AUTHOR=Maggi Andrea , Garmatter Dominik , Sager Sebastian , Stoll Martin , Sundmacher Kai 

TITLE=Power-to-Syngas: A Parareal Optimal Control Approach

JOURNAL=Frontiers in Energy Research

VOLUME=9

YEAR=2021

URL=https://www.frontiersin.org/journals/energy-research/articles/10.3389/fenrg.2021.720489

DOI=10.3389/fenrg.2021.720489

ISSN=2296-598X

ABSTRACT=<p>A chemical plant layout for the production of syngas from renewable power, H<sub>2</sub>O and biogas, is presented to ensure a steady productivity of syngas with a constant H<sub>2</sub>-to-CO ratio under time-dependent electricity provision. An electrolyzer supplies H<sub>2</sub> to the reverse water-gas shift reactor. The system compensates for a drop in electricity supply by gradually operating a tri-reforming reactor, fed with pure O<sub>2</sub> directly from the electrolyzer or from an intermediate generic buffering device. After the introduction of modeling assumptions and governing equations, suitable reactor parameters are identified. Finally, two optimal control problems are investigated, where computationally expensive model evaluations are lifted <italic>via</italic><monospace>parareal</monospace> and necessary objective derivatives are calculated <italic>via</italic> the continuous adjoint method. For the first time, modeling, simulation, and optimal control are applied to a combination of the reverse water-gas shift and tri-reforming reactor, exploring a promising pathway in the conversion of renewable power into chemicals.</p>