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Title: Characterization of reactive CaCO 3 crystallization in a fluidized bed reactor as a central process of direct air capture

A laboratory-scale, fluidized-bed pellet reactor (BPR) was used to investigate a CaCO 3 crystallization process for the recovery of CO 2 in a Direct Air Capture (DAC) process. The BPR performance was validated against data from a pilot-scale unit. Subsequently, the pellet growth under process-relevant conditions was studied over a period of 144 h. The experimental results with the BPR, containing a bed of pellets sized between 0.65 and 0.84 mm, have shown that a calcium retention of 80% can be achieved at a fluidization velocity of 60 m h -1 and a calcium loading rate of 3 mol h -1. This result is consistent with calcium retention observed at pilot scale operation and hence, results from the BPR are considered representative for the pilot scale unit. Starting with a bed of pellets sized between 0.15 and 0.5 mm, the average pellet growth rate, G, at the reactor bottom increased from 8.1E-10 to 11E–10 m s -1 at the onset and decreased to 4.9E–10 m s -1 over the course of a 144 h test. The calcium retention over the course the test showed the same trend (initial increase and final decrease) as the pellet growth rate. A theoretical bedmore » growth model was developed and validated against data from the pilot scale and benchtop pellet reactors. The model was used to calculate the bed porosity and total pellet surface area in each control volume. Lastly, the pellet surface area growth at the bottom of the reactor reproduced the pellet growth and retention data trends.« less
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  1. The Univ. of British Columbia, Vancouver, BC (Canada)
  2. Carbon Engineering Ltd., Squamish, BC (Canada)
Publication Date:
Grant/Contract Number:
Accepted Manuscript
Journal Name:
Journal of Environmental Chemical Engineering (Online)
Additional Journal Information:
Journal Name: Journal of Environmental Chemical Engineering (Online); Journal Volume: 5; Journal Issue: 6; Journal ID: ISSN 2213-3437
Research Org:
Carbon Engineering Ltd., Squamish, BC (Canada)
Sponsoring Org:
USDOE Office of Fossil Energy (FE)
Country of Publication:
United States
37 INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; 54 ENVIRONMENTAL SCIENCES; Direct air capture; Crystallization; CaCO3; Fluidized bed crystallization; Particle growth rate
OSTI Identifier: