Fuel Ethanol still using Vapor Management
Boiler, can be made of an oil drum for instance ( 200 litres/50 US gallon or smaller) and be heated by fire, steam, with a gas burner or an electric heater.
Alcohol is highly inflammable. If open fire is used as heat source; make sure the still is in a well ventilated area.
The speed of this still is controlled by a ball valve. This makes it easier to adjust speed so it can produce high strength. It is capable of producing 95% alcohol and is independent on how much cooling water is used as long as enough is provided to cool down all vapor. It has a handy extra feature, when there is no alcohol left in the boiler the product flow will automatically stop.
Detailed instructions of the column:
1. Column, 3” one meter, filled with packing. The column should be filled with packing up to the product coolers outlet. The outlet shouldn’t be covered with packing. The top of the column is sealed.
2. Product cooler. From the side of the column a pipe is connected. Horizontally on the pipe a ball valve with the same diameter as the pipe is connected. Proper size on the pipe is about 30-40 mm. The cooler should be at least 700 mm. Either straight down as in the picture or at a 45 degree angle down. Using it in an angle down will balance the weight better since the reflux cooler is rather long.
3. Reflux condenser. Inner pipe 40 mm, one meter long, outer tube 50 mm diameter 800 mm long. A hole is made into the column and the cooler is welded into place, the angle is not critical but use something close to that on the picture. The bottom end in the column should be close to the center of the column. Important! The other end has to be open to air.
Connect cooling water like this:
Cooling water inlet at the bottom of the product cooler. Water from the outlet of the product condenser goes to bottom of the reflux condenser.
How to operate this still:
Make sure there is at least 30 cm (1 foot) free space in the boiler when it is filled up with mash.
The ball valve on the outlet determine the speed of the still. If it is almost closed, most vapor will go up to the reflux condenser, vapor condense and is returned to the column. This increase strength, speed goes down.
Use the thermometer at the top of the column to see if the speed is too high, if the temperature is above 78-79 °C close the valve a little and in a matter of minutes the temp goes down. The still is capable of producing an end product of 95,5% if fine cuttings are used as packing and the ball valve is just a little open. If the valve is opened too much strength will drop, speed increase. Even at fully opened some reflux will be provided by the reflux condenser so strength will be over 60-70%
Close the ball valve completely. Heat up the still and turn on cooling water. When the temperature start to rise at the top of the column, keep the valve closed for another 10 minutes. Then open the ball valve slightly and collect product. This will make high proof alcohol until the boiler temp is around 97 C. How much the valve can be opened depends on how much power is used and the alcohol content in the mash. Watch the top temperature, it should be steady at 78. If it rises, close the valve more. It takes a few runs to learn how much the valve can be opened to achieve high strength and good speed.
For producing high quality drinking alcohol it's necessary to first remove heads. At the beginning when the product start coming out, product will contain volatile substances called heads. Remove them slowly with the ball valve just a little opened. It has a strong smell and will taint the alcohol if not removed. It takes about an hour or two to remove them completely. After that pure ethanol is withdrawn until boiler temp is around 97 C. Run the still slow the first few runs to learn what quality can be achieved. Then increase speed. The slower the still is ran the better the quality become.
The thermometer on the boiler is optional but it is practical to see when it's time to stop distillation. When it's close to 100 °C it's time to turn the still off.
Packing: It is essential to have some kind of packing into the column. There are several options. Either use 9 mm raschig rings made of ceramics. Or cut 10 mm copper pipe in 10 mm pieces. Or use pot-scrubbers that are made from stainless steel.
Lathe cuttings from stainless steel are a very good packing. This is the preferred choice.
If raschig rings are used it’s necessary to have some kind of packing holder at the bottom of the column. A plate with many holes. Pot-scrubbers and cuttings doesn’t need any plate, it will stay in place by the column wall.