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4.5.
NON-ISOTHERMAL
TEMPERATURE
mode:
Prediction of the reaction progress
(-)
and reaction rate d /dt
(s-1) for chosen heating rates (°C/min) and selected starting temperatures.

Example:

Figure: Reaction rate d /dt
(DTG, normalized signals) of hydromagnesite decomposition as a function of the
temperature for different heating rates. The values of the heating rate in
°C/min are marked on the curves.
Comments:
In general, non-isothermal scans with different heating rates are carried out
within a much wider temperature range than is possible, from the experimental
point of view, in isothermal conditions. This allows discernment between the
different reaction paths involved in the kinetic process because the data
contain the necessary information on the time-temperature dependence of
particular processes which is a prerequisite for the correct identification of
the complex nature of the investigated reaction.
Computations are usually made with the results obtained from at least 5 heating
rates. The application of heating rates too close to each other should be
avoided. If they are very close, they become tantamount to a model-fitting
analysis using single heating-rate methods. Consequently, they may fail the
required purpose as amply reported in the literature [2, 15].
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