What is low-sulfur fuel oil
Fuel oil is one of the by-products of crude oil and is the remaining product separated after gasoline, coal and diesel during crude oil processing. It is a type of heavy oil. Fuel oil is mainly made of petroleum cracked residue oil and straight-distilled residue oil. It is characterized by its high viscosity and contains non-hydrogen compounds, gums, and asphaltene.
Fuel oil is widely used and is mainly used in the fields of ship transportation, electricity, industry, etc. Among them, the demand for ship transportation accounts for about half of the uses of fuel oil. Marine fuel oil is the source of power for ship transportation, and its quality must meet the requirements for the use of ship internal combustion engines. Marine fuel oil is divided into distilled fuel oil and residue fuel oil. Distillate fuel oil is mainly oil products mainly composed of light oil (diesel), including light diesel oil (MGO maritime gas oil) and heavy diesel oil. The difference between the two is different in terms of viscosity; residual fuel oil is oil products mainly composed of heavy fuel oil. It is divided into 7 viscosity and 6 mass levels according to its mass and viscosity, with a total of 11 grades, namely RMA10, RMB30, RMD80, RME180, RMG180, RMG380, RMG500, RMG700, RMK380, RMK500, and RMK700.
Low-sulfur fuel oil is one of the above-mentioned heavy oils, but after a series of chemical treatments, the sulfur content in the fuel oil is reduced. According to the sulfur content, marine fuel oil can be divided into three levels: I, II and III. The corresponding standards for marine residue fuel oil are no more than 3.50%m/m, 0.50%m/m, and 0.10%m/m, respectively. Excessive sulfur content in fuel oil can cause corrosion of metal equipment and environmental pollution. In order to protect the marine environment and control ship exhaust emission pollution, the International Maritime Organization (IMO) adopted the MARPOL Convention in 1997, in which the Annex VI restricted the SOX emission content in ship exhaust gas and stipulated the Emissions Control Area (Emissions Control Area, the initially Baltic Sea, North Sea, North America, and the Caribbean Sea region of the United States). The sulfur content limit of ECA has dropped from 1.5% in 2010 to 0.1% after 2015. In 2016, IMO stipulated that the sulfur content of fuel used by ships sailing in the global waters shall not exceed 0.5% from January 1, 2020, and subsequently stipulated that ships without washing equipment shall be prohibited from carrying high-sulfur fuel from March 1, 2020. This is called the IMO2020 new policy in the industry, which has triggered a huge change in the entire shipping industry.
