Session: 17-06: Symposium Steinfeld - Radiative and materials characterization and solar technology development

Paper Number: 142317

142317 - Safe and Performant Fuel Production via a Glass Flow Reactor for Solar Sabatier Process 

Abstract: 

The solar Sabatier process serves as a promising approach to CO₂ reduction and renewable fuel production. A plate-shaped glass flow reactor packed with plasmonic catalyst of Ru@γ-Al₂O₃ nanoparticles has been designed for this process. Here we look at operation under concentrated sunlight. Given the strongly exothermic nature of this reaction, thermal management is implemented in the form of two cooling fluid channels configured above and below the catalyst channel to prevent destructive thermal runaway. The reactor safety is subject to narrow operating windows constrained by the glass, the catalyst and the cooling fluid, requiring careful choice of reactor operation to avoid temperature or pressure overshooting that can lead to glass breakage. The production of high-quality methane that meets the synthetic natural gas (SNG) injection standards of the EU (Wobbe index∈[46.44, 54.0] MJ/m³, CO₂ concentration < 5%, H₂ concentration < 10%) without auxiliary purification processes remains a second challenge. Herein, expanded upon our previous work [1], a 2D multiphysics model that couples heat and mass transfer, fluid flow, and reaction kinetics is developed for the Sabatier reactor to predict its behavior under both steady and transient conditions, with the goal to achieve safe and performant fuel production for SNG grid injection. The multiphysics model is first validated using experimental data when the reactor is operated at suboptimal but safe conditions. Subsequently the effects of different operating conditions are explored to assess the temperature distribution, the pressure drop, the reactant conversion, as well as the quality of the gas products (Wobbe index and the species concentrations). A constrained multi-variable optimization is formulated to maximize the fuel production by satisfying both the SNG injection standards of the EU and the safe operating window of the glass reactor. Except for the optimal inlet temperature of the cooling fluid that remains constant at 200 °C, all other optimal conditions vary with the concentrating solar irradiance. The maximum fuel production is found to increase with the concentrating solar irradiance until reaching its saturation point at around 20 kW/m² irradiance. The dynamic response of the reactor to step changes in concentrating solar irradiance is simulated under their optimal operating conditions. While thermal and chemical hysteresis is observed, we urge caution on temperature overshooting occurring during the positive step change, and possible control strategies to mitigate this issue are further discussed.

Reference

[1] Sha Li, and Sophia Haussener. "Design and operational guidelines of solar-driven catalytic conversion of CO2 and H2 to fuels." Applied Energy 334 (2023): 120617.

Presenting Author: Sha Li &#201;cole polytechnique f&#233;d&#233;rale de Lausanne (EPFL)

Presenting Author Biography: Sha Li obtained her PhD degree in Mechanical Engineering from the Australian National University (ANU) in 2020. She was the recipient of the 2020 ASME SED Graduate Student Award. She also won the Best Oral Presentation–Third Place at the 2020 ASME Energy Sustainability Conference. Currently, she is a postdoc researcher working with Prof. Sophia Haussener at EPFL, Switzerland since April 1, 2021. She is a recipient of the Spark Grant of the Swiss National Science Foundation in 2023.

Authors:

Sha Li École polytechnique fédérale de Lausanne (EPFL)
Kai Risthaus DLR
Jonathan Van Den Ham TNO
Nicole Meulendijks TNO
Pascal Buskens TNO
Charlotte Wiles Chemtrix
Freek Snijders Chemtrix
Charl Stemmet Chemtrix
Sophia Haussener EPFL