Conversion of Phenol-Based Tars over Biomass Char under H₂ and H₂O Atmospheres

Abstract

This study focused on the effect of a wood char on tar cracking and reforming in the context of fluidized-bed gasification. Phenol was used to create in situ a mixture representative of tars produced by pyrolysis and gasification in a dual fluidized-bed reactor. The wood char was placed in a fixed-bed reactor, and atmospheres composed of H2 and steam were tested both together and separately. Gasification of the wood char under the different atmospheres was characterized. The char was found to be highly catalytic with tars in the presence of steam. The influence of H2 on catalytic activity remained low. A comparison to the results on olivine under the same reaction conditions showed that chars were much more efficient and may have a strong influence on tar reduction in fluidized-bed biomass gasification. (Résumé d'auteur

The impact of dry torrefaction on the fast pyrolysis behavior of ash wood and commercial Dutch mixed wood in a pyroprobe

“…This effect of temperature on the phenol yield is consistent with literature [13,20,35]. Phenol mainly derives from lignin degradation [3,36] and at high temperature (> 850°C) phenol is converted mainly to non-oxygenated aromatics (naphthalene and benzene) and secondly to noncondensable species (CO and CO 2 ), instead of char [35,37]. As torrefaction typically results in increasing the lignin content [4], torrefied feedstocks are expected to result in a higher phenol yield.…”

“…The evolution of analyzed species is similar to Torrcoal wood samples, except for species heavier than phenanthrene which remained the same after the pyrolysis step in the gasifier. This shows that phenol was converted to naphthalene but also to other species in the gasifier, such as benzene and CO 2 [37].…”

Activity of chars and activated carbons for removal and decomposition of tar model compounds – A review

“…Such steps retrace the mechanism proposed by Hosokai et al [37], a mechanism which is also corroborated by Nitsch et al [54], who further investigated the role of steam in the interaction between tars and the char surface.…”

Products Distribution During Sewage Sludge Pyrolysis in a Sand and Olivine Fluidized Bed Reactor: Comparison with Woody Waste

“…This accumulation of char in the reactor can have significant effects on the evolution of syngas properties (yield and composition) [30][31][32][33]. However, the observation of the evolution of the composition of the dry gas versus time showed the presence of a steady state.…”