LNG as a ship fuel is gaining momentum in Europe, the US and Asia. This supports Det Norske Veritas in its prediction of 1,000 LNG powered vessels by 2020
The Port of Hamburg welcomed its first LNG-fuelled ship in June this year. Not surprisingly, it was a Norwegian[ds_preview] ship: the »KV Barentshav« belonging to the Norwegian Coast Guard. The occasion for the ship’s visit was the conference »LNG – The Norwegian Experience« organized in Hamburg by the German-Norwegian Chamber of Commerce, Innovation Norway and Det Norske Veritas (DNV) Germany.
DNV believes LNG will be an important solution for meeting upcoming air emissions regulations. It is likely to be more economically favourable for shipowners amidst current, extremely high heavy fuel oil (HFO) costs. Decoupled from oil prices due to sources such as shale gas, LNG is expected to remain competitive for the lifetime of new vessels entering the market.
Interest in Germany is growing. For example, the Hamburg Port Authority (HPA) and Linde Group are currently preparing a feasibility study on the commercial use of LNG in the Port of Hamburg. The findings will form the basis for the required infrastructure developments in Hamburg. Bruns-
büttel Ports and Gasnor have already embarked on plans for LNG bunkering at the Elbehafen Brunsbüttel close to the entrance of the Kiel Canal. »For LNG bunkering it is necessary to bring together safe operations on land and safe operations on ships. This has successfully been done more than a thousand times per year already«, Jan Tellkamp, Project Manager R&D at DNV Germany, says.
2010 in Gothenburg safe bunkering of a RoPax ferry with LNG was evaluated during normal loading and unloading operations. No safety show-stoppers were identified and DNV has issued approval in principle. In Germany DNV is sharing the experience from projects like the Gothenburg project and from operational feedback of approximately 30 LNG fuelled vessels with the partners in the Bungas project underway.
Bungas aims to develop a ship-to-ship LNG bunkering system for refuelling commercial vessels. The project involves the development of the necessary technical and organisational solutions to refuel a growing fleet of vessels operating with LNG as fuel.In addition to this and a wide set of bunkering facilities in Norway, small scale bunkering facilities for LNG vessels are underway in Zeebrügge and Rotterdam and plans have been developed for small-scale LNG terminals in Rostock, Gothenburg, Turku, Swinoujscie, Padilski, and Porvoo.
The main maritime engine manufacturers are already introducing more new LNG fuelled engine models than heavy fuel oil engine models. Their confidence is reflected in a recent move by Wärtsilä and Shell. These companies have signed a joint cooperation agreement aimed at promoting and accelerating the use of LNG as a marine fuel. LNG will firstly be made available in the US Gulf area and then further afield.
The ability to bunker LNG globally is important for the fuel’s adoption by the blue water fleet and Singapore has also taken steps to prepare for LNG bunkering with the commencement of a joint industry project early this year to investigate its operational feasibility.
DNV has developed a large scale computer simulation model using shipowner and cargo fleet census data that predicts
the deployment of emission reduction technologies up to 2020. An analysis of fuel choices reveals that between 10 and 15 % of the newbuildings delivered before 2020 will have the capacity for burning LNG as fuel. This equates to 1,000 ships.
»Our modelling indicates that about 40 % of the world fleet will be affected by the 0.1 % sulphur limit in 2015«, says Dr. Gerd-Michael Würsig, Business Director for LNG fuelled ships at DNV. »Besides vessels operating completely in the SECAs/ECAs, small tankers, container feeders and general cargo ships will be significantly affected.« Using LNG as fuel will not be the primary solution for every vessel, but it will be a solution for a significant number, Würsig predicts.
»LNG can become cost effective when a vessel spends more than 30 % of its sailing time in ECA. Large vessels burning large volumes of fuel will benefit from economies of scale gained from the switch to LNG which in the long run we anticipate will be even cheaper than heavy fuel oil«, the DNV manager points out. »On a fleet or individual ship level DNV advisory services help owners to decide if the change to low sulphur fuel, applying scrubber technology or the change to LNG is the commercially best way to comply with SECA/ECA requirements.«
Taking into account the potential for even stricter emission regulations in 2020, LNG is definitely the way of the future, continues Würsig: »When we talk about the risk of applying a new technology like LNG we also have to consider the consequences of not applying it. Strict emissions regulations will force shipowners to act.«
DNV’s survey of the market indicates that scrubbers will not be the highly sought-after solution. Many shipowners have been hesitant to commit to scrubbers, exhaust gas recirculation and selective catalytic reduction systems as they have little at-sea operational experience to commend them. Other hydrocarbon gases could be considered as bunker fuel, but for example, LPG (Liquefied Petroleum Gas) is more expensive than LNG and supply is limited. It also carries safety concerns as it has different flammability and dispersion properties to LNG.
Another alternative might be CNG (Compressed Natural Gas). The existence of distribution grids is an advantage for CNG but twice the volume of CNG is required to achieve the same sailing distance as LNG. LNG is cheaper than distillates and contains more energy per kg.
Marine gas oil and marine diesel oil can be supplied with sulphur content below 0.1 % and switching to such fuel only requires minor modifications to the fuel system onboard ships. However, the availability of low sulphur fuel is already limited and rising demand is expected to increase its uncertainty in price.
An LNG fuelled ship will be some 10 % more expensive to build than a ship with conventional fuel, but the investment will be returned through less fuel consumption, less maintenance and most probably a cheaper fuel for the life of the vessel. For example, the payback time for installing LNG propulsion engines on a shortsea 8,000 dwt bulk carrier newbuilding trading exclusively in ECAs is six years.
Installing LNG propulsion adds 6 mill. $ to the initial vessel costs, but compared to the costs of installing selective catalytic reduction technology and burning more than 3,000 t of marine gas oil a year, LNG represents an alternative, economical solution.
Boil-off gas has been used as a fuel for LNG carriers for over 40 years and there is more than ten years of experience in Norway with LNG fuelled ferries, offshore supply vessels and patrol vessels. With appropriate storage, piping arrangements and emergency shutdown systems in place, LNG is a clean solution without the potential for HFO oil spills, most recently highlighted again in the world’s media by the grounding of the containership »Rena« at the coast of New Zealand.
Currently all existing maritime installations involve robust pressure tanks designed according to IMO Type C requirements. In current applications these tanks are vacuum insulated to ensure a low heat transfer from the ambient into the cold LNG (approximately -160 °C) inside the tank. These tanks are located away from the sides and bottom of the vessel.
»Separation of all parts of the fuel gas system from the rest of the ship by for example double wall piping, separated by ventilated channels, is one of the most important basic principles to ensure the safe use of LNG as a ship fuel«, says Würsig.
DNV rules have been applied for ships using LNG as fuel for more than ten years. DNV has performed numerous safety analyses for all kinds of LNG applications for ships and onshore. »As a result of our experience with LNG, we see no safety barrier to apply LNG for seagoing ships.«
The worldwide application of LNG as a ship fuel is already reality. As an example among others, two new LNG-fuelled ships are under construction for Nor Lines to DNV class. One of them will soon trade along the German coast. LNG was chosen for the coastal RoRo/cargo ships as it fitted with Nor Lines’ environmental and future-oriented profile.
DNV also has demonstrated the feasibility of large LNG fuelled ships through
concept studies: »Quantum«, a 9,000 TEU container ship; »Triality«, a VLCC size oil tanker; and two different sized bulk carriers.
Following the »Quantum« concept, Kawasaki Heavy Industries (KHI) has already gained DNV approval in principle for a new container ship. The vessel will operate efficiently at speeds of less than 10 kn and more than 22 kn and will have a MAN Diesel & Turbo ME-GI main engine fuelled by LNG stored in KHI-designed space-saving prismatic tanks.
Oshima Shipbuilding has selected DNV as its partner for the development of a series of »Eco-Ship« bulk carriers for delivery in 2020 and beyond. Oshima is already building Handymax and Panamax bulk carriers with fuel efficiency improved by some 20 % using hull lines and propulsion optimisations. Also, a concept design developed by Oshima is in place for a 30 % more efficient postpanamax bulk carrier.
With these designs in place, the yard is collaborating with DNV to push towards a 50 % more efficient bulker through the addition of LNG. The open hatch bulk carrier markets are driven by the expansion of Brazil’s supply of forest products and European and Asian buyers will be increasingly trading to South America, which will lengthen the voyage and potential energy gains.
The global expansion of LNG usage raises the need for worldwide applicable safety standards and standardisation of operating procedures and equipment. The International Maritime Organization has issued interim guidelines for LNG as a ship fuel which came into force in 2010 (MSC-285(86)) and is developing a more general code for the use of gas as ship fuel (IGF-Code).
Most classification societies have issued rules considering the current IMO regulations. Based on a proposal from Norway the standardisation of bunkering has been initiated by ISO; DNV is leading this work to develop a guideline for bunkering of LNG as a fuel for ships.
»Beside the SOx and NOx reduction efforts we predict that new buildings in 2020 will emit up to 30 % less CO2 than today’s ships«, says Würsig. Det Norske Veritas has developed a computer model to support owners and managers in their environmental decision-making by providing ship-specific analyses of all applicable technologies as well as more broadly based market predictions that could affect their cost-benefit calculations.
Det Norske Veritas
