DMS (Dimethyl Sulfide)

Dimethyl Sulfide (DMS) is a low molecular weight sulfur compound with a distinctive garlic-like odor. It possess a low level of toxicity, and is used as a flavor component in the US and other parts of the world.

Exact-S® Dimethyl Sulfide has applications in the hydrocarbon industry, including the production of ethylene. Dimethyl Sulfide is also used in certain chemical reactions of importance to the pharmaceutical Industry.

Key Applications for Dimethyl Sulfide

• As an effective presulfiding agent. DMS is used as a sulfur source for industrial catalysts used in hydrodesulfurization, hydrodenitrification, and catalytic cracking. These catalysts are supplied in their oxide form, and must be modified with sulfur prior to use as a furnace passivation agent. The service lifetime of pyrolysis furnace tubes used to manufacture ethylene is extended when treated with low levels of DMS. Furnace tubes used to reduce iron ore are protected in a similar way.
• As a “back-up” odorant in gas products. DMS is blended with common gas odorants as a protective measure. When odorants such as methyl mercaptan oxidize, their odor diminishes. DMS is not as susceptible to this problem.
• In chemical synthesis, DMS is alkylated to produce trimethylsulfonium halides, which are useful epoxidation reagents. DMS-BH3 is used in hydroboration-oxidation and related reactions.

Exact-S®

Exact-S® Dimethyl Sulfide has been the gold standard in presulfiding and ethylene applications for over twenty years. It offers an economical combination of low toxicity and high sulfur content for use in the petrochemical industry.

Exact-S is the most widely used agent for presulfiding of hydrodenitrification (HDN), Hydrodesulfurization (HDS) and cracking catalysts.

Key Applications for Exact-S® DMS

• As a Reliable and Safe sulfur source for catalyst applications. Exact-S® DMS is a proven presulfiding agent, with a better safety profile than alternative products
• Ethylene Furnace tube passivation. DMS prolongs the service lifetime of pyrolysis furnace tubes.
• Direct Iron Ore Reduction. DMS prolongs furnace tube life, and inhibits coke deposition responsible forhigher operating expenses.

 

Synthesis

Dimethyl Sulfide (DMS) has several applications as both a solvent (organometallic reactions) and a reagent (BH₃-DMS adduct, trimethylsulfonium halide salts).

The dramatic effect of DMS in certain conjugate addition reactions was recently described by Jess Dambacher and Mikael Bergdahl of San Diego University (J.Org Chem. 70 (2), 580-589 (2005). They demonstrated that Gilman-type silylcuprates add in high yield to α,ß-unsaturated carbonyl compounds in high chemical yield and diastereomeric ratio of the products: