Paving the way for a greener future
To date, IMO is the only organization worldwide that has adopted energy efficiency measures that are legally binding across the world. IMO also regulates the emission standards for ships, which are more strict in areas designated as Emission Control Areas (ECAS). As the MARPOL Annex 6 regulations restricting air pollution, another of IMO’s measures, is progressively setting more exacting standards, the shipping industry is looking for alternatives; such as ships powered by distillate fuels, using scrubbers, alternate fuels such as LNG, Hydrogen, or ammonia, even nuclear powered or completely battery-powered ships are a possibility. However one of the most feasible possibilities in the short to mid future is LNG.
The current engine technology regarding LNG is mature enough and the price of natural gas is generally lower than diesel and it is widely available. Even factors such as the prior experience of the marine industry with LNG storage and handling aboard LNG transport vessels have caused the marine industry to have an inclination to LNG as a fuel.
The rising cost of logistics and the advantages of LNG
LNG tankers which transport LNG, conventionally route the gas that boils off the cargo to the engines. So LNG as a fuel is not completely new; this is the reason guidelines and standards are already issued for use, bunkering, and carriage of LNG as a fuel.
LNG is generally cheaper than the marine diesel used conventionally. The price for retrofitting a ship to make it compatible with using LNG as a fuel varies, but as a rule of thumb, the larger the ship the more uneconomical it gets to retrofit it. Hapag-Loyd’s ultra large container ship SAJIR is in the process of being converted to use LNG as fuel. A move which has been deemed to be the world’s first such conversion.
For smaller ships, the conversion to LNG is economically favorable to installing a scrubber. The sulfur limit in the regions designated as ECA’s (Emission Control Area) by the IMO are stricter than the open seas, so the ships that spend a considerable amount of their time in the ECA’s have a greater financial incentive to convert to LNG.
Low sulfur fuels and distillates that are lighter and more refined can cost up to four times the normal bunker fuels. Installing Scrubbers to reduce the environmental impact can take up to 2 years. Naturally, the transportation costs are set to increase. Shipping companies like Maersk are passing on at least a part of this economic impact on the customers. The global shipping industry could spend up to 15 billion USD in compliance with the IMO sulfur cap. The Low sulfur surcharge (LSS) is an additional fee to cover the extra cost incurred by the shipping companies in complying with the sulfur cap. The costs are set to rise, economic pressure is increasing all around. Natural gas engines that have not yet reached their fullest potential could provide a much-needed reprieve.
Global LNG terminal infrastructure
The development of LNG bunkering and subsequent terminals are heavily influenced by an ample supply of natural gas resources. Japan and South Korea are emerging as vehement advocates of LNG, with several high output LNG terminals such as the Futtsu LNG, Negishi LNG, Senboku II, and Sodegaura LNG in Japan and Tongeyong LNG, Incheon, Pyeongtaek LNG in South Korea. However LNG terminals in Europe are still sparse, Hammerfest LNG in Norway, a terminal owned by Gasum in Pori, Finland, and another in Tornio, Finland are the only operational LNG terminals in Europe. A major LNG terminal construction has begun in Brunsbuttel, Germany. The parent companies are Oiltanking GmbH, Gasuine, and Vopak LNG. The terminal is expected to start operations in 2023. The construction of this project started in 2017, and for a long time was an unprofitable venture but in June 2020 the company Oiltanking GmbH announced that it will have a definitive positive investment decision by 2021, and will attract investments. The company also made the statement that they were in the process of negotiating binding legal contracts with RWE, a major power producer in Germany, for potentially 5 billion cubic meters of imports.
Hazards of using LNG
There are considerable risks and hazards inherent in using LNG as fuel. The gas itself has high energy density and there is a considerable amount of chemical energy stored in an LNG tank. The gas must be stored cryogenically at about – 162 degrees. Leaks and spills of the gas may easily occur and exposure may cause frostbite and cryogenic burns to personnel.
There are risks of explosions and fire hazards such as flash fire, pool fire, jet fire, and BLEVE (Boiling Liquid Expanding Vapor Explosion), where a containment vessel is heated up, any rupture in the containment system leads to an explosion. There can be trapped residual LNG in the pipes after the bunkering process which can expand into vapor and cause ruptures and explosions in the pipes.
LNG is also an aggressive greenhouse gas. Any leakage across the whole logistics chain from production, through processing until delivery has effects that are much greater than CO2 leaks of the same magnitude.
Mitigating the risk and maximising the advantages
Proper training, protocol, and incident reporting can considerably reduce the risks associated with the handling and use of LNG. QC/DC coupling is used for bunkering, owing to the pressure-tight coupling and fast connect/disconnect time of QC/DC couplings. In addition, proper gear such as protective cryogenic gloves, safety goggles with face shield, and side protection is a necessity. Clothing for personnel is full-body comprehensive, cryogenic retardant, and flame resistant. The team performing the bunkering must be prepared and have proper coordination and communication to ensure safety before, during, and after the LNG bunkering process takes place.
The environmental benefits of using LNG in place of conventional heavy fuel are considerable. LNG boasts a 25% reduction in CO2 emissions, a 90% reduction in NOx emissions, and a 100% reduction in SO2 and particle emissions. With the statutory laws of the IMO becoming increasingly stringent, the economically feasible LNG could one day become as ubiquitous as the other petroleum derivatives that we use today.