Short cut to rigorous distillation

[thubelihle]

If l have results from short cut distillation (actual number of stages,feed stage and reflux ratio), then plug these into a rigorous column and the product purity is not achieved. In industry, what is then varied to obtain product purity? Is number of stages or reflux ratio? Which one is the best. Thanks

[hkooijman]

that depends on the relative volatilities and stages already applied. generally stagescare cheaper but i suggest trying both

[thubelihle]

Thank you for the answer. Was wondering, l did a material balance by hand before embarking on a simulation. I obtained distillate rate and bottoms rate. I then used the minimum reflux ratio obtained from shortcut method and bottoms flowrate as specifications of the rigorous distillation column. I then used number of stages to optimize my column but it seems the number of stages do not affect my parity. Was wondering if the number of stages have any effect on bottoms and distillate rate?

[jasper]

Bottoms flowrate, and what is your second specification?

[thubelihle]

Reflux ratio

[thubelihle]

Which was 1.5 minimum reflux ratio

[thubelihle]

May be the question is if l fix the bottoms flowrate, hence ultimately fixing the distillate flowrate, can l improve distillate purity by changing the number of stages with the reflux ratio fixed

[hkooijman]

May I suggest you to text books on the material? For example https://www.wiley.com/en-us/Separation+ ... 1119239598 or else Perry's Handbook of Chemical Engineering? I think both have explanations on how to apply short cut methods. Faster may be to follow the slides from https://cheguide.com/wp-content/uploads ... risafi.pdf that the web-site https://cheguide.com/2017/06/shortcut-distillation/ points to.

[thubelihle]

Thank you so much