A kinetic model for hydroconversion processing of vacuum residue

Hydroconversion is a complex process involving many chemical reactions. Mathematical models of hydroconversion processes often have more kinetic parameters than can be estimated from data. In this work the identifiability and estimability of parameters in a model describing the hydroconversion processing of vacuum residue are analyzed. The model under consideration contains five states, two outputs, and seven parameters. This lumped model was developed by grouping molecules based on their solubility characteristics. The model parameters were found to be identifiable. However, using previously published experimental data, the model parameters were found to be inestimable. It is shown that the model can be reparameterized using a linear transformation in the parameter space. This transformation allows the model outputs to be predicted based on only three pseudo-parameters. Confidence intervals for the three pseudo-parameters and the mean responses were calculated.