Chemical class separation and characterization of organic compounds in synthetic fuels

A separation method is described for the identification of organic compounds in synthetic fuel products. Prefractionation of crude synfuel materials into discrete chemical classes was prformed by adsorption column chromatography using small quantities of neutral aluminum oxide and silicic acid. Subsequent high-resolution separation of individual components was achieved by using capillary column gas chromatography, and specific compound types were determined by gas chromatographic retention data and combined gas chromatography-mass spectrometry. The principal chemical classes investigated in a solvent-refined coal liquid were aliphatic hydrocarbons, polycyclic aromatic hydrocarbons, polycyclic aromatic sulfur heterocycles nitrogen polycyclic aromatic compounds, and hydroxyl polycyclic aromatic hydrocarbons. The nitrogen-containing aromatic compounds were further separated into secondary nitrogen polycyclic aromatic heterocycles, amino polycyclic aromatic hydrocarbons, and tertiary nitrogen polycyclic aromatic heterocycles to facilitate their identification.