Integrated screening and intensified process evaluation of DETA/AMP/PZ blended solvents for energy-efficient CO2 capture in a rotating packed bed

Abstract

The development of energy-efficient CO2 absorbents suitable for intensified operation remains a critical challenge in advancing post-combustion carbon capture technologies. In this study, nine ternary amine blends (DAP-1 to DAP-9) composed of diethylenetriamine (DETA), 2-amino-2-methyl-1-propanol (AMP), and piperazine (PZ) were systematically screened to identify a high-performance solvent for rotating packed bed (RPB) operation. Vapor–liquid equilibrium (VLE), wetted-wall column (WWC), and differential reaction calorimeter (DRC) experiments were conducted, and regeneration energies were estimated using a thermodynamic model. All blends exhibited higher CO2 solubility and mass-transfer performance than 30 wt% MEA, with CO2 loading mainly governed by DETA content and absorption kinetics promoted by PZ. Among the screened formulations, DAP-3 provided the most favorable balance of cyclic capacity, reaction heat, and regeneration demand, achieving the highest cyclic capacity (0.24 mol-CO2/mol-amine) and the lowest theoretical energy requirement, primarily due to its significantly reduced sensible-heat contribution. DAP-3 was subsequently evaluated in an RPB-based CO2 capture process and consistently required less regeneration energy than MEA across variations in reboiler temperature, gas and liquid flow rates, and rotational speed, exhibiting 13–20% reductions at optimal conditions. Regeneration energy decreased under lower reboiler temperatures, intensified gas throughput, and higher rotational speeds, while a characteristic V-shaped dependence on liquid flow rate revealed an optimal circulation level that minimized heat duty. These findings demonstrate that DAP-3 effectively balances absorption kinetics and energy consumption, establishing it as a promising solvent for intensified CO2 capture in RPB-based post-combustion applications.