LNG delivery by container helps supply issue

Concerns about LNG fuel delivery to vessels and the limited infrastructure are being by addressed Marine Service GmbH, an engineering consultancy that has developed what it confidently puts forward to be a reliable solution that will allow delivery of LNG to vessels worldwide by standard 12m fuel tank containers. Clearly there would be some limitations to this, such as the amount of fuel, and storage on board certain types of vessels.

This concept however, is one that could possibly get the ball rolling and give some owners a degree of confidence that if they do change over to dual-fuel, there will always be a supply waiting for them when they reach port. Medium sized vessels and particularly container vessels would be the most likely candidates, on a regular run to known ports so supplies can be waiting for them.

While this is a first and relatively small step, it shows that there are solutions out there. The lack of infrastructure could perhaps start to be addressed initially with a portable and mobile supply.

It is widely accepted that LNG is the most promising long-term solution to the emissions and environmental issues facing shipowners, but until the infrastructure outside Scandinavia is in place or at least improved, it is not necessarily the most viable solution at the moment.

Even with the 2015 ECA emission directive looming, many owners are reluctant to convert or order new LNG-powered vessels, preferring to wait and see what happens over the next few years. The delivery of fuel by container is certainly a significant step forward, and one that should allow a degree of confidence that, for instance, if a vessel was converted to run on LNG, the fuel cells could be delivered worldwide to meet the vessel.

The delivery of fuel by container is not really a long-term solution, but one that will bridge a gap and get the ball rolling. If enough owners can be persuaded to start converting to LNG knowing that there is a reliable mechanism in place to secure worldwide LNG fuel delivery, then the investment will come to make permanent provision in key ports around the globe. This will be a gradual process – rather like when the world changed from coal power to oil.

“The container can be understood as a replaceable and rechargeable battery,” explains Jörg Redlin, director of marketing and LNG division at Marine Service. “The LNG fuel tank containers can be loaded aboard like every other (International Maritime Dangerous Goods) IMDG container. Ships using these containers achieve independence of the availability of LNG bunker facilities.”

The containers would be filled at dedicated LNG terminals, and then transported to their destination by sea, rail and road. The containers can be transported either to a holding station in preparation for forwarding, or direct to the end user. They can be used either as replacement or exchange cells on vessels, or can be installed as permanent storage if the vessel is operating in an area where shore LNG bunkering is available. Empty containers, once exchanged, are shipped to the nearest filling facility, and the cycle begins again.

The vacuum insulation on the containers allows LNG to be stored for up to 80 days, before the pressure inside the container reaches the set value of the safety vent. The sturdy construction of the containers allows them to be stacked up to six containers high. The inner and outer material of the tanks is standard 304-grade stainless steel, and the frame is made from high-strength carbon steel. The maximum loaded weight of a container is 30,800kg.

The actual cost of converting most ships’ engines to operate on LNG in not excessive, but the real cost involved is in modifying vessels to fit suitable permanent storage, usually below deck.

LNG fuel tank containers offer a realistic alternative, particularly if there is room to store one container (or more when stacked) on deck. They can be connected with dry-quick-couplings to the gas handling system and the fuel system of the LNG fuel-modified engine. “The concept of the Marine Service LNG Fuel Gas System is designed for on-deck stacking for safety reasons,” says Mr Redlin.

Control and regulation of the correct gas pressure for the propulsion system is managed by a separate control unit. The gas control valve group is supported by a gas handling unit. This unit can be deployed in a separate container and installed next to the LNG fuel tank containers. The LNG Fuel Gas System, developed by Marine Service, was approved in principle by Bureau Veritas in July 2011.

“With the LNG fuel tank container, the safe connections and couplings and the existing infrastructure for IMDG containers, Marine Service provides the perfect solution for matching the ECA regulations,” says Mr Redlin. MP