The reasons are as follows: first, a lot of endothermic reaction
processes are ignored when adopting the single-step chemical reaction; thus, the temperature and velocity obtained are higher.
Above the combustion zone (4 cm up to the grate), temperature decreases because of the presence of endothermic reactions
in the reduction, pyrolysis, and drying zones, with the exception of the shift reaction (CO + [H.sub.2]O [right arrow] C[O.sub.2] + [H.sub.2]).
Increasing pressure during the gelatinization process causes an increase in the peak reaction temperature, or the temperature at which the endothermic reaction
occurs at a maximum.
Figure 1 shows that a small decreasing effect of temperature profile is found for increasing values of E for exothermic reaction ([beta] = 1), but mark opposite effects are found for endothermic reaction
in Figure 1.
The endothermic reaction
occurring in that region is the breakdown of the kaolin molecules releasing water, which is then driven off by the high heat ([Al.sub.2][O.sub.3] x 2Si[O.sub.2] x 2[H.sub.2]O [right arrow] [Al.sub.2][O.sub.3] x 2Si[O.sub.2] + 2[H.sub.2]O).
It is found that the 250 [micro]m particles absorb around -3.4 mW of energy during endothermic reaction
and found -4.6 mW for 2057 [micro]m particles.
5 also indicates how the endothermic reaction
approaches to equilibrium.
It forms aluminum oxide at 180[degrees]C to 200[degrees]C via an endothermic reaction
that absorbs heat from the fire.
Pyrolysis is an endothermic reaction
requiring a net input of energy.
The hydrocracking of DNM is an endothermic reaction
, and higher temperature is favorable for the reaction.
Two different thermal behaviors have been found with endothermic reaction
occurring in first stage.