Mechanistic Aspects of Soot Formation from the Combustion of Pine Wood

Abstract

Carbonaceous soot has been generated from pine in a range of appliances to simulate different combustion conditions. The fuel as well as biomass cell wall components have been studied by pyrolysis-GC-MS and pyrolysis-GC-TCD. In addition, the soots have been probed using both pyrolysis-GC-MS and direct inlet mass spectrometry (DI-MS). The material collected from the pine combustion is smoke, and the major component is a carbonaceous soot. The soots contain both organic carbon (adsorbed species) and black (solid) soot, and the organic carbon consists of primary pyrolysis products from the cell wall components, as well as decomposition products, PAH and oxidized PAH. The black carbon contains oxygen functionality (of the order of 5-10 wt % O), and there are indications that this is incorporated during soot growth, although surface oxidation on reactive sites could also be important. The decomposition products suggest an important additional PAH route is via cyclopentadiene, which is derived after cracking of lignin monomer fragments. Kinetic modeling also highlights the lignin monomers as important contributions to the soot production pathways. A model is proposed which, in addition to the hydrogen abstraction carbon addition (HACA) mechanism, incorporates the cyclopentadiene and the O-PAH addition routes to soot.

Cynara cardunculus L. gasification in a bubbling fluidized bed: The effect of magnesite and olivine on product gas, tar and gasification performance

“…With increasing temperature these functional groups are cleaved from the aromatic ring generating permanent gases CO, H 2 , CO 2 , CH 4 , C 2 H 4 and cyclopentadiene radicals, responsible for the increase of PAHs [45,46]. PAH tertiary tars (see Table A2) increased with temperature which is in accordance with observations reported in literature for magnesite in the same temperature range [47,48].…”

A study of smoke formation from wood combustion

“…m/z=-41, C 2 HO -) consistent with the large number of oxygenated compounds in chromatograms of the products of pyrolysis and combustion of softwood (pine) observed in our previous work [4]. A major oxygen -containing species in both willow and softwood soot spectra correspond to a peak at m/z -59 previously [7,8] used to distinguish levoglucosan and sugars from eugenol.…”

“…The general mechanism of biomass combustion has been extensively studied over a number of years [3][4][5][6][7][8][9][10], but recently much attention has been directed to the emission of fine particles, that is below 2.5µm. In previous work, we considered that the cellulose and lignin components can be treated separately in relation to their emissions [4,5].…”

“…In previous work, we considered that the cellulose and lignin components can be treated separately in relation to their emissions [4,5]. Cellulose decomposes largely to CO and H 2 together with other small molecules, while lignin decomposes to more complex aromatic products.…”

Polycyclic aromatic hydrocarbons in post-fire soils of drained peatlands in western Meshchera (Moscow region, Russia)

“…Numerous works are devoted to PAH formation from vegetation components influenced by flaming and smoldering combustion. Burning conditions (the amount of available oxygen, the duration of heating, the temperature) and the type of vegetation define the amount and composition of PAHs (Ramdahl and Bechler, 1982;Jenkins, 1996;Nussbaumer, 2003;Medeiros and Simoneit, 2008;Simoneit, 1999;Schauer et al, 2001;Nakajima et al, 2007;Fitzpatrick et al, 2008;Kakareka et al, 2004).…”