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.