Adsorption-Driven Heat Pumps: The Potential of Metal–Organic Frameworks

Reticulated Replica Ceramic Foams: Processing, Functionalization, and Characterization

“…[56][57][58][59][60][61] MOFs are currently under comprehensive investigation, for example, in energy storage and heat pumping applications, catalysis as well as gas sensing or storage. [62,63] The crystallization coating of HF-etched, SiO 2 bonded 30 ppi alumina foams with the copper MOF Cu 3 [C 6 H 3 (COO) 3 ] 2 Á xH 2 O (synonym: HKUST-1) was first shown by Granato and co-workers. [64] The synthesis gel consisted of Cu(NO 3 ) 2 Á 3H 2 O and 1,3,5-benzenetricarboxylic acid in a mixture of ethanol and water.…”

Effect of pore size and shape on the thermal conductivity of metal-organic frameworks

“…This issue is an important consideration in applications such as natural gas storage in passenger vehicles, where tanks need to be refilled quickly to compete with traditional gasoline/diesel-based vehicles. Similarly, sharp drops in temperature during unloading can be a concern for sorption-based heat pumps, 5,6 where the working fluid needs to be both adsorbed and desorbed quickly. To dissipate/recover the generated/lost heat quickly and thereby mitigate sharp temperature rises/drops requires the adsorbent to have a high thermal conductivity.…”

Record Atmospheric Fresh Water Capture and Heat Transfer with a Material Operating at the Water Uptake Reversibility Limit

“…10 This temperature difference can be achieved with a cooling capacity per cycle of ∼400 kWh m –3 (Figure 4A), at least 50 kWh m –3 higher than that of any known adsorbent, regardless of regeneration temperature. 10 In a hypothetical AHP using low-grade heat sources, compound 2 can be regenerated using waste heat of only 55 °C (Figure S12). 8,10 Such a device would have a material-based coefficient of performance (COP), defined as the ratio of useful cold energy output divided by input heat energy, of 0.885 (Figure 4B).…”

“…The pore hydrophilicity must be sufficient to allow for water nucleation and pore filling below approximately 30% RH for most applications. 10,13 Finally, to avoid undesirable hysteresis upon water desorption, the pore size must be below the critical diameter ( D c ) of the working fluid, defined as the pore size at which the mechanism for adsorption changes from continuous pore filling to hysteretic capillary condensation. 20 For vapor phase liquids, D c is given by the equation D c = 4σ T C /( T C – T ), where σ and T C are the van der Waals diameter and critical temperature of the adsorbate, respectively, and T is the adsorption temperature.…”

“…In turn, the characteristic curve allows for the extrapolation of an isotherm at a given temperature to temperature and pressure values relevant for various devices. 10,27,28 The characteristic curve for 2 (Figure S8) was validated by measuring water vapor isotherms at 283, 293, and 298 K (Figure S9). We then used this characteristic curve to generate adsorption and desorption isotherms at temperatures relevant for AHP and AWG applications (Figures S10 and S11).…”