Kinetic Analysis of Devolatilized Diesel-Soot Oxidation Catalyzed by Ag/Al<sub>2</sub>O<sub>3</sub> and Ag/CeO<sub>2</sub> Using Isoconversional and Master-Plots Techniques
Boonlue Sawatmongkhon, Punya Promhuad, Thanawat Thaisruang, Kampanart Theinnoi, Sak Sittichompoo, Thawatchai Wongchang, Ekarong Sukjit
Abstract
High Resolution Image Download MS PowerPoint Slide This work presented the kinetic analysis of devolatilized diesel-soot combustion accelerated by Ag/Al 2 O 3 and Ag/CeO 2 catalysts. Isoconversional and master-plots techniques were employed to estimate activation energy and identify the reaction model. The apparent activation energy of uncatalyzed soot oxidation was 101.85 kJ/mol, and it was reduced to 61.85 and 82.78 kJ/mol for the combustion catalyzed by Ag/Al 2 O 3 and Ag/CeO 2, respectively. The reaction-order model, f (α) = (1– α) n, with n of 1.4, 1, and 1 showed the best fit for the uncatalyzed soot oxidation and soot oxidation catalyzed by Ag/Al 2 O 3 and Ag/CeO 2, respectively. The proposed single-step reaction models were quite capable of reproducing experiments for the uncatalyzed soot oxidation and soot oxidation catalyzed by Ag/CeO 2 . In the presence of Ag/Al 2 O 3, the oxidation rate at the first 20% of conversion was faster than the 1st-order reaction reflecting that the soot was rapidly oxidized by highly active species generated by Ag/Al 2 O 3 . The oxidation of the remaining soot closely followed the 1st-order reaction mechanism.