Transient Mass and Heat Transfer During Gas Adsorption into MOFs

Using molecular dynamics simulations, we have investigated transient mass and heat transfer phenomena during gas adsorption into a metal-organic frameworks (MOFs). This study was motivated by the challenge of quickly dissipating heat generated in metal-organic frameworks (MOFs) during gas adsorption.
Our transient simulations capture the full adsorption process, including gas adsorption, heat generation during gas adsorption, and subsequent heat transfer. From the spatial distribution, time evolution, and equilibrium condition of gas density, gas (here methane) temperature, and MOF (here HKUST-1) temperature, in our transient simulations, we found that thermal transport in HKUST-1 occurs two orders of magnitude faster than methane diffusion. However, a large thermal resistance at the HKUST-1/methane interface and within the pure gas region, prevents fast release of heat generated during adsorption. The mass transport resistance of the HKUST-1/methane interface is equivalent to 1 nm of bulk HKUST-1 and does not introduce a bottleneck in the adsorption process.