changing the remaining setup. This modular structure is also reflected in the object-oriented dynamic model. Model calibration is based on the heat flows of all components. This measure allows the gain of deep insight into the system behavior and a quantitative comparison of model accuracy. The calibrated model is validated by predicting the system behavior for different operating conditions and also changed adsorbent materials. Adsorbent materials silica gel 123 and zeolite 13X are investigated. Operating points vary in cycle time, as well as temperatures of evaporation, adsorption, and desorption. The model exhibits excellent prediction capability for the coefficient of performance and for the cooling power. The modular setup of the model is then used for targeted optimization of the adsorption system; the cycle time and the sizing of the heat exchangers are rigorously optimized, leading to adsorption chillers with maximum cooling power.
Bridging the Scales from Catalyst Synthesis to Sustainable Processes: CO2 Hydrogenation to Methanol
Spiekermann, Lukas; Pinheiro Araújo, Thaylan; Seiler, Jan; et al. (2023)
A modular experimental and simulation approach for the systematic development of adsorption heat pumps
Lanzerath, Franz; Seiler, Jan; Bau, Uwe; et al. (2014)
International Sorption Heat Pump Conference (ISHPC 2014)

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Jan Seiler

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