The History and Future of Marine Fuels

Ocean transport using ships has been around since ancient times. Fuels and propulsion systems have come and gone, and transport capacity has been improved with modernization, but today, efforts to reduce environmental impact are accelerating. Let’s take a look at how fuels have changed over the years.

• Before fuel was used as a source of power to move ships, mariners relied on wind for propulsion. In the 15th century, large sailing ships, called carrack ships, were built mainly in Spain and Portugal, and in 1492, Columbus crossed the Atlantic Ocean on the Santa Maria. And from 1519-22, Magellan’s Victoria completed a circumnavigation of the world. Sailing ships continued to develop, opening up new horizons of exploration and trade.

• In the 1800s, the Industrial Revolution brought steam engines and coal-fueled steamships gradually became popular. In 1807, the Clermont, an outer-wheel steamboat, began commercial service carrying passengers between New York City and Albany on the Hudson River. In 1878, 25 years after the arrival of the “black ships” in Japan, Mitsui O.S.K. Lines built its first steamer, the Hideyoshi Maru, to transport coal produced in the Miike coal mine.

• In the 1900s, oil superseded coal as the mainstream marine fuel. Oil has a higher energy density than coal, meaning more energy can be gained from the same volume. This meant less onboard space had to be devoted to fuel storage, so ships could carry more cargo. It also eliminated the need to constantly shovel coal into the boilers, reducing the number of crewmembers needed. Since the 1950s, a fuel called marine heavy fuel oil, made up largely from residues generated in the oil refining process, came into wide use, and remains the mainstream marine fuel to this day.

• Heavy fuel oil is an inexpensive and convenient fuel, but its combustion in an engine generates air pollutants such as sulfur oxides (SOx) and nitrogen oxides (NOx), and greenhouse gases (GHGs) such as CO₂. For this reason, marine emission regulations have been progressively tightened for ships, as with automobile emission regulations. The shipping and shipbuilding industries are working toward the goal of zero-emission vessels, and various initiatives are underway to enable the use of new next-generation marine fuels to achieve zero emissions from ships.