Benzylamine (BZA), biodegradable with bacteria, has advantages over monoethanolamine (MEA) in terms of corrosiveness, resistance to oxidative degradation, viscosity, mass transfer, and energy consumption for CO2 capture. The current work examined the CO2 absorption-desorption performances of three BZA-based solvents to improve the amine scrubbing process with significant reduction of the energy consumption especially during the solvent regeneration. The experimental results approved that BZA-1DMA2P reduces the energy cost, increases the cyclic capacity, and increases the CO2 desorption rate by 55.3, 478.8, and 189.2% compared to MEA, respectively. Based on the discoveries from the designed experiments, an evaluation parameter of energy-operation-window was proposed to quantitatively describe the flexibility and capability of CO2 extraction from a CO2-rich solution with a certain amount of energy. A combined desorption parameter (DP) was also developed to evaluate the energy performance of an amine solvent. The universal applicability of DP was validated with a series of data extracted from literature studies with different amine systems with and without catalysts. All these results confirmed that DP could be an efficient parameter to predict the energy efficiency of a solvent for a fast screening process without directly measuring the heat cost.