On-Line Optimization of a Crude Distillation Unit with Constraints on Product Properties

Abstract

The optimization of chemical processes has gained immense importance in the present day. This work is aimed at the on-line optimization of an industrial crude distillation unit (CDU). A nonlinear, steady-state CDU model has been developed in-house for this purpose. Model tuning parameters in the form of vaporization efficiencies were incorporated to minimize the discrepancy between the measured and simulated column parameters on-line. The crude feed composition, represented by the true boiling point (TBP) curve, is known to vary with time. A procedure was developed to back-calculate the TBP curve using on-line plant data. Finally, the objective function was formulated to simultaneously maximize the net achievable profit and set the product properties within a user-specified range. The entire scheme was tested using real plant data off-line, but the problem formulation is suitable for supervisory-level on-line optimization without further modifications. It is shown that substantial increases in profitability can be achieved using supervisory on-line optimization.

Performance Evaluation of Real Industrial RTO Systems

“…Common criteria used to select df are the easiness of variable manipulation in the plant, the requirements of the industry and the effects of the decision variables on process performance [34]. Characteristics of the feed, such as flow rate and temperature, are commonly assigned as decision variables.…”

Simultaneous optimization of heat-integrated crude oil distillation systems

“…Some advances in crude oil distillation process include improving heat exchanger network structure [1][2][3], investigating the effect of mixing different crude oils on product profit to increase economic profit [4,5], optimizing operating parameters of distillation unit to maximize product profit [6][7][8][9], and improving production program by solving nonlinear programming (NLP) problems [10,11]. Liebmann et al put forward design procedures of a heat-integrated conventional crude oil distillation tower using pinch analysis [12].…”

Modeling and optimization of a crude distillation unit: A case study for undergraduate students

“…They are similar to the different fractions of crude and they have physical properties that represent an average of the properties of various compounds. Thermodynamic properties such as density, viscosity, acentric factor, and critical points are estimated using the calculated average boiling point and molecular weight of the pseudo‐component 11.…”