AAAR 35th Annual Conference October 17 - October 21, 2016 Oregon Convention Center Portland, Oregon, USA
Abstract View
Investigating the Phase Transitions of Lower Alkanes - Pentane, Hexane, and Heptane - in a Supersonic Laval Nozzle
KEHINDE OGUNRONBI, Barbara Wyslouzil, The Ohio State University
Abstract Number: 178 Working Group: Aerosol Physics
Abstract Probing the vapor-liquid phase transitions of hydrocarbons is important to improving their separation from raw natural gas before transportation in a pipeline. If they are not removed these materials can condense creating a two-phase flow, and thereby greatly increasing the pressure drop in the pipe. We have investigated the phase transitions that lead to the formation of pentane, hexane, and heptane nanodroplets, on the microsecond timescale in a supersonic Laval nozzle. We conducted position-resolved pressure trace measurements (PTM) for the three n-alkanes at stagnation pressure of 30.1kPa and stagnation temperatures of 293 K and 303 K. We evaluated the temperature, pressure, mass fraction of condensate, flow velocity, and area ratio of flow by PTM. For these relatively short alkanes, we observe condensation at temperatures below 180 K. To reach these conditions, the experiments use argon, rather than nitrogen as the carrier gas and a more rapidly expanding nozzle than our earlier work. In addition we have made FTIR measurements to follow the vapor-liquid-(solid) transitions of pentane, hexane and heptane, and found evidence for freezing in the latter two compounds.