Volume 8: Advances in Energy Innovation and Development

Treatment of natural gas with varying CO2 concentration using supersonic flows Jiang Bian, Xuewen Cao, Dan Guo, Wenjuan Sun, Xiaodan Song, Wenming Jiang

Abstract

In order to reveal the supersonic condensation characteristics of carbon dioxide (CO2) in natural gas under low temperature condition, the mathematical models and numerical schemes for the CH4-CO2 mixture gas under supersonic flow condition were established, and the influence of inlet CO2 concentration on the CO2 removal efficiency of Laval nozzle was investigated. The results show that with the increase of CO2 concentration at nozzle inlet, the initial nucleation position is closer to nozzle throat, the maximum nucleation rate and the droplet number decrease but the droplet radius increases significantly, which eventually leads to an increase in liquefaction rate. When the inlet CO2 mole fraction is lower (less than 10%), the CO2 fraction in gas phase is almost 0, which indicates that low-temperature separation technology is practicable for the removal of CO2 from natural gas.

Keywords CO2, natural gas, supersonic, condensation