Effectiveness Factor for Nonisothermal Catalyst Pellets

Apparently we operate in the high t] region and thus expect Equation 6.57 to be more accurate than Equation 6.58. Ibis is confirmed when using the much more accurate approximation 6.59 to calculate the effectiveness factor  

Thus the value of t] obtained will be more than accurate enough for all practical cases. 

9 Nonisothermal Catalyst Pellets and First-order Reactions 

A reaction of the order Vi is carried out in a spherical catalyst pellet. For the given surface temperature and concentration the product ksCAjmii equals 0.2 s 1. The effective diffusion coefficient has been determined as 2 x Iff7 m2 s 1. The diameter of the sphere is 6 mm. Fur- 

The effectiveness factor must be calculated, with and without neglecting the heat effects. According to Equations 7.13 and 7.14, for the Aris numbers 

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