Presentation Profile
Oxygenates in Hydrocarbon Cargoes by Multidimensional GC 28 Years Later and This Time it's Lowox in Pygas
Currently Scheduled: 10/12/2021 - 1:10 PM - 1:50 PM
Room: Daffodil Room
Main Author
Mike Setzer - Coastal Gulf & International, Inc.
Abstract:
Decades ago Mike became the independent analytical standard for cargoes of the oxygenated fuel additives MTBE & ETBE.
Then for cargoes of motor gasoline & blendstocks to more reliably determine the oxygenate content at percent levels, ASTM D4815 was advanced well beyond what was otherwise available.
Today further techniques are employed in order to determine trace oxygenates which are usually present in pyrolysis gasolines, but which are considered undesirable components.
Relying on the specialized PLOT GC columns, such as the original Lowox column introduced in the 1990's by Jaap de Zeeuw, oxygenated and highly polar compounds in the lighter portion of the sample are "trapped" by this secondary Gas-Solid Chromatography column, and eluted subsequent to the accompanying hydrocarbons which pass through nearly unretained, after both groups exit the ordinary GLC precolumn together in the multidimensional arrangement.
Since 2009 method ASTM D7423 has employed this type apparatus to determine trace oxygenates in light hydrocarbon cargoes but the method scope is limited to primarily LPG cargoes or those containing not much heavier than C5 hydrocarbons. Regardless of how often it is requested for Pygas, D7423 has been found to be unsuitable for most Pygas which is not usually very well within the scope at all.
Pygas is its own animal.
Unsuitable for most laboratories, most laboratories unsuitable for it.
Adjustments have been made to tame the beast.
