Modeling and optimization of a semiregenerative catalytic naphtha reformer

Authors

  • Unmesh Taskar,

    1. Dept. of Chemical Engineering, Texas Tech University, Lubbock, TX 79409
    Current affiliation:
    1. Aspentech, Inc., Houston, TX
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  • James B. Riggs

    Corresponding author
    1. Dept. of Chemical Engineering, Texas Tech University, Lubbock, TX 79409
    • Dept. of Chemical Engineering, Texas Tech University, Lubbock, TX 79409
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Abstract

Modeling and optimization of a semiregenerative catalytic naphtha reformer has been carried out considering most of its key constituent units. A detailed kinetic scheme involving 35 pseudocomponents connected by a network of 36 reactions in the C5–C10 range was modeled using Hougen-Watson Langmuir-Hinshelwood-type reaction-rate expressions. Deactivation of the catalyst was modeled by including the corresponding equations for coking kinetics. The overall kinetic model was parameterized by bench-marking against industrial plant data using a feed-characterization procedure developed to infer the composition of the chemical species in the feed and reformate from their measured ASTM distillation data. For the initial optimization studies, a constant reactor inlet temperature configuration that would lead to optimum operation over the entire catalyst life cycle was identified. The analysis was extended to study the time-optimal control profiles of decision variables over the run length. In addition, the constant octane case was also studied. The improvement in the objective function achieved in each case was determined. Finally, the sensitivity of the optimal results to uncertainty in reactor-model parameters was evaluated.

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