Authors: Bojan Janković
Publish Date: 2014/04/30
Volume: 21, Issue: 4, Pages: 2285-2314
Abstract
This work deals with the isothermal pyrolysis of Pine and Beech wood samples and kinetic studies using the thermoanalytical technique at five different operating temperatures Pyrolysis processes were investigated by using the distributed apparent activation energy model which involves the complex mixture of different continuous distribution functions It was found that decomposition processes of wood pseudocomponents take place in different conversion areas during entire pyrolyses whereby these areas as well as the changes in apparent activation energy E a values are not the same for softwood and hardwood samples Bulk density Bden and energy density ED considerations have shown that both biomass samples suffer from low Bden and ED values It was concluded that pyrolysis can be used as a means of decreasing transportation costs of wood biomass materials thus increasing energy density The “pseudo” kinetic compensation effect was identified which arises from kinetic model variation and wood species variation In the current extensive study it was concluded that primary pyrolysis refers to decomposition reactions of any of three major constituents of the considered wood samples Also it was established that primary reactions may proceed in parallel with simultaneous decomposition of lignin hemicelluloses and cellulose in the different regions of wood samples depending on the operating temperature It was established that endothermic effects dominate which are characterized with devolatilization and formation of volatile products It has been suggested that the endothermic behavior that arises from pyrolyses of considered samples may indicate the endothermic depolymerization sequence of cellulose structures
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