For diffusion flames, the combination of oxygen enrichment and fuel dilution results in an increase in the stoichiometric mixture fraction, Zst, and alters the flame structure, i.e., the relationship between the local temperature and the local gas composition. Increasing Zst has been shown to result in the reduction or even elimination of soot. In the present work, the effects of variable Zst o...

The soot combustion mechanism over potassium-supported oxides (MgO, CeO2 and ZrO2) was studied to clarify the active sites and discover unified reaction intermediates in this typical gas-solid-solid catalytic reaction. The catalytically active sites were identified as free K(+) rather than K2CO3, which can activate gaseous oxygen. The active oxygen spills over to soot and forms a common interme...

Although it is known that soot particles are emitted in large quantities to the atmosphere, our understanding of their environmental effects is limited by our knowledge of how their composition is subsequently altered through atmospheric processing. Here we present an on-line mass spectrometric study of the changing chemical composition of hydrocarbon soot particles as they are oxidized by gas-...

The role of soot and volatile aerosol in controlling ice particle formation in cirrus clouds is of global importance for climate. In particular, contrail studies may help to better understand the role of various aerosols in ice formation. Recent results suggest that contrails may contribute a large share to the climate impact of aviation. Hence, better knowledge on contrails is needed for devel...

Biomass burning is one of the largest sources of carbonaceous aerosols in the atmosphere, significantly affecting earth's radiation budget and climate. Tar balls, abundant in biomass burning smoke, absorb sunlight and have highly variable optical properties, typically not accounted for in climate models. Here we analyse single biomass burning particles from the Las Conchas fire (New Mexico, 201...

A new method is described for large-scale production of Single Wall Carbon Nanohorns (SWCNH). In a prototype reactor (a 30 kW plant for an estimated production of about 100 g/h of soot) optimal thermodynamic conditions that favour nanohorn formation were determined. The characterization of collected soot was performed by several techniques: thermogravimetric analyses (TGA), Raman spectroscopy, ...

Nowadays, in the after-treatment of diesel exhaust gas, a diesel particulate filter (DPF) has been used to trap nano-particles of the diesel soot. However, as there are more particles inside the filter, the pressure which corresponds to the filter backpressure increases, which worsens the fuel consumption rate, together with the abatement of the available torque. Thus, a filter with lower backp...

Introduction Conclusions References

Smoke agglomerates are made of many soot sphcres, and their light scattering response is of interest in fire research. The numerical techniques chiefly used for theoretical scattering studies are the method of moments and the coupled dipole moment. The two methods have been obtained in this tutorial paper directly from the monochromatic Maxwell curl equations and shown to be equivalent. The eff...

The problem of soot emissions from diesel engines is introduced and the possible solution of combining doped perovskites and microwave (mw) irradiation to "clean up" diesel soot filters is outlined. Eighteen doped perovskite catalysts are synthesized and tested for propane and CO oxidation, which are taken as model components for soot. The activity, selectivity, and SO2 tolerance are compared u...