CuO nanofluid system with phase transfer characteristics for enhancing CO2 gas–liquid absorption/regeneration process

Different nanoparticles were introduced into the N-ethylethanolamine/diethylaminoethanol/p-Xylene biphasic absorbent to form nanofluid systems, and the CO 2 capture performance was investigated. The CO 2 capture performance of the absorbent was significantly enhanced by introducing 0.1 wt% CuO nanoparticles, with a first absorption carbon capacity of 0.09952 g CO 2 ·g −1 absorbent. In the first cycle of regeneration, [email protected]  % CuO nanofluid had a carbon capacity of 0.07654 g CO 2 ·g −1 absorbent, achieving an efficiency improvement of 35.73 %. Its regeneration energy consumption was reduced by 0.3256 GJ·t -1 CO 2 , representing a 15 % decrease compared with the base liquid. The cyclic absorption capacity was enhanced significantly after the addition of CuO, with a CO 2 capacity at 0.0690 g CO 2 ·g -1 absorbent after four cycles. The characterization of CuO revealed the stability of nanoparticles in nanofluids. In addition, it was found that the nanoparticles exhibited phase-transfer characteristics. After absorption, they accumulated in the rich phase and then became uniformly distributed throughout the entire liquid phase following regeneration. This behaviour could promote a more efficient desorption process. This study provides a new approach for green chemistry and carbon capture applications.