The Importance of Sulfur Recovery

Sulfur is a natural component of crude oil and natural gas. However, it is important to remove or reduce the amount of sulfur during refining and processing.

For crude oil, reducing the sulfur content in gasoline and diesel improves emission controls. The sulfur recovery process removes sulfur compounds from the product and thus reduces air pollution created by the fuel combustion process when the products are used. In fact, regulations require the removal of hydrogen sulfide (H2S) and sulfur dioxide (SO2) for many products such as marine fuel and ultra-low-sulfur diesel. Most of these mandates come from the Federal Clean Air Act and the Environmental Protection Agency.

Sulfur also presents a problem for natural gas. When natural gas contains significant amounts of hydrogen sulfide, it is called sour gas. Not only does sour gas smell like rotten eggs, but it is also toxic and incredibly hazardous to your health. If inhaled at a high enough concentration, it can be
fatal. Natural gas containing hydrogen sulfide is very corrosive, which creates an issue since the vast majority of natural gas is transported by pipeline. Like crude oil, natural gas is also subject to regulations. State laws set the requirements for sulfur recovery and emission limits for natural gas.

Oil and gas producers must mediate the issues caused by sulfur compounds. This process is known as sulfur recovery or sweetening. Once hydrogen sulfide (H2S) is converted to elemental sulfur, it can be used as fertilizer, feedstock or other byproducts. Recovered sulfur most often used to create sulfuric acid, which is one of the most commonly used chemicals in manufacturing and industrial applications. Sulfur can also be used in many household applications such as rubber products, detergents, paints, carpets and pharmaceuticals.

Many producers choose to extract sulfur and market the byproduct on its own because of sulfur’s many applications. However, sulfur sales rarely contribute significantly to a plant’s bottom line. Profit margins are low due to transportation costs and also because sulfur supply often exceeds demand. Consequently, sulfur recovery strategies must be carefully designed and implemented.

The true driver for sulfur recovery is the need to reduce emissions. Sulfur recovery is a regulatory requirement for oil and gas producers. Removing sulfur, helps curb air pollution while creating a useful byproduct and eliminates the need to mine sulfur directly from sulfur
rich earthen deposits.