Modeling of an Industrial Delayed Coker Unit

The fact that the low-valuable residues such as fuel-oil are not preferred due to air pollution has decreased the demand for these products and brought different fuel conversion processes to the agenda. One of these processes is Delayed Coking which converts the vacuum residual feedstock to lighter and more valuable products such as motor fuels and eliminates the low-order and environment-damaging streams (see Fig.1). Moreover, this unit also produces needle coke. Thus, optimal operation of the Delayed Coker Unit (DCU) provides a great economic return¹. In this direction, we have modeled an industrial DCU which exists in the TüpraÅŸ Ä°zmit Refinery. The obtained model was used for optimization of the unit by predicting the coke level over time in the coke drums where the reaction takes place and the distribution of the products.

Figure 1- Simplified diagram of the delayed coking process

In order to control the process in an optimum way, the unit behavior was examined by using the first-principle model. The model parameters were estimated using the plant operating data. The first step is to determine the contents of the reactor input and output by characterizing the coke drum outlet and furnace input streams. A simplified new methodology for the estimation of coke drum effluent was developed by examining the techniques suggested in the literature^2,3. The developed model has been validated by comparing obtained results with actual process conditions. Calculations were carried out in a simulation platform where MATLAB, Microsoft Excel, Aspen HYSYS and Python programs are integrated. After the input stream of the coke drums was estimated, the reactor model was successfully developed.

Keywords: Modeling, Integrated programing tools, Optimized process parameters

References

[1] Sawarkar, A.N., Pandit, A.B., Samant, S.D., Joshi, J.B., 2007. Petroleum residue upgrading via delayed coking: a review. Can. J. Chem. Eng. 85 (2), 1–24.

[2] Borges, C. N., Mendes, M.A., Alves, R. M. B., 2015. Mathematical Modeling of an Industrial Delayed Coking Unit, 12th International Symposium on Process Systems Engineering and 25th European Symposium on Computer Aided Process Engineering. May – 4 June 2015, Copenhagen, Denmark © 2015 Elsevier B.

[3] Kaes, G.L. Refinery Process Modeling: A Practical Guide to Steady-State Modeling of Petroleum Processes, 1st Edition, 2000.