LNG-fuelled shipping cuts emissions by 23%: study

An independent study shows that LNG as a shipping fuel can reduce well-to-wake greenhouse gas emissions by up to 23% compared with the use of diesel.

The study, commissioned by industry association SEA-LNG and the Society for Gas as a Marine Fuel (SGMF) and undertaken by Sphera, concluded this reduction was possible using LNG in two-stroke slow-speed dual-fuel engines, instead of very low sulphur fuel oil. LNG produces also 21% less emissions than marine gasoil.

According to the study which was published April 13, two-stroke slow-speed Otto dual-fuel engines achieve smaller reductions of only 14% compared with very low sulphur fuel oil and 12% compared with marine gasoil.

The study shows "beyond question" that LNG can contribute significantly to the International Maritime Organisation's greenhouse gas emissions targets, SEA-LNG said.

"The updated Sphera study ensures that the industry has access to comprehensive research that is fully up to date," SEA-LNG chairman Peter Keller said. "It is clear that LNG plays an important role in decarbonisation today with benefits available now. As we look ahead, it is essential that detailed emissions analysis from well to wake such as those performed by LNG are available for all alternative fuels contemplated, enabling shipowners to make the right decisions for their fleet."

Keller noted that often out-dated data was used to criticise LNG because of the issue of methane slip, when methane passes through ship engines but is not burned. The study notes the significant progress that has been made to address this problem, noting that high-pressure two-stroke slow speed diesel cycle engines have no methane slip, and that by 2030, slip from other engine types should also be eliminated.

"The facts consistently confirm that there is no deep-sea alternative fuel in the short to medium term other than LNG," Keller continued. "LNG remains the clear starting point for a carbon-neutral future for shipping, especially as the pathway forward includes bio and synthetic products. Waiting is not an option. The industry must act now to capture the benefits that are clearly there for the taking by using LNG."