Shipowners and operators of LNG carriers and LNG dual-fuel tonnage will increasingly need to consider the methane emissions of their vessels as new regulations come in.

Methane emissions
  • Methane accounts for just over 17% of greenhouse gases.
  • It is a short-lived greenhouse gas, with an average lifetime in the atmosphere of about 12 years, but it is more potent than CO2, albeit over that shorter time frame. One tonne of methane generates about 28 times the amount of warming as the equivalent amount of CO2.
  • So tackling methane emissions can present a quick-fire way to tackle greenhouse gas emissions.

All eyes are currently on how they will be referenced in the European Union’s Emissions Trading System (ETS), which will apply to shipping. In particular, whether this will consider methane under the global warming potential (GWP) by a 100-year or 20-year metric.

There is also a perception that at some stage, methane could become a factor that will be incorporated into the Carbon Intensity Indicator (CII) for vessels.

Panayiotis Mitrou, global gas segment director at Lloyd’s Register, is concerned that “the perfect storm” is brewing for LNG carriers, particularly those with low-pressure two-stroke and dual-fuel diesel-electric propulsion systems that have higher levels of methane emissions.

He said four-stroke, LNG dual-fuel engines used by cruise and ferry companies also produce higher methane emissions.

Mitrou pointed to major chartering tenders that have specified low-pressure engines.

“To me, this is an excellent example of the need to drive awareness,” he said, adding that discussions with charterers’ technical teams revealed they did not have a clear idea of the risk.

“Regulatory wise, things will become very tight on methane emissions at some point. I am not sure the gas shipping industry yet realises this.”

Panayiotis Mitrou, global gas segment director at Lloyd’s Register, said the ‘perfect storm’ could be brewing for LNG carriers. Photo: Capital Link

Efforts are already in play to get a more accurate picture of shipping’s methane emissions as the oil and gas industry tries to get to grips with measuring and abating these over the whole supply chain.

In March and April 2021, the methane emissions were measured onboard a GasLog LNG carrier newbuilding — chartered to US producer Cheniere Energy — that was on a US-to-Europe round trip.

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Cheniere, Chevron, Equinor, ExxonMobil, Pioneer Natural Resources, Sempra LNG and Shell were involved in the research.

Energy major Shell is also pursuing its own research on methane emissions.

Carl Henrickson, shipping and maritime technology, innovation and digitalisation general manager at Shell, said the company has started laboratory-based measurements on methane slip to check the accuracy of the equipment and understand how other products in the exhaust gas influence methane measurement.

“The initial research has shown that the impact is significant and, as far as we know, this will be the first measurement campaign of its kind that considers this particular phenomenon,” Henrickson said.

Henrickson revealed that Shell has recently installed the equipment on its 6,500-cbm chartered-in LNG bunker vessel New Frontier 1 (ex-Cardissa, built 2017).

“The equipment is now online and we hope to start the validation process when we have enough data from the full operating range,” he said.

Henrickson said Shell can explore opportunities to transfer the equipment to other owners once its own campaign has been completed.

“The main aim of this campaign is to deliver accurate methane emissions data that will support the development of methane abatement technology,” he said.

“This can be as simple as adjustments to engine settings or the development of after-treatment technologies that are optimised for actual methane slip across the load range.”

Onboard methane abatement technologies — or, as one industry player has dubbed them, “scrubbers for LNG” — are starting to emerge.

Swiss-headquartered Daphne Technology is working separately on different projects with both Lloyd’s Register and DNV. In June, both class societies granted approvals in principle for the onboard installation of the company’s methane abatement technology, SlipPure.

In the same month, VTT Technical Research Centre in Finland launched the Green Ray initiative to develop solutions for reducing methane slip from LNG-fuelled engines in both new and existing vessels.

Those participating in this initiative include Chantiers de l’Atlantique, CMA Ships, Wartsila, Shell, DNV, the Finnish Meteorological Institute, MSC Cruises Management and MSC Malta Shipyard Management.

Henrickson said the consortium will develop two engine technologies and one after-treatment technology for existing ships and newbuildings.

“In addition to two engine-focused technologies, the programme will further develop Shell’s sulphur-resistant catalyst system, which would potentially reduce methane slip emissions by up to 95%,” he said.

“LNG-fuelled shipping is growing rapidly and there is increasing awareness of the impact of methane emissions by our industry and wider society. We anticipate growing demand for low-methane emissions ship designs and after-treatment technologies, where appropriate.”

Mitrou said: “We have a number of promising technologies. We need to focus on commercialising these technologies and coming up with solutions that will have a chance in the current shipping landscape.

“We need to make sure that ships are assets that will be continuously monitored against their methane emissions performance.”