Modeling and Simulation of Potential Adsorbents for CO2 Capture in Fixed-Bed Systems Using Aspen Adsorption

Abstract

Ongoing carbon dioxide (CO₂) buildup in the environment aggravates the Earth's planet, leading to climate change and environmental issues. The post-combustion carbon capture via physical adsorption using an adsorbent is an effective treatment for capturing CO₂. Aspen Adsorption is an optimistic design tool for gas adsorption in a fixed-bed capture unit. Aspen Adsorption is widely applied for simulating and optimizing fixed-bed adsorption processes, providing an effective platform for designing and evaluating CO₂ capture systems. In this study, the adsorption-based fixed-bed capture unit is developed for CO₂ capture using Aspen Adsorption. Three different adsorbents are derived from three classes of biomass materials: (i) coconut shell, (ii) rice husk, and (iii) eucalyptus wood. The characteristics of the developed adsorbents are analyzed and studied. The adsorbents’ performance is evaluated in the fixed-bed adsorption system to examine CO₂ and N₂ adsorption efficiencies. A critical parameter on the main operating conditions, surface textural features, and dimensions of the capture unit, namely, (i) adsorption and desorption temperature and pressure, (ii) adsorbent materials’ surface textural characteristics and physicochemical properties, and (iii) adsorption column dimensions, is considered for the adsorption study. Overall, 60% CO₂ and 40% N₂ gas compositions are employed as the inlet gas stream. The adsorbents’ adsorption efficiency and parameters are evaluated and discussed. The simulation results indicate a maximum CO₂ recovery rate of 68% and a CO₂ purity of 97%. Approximately 5.0 GJ/t of CO₂ is the energy consumption required for regeneration.