Gaseous argon is tasteless, colorless, odorless, non corrosive, and nonflammable. Argon belongs to the family of rare inert gases. It is the most plentiful of the rare gases making up approximately 1% of the earth’s atmosphere. It is monatomic and extremely inert, forming no known chemical compounds.
Special materials of construction are not required to prevent corrosion. Vessels and piping should be designed to American Society of Mechanical Engineers (ASME) or Department of Transportation (DOT) codes for the pressures and temperatures involved.
Argon may be compressed into cylinders by water or oil-lubricated compressors or by dry compression systems. To determine the amount of argon in a cylinder, use the appropriate pressure and temperature capacity chart for a specific size cylinder. (The higher the pressure, the larger the amount of argon in the container.)
Argon is produced by an air separation unit(ASU) through the liquefaction of atmospheric air and separation of the argon by continuous cryogenic distillation. The argon is then removed as a cryogenic liquid.
The ASU manufacturing process begins with a main air compressor and ends at the output of the product storage tanks. Air is compressed and sent through a clean-up system where moisture, carbon dioxide, and hydrocarbons are removed. The air then passes through heat exchangers where it is cooled to cryogenic temperature. The air then enters a high pressure distillation column where it is physically separated into a gaseous form of nitrogen at the top of the column and a liquid form of “crude” oxygen (~90%) at the bottom.
Argon is the major contaminant in this crude oxygen, which is then sent to a low-pressure distillation column where the oxygen is purified. The argon-rich waste stream from the low pressure column is sent to an argon distillation column. Some argon technologies distill the argon directly to its final manufacturing purity, while others utilize a separate step to purify it, for example, hydrogen deoxo. Purified argon is stored as a liquid in storage tanks at the site.