General homogeneous shrinking core problem

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SUMMARY

The discussion revolves around the derivation of the general non-catalytic shrinking core model, specifically focusing on the transient behavior of the retreating interface as outlined in Ishida's paper from AIChE Journal (1968). The equation presented involves differentiating with respect to concentration (c) and includes hyperbolic sine functions. The solution provided by Ishida is confirmed, but the original poster, Jason, struggles to replicate it. Ultimately, Jason resolves his confusion with assistance from the community.

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jpmann
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Hi Guys,

First post here. I'm just wondering if anyone could lend a helping hand in the following derivation. It is taken from Ishida AIChE J 14 (1968) 311 (also very similar to that derived by Ausman Chem Eng Sci 17 (1962) 323) and concerns the derivation of the general non-catalytic shrinking core model.

The step which is confusing me concerns the derivation of the transient behavior of the retreating interface. This is achieved through setting [tex]a' = a[/tex] and [tex]X = 0[/tex] and differentiating with respect to [tex]c[/tex] within the following equation

[itex]X = 1 - \frac{{\sinh \left( {ab} \right)}}{{a\sinh \left( b \right)}} - \frac{{\sinh \left( {ab} \right)}}{a}\int_{c1}^{c} {\frac{{{{a'} \mathord{\left/<br /> {\vphantom {{a'} {\sinh \left( {a'b} \right)}}} \right.<br /> \kern-\nulldelimiterspace} {\sinh \left( {a'b} \right)}}}}{{1 + d\left[ {1 - a + \frac{a}{{Sh}}} \right]\left[ {a'b\coth \left( {a'b} \right) - 1} \right]}}} dc[/itex]

The solution given by Ishida is

[tex]\frac{{dc}}{{da'}} = - \frac{1}{{a'}}\left[ {a'b\coth\left( {a'b} \right) - 1} \right]\left[ {1 + d\left[ {1 - a + \frac{a}{{Sh}}} \right]\left[ {a'b\coth\left( {a'b} \right) - 1} \right]} \right][/tex]

however, no matter how hard I try, I can't seem to arrive at their answer. I know I'm missing something simple, but I just can't see it. Any help on a way forward with this problem would be greatly appreciated.

Thanks and kind regards,

Jason
 
Last edited:
Engineering news on Phys.org
Problem solved. Thanks for anyone who had a look.
 

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