Heteroatomic Polycyclic Aromatic Compounds in Coal Liquefaction Process Materials

摘要

In general, polycyclic aromatic compounds (PAC) are the principal chemical constituents of direct coal liquefaction process materials. Non-functional polycyclic aromatic hydrocarbons (PAH), such as naphthalene, phenanthrene, pyrene, etc., are frequently the most prevalent chemical class of PAC in coal-derived synfuels. Aromatic compounds with a nitrogen, oxygen, or sulfur heteroatom comprise other classes of PAC that occur in coal liquids. These classes of heterocyclic PAC typically range in concentration from less than or equal to 1% to greater than or equal to 30% (by weight) in coal liquefaction products, depending on the process and distillation history of the sample material. Thiophene and its benzologues are the major class of coal liquid polycyclic aromatic sulfur heterocycles. Species of nitrogen-containing PAC include: pyrrole-type PAH or 2 exp 0 -PANH (indoles, carbazoles, etc.), pyridine-type PAH or 3 exp 0 -PANH (quinolines, benzoquinolines, benzacridines, etc.), amino-PAH (naphthylamines, aminobiphenyls, aminophenanthrenes, etc.), and cyano-PAH (cyanonaphthalenes, cyanophenanthrenes, etc.). Polar hydroxylated-PAH, such as phenols, naphthols, hydroxybiphenyls, etc., furan and its benzologues, and to a lesser extent PAH ketones and quinones are classes of oxygen-containing PAC that may occur in coal liquefaction materials. Mixed-functional PAC with two or more heteroatoms have been found in coal liquids, but are generally present at only trace levels. 31 references, 1 figure, 1 table. (ERA citation 09:039285)