Anyone who know where I can buy this kind of alcohol?
Neutral grain spirit or grain neutral spirit (GNS)) is a clear, colorless, flammable liquid that is distilled from cereal grain and has a very high ethanol content. The term neutral refers to the fact that it lacks any flavor derived from the mash used to distill it, nor does it have any flavor added to it after distillation. The grain from which it is produced can be any of the common cereal grains. Other kinds of spirits, such as whisky, are distilled at lower alcohol percentages in order to preserve the flavor of the mash.
Generally, any distilled spirit of 170 proof or higher that does not contain any added flavoring is considered to be neutral alcohol.
The purity of neutral grain spirit has a practical limit of 190 proof because a mixture of ethanol and water becomes an azeotrope at 95.6% ABV (191.2 proof).
Neutral grain spirit is only one type of neutral spirit. Neutral alcohol can also be produced from grapes, sugar beets, sugarcane, or other fermented plant material. In particular, large quantities of neutral alcohol are distilled from wine, a product that is referred to as vinous alcohol.
Neutral grain spirit is used in the production of blended whiskey, cut brandy, some liqueurs, and some bitters. As a consumer good, it is almost always mixed with other beverages to create such drinks as punch and various cocktails, or to produce homemade liqueurs.