Abstract View
Investigating Homogeneous Nucleation of Propane and n-Butane in Supersonic Nozzle Expansions
JIAQI LUO, Barbara Wyslouzil, The Ohio State University
Abstract Number: 243
Working Group: Aerosol Physics
Abstract
Supersonic separators have been proposed as a more environmentally friendly separation method than membrane, absorption, and adsorption in the separation processes of natural gas. From a technical perspective, understanding the non-equilibrium vapor-liquid phase transitions of n-alkanes is essential to the development of these devices. Homogeneous nucleation rates have been measured in supersonic nozzles for n-alkanes down to n-pentane. Thus, n-butane and propane are the next logical candidates to improve our understanding of vapor-liquid phase transitions of short-chain alkanes from both the experimental and theoretical points of view. Since a second goal of our research is to determine the critical cluster sizes from isothermal nucleation rate measurements, two supersonic nozzles with different cooling rates are used. All experiments use argon as the carrier gas. Pressure Trace Measurements (PTMs) are used to estimate the temperature, pressure, mass fraction of condensate, flow velocity, and area ratio of flow. The conditions corresponding to the onset of condensation and the characteristic times required by the phase transition are presented and discussed for n-butane and propane. Small Angle X-ray Scattering (SAXS) will be used to determine the nucleation rates by combining the measured number densities with the results of PTMs. SAXS experiments will be conducted once the Advanced Photon Source is again available for outside researchers.