Polycyclic Aromatic Hydrocarbons from Fossil Fuel Conversion Processes

摘要

Benzo(a)pyrene continues to be the most widely accepted indicator of PAH content and biological significance. The concentrations of BaP in synfuels related materials are summarized. Petroleum crude is estimated to contain approximately 1 ppM of BaP. Both shale- and coal-derived crudes contain approximately three times as much BaP. Depending on the source (coal, process, process conditions), coal-derived crude oils contain BaP ranging from the same amount as petroleum crudes to ten times as much. High boiling distillates and distillate residues are generally enriched in BaP content as should be expected. While enriched in BaP relative to petroleum crudes, coal-derived crude oils contain two to three times less BaP than do coal tar, coal tar pitch, and petroleum pitch. Mutagenic activity is observed in the PAH fractions containing three-ring PAHs to those containing PAHs greater than five rings in size. The specific activity tends to ''peak'' for the 4-ring and 5-ring fractions, i.e., those containing the most common (benzo(a)pyrene, benzo(c)phenanthrene, 3-methylcholanthrene, etc.) known carcinogens. Of particular interest is the observation that fractions corresponding to PAHs of 4-rings and larger contain constituents which do not require metabolic activation to express histidine reversion. It is also important to note that mutagenicity of the fraction is produced by at most 4-12 wt % (depending on whether enzyme activation is employed) of its constituents. (ERA citation 03:007859)