Miscellaneous: Ethanol purification (method 2)

Water is effectively absorbed by completely dry sodium chloride. On the other hand, NaCl absorbs ethanol poorly. Therefore, these facts can be used for ethanol purification. In case one starts with 96% ethanol, it would be best to distill ethanol first (after reacting it with calcium oxide), and then further purify the ethanol by implementing the following method.

One should prepare sodium chloride in form of somewhat larger crystals. Water softeners based on sodium chloride are a good choice since they come in the preferable form, and are usually cheap. This kind of salt usually already contains some moisture, so it should be heated in an oven at a temperature higher than 100 °C, for about 30 to 60 minutes.

Such sodium chloride must then be poured in some kind of pipe or tube (that can have various dimensions and can be made of various materials). On one end of the tube one should attach a gauze or something similar, in order to prevent NaCl from pouring out.

On the upper side of the tube, a funnel is attached and alcohol is then slowly added. In a few moments, purified alcohol should start dripping from the other end of the tube. This can be done several times.

This method of ethanol purification is suitable for alcohol containing 1 to 2% of water. By using this method, one can obtain fairly pure ethanol, which should be stored in an airtight container soon after the purification is done.