The role of static diffusion during storage in the immediate breakthrough of activated carbon bed cyclically exposed to vapour

Simulative Investigation of the Application of Nonimpregnated Activated Carbon in a Multilayer Adsorber for the Separation of Hg0 from Discontinuous Waste Gas Streams

“…Physisorptive interactions dominate in the simulated system and are very fast compared to the diffusive transport through the boundary layer around the adsorbent grain and in the pore system. So, for the simulation with the LDF model, the diffusive mass transport is assumed to be the rate-determining step. ,,− The homogeneous diffusion model ,, with an effective diffusion coefficient (Table ) is used to describe the mass transfer in adsorption.…”

“…The concentration profile in the gas phase of the adsorber is smoothed out during the night shift, and the concentration decreases, which is due to two overlapping effects: When switching to the bypass pipe, there is no more heat input, and the adsorber cools down to ambient temperature. As the temperature decreases, the capacity of the adsorber increases, so that more Hg 0 is adsorbed and the concentration of Hg 0 in the gas phase (displayed in Figure ) declines. The gradient in the concentration profile is reduced during the night shift by molecular diffusion from the highly loaded zones to the lower loaded areas so that the curve is flatter and broader. …”

“…The gradient in the concentration profile is reduced during the night shift by molecular diffusion from the highly loaded zones to the lower loaded areas so that the curve is flatter and broader.…”