Systematic optimization and energy integration of a blended amine-based CO2 capture process: From solvent selection to process intensification

The escalating accumulation of atmospheric CO 2 underscores the urgent need for energy-efficient capture technologies to mitigate climate change. This study presents a systematic optimization of a 100000 t/y post-combustion CO 2 capture process using Aspen Plus V11, progressing from solvent selection to process intensification. A conventional 30 wt% monoethanolamine (MEA) process was first established as a benchmark, with a specific regeneration energy of 4.322 GJ/t CO 2 . Solvent optimization using a blended MEA/N-methyldiethanolamine (MDEA) solvent (30 wt%, 1:1 mass ratio) reduced the energy demand to 2.664 GJ/t CO 2 -a 38.36% reduction. Subsequent integration of inter-stage cooling and rich liquid-split configurations further lowered the energy consumption to 2.522 GJ/t CO 2 , representing an additional 5.33% saving and a total reduction of 41.65% from the MEA benchmark. Comparative analysis with literature data indicates that this value represents a competitive energy performance among non-ionic-liquid amine-based systems operated under industrially relevant conditions (flue gas CO 2 partial pressure 10-15 kPa, capture efficiency ≥90%), and is lower than those reported for most conventional and optimized single-amine configurations under comparable constraints. This work presents a validated, stage-wise framework for designing low-energy carbon capture processes, underpinned by the quantified energy contribution of each optimization stage.