Complex reaction network generation for Steady State Isotopic Transient Kinetic Analysis: Fischer-Tropsch Synthesis

Abstract

A versatile modeling strategy for Steady State Isotopic Transient Kinetic Analysis (SSITKA) data, acquired in a plug flow reactor, is elaborated with particular attention to complex reaction networks and Fischer-Tropsch Synthesis as example. A spatial discretization scheme optimizing accuracy and CPU time is developed. For low switch time constants, the van Leer and van Albada flux limiter functions used in conjunction with the DASPK solver yields the lowest CPU time for the integration of the resulting ordinary differential equations. For larger switch time constants, conventional central differencing can be applied. A network generation methodology is implemented accounting for the isotopic labeling. It reduces the exponential dependence of the number of considered species on the carbon number to a quadratic dependence. For a reaction network allowing a maximum chain length of 5 carbon atoms a gain in CPU time up to a factor of 10 can be achieved.