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Title: The separation and characterization of aromatic nitrogen-containing compounds in coal liquids by liquid chromatography and spectral techniques

Thesis/Dissertation ·
OSTI ID:5002770

The retention characteristics of 38 aromatic nitrogen containing model compounds were studied with a variety of high-performance liquid chromatographic (HPLC) systems to develop separation methods for aromatic nitrogen compounds. With a normal-phase HPLC system, the nitrogen model compounds were separated into three main compound classes: basic, nonbasic and amino-type. Further investigation of the nitrogen model compounds and six polycyclic aromatic hydrocarbon model compounds showed that the simple Snyder chromatographic adsorption model approximated the retention of the model compounds. Reversed-phase HPLC data demonstrated that the nitrogen model compounds, generally, could be separated on the basis of molecular weight. A detailed investigation was undertaken to isolate and characterize the nitrogen compounds in coal liquids. Initially, the nitrogen-rich oils and asphaltenes fractions were isolated from a nondistillable Wyodak solvent refined coal sample. Then overlapping large-ring PAH material was removed from these fractions with a normal-phase silica HPLC system, and the nitrogen compounds were then recovered by a backflushing step. The nitrogen fractions were further separated into basic-type and non-basic type compound fractions with a normal-phase HPLC system developed in this work. Also a reversed-phase HPLC system was used to separate basic and non-basic nitrogen compound fractions from oils into low and high molecular weight subfractions. All of the HPLC derived fractions were characterized with IR and NMR spectrometry. Elemental analysis was obtained on selected fractions, and these fractions were also characterized, in detail, by FIMS.

Research Organization:
Wyoming Univ., Laramie, WY (USA)
OSTI ID:
5002770
Resource Relation:
Other Information: Thesis (Ph. D.)
Country of Publication:
United States
Language:
English