The Oxidation of Soot Deposits from Diesel Engines

Investigation on Particulate Oxidation from a DI Diesel Engine Fueled with Three Fuels

“…For diesel soot, the following reported lower activation energy than those obtained in this study : Jung et al (2005) with 25 ppm cerium-dosed case (line a, 107 kJ/mol); Jung et al (2003) with lube-oil-dosed case (line b, 101 kJ/mol); Higgins et al (2003) with regular diesel fuel (line e, 108 kJ/mol); Ahlström and Odenbrand (1989) with flow reactor study of diesel particles (line h, 106 kJ/mol). On the other hand, Miyamoto et al (1988) obtained higher results using TGA for uncatalyzed diesel soot (line f, 191 kJ/mol) and the following two obtained similar results: Higgins et al (2002) using diffusing flame-generated soot (line d, 164 kJ/mol) and Otto et al (1980) using TGA for diesel particles (142 kJ/mol). Clearly, the activation energy depends on the type of fuel, the treatment of the fuel or the soot, and the methods of measurement.…”

“…From top to bottom: (A) biodiesel particle collected at 0.08 MPa; (B) LSD particle collected at 0.08 MPa; (C) ULSD particle collected at 0.08 MPa; (D) biodiesel particle collected at 0.7 MPa; (E) LSD particle collected at 0.7 MPa; (F) ULSD particle collected at 0.7 MPa. Thin lines show previous works: (a) Jung et al (2005), 25 ppm cerium-dosed case (107 kJ/mol); (b) Jung et al (2003), lube-oil-dosed case (101 kJ/mol); (c) Jung et al (2006), pure biodiesel (89 kJ/mol); (d) Higgins et al (2002) using diffusion flame-generated soot (164 kJ/mol); (e) Higgins et al (2003), diesel particles with regular diesel fuel (108 kJ/mol); (f) Miyamoto et al (1988) TGA of uncatalyzed diesel soot (191 kJ/mol); (g) Otto et al (1980) TGA of diesel particles (142 ± 21 kJ/mol); (h) Ahlström and Odenbrand (1989) particulate agglomerates (Strzelec et al 2011). The larger specific surface area improves the exposure of the particles to oxygen in the oxidation process, leading to the higher oxidative reactivity of biodiesel particles, compared with the ULSD and LSD particles.…”

Diesel Soot Oxidation under Controlled Conditions

“…The density of diesel soot particles is usually taken as 2g cm 3 [Amann and Siegla, 1982;Heywood, 1988;Otto et at, 1980].…”

“…Some studies on oxidation were carried out on diesel soot deposits but these were at low temperatures ranging from 573 to 1073 K [Ahlström and Odenbrand, 1989;Marcuccilli et al, 1994;Neeft et al, 1997;Otto et al, 1980]. These studies could not provide information on the oxidation of suspended diesel soot at higher temperatures similar to those in diesel engine combustion chambers.…”

Experimental investigation of catalytic soot oxidation and pressure drop characteristics in wall-flow diesel particulate filters

“…In the literature the published values of activation energy of thermal soot oxidation is found to cover a range between 140 and 210 kJ/mole. Low values of the order of 140-150 kJ/mole reported by Ciambelli et al [91] and Otto et al [92]. Neeft et al [93], report a somewhat lower value of 170 kJ/mol, for the oxidation of flame soot in a flow reactor with a different atmosphere (10% O2 in Ar).…”