Thermogravimetric analysis (TGA)
has been extensively used in the
bitumen literature to investigate its thermal stability and various
stages of thermal decomposition. The primary aim of these studies
has been to calculate the kinetic parameters, such as activation energy
and the pre-exponential factor of each thermal event. However, in
our current paper, we explore the application of three machine learning
(ML) techniques, namely, support vector regression (SVR), random forest
(RF), and gradient booster regression (GBR), to predict the TGA data
for the asphaltenes extracted from the feed and products of visbreaking
of three types of materials: (i) deasphalted oil (DAO), (ii) DAO doped
with 5.55 wt % indene, and (iii) DAO doped with 11.11 wt % indene.
The addition of indene was shown to significantly affect the free-radical
chemistry of DAO in a previous work, and the key contribution of our
work in this paper was to minimize the requirement of the TGA instrument
to obtain the mass loss curves by employing ML techniques on available
experimental data. This will reduce the human errors involved in sample
preparation and data collection as well as decrease the process time
in obtaining the TGA data as compared to experimentation. We observed
that the regression techniques based on decision trees, i.e., RF and
GBR, showed the best performance and highest prediction accuracy of
>0.99 for predicting the TGA data of the asphaltenes extracted
from
the feed and products obtained by reacting the feedstocks at visbreaking
reaction times of 30, 45, and 60 min. A number of inputs were considered
for the ML models, such as the temperature of the TGA chamber and
sample, heat supplied to the sample, visbreaking time, and time spent
inside the TGA chamber. The novelty of our work lies in the fact that
no previous study has reproduced the TGA data for asphaltenes extracted
from DAO and indene-added DAO and their visbroken products through
ML approaches, and we believe that the results of this work will help
in fastening the process times in the heavy oil industry by eliminating
the need for offline measuring instruments.