Modelling heat of reaction in biomass pyrolysis with detailed reaction schemes

FUEL

卷:206

Article

Anca-Couce, Andres¹  Scharler, Robert^1,2 

[1] Graz Univ Technol, Inst Thermal Engn, Inffeldgasse 25b, A-8010 Graz, Austria

[2] BIOENERGY 2020 GmbH, Inffeldgasse 21b, A-8010 Graz, Austria

关键词: Biomass pyrolysis;    Heat of reaction;    Detailed reaction scheme;    Modelling;    Single particle;    Exothermicity;   

DOI  :  10.1016/j.fuel.2017.06.011

来源: Elsevier

【 摘 要 】

Primary devolatilization and the exothermic heterogeneous secondary charring of the primary volatiles need to be described in a consistent manner in order to correctly predict the heat of reaction of biomass pyrolysis. Detailed reaction schemes can currently predict mass loss and product composition of biomass pyrolysis with good accuracy, but have a weakness in the description of the heat of reaction. In this work it is shown for the first time that including secondary charring reactions a detailed reaction scheme can predict the evolution of the heat of pyrolysis for different conditions. The enthalpy of reaction is calculated for each reaction as the difference between the net calorific value of reactants and products. The presented model is able to describe the heat evolution in micro-TGA-DSC experiments conducted without a lid, where pyrolysis is endothermic, and with a lid, where secondary reactions are enhanced and the global heat of reaction shifts to exothermic. Furthermore, when it is coupled to a particle model, it correctly describes single particle pyrolysis experiments conducted with beech spheres where there is a remarkably exothermic peak in the centre temperature. (C) 2017 Elsevier Ltd. All rights reserved.

【 授权许可】

Free