Simulated moving bed adsorption process based on a polyethylenimine-silica sorbent for CO2 capture with sensible heat recovery

Highlights: • A heat-integrated simulated moving bed adsorption process with a PEI-silica sorbent was proposed. • Rigorous mass/heat balance and energy demand models were used to analyze the process. • The process as proposed requires 255 kWh/tCO₂, far below that of the MEA-based process. • Sensible heat is the most important target to challenge for further energy demand reduction. A simulated moving bed (SMB) adsorption process with heat integration was numerically investigated and is proposed as a viable option for CO₂ capture. An amine-functionalized silica sorbent, 0.37 EB-PEI, was used for the SMB process. The process was configured by directly converting a moving bed process; it consists of four separate stages with internal plate heat exchangers for adsorption, cooling, heating, and desorption. The proposed process was extended to the multi-bed scale for continuous capture of CO₂ and full integration of the heat produced during the process. A dynamic simulator was constructed to analyze the process behavior, focusing on the energy demand under various operating conditions. As a result, the proposed SMB process was estimated to require 255 kWh/t-CO₂ of energy up to CO₂ liquefaction; this work reveals the potential of the SMB process for commercial carbon capture through further improvement of the sorbent material.