Vmin question

At 12:00 15.01.2004 +0000, you wrote:
>good day Mr sigurd
>i hope that you are in a good health.
>i have some quetions about the " distillation column"
>i beg that you give me a help
>1- is there any relation between the location of the feed plat and the
>energy consumed inside the distillation column (i.e. if the feed plate is
>not optimal is it affects the energy consumed inside ( binary
>separartion) .

Yes, of course, but around the optimal location it is relatively flat.

>2- you have said in our paper " dynamic control of a distillation column"
>' with an infinite number of stages, we can reduce the reflux( the energy
>consumption ) until a pinch zone occures some where inside the column.
>can we deduce from it that if the feed stage is not optimal this means
>that Vmin2>Vmin1.

The feed location is not an issue when you have an infinite number of stages.
If you use Vmin2 > Vmin1 then this simply means that you are using too much
energy without any benefit.
For a finite number of stages Vmin2>Vmin1 could imply that you are
overpurifying the products.

Best regards,
Sigurd Skogestad

>tanck you for all.

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Sigurd Skogestad, Professor and Head Phone: +47-7359-4154
Department of Chemical Engineering Home: +47-7393-6855
Norwegian Univ. of Science and Technology (NTNU) Fax: 7359-4080
N-7491 Trondheim email: skoge@chemeng.ntnu.no
Norway users/skoge
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Received on Fri Jan 16 16:44:24 2004