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COOLING/HEATING METHOD AND DEVICE BASED ON METAL-ORGANIC FRAMEWORKS AND INDUCED BY PRESSURE MODIFICATIONS
WO23012393
The present invention relates to a cooling/heating method comprising the application and removal of a pressurising gas on a hybrid organic-inorganic porous material (MOF) whereby a breathing transition is produced. In this transition, a change in volume in the structure of the compound occurs when its pores open/close, together with adsorption/desorption of a gas after applying and removing a pressurising gas on the compound; and breathing which occurs at temperatures close to ambient temperature (from -20 degrees centigrade to 60 degrees C) and at low pressures (from 10-5 bar up to 50 bar) and with great isothermal entropy changes (> 100 J K-1 kg-1). The invention also relates to a cooling/heating device comprising the hybrid materials defined above.
Advantages / Differential Points Comparative advantages noted: Unlike adsorption MOF cooling, this approach does not require water (avoids evaporation/water footprint) and can operate at/under 0 °C. [wo23012393 | PDF] Compared to many barocaloric solids, the invention targets much lower operating pressures (≤ 50 bar for MOFs vs. hundreds–thousands of bar reported for some materials). Breathing‑MOF mechanism: Uses first‑order “breathing” transitions (pore opening/closing with gas adsorption/desorption) triggered by pressure cycling, distinct from conventional adsorption or prior barocaloric solids. Operation near ambient and at low pressure: Target ranges −20 °C to 60 °C and 10–50 bar with large isothermal entropy change (≥ 100 J K⁻¹ kg⁻¹); preferred embodiments report 250–400 J K⁻¹ kg⁻¹ in some cases. Benign working gases & vacuum options: Pressure applied/removed using N₂, CO₂, CH₄, or air, and vacuum can be used for depressurisation—enabling flexible, closed‑loop operation. Defined pressure–temperature cycling protocol: Four‑step cycle (pressurise/hold → desorb heat; depressurise/hold → absorb heat) with typical hold times ~1 s (generally 0.05–60 s). Device architecture: Claims a cooling/heating device comprising the breathing MOF plus means to apply/remove pressure, optionally a heat sink, heat‑transfer fluid, and a space/cavity to be cooled. Material forms & integration flexibility: MOFs used as powders in a reservoir, coatings on gas‑conduction pipes, thin films for electronics, or particles embedded in textiles (e.g., PPE/clothing/footwear). Extra Applications HVAC, air‑conditioning, heat pumps; domestic/commercial/industrial refrigeration; refrigerators and freezers. Electronics thermal management (e.g., smartphones, electronic apparatus using thin‑film MOFs) Automotive thermal management. Wearables & PPE: Particles embedded in fabrics for garments/footwear/personal protective equipment.