Molecular Simulations of Adsorption and Energy Storage of R1234yf, R1234ze(z), R134a, R32, and their Mixtures in M-MOF-74 (M = Mg, Ni) Nanoparticles

Abstract

The refrigerant circulation heat can be enhanced through the mutual transformation between thermal energy and surface energy during the adsorption and separation process of fluid molecules in porous materials. In this paper, the adsorption and energy storage of R1234ze(z), R1234yf, R32 and R134a, as well as their mixed refrigerants in Mg-MOF-74 and Ni-MOF-74 nanoparticles were investigated by means of molecular dynamics simulations and grand canonical Monte Carlo simulations. The results suggested that, in the case of pure refrigerant adsorption, the adsorption quantities of R32 and R134a in MOFs were higher than those of R1234yf and R1234ze(z). However, in the case of saturation adsorption, the desorption heat of R32 was lower than that of R1234yf and R1234ze(z). The addition of MOF-74 nanoparticles (NPs) could enhance the energy storage capacity of the pure refrigerant; besides, R1234yf and R1234ze(z) nanofluids had superior enhancement effect to that of R32 nanofluid. In mixed refrigerant adsorption, the adsorption quantities of R1234ze(z) and R1234yf were lower than those of R32 and R134a; with the increase in temperature, the adsorption of R1234ze(z) and R1234yf showed a gradually increasing trend, while that of R32 was gradually decreased.

Non-CO2 greenhouse gas separation using advanced porous materials

“…The adsorption capacity of other refrigerants (R1234yf (CH 2 CFCF 3 ), R1234ze(z) (CHFCHCF 3 ), R32 and their mixtures) in MOF-74 was also studied with molecular simulations. 278 The cooperative binding through a functionalized ligand and OMS is another approach. For instance, a Fe-based MOF (LIFM-26 (Fe)) constructed by perchlorinated linear dicarboxylate showed a high adsorption capacity of R22 (6.5 mmol g À1 ) and R22/N 2 (10 : 90) selectivity of 202 at 298 K, 1 bar.…”

“…The adsorption capacity of other refrigerants (R1234yf (CH 2 CFCF 3 ), R1234ze(z) (CHFCHCF 3 ), R32 and their mixtures) in MOF-74 was also studied with molecular simulations. 278…”

Engineered Nanoporous Frameworks for Adsorption Cooling Applications

“…Furthermore, both radial distribution function (RDF) data computed from force field-based molecular dynamics simulations and 19 F NMR data suggest that F R12 prefers to interact with metal nodes via a C–F R12 ···metal ion adsorption orientation (Figure b–d). Cai et al confirmed the impact of OMSs on the adsorption capacity and energy storage by investigating the adsorption of HFCs (R32 and R134a) and HFOs (R1234yf and R1234ze(z)) in M-MOF-74 (M = Mg, Ni). These authors suggest that the adsorption capacity of all pure fluorocarbons over Mg-MOF-74 is superior to that over Ni-MOF-74 due to the higher concentration of available Mg 2+ OMS.…”

Adsorption Characteristics of Refrigerants for Thermochemical Energy Storage in Metal–Organic Frameworks

“…The capture of refrigerants using porous materials, and in particular HFC, has been extensively investigated in the literature. Recently, Yancey et al, and Wanigarathna et al, reviewed the capture of HFC in porous materials, such as zeolites, − silica gel, , activated carbons, − and metal–organic frameworks (MOFs), − discussing their practical applications. Among the rest of the porous materials, MOFs are emerging as promising adsorbents for capturing and separating fluorocompounds.…”