There is a lot of excitement around liquefied natural gas as a fuel. But while it
is true to say we are past the initial tipping point, there is still a need for owners to be realistic about the decision to use LNG, writes Sean Bond from ABS
The potential of liquefied natural gas (LNG) as a marine fuel has rapidly captured the imagination of ship designers, builders[ds_preview] and owners, quickly becoming embedded in both newbuilding and conversion projects. Certainly there is a drive to adopt LNG for reasons of regulatory compliance, primarily in the current Emission Control Areas (ECAs) to meet upcoming limits for sulphur and nitrogen oxides (SOx and NOx), but this will radiate out as new ECAs are adopted. In addition to these requirements, the adoption of LNG is supported by two interlinked assumptions: that the fuel will be available and that it will be low cost. In the European Union, the Commission has indicated that it expects its so-called TEN-T core ports to have LNG available by 2020. The EU Sulphur Directive mentions LNG as a potential future fuel solution and invites governments to make it attractive in terms of supply.
Whether this will result in subsidised product being made available is open to question, though the first LNG-powered ferries operating in Norway were subsidised by a tax on NOx emissions. Moves by supra-national government bodies to encourage LNG supply do not necessarily mean adoption will be easy for the user. Regional developments such as the US shale gas boom has created the perception that gas will be a plentiful and therefore relatively cheap alternative. It is reasonable to expect that an LNG bunker supplier, whether in a North American or European ECA zone, will be able to compete favourably with low sulphur marine gas oil (MGO). But prices will vary by region, at least initially. LNG’s feasibility as a ›global‹ marine fuel is somewhat dependent on having a fungible level of pricing worldwide. Until then it will likely be driven by a combination of local price and regional regulation.
Perhaps more important to shipowners is lifecycle cost in the context of the other solutions available to address the same issues. LNG as fuel is still a big bet, but attractive to some other alternatives because it provides a near-single solution. It will deliver low or no sulphur emissions to meet ECA requirements. Depending on type of engine solution selected it may also meet NOx emission requirements.
Several factors have to be taken into account
The decision to go ›all-in‹ on LNG must take into account the vessel design, how it is operated, where and for what length of time. There are multiple design issues associated with making LNG fuel the right solution. It could be that for some owners, depending on the factors noted above, a solution employing more conventional diesel fuel with appropriate environmental mitigating technologies or operating procedures could also be a realistic alternative.
Other design issues for owners to consider include whether the ship will burn LNG only within an ECA but use conventional fuel outside it. Switchover between the two creates its own technology and safety issues. If the vessel is to be LNG only, LNG storage capacity requirements, issues associated with lost cargo space and handling gas boil off must also be considered.
Once the decision to adopt LNG has been made, the next stage is for the owner to look more closely at the technical and operational components of that decision. As with using conventional fuel, much will depend on working closely with stakeholders that can support the move to LNG.
The technical feasibility of using LNG as fuel is not in question. The equipment is available and there are engine manufacturers which can supply LNG-powered engines. Working closely with shipyards is also vital as some frequently have preferred suppliers, so looking at how well the yard can support a project is a big part of making the determination.
Technology developments have also improved on areas of previous concern. Problems such as methane slip in Otto cycle dual fuel engines have been worked on incrementally and improved. And with the introduction of new gas burning engine models, a wider range of prime movers is available.
Lessons learned are being implemented into equipment and product designers have a good understanding of what still needs to be improved. There is still more to learn and again the progress is regional: Where there is a local driver towards adoption then we are likely to see an increase in demand and therefore development of expertise to meet that demand.
In terms of the global regulatory backdrop, the key item remains the International Maritime Organization’s global low sulphur compliance deadline; either 2020 or 2025 depending on the outcome of a low sulphur fuel availability review in 2018.
Development by the IMO of the International Code for the Construction and Equipment of Ships Carrying Liquefied Gases in Bulk (IGF Code) is ongoing and while a specific expected adoption date is difficult to predict, we can expect it will be a few years before it comes into force.
Also important is how flexible local regulators are prepared to be. For example, a US containership operator which is converting vessels to run on LNG has been able to obtain a temporary relaxation of ECA compliance on the understanding that they will be switching to full LNG operations in due course.
Another issue for operators remains what controls regional administrations and port authorities will require in terms of safety management. Will the ship be able to bunker at the desired rate, in the preferred location and at a time that suits the schedule? This too is part of the decision process and owners will need to consider the current and expected thinking of such regulators in having their concepts developed. In some cases final decisions may not have been made, but the authorities know LNG as fuel is coming and they are working on towards it, even if rule-making is not complete.
First LNG-powered containerships classed by ABS
ABS continues to support its clients and the wider industry as shipping moves with speed towards a future in which LNG will play an increased role in vessel propulsion. In addition to classing the first offshore support vessels to be powered by LNG, for US operator Harvey Gulf, ABS will class the first containerships to be powered solely by LNG for US Jones Act operator Tote Maritime (see picture on the left page).
For those owners who are not yet ready to move to LNG but are conscious of keeping pace with the changes, a focus has been on assessing the design of ships that are »LNG ready« – powered by conventional fuel but capable of being converted to LNG at a later date. This would typically include considering necessary space and arrangements for new equipment in the engine room, considering how bunkering would be approached in terms of a bunker station, associated piping and fuel tanks, and any features required to simplify modifications required for fuel preparation.
ABS’ support also takes the form of advice, training and guidance that act as reliable reference for owners investigating the feasibility of a switch. The classification society also plays a role in developing standards of best practice in LNG as fuel through its development of relevant requirements and membership on industry committees, such as the recently formed Society for Gas as a Marine Fuel.
To align internal resources with the needs of its clients, in particular related to LNG shipping and LNG as fuel, ABS also formed a Global Gas Solutions Team. It brings together industry-focused professionals whose objective is to work alongside owners, shipyards and equipment manufacturers to promote the use of LNG-fueled propulsion systems as a way to meet more exacting exhaust gas emissions requirements.
Author:
Sean Bond
Director Environmental Solutions Group American Bureau of Shipping (ABS)
www.eagle.org
Sean Bond
