Abstract：
The basic properties, thermogravimetry, pyrolysis characteristics and combustion characteristics of Jihua oil sludge were
determined in this manuscript. The results show that the oil content of Jihua sludge is 14.74
%
and the water content is 72.82
%
. The
characteristics and kinetic parameters of pyrolysis and combustion were obtained by using thermogravimetric analysis with heating
rates of 5, 10, 15, 20 and 30 ℃ /min. The pyrolysis process includes volatilization and pyrolysis stages. One is the volatilization of
organic matter at 150~380℃, and a small proportion of reactive heteroatoms is pyrolyzed. The other is the pyrolysis process of a small
amount of volatile heavy components at 380~550℃. The combustion process includes the volatilization combustion stage and the fixed
carbon combustion stage. The combustion of Jihua sludge in the first stage is the volatile combustion of small molecular organics. The
second stage is the volatile combustion of large molecular organics and pyrolysis combustion, and the diffusion of oxygen into the cru
cible to produce fixed carbon combustion. The effect of heating rate on combustion is small, and the activation energy will not increase
significantly due to the consumption of organic matter. In addition, the volatilization combustion stage occurs with more difficulty than
pyrolysis volatilization, and the fixed carbon combustion stage occurs more easily than pyrolysis.
Two models, Coats-Redfern and the Distributed Activation Energy Model (DAEM), are used to calculate the kinetic pa
rameters and the results are compared with those of normal treatment methods to optimize the calculation process. In the DAEM
model, the activation energy of the volatilization stage is 61.82 to 81.05 kJ/mol, while the activation energy in the pyrolysis
stage increased from 121.60 kJ/mol to 237.11 kJ/mol with the increase of conversion. When the DAEM model is applied to
the calculation of the combustion process of oil sludge, the combustion activation energy ranges from 73.95 to 110.93 kJ/mol,
which is then compared with Coats-Redfern model and pyrolysis process. Coats-Redfern model assumes that the reaction is
single, and the activation energy obtained is the mean value of a certain range, which has great limitations. The DAEM model is
more suitable for the complex composition of oil sludge, and the method is better. In the pyrolysis calculation, the peak splitting
method separates the pyrolysis stage from the volatilization stage, and the kinetics obtained are closer to the real data. According
to the research, the DAEM model is more accurate and reliable. The research results of this paper can provide experimental data
foundation support for the sludge pyrolysis treatment technology.
