Enhanced CO₂ separation using aqueous amine blends and nanofluids in PVDF hollow fiber membrane contactor

This study aimed to assess the effectiveness of various aqueous amine solutions in post-combustion CO₂ capture using polyvinylidene fluoride (PVDF) hollow fiber membrane contactor (HFMC). The aqueous amine mixtures included several types of amines such as monoethanolamine (MEA), diethylenetriamine (DETA), diethanolamine (DEA), aminomethyl propanol (AMP), methyldiethanolamine (MDEA), ethylenediamine (EDA), activator amines, and different nanofluids. We have examined the impact of several blends of amines and nanoparticles, as well as their concentrations, gas and solvent flowrates, on the efficiency of CO₂ removal. The results indicated that the effectiveness of CO₂ removal improved as the flow rate of the solvent increased, whereas the flow rate of the gas stream had a contrary impact. Among the six studied amines solutions, the DETA +piperazine (PZ) achieved the highest CO₂ removal percentage of 78 % followed by MEA + PZ (69 %), EDA + PZ (67 %), DETA + piperazinyl-1, 2-ethylamine (PZEA) (66.5 %) and EDA + PZ (66.5 %) with all constituents in 5 wt% concentration. The addition of 5 wt% of activator amines, PZ and PZEA, alongside the amine solutions resulted in a marginal improvement in the removal efficiency of CO₂. Additionally, the dispersion of carbon nanotubes (CNTs) in an aqueous solution of MDEA resulted in enhanced efficacy in the elimination of CO₂. The impact of SiO₂ nanoparticles seemed insignificant when compared to CNTs.