Very Low Sulphur Fuel Oil (VLSFO) or Low Sulphur Fuel Oil (LSFO), this type of marine fuel contains less sulphur and therefore complies with the IMO 2020 regulations. Usually these are marine fuel types IFO 180 or IFO 380, which have been desulfurized.
Heavy Fuel Oil (HFO) are mainly used as marine fuel, and HFO is the most widely used marine fuel at this time; virtually all medium and low-speed marine diesel engines are designed for heavy fuel oil. But older steam locomotives and oil-fired power plants also generate energy from heavy fuel oils.