CO₂ Capture by Temperature Swing Adsorption: Working Capacity As Affected by Temperature and CO₂ Partial Pressure

Abstract

Even though the performances of CO2 adsorbent materials for temperature swing adsorption (TSA) are typically assessed based on the equilibrium adsorption capacity, the actual feasibility of a sorbent in real applications cannot be reliably inferred from only this parameter. Indeed, more than the maximum CO2 uptake achievable at equilibrium, it is necessary to know the real quantity of CO2 that can be captured in a complete adsorption/desorption cycle, namely, the difference between the quantity of CO2 adsorbed under adsorption and desorption conditions, which is defined as the CO2 working capacity. In this work, dynamic breakthrough and regeneration tests have been performed using a fine porous activated carbon in a lab-scale TSA sound-assisted fluidized-bed rig to experimentally evaluate the CO2 working capacity. In particular, the standard sound-assisted fluidized-bed TSA cycle has been modified by applying the heating and purging (H&P) strategy to increase the cycle performances with regard to the CO2 purity and recovery. Then, the effect of adsorption/desorption temperatures (25–150 °C) and CO2 partial pressure (0.05–0.20 atm) has been evaluated.