4 replies to this topic

[toiletduck]

Good day to all:

I have completed year 3 of ChemE education,and going towards year 4 in August.
I am now interning in an Ethylene plant.

My tasks involves multi component distillation simulation(debutanizer) and I use the Thiele Geddes distillation method, with the excel file provided by this experienced engineer's website, http://www.chemecalcs.com/tg.php.

I have 9 components and some of these components's VLE K values do not have correlation Equations of the Depriester chart(e.g benzene).

I am not allowed to use Aspen Software because I am not licensed to use it.

Because I read about the UNIFAC method,I decide to write the excel vba program myself(using the Modified Raoult Law to calculate K values) and the code is insanely long. I do not have other softwares apart from Excel vba and matlab to write my program to calculate activity coefficient using UNIFAC method.
And I feel its quite difficult to calculate the residual part of the UNIFAC Equation because I have 9 components.I obtained values of 0.53 to 0.000000000000000000000XXX for my activity coefficient which seems ridiculous.

Therefore I ask if there's any other available means other than Aspen for me to calculate my activity coefficient?

[breizh]

Hi ,

Let you try this resource .
http://www.engg.uaeu...r/downloads.htm

Hope this helps

Breizh

[toiletduck]

Hi Breizh:

Thanks! I previously saw this but don't know how to use.

I think I have to download the XSEOS add in to excel before using.

Will it be possible for me to access the code within XSEOS because I want to see how they program UNIFAC in excel VBA. It seems amazing how they managed to program the unifac function with just the qK and rK values of each component.

Suppose you use a chemical process simulator,such as ASPEN,is calculating the activity coefficient a piece of cake?

Thanks again.Will post if I met difficulty regarding XSEOS.

[toiletduck]

Hi:

May I know how to access the code of the formula,unifac?
I wish to know how they program their Macro.
Since they mention the code are open-source.

Thanks in advance!

[toiletduck]

Ok found out.
I guess I may to add in the XSEOS package first,then open a macro and go to project explorer...