Modeling CO <sub>2</sub> and H <sub>2</sub> O Co-desorption in an Internal Joule Heating-Assisted Vacuum-Structured Packed Bed DAC Contactor
Bibliographic record
Abstract
Direct air capture (DAC) technologies offer a promising avenue for mitigating climate change by removing CO 2 from the atmosphere. Innovations in energy-efficient DAC technologies are essential to increase their deployment and reduce costs, making them a more viable and accessible solution for carbon removal. Currently, DAC is an energy-intensive process, and reducing its energy consumption is vital for cost-effectiveness. This research focuses on enhancing the DAC process, specifically the regeneration phase, by utilizing structured packed beds coated with zeolite 13X. The goal is to achieve faster and more energy-efficient desorption of CO 2 and H 2 O. We investigated the dynamic behavior of the co-desorption of CO 2 and H 2 O during the solid-based DAC process that uses structured packed beds coated with zeolite 13X and heated by internal Joule heating via a two-dimensional unsteady-state, nonisothermal, two-scale heterogeneous model. The study examines how the magnitude and time evolution of the volumetric energy source heating the packed bed, along with CO 2 and H 2 O uptake, coated zeolite layer thickness, and packed bed height affect the desorption process and energy consumption in DAC units, specifically comparing structured and random packing configurations. The results indicate that under similar starting regeneration conditions (same total mass of CO 2 and H 2 O adsorbed in the unit, quantified in kilograms), the specific energy requirements associated with the CO 2 desorption process are lower in a DAC unit with structured packing than in a unit with random-packing spherical zeolite particles. On the other side, at the same starting CO 2 and H 2 O uptakes (quantified in mol/kg) and high CO 2 uptake levels (>2.0 mol/kg), structured packing and packed beds with spherical particles exhibit similar specific energy requirements for CO 2 and combined CO 2 and H 2 O desorption processes. In DAC systems, using structured packing instead of randomly packed units for CO 2 and H 2 O desorption can significantly reduce the duration of the desorption process and improve the H 2 O desorption efficiency.
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How this classification was reachedexpand
Full frame machine prediction
Teacher imitationNot calibrated prevalence, not ground truth. Human validation pending. The Gemma side is a direct model label for every work in the frame, read from the title-only record. The Codex side is a classifier learned from the 10,348 direct Codex labels and calibrated to design-weighted sample rates; fields without enough sample support carry no Codex call. Candidate is the union of the two sides; consensus is their intersection. These outputs are machine_predicted_unvalidated and are not human labels.
Distilled classifier scores by category (both heads)
| Category | Codex | Gemma |
|---|---|---|
| Metaresearch | 0.000 | 0.000 |
| Meta-epidemiology (narrow) | 0.000 | 0.000 |
| Meta-epidemiology (broad) | 0.000 | 0.000 |
| Bibliometrics | 0.000 | 0.000 |
| Science and technology studies | 0.000 | 0.000 |
| Scholarly communication | 0.000 | 0.000 |
| Open science | 0.000 | 0.000 |
| Research integrity | 0.001 | 0.000 |
| Insufficient payload (model declined to judge) | 0.001 | 0.000 |
Machine scores (provisional)
The two teacher heads of the student model, read on this work. A score orders the frame for review; it never asserts a category, and the validation status ships verbatim with every row.
Baseline scores from an immature model (maturity gate not passed, 7 training rounds). Scores rank; they never assert a category.
score_only:v0-immature-baseline · verbatim from the scoring run: score_only means the number may rank works, and no category label ships from itClassification
machine, unvalidatedMachine predicted; a candidate call from one source (direct Gemma or distilled Codex), not a consensus.
How this classification was reached, model by model and score by score, is at the end of the page under "How this classification was reached".