Lime Salts- Purpose and Process

[gundog48]

I understand the basic principle of lime salts, basically to scavenge the carboxylic acids from the waste streams of the spirit run by locking them up as salts, separating them, then dissolving them in ethanol with the addition of sulphuric acid to liberate the acids and leave calcium sulphate. Now dissolved in an overabundance of ethanol and with sulphuric acid as a catalyst, the carboxylic acids can readily esterify under reflux.

This makes a lot of sense, but I'm hung up on one particular aspect of the mechanics of it, the separation of the calcium + carboxylic acid salts. As far as I can tell, the only way to separate them is through evaporation. Evaporating such a large volume of mostly water would require quite a lot of energy. At that stage, what is the purpose of actually evaporating it into a dry powder? Would it not be equally as effective to reduce the volume enough that high strength ethanol could be added to bring the ABV up enough for sufficient esterificaton?

My plan looks something like:

• Carry out fermentations and stripping runs as usual

• After the spirit run, combine the clear backset and deep tails (or just cease distilling earlier)

• Add sufficient CaOH to raise the pH to something like 12+

• Separate out the calcium salts (this is where I'm struggling) or significantly reduce the volume

• Add clean alcohol to a minimum of 60% ABV

• Add sulphuric acid to precipitate out calcium sulphate

• Reflux the resulting spirit until reactions are deemed complete

• Distil the mixture, collecting a concentrated ester distillate for blending and leaving behind the calcium sulphate salts.

• This is to be carried out in a stainless boiler to prevent reactions with copper

I'd love to know your thoughts, and if there is a procedure for separating out the lime salts without boiling off loads of water!