raw · papers · ingested 2026-06-26
Effective thermal conductivity of packed-bed adsorbers (Rouhani & Bahrami)
Source: https://www.sciencedirect.com/science/article/abs/pii/S0017931017328867
Source: Int. J. Heat and Mass Transfer 2018 (Part 2, theoretical model, validated to 2-3%); Int. J. Refrigeration 105, 2019 (FAM-Z02 measurements). Full texts via SFU repository. Credibility: High (peer-reviewed, validated). Confidence: high.
Key findings
- Adsorbent material conductivity only 0.1-0.8 W/m·K; bed effective conductivity even lower — 0.047 W/m·K (closed) to 0.103 W/m·K (open) for 2 mm FAM-Z02 at 30 °C (low-pressure interstitial vapor conducts poorly — Knudsen effect).
- This low conductivity “suppresses overall performance through slow desorption and adsorption” — it throttles cycle speed → SCP, not equilibrium uptake.
- Raising uptake 0 → 0.3 kg/kg changes bed conductivity only ~17-18% — heat transport stays poor regardless of loading.
- Conductivity set by particle size, number of layers (bed thickness), porosity, contact pressure — geometric/structural variables. An optimum particle size maximizes bed conductivity per volume.
Relevance
Mechanistic core of fractal-hierarchical-bed-geometry: the dominant resistance is transport (conduction + contact), geometrically tunable, independent of capacity.