M.Sc Thesis

M.Sc StudentElkayam Nimrod
SubjectAdsorption-Mediated Mixture Separation by an Acoustic Field
DepartmentDepartment of Energy
Supervisor ASSOCIATE PROF. Guy Ramon


In adsorption-mediated acoustic separation, a time-averaged mass flux is created due to interaction between the oscillating velocity field and pressure-induced mass exchange with a sorbing boundary. The generated flux is preferential such that in a binary-mixture, in which one species reacts with the boundary and one is inert, the fluxes of the two species are of opposite directions. In a closed system those fluxes accumulate on the sides of the system such that a difference in the concentrations between them is achieved. The phase between velocity and pressure, termed here as the acoustic phase, affects this separation process together with the properties of the mixture and the geometry of the system. These effects are studied here in-depth while verifying theory with experimental measurements. It is then concluded that in order to achieve the highest rate of separation, a traveling acoustic wave with a high pressure amplitude and a small velocity amplitude sustained in a tight geometry is preferable. The underlying physical phenomenon is then explained qualitatively, in a way that agrees with achieved conclusions.

For an acoustic separation system to be applicable, the separated mass is expected to be continuously replaced with raw mixture. For this, the second part of this work is dedicated to the investigation of an open system configuration. Performance indicators of energetic efficiency and separation ratio are drawn for two typical separation applications, one of water separation from air and one of carbon-dioxide removal from natural gas. These results enable comparison between acoustic separation and established technologies. In addition, the effects several design parameters have on efficiency and separation are investigated. To conclude, suggestions are made for ways in which higher separation and recovery rates can be achieved and what is the predicted cost for these enhancements in terms of efficiency.