Experimental study on comprehensive carbon capture performance of TETA-based nanofluids with surfactants

Abstract

Absorbents have become a vital factor in determining the performance of chemical absorption technique for CO2 capture. In recent years, amine-based nanofluids have shown a promising potential to develop high-performance absorbents. Thus, a bubbling reaction system was implemented to comprehensively study the CO2 capture properties of TETA-based nanofluids in this work. Three kinds of nanoparticles and surfactants were adopted to prepare nanofluids. The important parameters, such as ultrasonic vibration time, particle size and surfactants mass fraction, were considered to evaluate the comprehensive CO2 capture performance. It was found that nanofluids shows better CO2 capture performance than blank TETA solutions, which is mainly due to the enhancement of liquid-phase turbulence and the microscopic motion of nanoparticles. 1.0 h is considered as the most reasonable ultrasonic time for CO2 absorption in this experimentation. There is an optimal SiO2-nanoparticle mass fraction of 0.10 wt.%, the enhancement factors of ab/desorption (Eab and Ede) can respectively increase up to 1.29 and 1.23. The larger size can reduce the relative particle surface area and energy, 45 nm SiO2-nanofluids show lower energy consumption when the CO2-loading reaches αs. Enhancement factors of both ab/desorption for TiO2 and SiO2 are very close and evidently higher than Al2O3 due to the nanoparticles’ different CO2 adsorption performance. The addition of surfactant C-Na can effectively promote the mass transfer performance of nanofluids, but Triton X-100 and SDBS will cause inhibition effect when mass fraction exceeds 0.01 wt.%.