Mathematical-Thermochemical Modeling of High Temperature Corrosion Processes in Waste Incineration Plants

Oleg Chizhko

International Independent University of Political and Environmental Sciences, Institute for Environmental High-Technologies, Post-Box 88, Cherkessk, Russia,

Oleg.Chizhko@alumni.uni-karlsruhe.de

We regard a model of the thermal destruction for municipal solid waste on the 'TAMARA' roasts. We add fine- dispersed metals in the form of a powder to the fuel (25% of coal, 15% nitrogen, till 5% hydrogen, 25% inert material and 30% water) with aim to investigate the formation of metal rest species.

In this reactor each of the M species has an activity . We compute an activity a_ji of the i-substance in the j-reaction as a difference of the total sums of chemical potentials for the N products and L educts, which take part in the j- reaction . a_j is the activity of the j-reaction. We search a solution of the differential equation in the form of Euler’s operator . n_i is the equilibrium concentration of the i-specie.

Following this iteration process we reach the start concentrations of the P elements (b_l) with the global error of 10^-7. The difference method is stable because of the continuous dependence of the n_i on imputed elementary balances in the interval I=[t₀,b_l]. The width of a step h is the calculated minimal value of a stechiometric coefficient in a case, when the activities of all substances in a chemical reaction are maximal (=1).

q_lm is the quantity of the l-element in a reaction. m is the number of species, which include the l-element.

The program complex ‘MeRS-data’ (metal rest species) is the computational program for the equilibrium activities of multi-component systems. The databases contain the 'IVTANTHERMO' constants and coefficients for the approximation of thermodynamic functions.