Desorption of polycyclic aromatic hydrocarbons from soot surface: five- and six-ring (C22, C24) PAHs.
The kinetics of thermal desorption of five soot-bound nonvolatile (C(22), C(24)) polycyclic aromatic hydrocarbons (benzo(ghi)perylene (BghiP), indeno(1,2,3-cd)pyrene (IdP), anthanthrene (Antha), dibenz(ah)anthracene (DBahA), dibenzo(ae)pyrene (DBaeP)) identified in laboratory-generated kerosene soot were studied over the temperature range 335-370 K in a low pressure flow reactor. The PAH desorption rate constants were measured using off-line HPLC monitoring of their concentrations in soot samples as a function of desorption time. The following Arrhenius expressions were determined for the desorption rate constants of the soot-bound PAHs studied: k(des) = 8.4 x 10(15) exp[-(129.7 +/- 4.4)/RT], 1.0 x 10(16) exp[-(130.6 +/- 6.1)/RT], 1.1 x 10(16) exp[-(131.6 +/- 3.2)/RT], 1.0 x 10(16) exp[-(128.0 +/- 3.9)/RT], and 1.4 x 10(16) exp[-(134.2 +/- 10.7)/RT] (k(des) are in s(-1) and activation energies in kJ mol(-1)) for BghiP, IdP, Antha, DBahA, and DBaeP, respectively. Analysis of the present and previous experimental data showed that PAH-soot binding energies linearly correlate with the number of PAH carbon atoms. The present data and those from previous studies are discussed in the frame of the existing theoretical gas-to-particle partitioning model.
Bedjanian
Yuri
Y
Institut de Combustion, Aérothermique, Réactivité et Environnement (ICARE), CNRS, 45071 Orléans Cedex 2, France. bedjanian@cnrs-orleans.fr
Nguyen
Mai Lan
ML
Guilloteau
Angélique
A
D007700:Kinetics; D011084:Polycyclic Aromatic Hydrocarbons / Q000737:chemistry*; D053260:Soot / Q000737:chemistry*; D013499:Surface Properties; D013696:Temperature; D013816:Thermodynamics
D011084:Polycyclic Aromatic Hydrocarbons; D053260:Soot