[Phantom]

Hello, I am currently being assigned in doing a project entitled "Extractive Distillation of C4 to Obtain Butadiene using DimethylFormamide(DMF)". It was rather challenging and I am heading nowhere as I had take a long time in trying to carry out the material balance. One of the challenges is to receive key data like operating temperature and pressure as well as its vapor and liquid composition after being distilled by different column.

The things go like this:
I am required to design a plant to produce 100kMT of Purified Butadiene annually. The feed consists of Butadiene (x=0.5), 1-Butene(x=0.38), Butane (x=0.1), Vinyl Acetylene (x=0.01), Methyl Acetylene (x=0.009) and water (x=0.001). The feed to the first extractive distillation column is 7 times the raw feed flow.

The problem is:
How should I calculate the vapor composition and liquid composition after the first extractive distillation step as well as its bottom and top temperature noting that the relative volatility of butadiene and vinyl acetylene change significantly (from very volatile to being able to come out in the bottom product, as I understand from literatures...)? I am only allowed to use manual calculation for this purpose and Aspen can only be used to check the accuracy of Manual calculation..can anyone please help me?

Thanks...

[eugenedakin]

Hello Phantom,

Good question!

Could you help me out by providing a process diagram, rates, reactants and stoichiometry of your project?

This will help me understand a little more of your exact process.

Thanks for your help,

Eugene