In the process of refining oil, a variety of chemicals are used, including the following:
- Halogenated hydrocarbons: Such as chloromethane (CHCl3), dichloromethane (CHCl2Cl), and trichloromethane (CHCl3).
- Sulfur compounds
- Nitrogen compounds
- Oxygen compounds: Oxygen (O), nitrogen oxide (NO), carbon dioxide (CO2), hydrochloric acid (HCl), and sulfuric acid (H2SO4).