A new methodology to estimate the steady-state permeability of roast and ground coffee in packed beds

In this work a methodology that will allow estimation of the permeability of coffee packed beds in steady-state was developed. Fitting measured flow rate - pressure drop data to Darcy's law resulted in permeability values in the range of 10−13-10−14 m2. Disagreement between the experimental and theoretical permeability, as estimated from dry measurements of particle size distribution and Kozeny-Carman equation, was found. Bed consolidation may have a larger effect on the packing structure than the mere decrease in bed bulk porosity. The Kozeny-Carman equation, corrected with a porosity-dependent tortuosity according to a power law, gave a good fit of the data.