Development Trend of Marine Fuel
1. Biofuels
Regarding the interim guidelines for the use of biofuels under Articles 26, 27, and 28 (DCS and CII) of MARPOL Annex VI (MEPC. 1/Circ. 905), for biofuels that meet the sustainability standards of the Carbon Offsetting and Reduction Mechanism for International Aviation (CORSIA) and have a full lifecycle greenhouse gas emission intensity not exceeding 33 gCO2e/MJ, the Cf of the fuel can be calculated by multiplying the calculated emission intensity value by the fuel's lower heating value (which cannot be less than 0). MEPC78 has approved the unified interpretation of MARPOL Annex VI, which states that for fuels mixed with no more than 30% biofuels, there is no need to re certify the engine's NOx emissions. Biodiesel: Fatty acid monoalkyl esters produced by reacting animal and vegetable fats or waste fats with alcohols, with the most typical being FAME, represented by BD100. Under the condition of non targeted modification of traditional diesel engines, the emission reduction potential is 17-30%.
2. LNG
Simulation analysis of synchronous operation of LNG refueling, loading and unloading at Yangshan Port in Shanghai
Global reserves are abundant, key technologies are becoming mature, industrial chain supporting facilities are gradually maturing, and ship regulations are improving. Clean fuel with high volumetric energy density (60% ship diesel), suitable for various types of ships with low liquefaction temperature and high storage and transportation costs. Methane escape exists, with limited emission reduction potential (10% -25%).
3. Methanol
The application condition power system is basically mature, the regulatory system is basically perfect, as a chemical product, the output is large (nearly 100 million tons in 2021), and the logistics chain is mature. There are many preparation methods and raw materials: coal, natural gas, renewable preparation (biomass, renewable electricity).
Low flash point, flammable and explosive. Has corrosion, swelling and low toxicity. The volumetric capacity density is relatively low (about 42% of ship firewood). Liquid at room temperature and pressure, convenient for storage on board. Clean and environmentally friendly, with low NOx and SOx emissions. High emission reduction potential (5% -95%).
16000 TEU methanol dual fuel powered container ship (under construction)
Methanol powered VLCC concept ship (fuel tank 7000m3)
4. Ammonia
It does not contain carbon itself, and burning it on board does not produce carbon dioxide. The preparation process is mature, the production raw materials do not require carbon sources, the volumetric energy density is low (about 32% ship diesel), and it has strong toxicity and corrosiveness. The marine power plant is still under development, the regulatory system is not mature, IGC rules are prohibited, and the energy consumption for production is relatively high. As a fuel, the energy conversion efficiency is around 30%.
Ammonia fuel VLCC concept ship (fuel tank 6000 m3 × 2)
4. Hydrogen
Based on current hydrogen storage technology, large ocean going vessels are still unable to directly use hydrogen as the main fuel.
Zero pollution, zero emissions; The electrolytic water preparation process is mature and belongs to renewable clean secondary energy; The volumetric energy density is too low (liquid hydrogen is about 24% of ship fuel); Liquefaction temperature -253 ° C, difficult to store and transport; The gas with the widest range of detonation (4% -75.6%); Immature high-power hydrogen power plant for ships; The regulatory system for ships is not yet sound.
The first hydrogen fuel powered ship in China, "Three Gorges Hydrogen Boat No.1"
5.electric
The world's largest capacity pure electric ship, the "Three Gorges No.1" on the Yangtze River
700TEU river sea direct pure electric container ship