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Study of the thermal decomposition of solids in a fluidized bed, III

The influence of the humidity upon the thermal decomposition of diammonium hydrogen phosphate under isothermal conditions

Journal of Thermal Analysis and Calorimetry
Authors: F. Margineanu, P. Kröbl, and C. Liteanu
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Abstract  

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.

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Study of the thermal decomposition of solids in a fluidized bed, II

Thermal decomposition with programmed temperature of diammonium hydrogen phosphate

Journal of Thermal Analysis and Calorimetry
Authors: P. Kröbl, F. Margineanu, and C. Liteanu
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Abstract  

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.

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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 thermal decompositions of solids. It is applied to metal oxide

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Theory of solid-state thermal decomposition reactions

Scientific stagnation or chemical catastrophe? An alternative approach appraised and advocated

Journal of Thermal Analysis and Calorimetry
Author: Andrew K. Galwey

Introduction It should, by now, be obvious to researchers interested in Thermal Decompositions of Solids that the theoretical foundations of this subject are (at best) of doubtful validity or (at worst) nonexistent. The

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Abstract  

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.

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Abstract  

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.

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