SOx control - other options, the wait continues!
19th March 2009 10:38 GMT

As students of the current MARPOL Annex VI will be aware there was, when it was adopted in 1997, the requirement for a number of Guidelines to be developed. To date those required exist – with one notable exception, that covering ‘..other technological methods..’ to control sulphur oxide (SOx) emissions in SOx Emission Control Areas (SECA); currently the North Sea and Baltic but with expectation of other areas in the future.

These controls would cover options such as onboard blending of high and low sulphur fuels or co-firing with gas (typically LNG cargo boil-off) and liquid fuels (usually residual but could be distillates). In fact existing, and currently operationally used, procedures.

With the revision of Annex VI, intended entry into force date 1 July 2010, the potential scope of application of these options has extended – equivalent arrangements could, subject to approval by the ship’s flag State taking into account relevant Guidelines, also be used to meet the global requirement as well as those of the Emission Control Areas for SOx and particulate matter control (ECA-SOx), the re-styled SECAs; 1.00% from 1 July 2010 and 0.10% from 1 January 2015. Since the global fuel oil sulphur limit is also set to decrease from 4.50 % to 3.50% on 1 January 2012 and thereafter to 0.50% from 1 January 2020 to 0.50%, subject to review, there is clearly going to be ever increasing pressure on the availability of compliant fuels, both ECA-SOx and globally. Hence the need for other options.

Already we have the Guidelines covering exhaust gas cleaning systems, where a medium such as sea water is used to neutralise and washout the SOx from the exhaust gas stream. Options such as that or alternatively onboard blending or co-firing make sense  - not taking a dedicated fuel round the world in some cases just to use it over the final leg of a voyage also permits a more optimised use of bunker capacity. Okay these are not for everybody, but that has never been the intent, they provide choice.

And, following the recent IMO BLG meeting charged with progressing and updating the Annex VI Guidelines, why don’t we have the Guidelines for these ‘other means’? – because a few took fright at onboard blending! Yes, we in FOBAS certainly have experience of how devastating an instance of fuel instability can be and would never underplay the need for caution in this area, but as we find from the bulk of our work where we are asked to test for compatibility that while it is something that should always be checked (and to that end even supply the necessary materials and instructions in our sample bottle packs) it is not an endemic problem.

A flexible, objective driven approach, as with NOx control requirements, to meeting a common objective allows all parties to adopt the most appropriate course of action. Onboard blending and co-firing, with due attention to the necessary checks, should be part of that. Let’s hope that in the near future a more realistic approach is generally adopted which enables, subject to approval, these options to form part of the industry’s compliance package. Meanwhile, still waiting.


Andy Wright ,
19th March 2009 10:38 GMT

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