Oxidation mechanism of carbon black by NO2: Effect of water vapour

Jeguirim, Mejdi; Tschamber, Valérie; Brilhac, Jean-François; Ehrburger, P.

doi:10.1016/j.fuel.2005.03.026

Cited by 97 publications

(65 citation statements)

References 20 publications

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“…Several authors have observed that the increase of water in the exhaust gas enhances the reaction of soot with NO 2 without modifying the global mechanism. As discussed by Jeguirim et al [39] it is attributed to the indicated potential formation of nitric and nitrous acids in presence of water and O 2 . This was also pointed out by Kirchner et al [40], who observed an increase in C-ONO2 and C-ONO groups in the reaction of soot when nitric acid is present in the exhaust flow.…”

Section: Dpf Regeneration Behaviourmentioning

confidence: 89%

Pre-DPF water injection technique for pressure drop control in loaded wall-flow diesel particulate filters

et al. 2015

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ElsevierBermúdez Tamarit, VR.; Serrano Cruz, JR.; Piqueras Cabrera, P.; Garcia Afonso, O. (2015 AbstractWall-flow type diesel particulate filter (DPF) is a required aftertreatment system for particle emission abatement and standards fulfilment in Diesel engines. However, the DPF use involves an important flow restriction, especially as the substrate gets soot and ash loaded. It gives as a result the increase of the exhaust back-pressure and hence a fuel consumption penalty. The increasing damage of fuel consumption with DPF soot loading leads to the need of the regeneration process. Usually based on active strategies, this process involves an additional fuel penalty but prevents from excessive DPF pressure drop and ensures secure soot burnt out.Under this context, new solutions are required to improve the state of the art DPF soot loading to pressure drop ratio. This paper presents a novel technique based on pre-DPF water injection to reduce the DPF pressure drop under soot loading conditions by disrupting its dependence on soot/ash loading. It provides benefits to engine fuel economy and also higher flexibility for DPF regeneration and maintenance. The work covers a test campaign performed in a passenger car turbocharged Diesel engine equipped with a wall-flow DPF. The main objective is to describe the technique, to provide a figure of its potential for pressure drop control and fuel consumption reduction. The results of the experiments also confirm soot and ash loading capacity increase and demonstrate the lack of negative effects on filtration efficiency and active and passive regeneration.

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Section: Dpf Regeneration Behaviourmentioning

confidence: 89%

Pre-DPF water injection technique for pressure drop control in loaded wall-flow diesel particulate filters

et al. 2015

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“…As a consequence, exogenous CO 2 might be formed through direct carbon oxidation already at 300 • C, as described by Jeguirim et al [34,41] (Eq. (9)).…”

Section: Exogenous Co 2 Formationmentioning

confidence: 99%

Catalytic effect of metal nitrate salts during pyrolysis of impregnated biomass

Eibner

Broust

Blin

et al. 2015

Journal of Analytical and Applied Pyrolysis

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b s t r a c tCatalytic pyrolysis is a promising way to improve bio-oil product quality. In this study, metal salts were directly impregnated in biomass to generate in situ catalysts and investigate their impact on pyrolysis products. Seven metals -Ce, Mn, Fe, Co, Ni, Cu and Zn -were selected and impregnated in eucalyptus using nitrate salts. A fixed-bed reactor, pre-heated at 500• C and inerted with N 2 flow, was used for pyrolysis. Both gas and bio-oil compositions were analysed, paying particular attention to the production of anhydrosugars. The anhydrosugar yields were found to be strongly influenced by the presence of metal salt catalysts. In particular, both Zn and Co salts yielded more anhydrosugars in comparison with catalyst-free sample. Moreover, LAC (1-hydroxy-(1R)-3,6-dioxabicyclo[3.2.1]octan-2-one) was produced in higher amounts than levoglucosan which is commonly produced without any catalyst. Metals were found to remain in all chars and tended to form metal-based nanoparticles (e.g. Cu 0 , Ni 0 , ZnO) able to act as in situ catalysts during the pyrolysis process. It seems that those metal nanoparticles are closely related to LAC production. In parallel to metal cations, nitrates were also suspected to play a significant role during pyrolysis. The suspected impact of anions on levoglucosenone production is discussed. Concerning gas yields, the impregnated nitrate salts were found to strongly affect CO 2 production.

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“…The chemistry of the oxidation of the CNT surface with the nitric acid thermal decomposition products can be described by a set of typical reactions, the most important of which are the processes of formation of oxygen-containing functional groups, processes of formation and transformation of nitrogen-containing surface formations, processes of elimination of oxygen-containing functional groups, processes of amorphous phase oxidation, and associated processes of interaction between reaction products. Water vapor present in the oxidizing mixture catalyzes the oxidation without changing the interaction mechanisms [13].…”

Section: Resultsmentioning

confidence: 99%

Modelling of carbon nanotube functionalization processes

2017

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Abstract. In the present paper, kinetic regularities of oxidative functionalization of carbon nanotubes in nitric acid vapors are studied. The catalytic effect of transition metal oxide particles on the formation of carboxyl groups is shown. Based on the information about changes in the degree of functionalization and composition of gaseous reaction products, the effective values of the thermal effect of the implemented process are determined. A model of the temperature field of the reaction zone of the gas-phase oxidative functionalization of carbon nanotubes process is proposed, thereby making it possible to determine the structural and mode parameters of the equipment.

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Oxidation mechanism of carbon black by NO2: Effect of water vapour

Cited by 97 publications

References 20 publications

Pre-DPF water injection technique for pressure drop control in loaded wall-flow diesel particulate filters

Pre-DPF water injection technique for pressure drop control in loaded wall-flow diesel particulate filters

Catalytic effect of metal nitrate salts during pyrolysis of impregnated biomass

Modelling of carbon nanotube functionalization processes

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