Abstract:
Realistic kinetic modeling of fluid catalytic cracking (FCC) units requires detailed composition of the feed stream in terms of paraffins, naphthenes and aromatics(PNA)which cannot be analyzed in a field laboratory. This paper presents an artificial neural network (ANN) model to predict detailed composition of FCC feed using routinely
measured properties such as density, ASTM distillation temperatures, Conradson carbon residue (CCR) content, sulfur and total nitrogen as inputs to themodel. Several feedforward-error back propagation networks with different number of neurons in hidden layers were studied using Levenberg–Marquardt (LM) training algorithm. Among different network architectures investigated, the ANN model with 8 inputs, namely density and ASTM distillation temperatures except IBP, FBP and only one neuron in the output layer to predict paraffin, naphthene and aromatic contents individually showed the best agreementwith the experimental resultswithin permissible limit. These compositionswhen usedwith a 10-lump kinetic model of FCC unit, successfully simulated plant performance for several different feeds.
