Optimisation of vortex tubes and the potential for use in atmospheric separation

Abstract

Climate change requires us to extract hundreds of gigatonnes of CO2 from the atmosphere over the next few decades. This requires we develop and scale up viable technologies to sequester CO2 from the highly dilute atmospheric concentrations. CO2 gas freezes at -78.5 °C and thus, in principle, can be separated from air, the nitrogen in which begins to freeze at -210 °C. Vortex tubes were investigated as a potential method of carbon capture through a series of geometrical and procedural optimisations. Ambient air is compressed and then separated by temperature due to the action of the Vortex Tube. These optimisations determined an increase in system pressure and length at cold mass fraction of 40% led to increased cooling. The heat profile of pipes suggested radiative cooling as the vortex propagated. An optimised single tube reached a maximum cooling of 39.9±2 °C. Vortex tubes thus present a method of separating and capturing components of the atmosphere. With further work, such as the successful combination of tubes in series, it is hoped that vortex tubes may prove to be a scalable solution capable of contributing to the reduction in atmospheric CO2 using the solar cyclone tower to provide the energy and air flows required for this task.