plumsmooth
Rising Star
Hi There, would like to contribute to this topic, as some may prefer to opt for the loss, rather than use ipa for FASI FASE. However, I'm sure there are other uses for this clean up/dehydration of drinkable alcohol.
I found this excerpt from this webpage:
Anyway, I did a little math and it looks as though to dry a 750 ml bottle of 95% grain alcohol, one would add 157.5 grams of Lime, then proceed to wait, then decant/filter etc...
DRYING WITH LIME
The oldest method of drying alcohol is dehydration with lime. This process is still used on a laboratory scale. It is similar to the salt absorption method just described except that, with this method, water is removed by a chemical reaction. Ordinary lime (calcium oxide, formula CaO) reacts with water to form calcium hydroxide (formula Ca(OH)2). The process is simple. The water-containing alcohol is mixed with lime at a ratio of about 35 pounds (or more) of lime for each gallon of water to be removed (as determined with a hydrometer) and allowed to “slake" for 12-24 hours with occasional stirring . The lime reacts with the water to form calcium hydroxide. The calcium hydroxide is insoluble in the alcohol and so the relatively pure (99.5%) alcohol goes to the top of the container and the calcium hydroxide settles to the bottom.
The usual method of separating the lime and calcium hydroxide from the alcohol is by distillation. Alternately, but less desirable, the alcohol can be carefully drawn off (decanted) and filtered to remove any suspended particles that give it a milky appearance.
An apparatus based on a 55-gallon drum (similar to that in Figure 13-1) can be built. A still head with thermometer (no reflux column is needed) and condenser should be added to allow simple distillation. Also, a small gate valve located 6-8 inches from the bottom (above the level of the lime) will allow the alcohol to be decanted, if desired.
After slaking in the apparatus, the alcohol should be distilled off through the simple still head and condenser. During distillation, the temperature should remain exactly at the boiling point of pure alcohol. Remaining after the pure alcohol has been distilled or decanted is wet calcium hydroxide and lime.
Some alcohol will also be trapped in the residue. To recover it, continue the distillation. The still head temperature will rise above 173 degrees F indicating that water is coming over with the remaining alcohol. When the still head reaches 208-212 degrees F all of the alcohol has been removed. The water/alcohol distillate should be added to the beer for the next run in the reflux distillation apparatus.
The calcium hydroxide may be converted back into calcium oxide and re-used. However, the temperatures required are quite high unless a vacuum drying oven is used. Since lime is relatively cheap, this process is not recommended.
I found this excerpt from this webpage:
Anyway, I did a little math and it looks as though to dry a 750 ml bottle of 95% grain alcohol, one would add 157.5 grams of Lime, then proceed to wait, then decant/filter etc...
DRYING WITH LIME
The oldest method of drying alcohol is dehydration with lime. This process is still used on a laboratory scale. It is similar to the salt absorption method just described except that, with this method, water is removed by a chemical reaction. Ordinary lime (calcium oxide, formula CaO) reacts with water to form calcium hydroxide (formula Ca(OH)2). The process is simple. The water-containing alcohol is mixed with lime at a ratio of about 35 pounds (or more) of lime for each gallon of water to be removed (as determined with a hydrometer) and allowed to “slake" for 12-24 hours with occasional stirring . The lime reacts with the water to form calcium hydroxide. The calcium hydroxide is insoluble in the alcohol and so the relatively pure (99.5%) alcohol goes to the top of the container and the calcium hydroxide settles to the bottom.
The usual method of separating the lime and calcium hydroxide from the alcohol is by distillation. Alternately, but less desirable, the alcohol can be carefully drawn off (decanted) and filtered to remove any suspended particles that give it a milky appearance.
An apparatus based on a 55-gallon drum (similar to that in Figure 13-1) can be built. A still head with thermometer (no reflux column is needed) and condenser should be added to allow simple distillation. Also, a small gate valve located 6-8 inches from the bottom (above the level of the lime) will allow the alcohol to be decanted, if desired.
After slaking in the apparatus, the alcohol should be distilled off through the simple still head and condenser. During distillation, the temperature should remain exactly at the boiling point of pure alcohol. Remaining after the pure alcohol has been distilled or decanted is wet calcium hydroxide and lime.
Some alcohol will also be trapped in the residue. To recover it, continue the distillation. The still head temperature will rise above 173 degrees F indicating that water is coming over with the remaining alcohol. When the still head reaches 208-212 degrees F all of the alcohol has been removed. The water/alcohol distillate should be added to the beer for the next run in the reflux distillation apparatus.
The calcium hydroxide may be converted back into calcium oxide and re-used. However, the temperatures required are quite high unless a vacuum drying oven is used. Since lime is relatively cheap, this process is not recommended.
