The main reasons for changes in the environment surrounding us are discussed on the basis of thermodynamics of irreversible
processes. Subsequently, relations between thermodynamics of irreversible processes and chemical kinetics are shown, then
the possibilities of theoretical determination of rate constants on the framework of the modified RRKM theory are presented.
These latter considerations are supplemented by a discussion concerning the possibilities of determining the activation barriers
and structural changes (necessary to account for entropy changes upon reaction) in molecules kept on the surface of crystalline
phases by combination of quantum chemistry methods for isolated molecules with those reflecting the influence of the environment
(i.e. interaction within the lattice). Finally, the future of theoretical methods in examining the reactivity of solid state
systems is briefly discussed.
Solid complexes of RE(NO3)3(Sm, Tb) and aspartic acid were prepared for the first time in aqueous solution. Based on chemical analysis, elemental analysis
and IR spectra, the formulae of the complexes were determined as RE(NO3)3(Asp)2·2H2O (RE=Sm or Tb,Asp=Aspartic acid). Their thermal decomposition mechanism were studied from ambient temperature to 700°C using a linear heating
program. The study indicates that the courses of thermal decomposition of the two complexes are very similar.
kinetics and mechanism of nickel oxide reduction by hydrogen. This alternative theoretical model has been developed during the last 20 years [ 24 – 33 ] to explain the kinetics and mechanisms of thermaldecompositionsofsolids. It is applied to metal oxide
It should, by now, be obvious to researchers interested in ThermalDecompositionsofSolids that the theoretical foundations of this subject are (at best) of doubtful validity or (at worst) nonexistent. The
The role that can be played in the elucidation of the limestone sulphation mechanism by thermal analysis methods with some
specific procedures is discussed. Contrasting examples of applications of thermoanalytical techniques using the variable conditions
are provided. These examples deal with the programmed thermal analysis using different gas sequences, the influence the calcination
and sulphation conditions on the capture of SO2, the effect of catalysts on limestone sulphation and the thermal stability of CaSO3. Two proposed mechanisms were supported by the phase identification of the solid products.
Authors:B. Pacewska, D. Szychowski, A. Klepańska, and P. Stefaniak
In the present work an attempt was made to obtain mineral-carbon sorbents by thermal decomposition of solid waste materials
containing, besides to mineral components, solid petroleum derivatives. The amount and the homogeneity of distribution of
coal product formed in decomposition of organic matter on the surface of the mineral matrix, as well as the porous structure
of the sorbents obtained depend largely on the conditions of calcination of the wastes used. The aim of this work was to find
optimum conditions of the process. The sorptive properties of the obtained material were checked in the process of reduction
of pollutants contained in industrial wastes.