2 replies to this topic

Hi, I'm new here. I'm currently doing a design project on azeotropic distillation. I'm supposed to separate methyl methacrylate from methanol. There is an acetone cyanohydrin by-product and a n-hexane entrainer is used to form another azeotrope with methanol so that a more pure methyl methacrylate can be obtained in the bottom stream. Right now I'm not sure how I should go about this design.

I've calculated the relative volatilities and obtained a min reflux ratio of 2.6 and min no. of stages at 5 for the rectifying section. The pressure across the column was assumed to be constant. I'm going to calculate the pressure drop across one plate and multiply it by the number of plates in the column. I will then use this overall pressure drop to estimate the condenser, reboiler and column pressure. After that, I will iterate it to get the optimum pressure.

Is what I'm doing correct? I'm also not very sure how to get the number of plates and optimum reflux ratio because currently, hysys keeps saying there is some error with my column and won't run. Please help!

[Ankur Shah]

hey!

i am dising an azeo system too. but different components. Hysys solves the problem at times but not always. have you obtained the VLE or VLLE plots for this? if not, then use a simulator like aspen or a database like dechema to get the plot. from there find out whether or not you neet hetero or homgeneous azeo distillation.

then using that figure out your stage purities and preferably how much concentration you shall obtain at the exits.

Find out these, and i shall help further.

Ankur

[ilkay]

Hi, I'm doing a project an azeotropic distillation too. I'm supposed to seperate toluene from methanol. There is an acetone entrainer is used to form another azeotrope with methanol so that a more pure toluene can be obtained in the bottom stream. With using simply fractional distillation (without plate) could we seperate them?

methanol+toluene BP at 63,8 C
Methanol+acetone BP at 55,7 C
I'm also not very sure optimum reflux ratio.