Compositional Simulation of a Refinery Coker Furnace - An Industrial Example of Two-Phase Flow with Chemical Reaction

Abstract

A computer program (KOKSOVN) has been developed for compositional steady-state simulation of a refinery delayed coker furnace. The main objective of this work has been to establish a tool for studying the effects that influence the deposition of coke on the inside walls of the tubes in order to maximize the time of operation (cycle time) between each cleaning of the tubes with a resulting stop in production. The program basically consists of a standard integration package which steps along the reactor (or pipeline) while solving the vapour-liquid equilibrium (VLE) and estimating physical properties for each step. Using a modular approach in the development, the resulting computer program has some general features which make it a possible simulation tool for any non-adiabatic plug flow reactor with two-phase flow. Depending on the chemical system, the routines for thermophysical and transport properties, phase equilibria and chemical reaction may be replaced by other methods. The program may also be used to simulate a pipeline with one or two-phase flow. Since, however, the total composition in this case is constant, it would probably be more efficient to use tables based on the pressure values, instead of performing tedious VLE calculations along the pipeline as is done in the present program.

Keywords

• Simulation
• numerical integration
• phase equilibria
• coke deposition