At the most recent meeting of IMO’s Marine Environment Protection Committee, MEPC 82, the committee made two important advances on the regulatory measures on greenhouse gas (GHG) emissions and nitrogen oxides (NOx) from marine engines. These changes will not present any concerns for operators of WinGD X‑DF and X‑DF 2.x (VCR) engines. 

GHG emissions: Mid-term measures

Although future IMO technical or economic measures to regulate GHG emissions have yet to take firm shape, the committee broadly agreed that – similar to European legislation – methane slip and N₂O should be included in any measure. This is expected to be carried through to any fuel standard or any accounting that goes towards a carbon cost in any form.

WinGD welcomes the progress towards a more holistic consideration of GHG emissions from shipping, which is validation of our continuous efforts to minimise methane slip as well as the inherent low air pollutant emissions of the X-DF design.

The latest generation of WinGD’s X-DF engines achieve average slip levels below 1 g/kWh, as demonstrated on the X72DF-2.0 VCR. European legislation and likely forthcoming IMO legislation use  1.7% as a default slip factor for Otto-cycle two-stroke engines, as based on X-DF-1.0 technology. However, all new X-DF engines deliver methane slip of 0.8% to 1.0%, well below this default value. Until a new default factor for the improved Otto-cycle two-stroke engines is established, the actual methane slip emissions can be used in place of default factors, as agreed in the regulations. The details of these regulatory mechanisms are currently being worked out in more detail.

NOx Technical Code and MARPOL Annex VI

MEPC 82 also agreed draft revisions to the NOx Technical Code and related parts of MARPOL Annex VI that aim to codify existing best practice around NOx certification. In particular, the amendments place new certification requirements on engines with multiple engine operating profiles (MEOPs) and those using auxiliary control devices. Furthermore, these revisions include a screening mechanism for emissions between and beyond the test cycle mode points (“off-cycle emissions”) to verify that the emission control strategy is “rational”, as requested by MARPOL Annex VI.

Having reviewed the proposed changes, WinGD confirms that our NOx emission control strategy has always been in line with these requirements and that the amendments pose no challenges for certifying X-DF and X-DF 2.x engines, which will remain fully compliant with all NOx regulations. As the lean-burn Otto-cycle concept inherently results in the lowest possible NOx formation of all available engine concepts, operators can rest assured that X‑DF engines will retain the NOx tier required for their operation, in all operational modes.

We hope that this provides the confidence that X-DF operators – and operators of other engine brands – are seeking in light of these regulatory amendments and related developments. For further clarification or discussion of your particular regulatory compliance queries, please do not hesitate to contact us.