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Enhanced weathering to capture atmospheric carbon dioxide: Modeling of a trickle‐bed reactor
Author(s) -
Xing Lei,
Darton Richard C.,
Yang Aidong
Publication year - 2021
Publication title -
aiche journal
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.958
H-Index - 167
eISSN - 1547-5905
pISSN - 0001-1541
DOI - 10.1002/aic.17202
Subject(s) - mass transfer , weathering , dissolution , residence time (fluid dynamics) , carbon dioxide , chemistry , calcite , volumetric flow rate , carbon capture and storage (timeline) , packed bed , atmosphere (unit) , trickle bed reactor , chemical engineering , environmental engineering , environmental science , mineralogy , thermodynamics , geology , chromatography , geotechnical engineering , biochemistry , physics , oceanography , organic chemistry , geomorphology , climate change , engineering , catalysis
Enhanced weathering (EW) of alkaline minerals can potentially capture CO 2 from the atmosphere at gigaton scale, but the reactor design presents great challenges. We model EW with fresh water in a counter‐current trickle flow packed bed batch of 1–10 mm calcite particles. Weathering kinetics are integrated with the mass transfer of CO 2 incorporating transfer enhancement by chemical reaction. To avoid flooding, flow rates must be reduced as the particles shrink due to EW. The capture rate is mainly limited by slow transfer of CO 2 from gas to liquid although slow dissolution of calcite can also play a role in certain circumstances. A bed height of at least 7–8 m is required to provide sufficient residence time. The results highlight the need to improve capture rate and reduce energy and water consumption, possibly through enriching the feed with CO 2 and further chemical acceleration of the mass transfer.