DMS Exact-S™ Grade: The North American standard for ethylene furnace sulfidation
The production of ethylene and light olefins using the steam cracking process is essential to the production of important plastics (polyethylene, polypropylene, EPDM rubber) and basic chemical raw materials (ethylene oxide, vinyl chloride). Installed global nameplate capacity was estimated in 2013 at over 140,000,000 MT (1) – making this perhaps the largest commodity chemical process in the world.
Dimethyl Sulfide (DMS), CAS [75-18-3]) plays an essential role as a sulfidation agent in the steamcracking process by both regulating the generation of carbon monoxide (CO) and controlling the formation of carbon deposits (coke). The ability to manage CO concentrations in the furnace effluent gas is important because CO affects hydrogenation operations at various points in the process. The rate at which coke forms in the furnace cracking coils impacts the profitability of an ethylene unit and must be managed.
Dimethyl Sulfide is the most widely used sulfidation agent in North America and has greater than 70% market share in this application in the US. It’s been in use for over 40 years around the world in and is accepted by ethylene technology licensors as a proven sulfidation agent.
DMS Exact-S™ Grade is manufactured by Gaylord Chemical. It enables ethylene furnace engineers to effectively manage CO levels and coking rates, thereby prolonging run lengths between decoking cycles and minimizing overall operational costs.
Benefits provided by Exact-S® from Gaylord Chemical include:
DMS Exact-S™ Grade is pure.
Careful feed contaminant management practices are essential to minimizing damage to the cracking coil and overall safe operation of the plant. Exact-S is manufactured to exclude impurity substances which can lead to premature furnace damage, poison process catalysts, and cause downstream safety concerns. Click here to learn more about these impurities and their potential effects in the steamcracking process.
DMS Exact-S™ Grade is proven.
DMS has been in use as an effective sulfidation agent for decades and has become the North American standard. It is also currently used in ethylene plants in Europe and the Middle East.
DMS Exact-S™ Grade is manufactured ‘on purpose’.
While other sulfur chemical products are made as byproducts of other chemical processes, Gaylord Chemical Company’s facility in Tuscaloosa, AL is dedicated to the production of Dimethyl Sulfide (DMS) and Dimethyl Sulfoxide (DMSO). Gaylord has over 40 years of experience in the production, handling and supply of DMS to ethylene manufacturers. We understand the sulfidation agent requirements of the ethylene industry and have never caused a supply interruption to one of our customers.
DMS Exact-S™ Grade Frequently Asked Questions. A compilation of performance, safety, and handling questions associated with the use of Exact-S as a furnace sulfidation agent.
The Science of Sulfidation. Although sulfur chemicals have been used for many decades in steamcracking applications, the basic phenomenon behind how they work is still poorly understood. This section of the site summaries the industrial and academic understanding of some specific subjects associated with the use of sulfidation agents.
 Koottungal, L. Oil and Gas Journal (July 1, 2013), 111,7.