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Clean power: LNG

Is natural gas fueling the future of shipping?

Natural gas is emerging as a leading alternative to heavy fuel oils as shipping companies continue to seek cleaner methods of propulsion. In this installment of our ‘clean power’ series, we ask: is it too soon to “dash to gas”?

Ever since early talks of climate change and global warming, shipping companies have considered ways that they can generate a positive impact on the environment. Flash forward to 2019, and tightening regulations set out by the International Maritime Organization (IMO) are being imposed. The global sulfur cap will come into effect on January 1, 2020, significantly reducing the amount of harmful sulfur that heavy fuel oils (HFO) can contain. Research into alternative fuel has grown rapidly, and it appears that liquefied natural gas (LNG) is a popular method with orders for LNG-fueled vessels increasing.

What is LNG?

A naturally occurring combination of methane and ethane, natural gas is plentiful and can be sourced all around the world. Gas is extracted from the ground before it undergoes a filtration process in order to remove any impurities. Finally, it’s cooled to temperatures as low as -162 °C (-259 °F) for liquefaction to occur. This end product, LNG, is what shipowners have been exploring as a reasonable alternative to heavy, toxin-emitting fuels.

Next-generation fuel

Reducing the carbon footprint of the global shipping industry has become a major focus in recent years. In response, the IMO has set out to reduce carbon emissions by at least 50% by 2050. When compared to traditional HFOs, LNG represents a significant reduction in levels of greenhouse gas emissions such as CO2, SOx, and NOx—a main target of the IMO 2020 global sulfur limit. This strengthens the viability of LNG as a marine fuel against other propulsion methods that use renewables such as methanol or fuel cells. LNG is clean-burning and emits almost no sulfur dioxide, meaning it meets the 2020 sulfur limit requirements without the need for additional equipment – such as exhaust gas cleaning systems. When coupled with low-cost production, it seems that LNG is a ‘future-proof’ option for compliance.

And a growing trend towards LNG is emerging, spearheaded by coalitions such as SEA\LNG, whose 36 members advocate the adoption of LNG as marine fuel. Organizations such as DNV GL, the Port of Rotterdam, and Shell are all on board, sharing knowledge, data analysis, and human resources to accelerate a widespread application of liquefied natural gas.

Key considerations for LNG adoption

When introducing relatively novel fuels and the required equipment, shipowners must consider crew training. Crewmembers require guidance on safe-handling of the substance and on maintenance of new machinery. In the case of LNG, additional precautions and training should be offered in order to avoid leaks or methane slip—which contributes to global warming.

Cost is another key consideration for any shipowner or operator, and fuel is a major contributor to operating costs. Retrofitting a vessel for LNG propulsion can vary, depending on whether the existing engine can be converted or if a complete overhaul is necessary. This uncertainty about the practicality of conversion to LNG could hinder its viability as a marine fuel. Although the liquid itself takes up minimal space on-board, being a super-cooled fuel, it must be stored in cryogenic tanks to ensure a stable state. Creating the necessary cryogenic supply chain for this is difficult without a strong market demand.

For LNG to become a commercially viable propulsion method, there is also a requirement for more bunkering facilities worldwide. As it stands, infrastructure is mainly concentrated in north-west Europe and the US east coast; the Port of Rotterdam being a pioneer for the use of LNG, dedicating their GATE terminal to the bunkering of the fuel. But the need for supply infrastructures worldwide will grow as more LNG vessels enter operation. The ‘chicken and egg’ conundrum surrounding supply and market demand for LNG is diminishing with investment proposals for new LNG projects on the rise.

A cleaner option—but is it viable?

Despite a boom in LNG-propelled vessels in Europe, it is a fossil fuel which means supplies will eventually run out. In addition, fuels can release emissions at any stage during the full lifecycle, from extraction to combustion, so cannot be considered completely clean due to upstream emissions. In addition, sceptics believe that LNG does not lead to a substantial enough reduction of CO2 for it to be a viable option in the long term; rather just as means to meet the 2020 regulations.

That being said, LNG still presents the potential to become an environmentally friendly and economic alternative to the high- sulfur fuel oils traditionally used in shipping. The market appears strong as more bunkering ports and LNG-fueled vessels enter operation. Should the industry invest in the necessary infrastructure, the course seems set for LNG to continue to grow in prominence in the maritime sector for years to come.

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