Rotating liquid sheet contactor: A new gas-liquid contactor system in CO2 absorption by nanofluids

In this work, the rotating liquid sheet (RLS) contactor was designed and introduced as a new gas-liquid contactor with many benefits compared to conventional technologies for CO2 absorption from CO2/N-2 gas mixtures using aqueous SiO2 and ZnO nano solutions as physical absorbents. To evaluate the performance of the RLS system, a helical slot in the wall of central tube was used to provide a high interfacial contact area between gas and liquid phases. The nanofluids were directly exposed to the gas stream to investigate the impact of different operational parameters including tube rotation rate, nanoparticles concentration, gas flow rate and CO2 concentration in the inlet stream. Obtained results clearly revealed that, tube rotation could enhance the characteristics of mass transfer from the gas stream to the liquid phase. Moreover, increasing the gas flow rate and CO2 inlet concentration resulted in the capture efficiency to decrease. Also, the absorption flux improves with increasing of the gas flow rate, while it first increases and then decreases with increment of CO2 inlet concentration. Ultimately, the CO2 absorption measurements confirmed that separation enhances significantly in presence of nanoparticles so that the ZnO nanofluids are more effective than SiO2 nanofluids at the all experimental conditions.

Automated summary

The research introduced a rotating liquid sheet (RLS) contactor for CO2 absorption, and found that tube rotation enhances gas-liquid mass transfer while increasing gas flow rate and CO2 concentration decrease capture efficiency. In all experimental conditions, ZnO nanofluids were more effective than SiO2 nanofluids.