Bronsted undesired formation

The Lewis and Bronsted acids lower the starting temperature of wood decomposition and charcoal formation and along with an increased char formation, diminish the yield of some volatile products of pyrolysis. The latter fact is an undesirable i enomenon if an energetic self-sufficiency in the carbonisation of wood is striven for (10), Therefore, the objective of the present investigation was to elucidate not only the effect of different available catalysts upon the yield of charcoal, but also that on the yield of volatile products. 

Bronsted sites, that initiate carbonium ion reactions, and Lewis sites, giving ton radical reactions, coexist, althouth it appears that in practical usage the Bronsted acidity predominates. When using y-Al O as a suppwn, undesirable side reactions such as cracking, isomerization and coke formation always exist. These give unwanted products and lead to catalyst deactivation. 

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