Today's gasoline is engineered to be the cleanest ever, protecting both the environment and our health. Several processes are used to remove impurities, including a sulfur-removal technique called hydrotreating. Sulfur in crude oil may be either attached to the surface of a hydrocarbon or part of its chemical structure. Either way, hydrotreating effectively removes sulfur from the hydrocarbon stream.
In hydrotreating, hydrocarbons and hydrogen are heated together and then fed into a reaction chamber containing a special catalyst. When the hydrocarbon and hydrogen molecules come in contact with the catalyst, a chemical reaction occurs that strips sulfur from the hydrocarbon to form hydrogen sulfide.
The hydrogen sulfide is removed and neutralized in a separate process. The sulfur compounds produced from this process are used in other applications such as fertilizers and pharmaceuticals.»next