Multi-Objective Optimization of TETA Blended Amines for Microwave-Regenerated CO2 Capture via RSM and Entropy-Weighted TOPSIS

To improve regeneration performance and shorten desorption time in amine-based CO2 capture, this study proposes an integrated “blended-amine solvent and microwave regeneration” process. Triethylenetetramine (TETA) was used as the primary absorbent and blended with diethanolamine (DEA) and 2-amino-2-methyl-1-propanol (AMP). Response Surface Methodology (RSM, Box–Behnken design) was employed to establish formulation–performance relationships, and an entropy-weighted TOPSIS method was further applied for multi-objective evaluation and optimization. The optimal formulation consisted of TETA, DEA, and AMP at a mass ratio of 6:1:2. Under the optimized conditions (20 wt% aqueous solvent, 30 °C absorption, 95 °C microwave regeneration), the solvent achieved an absorption capacity of 1.0 mol CO2·mol−1 amine with a CO2 recovery of 93.56%. Compared with conventional heating, microwave regeneration markedly accelerated CO2 desorption, reducing regeneration time from 30 min to 4 min. The estimated total regeneration energy was approximately 2.4 GJ·t−1 CO2 under microwave heating for the optimized blend. In addition, among the water/n-butanol formulations tested, the fully aqueous system showed the best overall absorption–regeneration performance. Overall, the data-driven solvent design coupled with microwave regeneration offers a practical route toward more efficient CO2 capture processes.