An experimental based optimization of a novel water lean amine solvent for post combustion CO₂ capture process

The development of new amine solvents without the major drawbacks of conventional amines is crucial to industrial applications of CO₂ capture. This paper presents a water-lean CO₂ capture solvent having a low regeneration energy and low degradation. The water-lean solvent, K₂Sol, is a sterically hindered diamine; because of the hindered amine site, K₂Sol easily forms bicarbonate, resulting in a high absorption capacity. The minimum solvent regeneration energy is obtained using Gaussian process Bayesian optimization (GPBO) and bench-scale pilot plant experiments. GPBO finds the optimal solution using the input and output relationship of experiments; thus, expensive first-principle model construction can be avoided. According to the pilot plant experiment, the optimal regeneration energies of monoethanolamine (MEA) and K₂Sol are 4.3 and 2.8 GJ/t CO₂, respectively, indicating that K₂Sol requires only 65% of the regeneration energy of MEA. Fewer than 30 experiments are required to find the optimal pilot plant operation for both the MEA and K₂Sol experiments. We also describe the superior properties of K₂Sol in terms of the CO₂ loading, cyclic capacity, regeneration temperature, and degradation.