This
study proposes a hybrid approach for the modeling of the fluid
catalytic cracking (FCC) process, with the aim to establish an adaptive
and accurate product yield prediction model. Because of the uncertainties
in crude oil quality and the complexity of the FCC process, which,
for example, has highly coupled process variables with high dimensionality
and strong interference, it is difficult for existing first-principles-based
methodologies to deliver accurate results. To tackle this, this study
proposes a machine-learning-based modeling approach that integrates
an intelligent feature selection strategy with random forest for the
process modeling. First, the adaptive immune genetic algorithm (AIGA)
is applied to screen for the most relevant process indicators from
the collected process data, including the operation parameters for
the relevant process devices and the property data of the feed stream.
Second, random forest (RF) is employed to establish the FCC process
models based on the selected process indicators in the first step.
The approach is illustrated by its application in a real FCC production
process, for which 10 months of historical production data were used
to train and test the proposed AIGA-RF model to determine the product
yield predictions for four products. Comparisons between the proposed
method and other methods were also conducted. The result indicates
that the proposed method is able to remove the disturbance variables
and is found to be adaptable to different product yield prediction
scenarios. It could be a good reference for online process optimization
and control of FCC processes.