A venturi reactor with an excellent mass transfer performance for carbon dioxide capture.

Mass transfer in liquid phase is the rate-limiting step for carbon dioxide capture by ammonia water, which results in a low total mass transfer coefficient and thus a poor carbon dioxide removal efficiency. For this issue, this study established a venturi reactor with an excellent mass transfer performance to promote mass transfer rate during carbon dioxide capture, and investigated the effect of operating parameters of the venturi reactor on carbon dioxide removal efficiency and overall mass transfer coefficient. The results showed that with an increasing flow rate of the jet from 8.31 to 12.73 L/min, the carbon dioxide removal efficiency decreased due to the increase of flow rate of flue gas, and the changing trend of overall mass transfer coefficient gradually transited from increasing to decreasing with the extension of reaction time. The carbon dioxide removal efficiency and the overall mass fraction coefficient increased upon the increase of ammonia concentration from 0.1 wt% to 0.75 wt%. With the increase of inlet carbon dioxide concentration from 7% to 19%, the carbon dioxide removal efficiency and the overall mass transfer coefficient decreased. Venturi reactor was of a fast mass transfer rate during carbon dioxide capture, and the maximum CO2 removal efficiency was 96.4% at ammonia concentration of 0.75 wt%, CO2 volume concentration of 15%, flow rate of jet of 8.36 L/min. This study provided a theoretical value for the development of venturi reactor for carbon dioxide capture.

Study on the Transport Properties of SO2 and NO at the Interface of H2O2 Solutions Using Molecular Dynamics.

Gas-liquid interfaces have a unique structure different from the bulk phase due to the complex intermolecular interactions within them and are regarded as barriers that prevent gases from entering solution or as channels that affect gas reactions. In this study, the adsorption and mass-transfer mechanisms of sulfur dioxide and nitric oxide at the gas-liquid interface of a H2O2 solution were comprehensively analyzed using molecular dynamics (MD) simulations. The analysis on molecule angle showed that H2O molecules tended to align parallel to the solution surface on the surface of the H2O2 solution. Regardless of whether the gas was adsorbed on the surface of the solution or not, H2O2 molecules were always perpendicular to the interface of the solution. The analysis on molecule angle and radial distribution function revealed that the H atoms of H2O molecules had a corresponding turn, and SO2 molecules were greatly affected by the attraction of H2O2 molecules during the adsorption of gas molecules on the interface. Steered MD was utilized to investigate the mass-transfer process of SO2 and NO molecules across the gas-liquid interface. The S atoms of SO2 molecules were significantly influenced by H2O2 molecules, while the O atoms of NO molecules gradually transitioned from the gas phase to the liquid phase. The results provided information on how gas molecules interacted with the surface of the solution and the specific details of the molecular orientation at the solution surface.