Unit 5 - Continuous Distillation - School of Life Sciences

Unit 5: Continuous distillationHere we see a wash, or beer, feed 24 trays above the steam entrypoint at the bottom of the stripping column, or concentrator. Therectifier has 40 trays with the product stream drawn off at tray 35 andfusel oil removed at tray 5. Propanol could be drawn off at tray 8 ifnecessary. The condenser system at the top of the rectifier providesreflux, allows some vapour to be vented and separates heads, whichare recycled to the stripping column. Feints are returned to thestripping section from the base of the rectifier.If the columns are built in stainless steel, then it is necessary toprovide some sacrificial copper in order to bring about thosereactions which remove unwanted compounds. This is done bypassing the feints stream through a tank packed with small coppercuttings.5.7 Neutral Spirit Production5.7.1 SpecificationsNeutral spirit is the spirit used in the production of gin, vodka andsome other drinks. It is odourless, tasteless, and is continuouslydistilled in column stills all over the world. Escaping the legaldefinitions attached to Scotch Whisky, it is most economically madeusing commercial enzymes rather than malt. The starch source isusually of cereal or sugar origin, but even whey and potatoes areused.There are legal definitions for neutral spirit though they are generallyset at easily attainable standards. Producers or purchasers of neutralspirit for high quality gin or vodka will have much tighterspecifications than those demanded by regulations.The main parameters of the European Union definition are comparedwith a typical product specification in Table 1.© 2001 The International Centre for Brewing and Distilling 24