This compound forms the largest group of nonhydrocarbons in petroleum.

• A. Nitrogen compounds
• B. Oxygenates
• C. Halogenated hydrocarbons
• D. Sulfur compounds

Answer: (D)

Sulfur-containing compounds are the most abundant nonhydrocarbon species in petroleum. Crude oils contain sulfur in many forms—mercaptans, sulfides, disulfides, and sulfur-containing aromatics like thiophenes—which together make up the largest share of heteroatoms. Nitrogen and oxygen-containing compounds are present as well, but their total amounts are typically smaller. Halogenated hydrocarbons are relatively rare in crude oil. So, among nonhydrocarbons, sulfur compounds form the dominant group.