I have used appropriate references for all the values and inputs that I have used for simulation. Please kindly help me out. I have been working through this for quite sometime.
I used unisim for carrying out this. File is attatched below if anyone is free to debug.
Arjun,
I haven't been able to open your file, since I'm locked down away from the Unisim license !! However there are a couple of things worth looking at. From your screenshot the equilibrium error is very big which makes me think you have either over specified the column unit or perhaps you have an immovable phase going in, ie your ether bottom stage is fully vapourized before it hits the column or your column operating parameters are outside the phase envelope everywhere?? Columns can be twitchy at best and careful specification is required. Have you looked at the UniSim knowledge base for example files? It's a little different from the Aspen KB but I believe there is some good help in there.
It may be worth posting up your work file in XML format. Then people with slightly older UNISIM versions may be able to open the file??
Hi Arjun,
I don't have unisim but I may have the feeling that your issues are not software related but theory/method related. Also I'm more used to work with Pro/II and Prosim, but I'll try to give you some lead.
Is your feed a classic mixture without anything specific (like not any azeotrope or whatnot?)
How did you calculate the NET and relfux ratio ?
Whatever the method you used to perform your preliminary "thermodynamic" sizing calculation (Shrotcut, McAbe&Thiele, Ponchot&Savarit or by some feedback) you should choose wisely the specification of your column.
After fixing the NET I would advise you to fix at first the reflux ratio and the specification. If this does not work, try to estimate the duties of you reboiler and condenser to put them as parameter of your column. This should get you close to the operating point you're searching and then you can update the initial guess and make some ajustments to obtain the operating point you want.
Sorry if my english is wrong,
Kind Regards
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