New Improvements In Modeling Kinetic Schemes For Hydrocarbons Pyrolysis Reactors

In recent years, significant improvements have been reached both in the technology of hydrocarbons pyrolysis for olefines production and in the modeling of the kinetic schemes involved. Some of the reasons for these improvements are: - New sophisticated instrumentation for continuous analysis of effluents from commercial units. - Economic interest for non-conventional feedstocks, e.g. vacuum gasoils, hydrotreated heavy gasoils, recycle fractions, reformed naphthas and/or other refinery streams. - Improvements in computer technology, hardware and software, which allow handling, in real time, complex systems of kinetic equations. - New strategies for on-line plant control and optimization. The rising needs of accuracy in predicting the reactor effluents under a wider range of feedstocks and different reactor coils demand models even more flexible and more detailed than the best ones actually available. In this paper the criteria for the developement of complex and non-regular kinetic schemes (up to thousands of reactions involved) are presented and discussed. The automatic generation of the elementary reaction stoichiometries and the non-Arrhenius behaviour of the kinetic constants are also considered. Some effort has also been devoted to the optimization and data reconciliation of the reactors effluents within the framework of the entire olefins plant.