Industrial & Engineering Chemistry Research, Vol.57, No.31, 10303-10314, 2018
Investigation of CO2 Sorption Mechanisms in Isothermal Columns via Transient Material and Energy Balance PDE Models
The behavior of an isothermal packed bed sorption column for CO2 is investigated based on combined mass spectrometry and calorimetry temporal measurements at different temperatures. The inclusion of the calorimetry data stream at multiple temperatures accentuates the limitations of our previous spatiotemporal model with a simple sorption mechanism to describe the experimental observations. We propose four models, which consider dispersion and convection with different descriptions of the sorption mechanism. The unknown parameters in the models are determined by minimizing the integral in time of the squared difference between model prediction and the experimental measurements. Analyzing the simulation results for thermodynamic consistency and site density, we conclude physical sorption followed by chemical sorption is a probable mechanism to describe the specific experiment data. We also conclude a combination of multiple measurement streams is required to verify the consistency of proposed mechanisms and establish a clear(er) macroscopic description of the underlying physicochemical phenomena.