FUEL 6 |
| Vapor pressure is highly dependent on a component's intra- and intermolecular interactions; the vapor pressures of polycyclic aromatic compounds (PACs) vary from 10-2 to 10-12 atmospheres at ambient conditions. Even though some PAC vapor pressures are twelve orders of magnitude less than atmospheric, they may still play a role in environmental transport processes. There is a distinct lack of available thermodynamic data concerning PACs, carcinogenic pollutants resulting from the incomplete combustion of coal and fossil fuels. This study focused on compounds with a parent anthracene molecule – a frequent constituent of coal byproducts – including chlorine, bromine, and carboxyl heteroatoms. The vapor pressures of these persistent organic pollutants were measured using the Knudsen effusion technique. Enthalpies of sublimation show strong dependence on type of heteroatom substituted as well as position on the parent molecule. We investigated these effects with an eye towards a group-contribution analysis; few literature data detail a systematic approach to describe thermodynamics of PACs. |
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Characterization of Fossil and BioFuels: Challenges and Progress
8:25 AM-12:10 PM, Sunday, August 19, 2007 Boston Park Plaza -- Arlington Rm, Oral
Division of Fuel Chemistry |