Technology that allows the use of Liquefied Natural Gas is not new as it is in use from last 40 years. Around 360 LNG carriers are using Boil-Off Gas (BOG) for ship propulsion. Also, there are no serious incidents revealing an excellent record of safety. The technology has been tested on more 34 vessels fuelled by gas and sailing in Northern Europe. However, there remains technological challenge of consumption of space due to LNG fuel tanks that also affects the freight earnings and ship productivity. The volume of LNG is 1.8 times more than the diesel oil besides which three to four times more space is required due to the cylindrically shaped fuel tank onboard and a whole system of LNG engine. The smaller tank fuel is placed onboard that is refueled frequently when shipping sails on regular routes. This mitigates the issues in a capacity loss when the hull-integrated tank is well-developed.
Liquefied Natural Gas
Big size of LNG fuel tanks on board ships also remains a challenge in terms of its locations with regard to retrofitting projects. This leads to a conclusion that LNG is better to be used as fuel for new ships as compared to those that need conversion.
Unburned methane (CH4) is emitted from LNG engines that is the major technical challenge as methane is a contributor to global warming to higher levels as compared to CO2. Thus, the environmental performance of LNG engines is at stake if the problem is not addressed in right ways.
Also, it can be said that new ships can make better use of LNG as there are lesser concerns to the environment as compared to those in the ships that are converted.
The LNG as fuel is highly safe as compared to the traditional bunkers on board. There has been no assessment of safety in the past and no designation of risk acceptance criteria is found for the ships with LNG fuels and bunkering procedures.
It can be said that the safety concerns regarding the gas explosions and cryogenic temperature are to be evaluated in future to determine the safe handling procedures and efficient handling of LNG onboard ships.
Many of the analysis indicate the regulatory gaps present in the implementation of the liquefied natural gas as a fuel ship. The gaps can be differentiated on the basis of three parts of regulatory framework: utilization of liquefied natural gas fuelled ships, liquefied cargo handling, and liquefied bunkering operation.
