Cryogenic hose technology is driving a rethink of LNG transfer in bunkering – and beyond.
Many backers of liquefied natural gas (LNG) as a marine fuel, as well as wider industry stakeholders, have for a while now suggested that it will soon enjoy exponential growth as a future bunker fuel. There are several factors behind this; the increasing number of emissions control areas (ECAs) requiring bunker fuel of 0.1 percent sulphur (SOx) to be burnt near coastal areas where the burning of dirtier heavy fuel oil (HFO) is forbidden. Most crucially, however, and undoubtedly the catalyst for such significant forecast growth, is the impending introduction of a ‘global sulphur cap’ in 2020 that will require all vessels to burn less than 0.5 percent sulphur marine fuel – spurring ship owners and operators around the world to look for compliant alternatives to marine gasoil (MGO) or marine diesel oil (MDO) distillates.
A recent report sheds light on just how dramatic this growth could be. Energias Market Research says the market for LNG bunkering will increase in value from $825 million in 2016 to nearly $25 billion by 2023 – that’s a compound annual growth rate of more than 62 percent.
Nevertheless, and despite these headline figures, LNG will still only represent a fraction of global bunker fuel supplies. So, why is this? Speaking after the naming ceremony of Shell’s dedicated LNG bunker vessel, the Cardissa, Shell LNG Fuel General Manager Lauran Wetemans said that the marine LNG sector had the potential to be ‘disruptive’ – just as the electric-powered car industry is disrupting existing supply infrastructure. However, he acknowledged that the ‘buy-in’ of owners is crucial if the use of LNG bunker fuel is to be stepped up from its current, relatively modest level.
Interestingly, Wetemans insists that the availability of LNG – an issue which is often cited as being a limiting factor – is not the challenge. Instead, he noted that LNG transference presents obstacles to be overcome, highlighting the need to be able to take that LNG in smaller quantities out of key hub terminals such as Rotterdam, Busan, Shanghai and Singapore.
The Real Challenge: Logistics
In addition to the growth of LNG as a bunker fuel, the global LNG market is evolving in such a way that necessitates the splitting of LNG into smaller parcels – both for use as a marine fuel, but also for power generation and terminal networks supplying communities who might be isolated from major hubs. Floating receiving and distribution terminals and coastal gas carriers are now an integral part of LNG activities and a crucial cog in the LNG supply chain. This is reflected in a diversifying LNG fleet. As the fleet passed 500 vessels earlier this year, its growth is accompanied by a broader range of vessel types. Today, the live LNG fleet includes around 26 FSRUs and 33 small-scale ships of 30,000m³ or smaller.
This shift requires us to rethink our approach to LNG transfer. While in some cases, it may be possible to replicate existing infrastructure, this may not always be feasible. Existing infrastructure at current hubs may not be suited to the range of vessel sizes represented in today’s fleet. At the same time, the need for LNG to be transferred in a wider range of locations presents challenges, as transfer must occur in locations that may be too deep or shallow for traditional jetties to be used, or where harsh environments make conventional jetty-based transfer difficult.
This is where the latest LNG hose technology holds the key to unlocking a wider range of transfer possibilities. Because LNG needs to be transported at a temperature of -163 degrees Celsius, LNG transfer solutions require specialized composite cryogenic hosing to safely transfer LNG to regasification plants. As such, considerable research has gone into the development of cryogenic hoses. These hoses, when used in floating configurations, have the potential to unlock a wide range of transfer options.
LNG Hose Technology 101
Composite LNG hoses typically consist of multiple, unbonded, polymeric film and woven fabric layers encapsulated between two stainless steel wire helices – one internal and one external. Essentially, the film layers provide a fluid-tight barrier to the conveyed product, with the mechanical strength of the hose coming from woven fabric layers. The outer protective hose draws on flexible rubber-bonded hose technology, which is known for its high resistance to fatigue and its ability to withstand harsh environmental conditions. Extra safety is provided by an integrated monitoring system that is able to detect even the slightest leak that may occur in the hose structure.
The system uses cutting-edge optical fiber technology that offers a fast, effective, and reliable control system, to monitor conditions during loading and offloading. This technology unlocks new options in both ship-to-ship and ship-to-shore transfer.
The rise of the new class of LNG bunker vessels such as the Cardissa and the Coralius underscores the need to examine how ship-to-ship transfers of LNG are conducted – a process which is already growing in importance thanks to the increase in carrier-to-FSRU transfer.
Two factors are critical in ensuring that ship-to-ship transfer is safe and efficient – proximity and time. The faster the transfer window, the lower the risk of an incident, and the further away the vessels are, the less likely a collision becomes.
By using floating cryogenic hoses in tandem configuration, vessels can be moored as much as 300 to 500 meters away from each other. The increased separation distance mitigates the risk of collision and ensures the safety of the vessels and crew and, moreover, the heavy-duty hose design reduces risk of damage to the hose during handling.
The flexibility and high flow rates achievable by cryogenic technology also makes it an ideal solution for ship-to-shore transfer. It increases the economic feasibility of marine bunkering projects located away from existing infrastructure – particularly in areas where jetty-based transfer would be unfeasible thanks to harsh conditions or environmental concerns. The same goes for terminal or power generation projects.
Trelleborg’s cryogenic hose-in-hose technology can negate the need for fixed onshore infrastructures; a concrete platform onshore combined with Cryoline hose transfer solutions offers an alternative that can be up to 80 percent more cost-effective for locations where fixed onshore infrastructure would be prohibitive.
Collaborations with partners such as Houlder, Wärtsilä, 7Seas and ConnectLNG demonstrate how ship-to-shore operations using cryogenic floating hoses can be further enhanced, and offer increased flexibility and a choice of transfer options. Floating transfer terminals or barges can be connected to the shore using Cryoline hoses, which can then easily connect with a vessel using a transfer system on a barge. These solutions can be built, outfitted and commissioned off-site in parallel with relatively light civil engineering activity. For instance, this could be a relatively infrastructure-light method of enhancing an existing LNG hub that needs to cater to a wider range of vessels – not just large LNG carriers.
The efficacy of this technology has recently been demonstrated with the first test of Connect LNG’s universal transfer system, which was based on this model. The UTS transferred LNG from the 15,600mᶾ Skangas-chartered small-scale LNG carrier Coral Energy to the onshore terminal at Herøya. Classed by DNV GL, the UTS took less than six months from design to hook-up. The system was installed in a day, and completed the transfer a day later.
As a self-contained mobile unit, a floating barge or transfer unit can be readily adapted for future and alternative deployment in the event of local changes or a desire to move location entirely, and individual components can be up or downscaled depending on requirements. A floating solution also allows for refuge to be sought in safe harbor during storms or hurricanes, deep maintenance to be undertaken at a shipyard, integration with a variety of LNGC mooring configurations, and the flexibility to support future, alternative applications. Moreover, the barge is also only used when transfer is underway, minimizing impact on the environment.
Evolving Solutions for a changing Market
The rapid evolution of the LNG fleet, both of vessels powered by and carrying LNG, reflect a market with huge growth potential, and rapidly changing dynamics. It is essential that, as LNG as a marine fuel grows, and the wider LNG market diversifies, that the solutions used to transfer it develop at the same pace – while simultaneously ensuring that efficiency, flexibility and safety are at their core. For this reason, cryogenic hose technology, and the multiple different transfer applications it enables, can ensure that transference is at least one obstacle that can be overcome.
Vincent Lagarrigue is Director of Trelleborg Oil and Marine.