On
May 25, 2018,
the scientific
research team from School of Agriculture and Biology, Shanghai Jiao
Tong University (China) with the collaborators from Aston University
(UK) published a paper entitled ¡°Theoretical Analysis of Double Logistic Distributed Activation
Energy Model for Thermal Decomposition Kinetics of Solid Fuels¡± in
Industrial & Engineering Chemistry Research.
Lignocellulosic biomass contains three major components: cellulose,
hemicellulose and lignin. Through pyrolysis, lignocellulosic biomass
can be converted into pyrolysis char and volatiles. The latter
comprises condensable products called pyrolysis oil, which can be
used both as an energy source and a feedstock for chemical
production.
The pyrolysis kinetics is fundamental to the computational fluid
dynamics simulation of biomass pyrolysis, the design and scaling-up
of pyrolysis reactors, and the optimization of process operation
conditions. Many models have been proposed for describing the
kinetics of biomass pyrolysis, of which the distributed activation
energy model (DAEM) is the most comprehensive and accurate.
The experiment results showed that there were two overlapped peaks
in the derivative conversion curves of biomass pyrolysis. The DAEM
with a single distribution could not accurately describe this
kinetic property because the thermal decomposition normally involves
multiple subprocesses of various components. The Gaussian
distribution is usually used to represent the activation energies.
However, it is not sufficiently accurate for addressing the
activation energies in the initial and final stages of the thermal
decomposition reactions of solid fuels. Compared to the Gaussian
distribution, the logistic distribution is slightly thicker at the
curve tail and suits better to describe the activation energy
distribution. The double
logistic DAEM has been developed and the systematic analysis of the
model has been performed including the derivation, numerical
calculation, physical meaning of model parameters, analysis of
typical processes of the double Logistic DAEM. The results also
showed that the double Logistic DAEM was a suitable model with
abundant flexibility in describing various thermochemical conversion
processes of other solid fuels.
Junmeng Cai, Associate Professor in Agricultural Engineering from
SJTU is the corresponding author, and Miss Zhujun Dong, Master
Candidate from SJTU is the first author. The other co-authors
include Dr. Wenfei Cai, PhD candidates Yifeng He and Meiyun Chai,
and Master candidate Biaobiao Liu from School of Agriculture and
Biology at SJTU, Dr. Yang Yang, Dr. Xi Yu, Dr. Scott W. Banks
and Prof. Anthony V. Bridgwater from European Bioenergy Research
Institute (EBRI), Aston University, UK, and Prof.
Xingguang Zhang from Department of Chemical Engineering at Nanjing
Forestry University. |