Industrial applications of multi-phase thermochemical simulation

The multi-component Gibbs energy simulation provides an efficient tool for quantifying measured data in complex industrial systems. The advantages of the multi-phase methods have been recognized and they are becoming widely accepted in different applications, ranging from metallurgy and mate rials processing to chemistry and energy and environmental technologies. The thermodynamic multi-phase theory provides an effective method to support industrial process development by quantitative process analysis. By using the Gibb senergy, based calculations the chemical equilibria in complex multi-phase systems are determined and quantitative results are received for all that can be defined with the thermody namic properties of their constituents. The multiphase Gibbs energy method enables simult aneous computation of chemical and energy changes. Further, the thermochemical approach provides a method to solve the bulk chemistry together with the speciation of man y minor constituents, such as harmful trace compounds.

Recent development has brought new phenomena, such as ion exchange and surface properties to the Gibbsian multi-phase domain. The thermochemical calculations can be applied e.g. on aqueous pulp suspensions to follow the chemical composition and alkalinity of the pulp and paper-making processes. New advanced algorithms also allow for the use of reaction rate constraints in multi-phase Gibbsian simulations. Combination of reaction rates with the thermochemical, method brings about simultaneous and interdependent models for chemical and energy changes in such reactors that involve endo-and exothermic reactions together with operator controlled heat and mass transfer effects. The practical applications include process internsification, optimization, troubleshooting, scale-up, study of new chemical concepts and search for new, more economic process alternatives.