Enhancing DACCS Flexibility: Evaluating Hardware Modifications for Cost-Effective Carbon Dioxide Removal - Preprint

[Geoengineering News]

https://papers.ssrn.com/sol3/papers.cfm?abstract_id=6416105

Authors: Patrik Postweiler, Tori Wiederhoeft, Daniel Rezo, Mirko Engelpracht, Benedikt Nilges, Sina Hoseinpoori, Carsten Wedler, Niklas von der Assen

14 March 2026

Abstract

Direct air carbon capture and storage (DACCS) is a promising option for carbon dioxide removal, but high costs constrain large-scale deployment. Flexible operation has been identified as a key lever for cost reduction in renewable-dominated electricity systems and there is growing interest in exploring how hardware modifications can further enhance flexibility. In this work, we extend a detailed dynamic process model of adsorption-based DACCS by adding two additional hardware modifications: enhanced passive airflow during adsorption, and direct electrical heating during regeneration. We combine the extended model with a rolling-horizon optimization framework to assess the impact of process flexibility under time-varying electricity prices, electricity-specific greenhouse gas emissions, and wind conditions. The process model is coupled to economic and environmental calculations, enabling a time-resolved evaluation of net carbon removal costs (NCRC). The results show that hardware modifications expand the feasible operating range beyond control adaptations alone, enabling further reductions in net carbon removal costs. Enhanced passive airflow reduces fan electricity demand and improves efficiency, with benefits that are strongly site- and implementation-dependent. At high-wind onshore locations, an omnidirectional windcatcher enables NCRC reductions of up to 19 € t-1 (-3.8 %). Direct electrical heating extends the operating range toward higher productivity and is most advantageous during periods with negative electricity prices. If negative electricity prices occur as often as in current electricity markets, such as Germany and South Australia in 2024, direct electrical heating alone can enable NCRC reductions of 13 € t-1 (-2.9 %) and 46 € t-1 (-14.4 %), respectively.

Source: SSRN