Oleum

Oleum is formed by adding oxygen to sulfur dioxide in the presence of catalyst vanadium pentoxide which forms sulfur trioxide. The sulfur trioxide is then added to sulfuric acid which forms disulfuric acid or Oleum. The newly formed Oleum is then added to water to make a very concentrated sulfuric acid. The key difference between oleum and sulfuric acid is that the olem is sulfur trioxide in sulfuric acid, whereas sulfuric acid is an inorganic acid which is a syrupy liquid that is highly water soluble. Only properly trained and equipped personnel should be permitted to (un)load oleum tank cars and tank trucks. Operators should wear approved PPE equipment including impervious clothing, footwear, gloves, and goggles. Oleum is dangerous to human health, and as a corrosive chemical, acute exposure can cause severe skin burns and eye damage. Do not breathe dust/fumes/mist/vapors as they can be fatal if inhaled. Use only outdoors, or in a well ventilated area.

What is Oleum?

Oleum is a widely used industrial chemical utilized as an intermediate to produce numerous organic and inorganic chemicals. It is used as a basic chemical for sulfonation processes (i.e. chemically adding sulfate to an aromatic hydrocarbon compound) and in the manufacturing of nylon, the production of dyes, and hydrofluoric acid (HF) production. Other names for Oleum include fuming sulfuric acid, Oleum sulfuric acid, and fuming Oleum iodisum.

Oleum is a cloudy, gray, fuming, corrosive liquid with a sharp, penetrating odor. When oleum comes into contact with air following a spill, it releases Sulfur Trioxide also referred to as “fuming Sulfuric Acid”

In the United States, Oleum is a “tight-fill” (closed-loop) loading operation and is loaded into rail cars via chemical hoses or 3” stainless steel loading arms. Oleum, if not handled properly can cause serious injuries and Personal Protective Equipment (PPE) is required. Additionally, because operators are on top of the vehicles during the loading process, robust, well-designed fall prevention is essential to ensure increased throughput, without compromising operator safety.

Although no two Oleum Loading solutions will be identical, the product itself determines much of the critical design criteria that will ensure that optimum safety and productivity can work together in harmony.

Oleum is typically shipped in 26,000 gallon DOT-111 insulated or non-insulated tank cars with safety valves that meet the DOT specification for the transportation of oleum and other like commodities. The rails cars themselves are ~ 9′ outside diameter with an overall length of ~45’ to 50′, with a 6’ x 6’ center opening or off-set crash box openings.

Tank truck (un)loading procedures are similar to railcar applications with the trailers meeting established DOT requirements for transporting Oleum or other like commodities. Approved DOT trailers include MC 307 or low pressure chemical ISO containers. Trailers and ISO’s are typically bottom unloaded. An extension pipe with two valves is flanged to the top of the trailer. All trailers must be equipped with pressure relief valves; and trailers with bottom outlets must be equipped with remote controlled stop valves.

Oleum is regulated by the U.S. Department of Transportation (DOT) and is classified as a corrosive hazardous material with the DOT identification number UN 1831.

First aid measures for exposure include – removing operators from the source of exposure and into fresh air. Remove contaminated clothing immediately; wash skin thoroughly with soap and water; flush eyes with tepid water for 15 minutes. If ingested do not induce vomiting, but immediately call your local poison control center. Aspiration into the lungs can cause fatal chemical pneumonitis. If ingestion has occurred, assume there is a risk of aspiration into the lungs.

Oleum decomposes when heated and produces toxic and corrosive gases including sulfur oxides. It also reacts with combustible and organic materials which generate a fire and explosion hazard. Oleum reacts violently with water and moist air producing sulfuric acid.

Oleum is corrosive to most metals including bronze, brass, carbon and milled steel, so great care should be taken to avoid contact with these materials. However, aluminum and stainless steel have little to no effect when exposed to Oleum.