explanation for this anomaly is the endothermic reaction of sulfur with H2S to polysulfanes H2Sx. Sulfur stockpile Huge amounts of elemental sulfur (billions of tons) are produced worldwide by the Claus process. The process has also to be applied to heavy petroleum extracted from oil sands deposits because sulfur accumulates in the heaviest fractions of hydrocarbons. Owing to the high sulfur content of the Athabasca Oil Sands, stockpiles of elemental sulfur from this process now exist throughout Alberta, Canada. Another way of storing sulfur, while reusing it as a valuable material, is as a binder for concrete, the resulting product having many desirable properties (see sulfur concrete). See also Amine treating Hydro-desulfurization Crystasulf Hydrogenation Acid gas Sour gas References Sulfur Chemical processes German inventions 1883 in science 1883 in Germany