3 replies to this topic

[rashed]

does anyone know how to calculate ideal gas heat capacity in aspen plus?
i will be grateful if u reply..............it is urgent.

[Zauberberg]

Rashed,

I'm not sure about AspenPlus, but you can use weighted average heat capacity of components present in the mixture - calculated by the following formula:

Cp = w1.Cp1 + w2.Cp2 + ... + wn.Cpn = SUM(wi.Cpi), where:

wi - weight fraction of component
Cpi - mass heat capacity of component

If you are dealing with small number of components, the calculation is straightforward and the references can be found in any engineering handbook (probably on the internet as well). If the number of components is huge, focus your calculation efforts on those components having the highest weight content in the overall mixture. This is an easy task.

Best regards,

[rashed]

thanks for ur reply.............but the problem is little bit different here. i need the values of Cp at
1700c-2000c for some components. but i cann't find the values of Cp at those temperature range in any of the chemical engineering handbook.

so...........if you know or anyone knows how to find values of Cp at those temperature range....plz inform me.

my design calculation has stopped for these data.

[Zauberberg]

Rashed,

What is the composition of your stream, and what is the pressure range we are talking about? Please update your post with required data.