compound catalytic distillation

[Jobson&Rusakova]

What does compound catalytic distillation consist of?

Thank you.

[Charles@AEppelTreow]

Not sure how it applies in beverage distillation, but in the specialty chemical world, catalytic distillation is a process where you use sieve plates loaded with catalysts beads, or formed saddles, rather than inert ones. There are several variations - for instance, I think there's an implementation where bubble plates are made from a catalytic metal.

The general idea is to do a reaction in the separation device to save building two pieces and pumping the recycle around. Not many commercial examples exist. Mostly, reactions and separations take place at incompatible conditions.

Consider a column still. It has an upward current of material (EtOH vapor), and a downward current (condensate). That's a counter-current operation - an important idea. In catalytic distillation, the downward moving stream carries the reactants. Reaction products move with the upward moving stream. Ideally, the reactants are consumed before they can reach the head of the still. The product is swept up and out, purified from the reactants. Also, the products effectively see a higher space velocity with the catalyst compared to the reactancts (less residence time) - so they don't get as much chance to back-react. You can use a scheme like this to drive a reaction past thermodynamic equilibrium.

I spent a couple years doing reactive chromatography - a related idea.

[Jobson&Rusakova]

That was a great explanation. I looked at couple of industrial examples but I did not see how the concept applied to separating ethynol from other chemicals. On Skyrocket Distillery's webpage they say they use a proprietary compound catalytic distillation process. I was just wondering what a compound catalytic distillation process might do.

Thank you for your response.

Robert

[Charles@AEppelTreow]

They're probably not doing what I described - which I realised later is usually described as reactive distillation. There are some S and N compounds in mash that are dealt with catalytically. All you need is lots of hot copper.