It is possible to separate alcohol from water in many different ways. The most common method involves heating the mixture; since alcohol has a lower boiling point than water, it rapidly transforms into vapor and then condenses in another vessel. You can also freeze the alcohol solution, thus allowing you to partially remove the non-alcoholic components and obtaining a more concentrated compound. Use common table salt to separate the isopropyl alcohol from the water. this method allows you to obtain a condensed compound that is not suitable for human consumption.
Steps
Method 1 of 3: by Distillation
Step 1. Create a closed distillation system
The simplest method involves the use of a spherical (boiling) flask, a condensation unit and a second glass vessel for the separating liquid. For such an experiment, it is recommended to insert a distillation column between the spherical flask and the condensation unit.
- For this process it is necessary that the two liquids have very different boiling points.
- This is a simple method that requires less heat and is simple to follow; however, the result is less accurate.
- It is also possible to get a more complex alembic, an instrument made specifically for distillation.
Step 2. Heat the mixture in the round flask
The boiling point of water corresponds to 100 ° C while that of alcohol is 78 ° C; as a result, alcohol turns into vapor faster than water.
- Use a heat source that allows you to quickly vary the temperature, such as an isomantel.
- You can also use a regular hot plate or propane flame.
Step 3. Insert the distillation column into the flask opening
It is a straight glass cylinder, inside which there are metal rings or plastic beads that trap the less volatile gases in the lower part of the column itself.
- As the vapor rises from the boiling liquid, the more volatile substances move upwards.
- When working with a mixture of water and alcohol, the latter reaches the upper ring.
- Insert a thermometer to measure the temperature of the gases contained in the distillation system.
Step 4. Wait for the vapor to cool and condense
As it passes through the distillation column, its temperature is reduced and it begins to return to the liquid state, that is, it condenses.
- The distillation process goes through the following phases: heat, evaporation, cooling and finally condensation;
- Condensing, the vapor becomes heavier and drips into the collection vessel;
- The distillation column should be wrapped in cooling tubes to speed up the process.
Method 2 of 3: by Freezing
Step 1. Make a 5-15% alcohol solution
You need a container that can be frozen and thawed safely and an environment where the temperature is below 0 ° C (a freezer or, if you live in a harsh climate, the outside of the house). This method exploits the different freezing points of water and alcohol, a bit like distillation which is based on different boiling temperatures.
- It is an ancient technique that has been practiced since the seventh century.
- You can do some research online to learn more about the history of this process.
Step 2. Put the solution in a bowl
Water expands when freezing, so make sure the container is large enough to prevent it from bursting. The water content of the solution expands, while the amount of alcoholic liquid is reduced due to the extraction of water.
- The freezing temperature of water is equal to 0 ° C, that of alcohol corresponds to -114 ° C; in other words, alcohol never freezes under normal conditions.
- Suck the liquid out of the frozen substance once a day; the longer the freezing period, the higher the alcohol content.
- If you are working with large quantities, use very large containers; choose food-grade plastics, as low-quality plastics may contaminate the solution.
Step 3. Remove the frozen material from the container
It should be mostly water while the alcohol, which has a lower freezing temperature, should remain liquid.
- The liquid residue should be highly concentrated, but not pure alcohol.
- It should also have a very strong flavor; for this reason, this technique is used for apple jack, traditional beer and ale.
- Apple jack takes its name from the preparation process which in America was known as "jacking".
- This method does not allow to remove impurities compared to distillation.
Method 3 of 3: with Salt
Step 1. Pour some salt into the alcoholic solution to proceed with the azeotropic distillation
This technique separates alcohol from water by dehydration. What you get is alcohol that can be used as fuel, to remove fleas and ticks from pets, as an antiseptic or to remove ice from the windshield.
- Dehydrated isopropyl alcohol is an essential part of the biodiesel creation process.
- This process is sometimes referred to as distillation by extraction.
Step 2. Collect the necessary materials
To separate the isopropyl alcohol you need an alcoholic mixture (with a concentration between 50 and 70%), a container to contain the extracted liquid, a large glass jar for mixing (two liters), 500 g of salt iodine-free and a fine-tipped pipette.
- Check that all tools are clean, jars and pipette included.
- You can buy isopropyl alcohol at a pharmacy without a prescription; usually, the bottles are 250 or 500 ml. For this experiment, 1 liter of alcohol is required for a 2 liter glass jar.
Step 3. Fill the bowl 1/4 of its capacity with salt
Check that it is non-iodized salt, otherwise you could contaminate the distillation process; the required dose corresponds approximately to a normal pack of table salt.
- You can use any brand as long as it does not contain iodine.
- You can use the doses you prefer, as long as you respect the proportions of four parts of liquid and one of salt.
Step 4. Pour the alcohol into the jar with the salt and shake it well
At this point, the container should be about 3/4 full; if there is more liquid, it does not have enough space to allow the expansion that occurs when mixing the two ingredients.
- Before shaking the jar, make sure the lid is tightly closed.
- Check the contents to make sure the salt and liquid are well mixed before you stop shaking.
Step 5. Let gravity separate the components
It takes about 15-30 minutes for the salt to settle to the bottom. The liquid that settles on the surface has a higher alcohol content and represents dehydrated isopropyl alcohol.
- Don't let the layers mix again.
- This happens because the molecules of salt, instead of those of alcohol, bind with the molecules of water.
- When you open the jar, proceed carefully to avoid shaking it too much; otherwise, you disturb the content and have to repeat the process.
Step 6. Use a pipette to extract the distilled alcohol from the top layer
Make sure you have another container on hand already labeled "distilled isopropyl alcohol".
- You have to use the pipette very carefully to draw up only a small dose of alcohol at a time.
- Be careful not to shake or tilt the jar or pour the liquid as you remove the alcohol.
Warnings
- Home distillation is illegal; check local and regional laws governing the production of alcohol.
- Isopropyl alcohol is not suitable for human consumption but only for topical use or as a fuel; a dose of 240 ml is lethal.
