Two-dimensional gas chromatography : a novel technique for iron low temperature Fischer-Tropsch selectivity studies

Fischer-Tropsch synthesis is a process that catalytically converts hydrogen and carbon monoxide into a large variety of hydrocarbons and oxygenated products. Over the years many researchers have attempted to describe the full product spectrum (ranging from C1 to C100+) but due to the complexity of the product and shortcomings of certain analytical techniques (or equipment) most researchers were only able to construct product distributions from extrapolations of data recorded from analysis of the C1 to C5 fraction of the Fischer-Tropsch product. With recent advances in analytical technology and the development of comprehensive two-dimensional gas chromatography (GCxGC) it may now be possible to analyze the complex Fischer-Tropsch products in a relatively short time while delivering good separation of even minor compounds such as oxygenates and branched compounds. The aim of this study was to investigate if two-dimensional gas chromatography (GCxGC) really results in improved separation and identification of compounds in the complex Fischer-Tropsch product spectrum and will lead to a more complete product distribution especially of the minor compounds such as branched hydrocarbons, ketones, aldehydes and acids. For this study GCxGC equipment, supplied by Zoex Corporation, was connected to a micro slurry phase reactor system to provide for both on-line gas analysis as well as off-line product analysis. GCxGC methods were developed to analyze the hot tail gas and oil products from Fischer-Tropsch synthesis. Thereafter a test sample (C6 to C30 oil product from Fischer- Tropsch synthesis process) was injected several times into both the GCxGC and 1D GC systems. The purpose of this was to compare the detection ability and accuracy of the two instruments.

Grantor dc:publisher.institution

Department of Chemical Engineering

Year dc:date.issued

2008

Author dc:creator

• Grobler, Thelma

Advisors dc:contributor.advisor

• Van Steen, Eric
• Janse van Vuuren, Matthys

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/11427/5327

OAI identifier oai:identifier

oai:open.uct.ac.za:11427/5327