Maritime University of Szczecin
Akademia Morska w Szczecinie
2011, 28(100) z. 1 pp. 78–82 2011, 28(100) z. 1 s. 78–82
LNG – the dominant fuel for merchant ships by year 2025
LNG – dominujące paliwo dla floty handlowej w roku 2025
Jerzy Listewnik
1, Antoni Wiewióra
2Maritime University of Szczecin, Faculty of Mechanical Engineering, Institute of Ship Power Plant Operation Akademia Morska w Szczecinie, Wydział Mechaniczny, Instytut Eksploatacji Siłowni Okrętowych
70-500 Szczecin, ul. Wały Chrobrego 1–2, e-mail: 1j.listewnik@am.szczecin.pl, 2a.wiewiora@am.szczecin.pl Key words: LNG fuel properties, calorific value LNG, examples of LNG ship propulsion system
Abstract
The paper considers and analyses the application of gas (LNG) as a marine fuel for the whole of the merchant fleet. From made considerations, it is evident that up to year 2025 LNG will become a general ships fuel. Słowa kluczowe: charakterystyka paliwa LNG, wartość kaloryczna LNG, przykłady zastosowań zakładu siłowni LNG
Abstrakt
Artykuł rozpatruje i analizuje zastosowanie gazu LNG, jako paliwa statkowego dla całej floty handlowej. Z dokonanych rozważań wynika, że do 2025 roku paliwem statkowym będzie LNG.
Introduction
In fact the thinking has started as long ago as May 1915 when Godfrey L. Cabot had patented an idea for “...handling and transporting liquid gas” – by river barge s.p.9 under Cabot’s patent 1915.
There is no record of any such craft having been built, but the idea was there and indeed, as will be seen later, Cabot had in fact anticipated many of basic characteristics of the present-day gas carriers.
The beginning of 1950s is to be recorder that the first attempts were made to find the materials and to establish practical design and building techniques for shipping liquefied natural gas (LNG) at its boiling point of minus 165C safely across the oceans of the world in commercial quantities. In a relatively short time span the transport of lique-fied natural gas (LNG) become a well established, highly sophisticated and safe branch of modern marine engineering. Ships of up to 300 000 m3
capacity and for their size the most expensive merchant ships afloat are now in regular service worldwide.
The year 1959 can be considered as the 52 anniversary of first transatlantic transport of LNG
from the USA to United Kingdom by the ship “Methane Pioneer” considered as a prototype. Thus, in the 1950s intensive fundamental research and development work was being carried out on both sides of the Atlantic – quite independently – with the USA having a good head and shoulders start. But the amount of reliable published information on LNG ship technology available during this period could be written on a single page of paper – contrary to todays – huge knowledge on LNG transport technology and secondly on the usage of LNG as a material for ship propulsion to a lesser degree, but gaining momentum for its application as ship’s fuel.
What is Natural Gas? NG is a mixture of hydrocarbons in which methane predominates – the mixture varies considerably according where and how the gas is found – and particularly according whether it is “associated” with crude oil reservoir – or “unassociated”. “Associate” gas is “richer”, because it contains a higher percentage of ethane (C2H6), propane (C3H2), butane (C4H10) – all of
which have a higher calorific value than methane (CH4). Natural gas may also contain a small
Methane itself cannot be liquefied by pressure alone unlike ethane, propane and butane. It must therefore be cooled in order to convert it into a liquid for marine transportation. It is normally cooled to its atmospheric boiling point of –165.5C or close to this temperature for economic shipment and in this condition occupies 1/600th of its volume as a gas.
The boiling point of a natural gas mixture will often differ somewhat from that of pure methane, being influenced by the boiling points of the other gases in the mixture.
Liquefied natural gas (LNG) is colorless and nontoxic. It has a relatively low flame speed, high percentage flammability level in air, high auto- -ignition point and is non-corrosive. Its weight is less than half that of water. Its main constituent, methane, is lighter than air at all temperatures above –110C (butane, propane and ethane are heavier than air gases at all temperatures). Were it not for its very low temperature, LNG would be a relatively begin product compared with, say, gasoline. But among other positive LNG data, the most important is its value of calorific value (kJ/kg) (see table 1).
Table 1. Calorific values of fuels [1] Tabela 1. Wartość kaloryczna paliw [1]
Fuel H:C ratio Calorific value, kJ/kg Methane Ethane Propane Kerosene Heavy fuel Benzene Coal 4:1 3:1 2.7:1 1.9:1 1.5:1 1:1 0.8:1 55 500 51 900 50 400 43 300 42 500 42 300 33 800
It becomes evident, that for a certain distance to be covered by the ship we need less fuel as a bunker (~30%).
As the shipping industry faces pressure to develop solutions that comply with existing and potential emissions regulations, there has been an increased interest in developing LNG as a solution because of its favourable properties when compared to oil-based fuels. With regards to air emissions, LNG is known to eliminate SOx and particulate matters, while NOx and CO2 emissions are reduced by 80% and 20% respectively.
However, there are a number of questions overshadowing the general adoption of LNG across most of the world fleet. The main concerns are that of the safety and technical issues, the loss of cargo space and equally pressing, the availability and safety of getting a good LNG bunker network in place.
Although LNG has been used on a small number of gas ships for a while, there are an increasing number of proposals for high-efficiency engine systems using high-pressure gas applications. Engine manufacturers and shipyards have deve-loped and validated viable solutions for different vessel types, many of which MER has written about previously.
Background
So far it has been mainly the cruise industry that has benefitted from this fuel, minimising its emission levels, but LNG has been used for many years on gas carriers with boilers (in the case of steam turbine propulsion), four-stroke Diesel mechanical propulsion or Diesel electric propulsion installed. All these solutions are based on consump-tion of readily available LNG as the fuel, and/or boil-off gas from the LNG tanks. In recent years, the LNG infrastructure, particularly in Norway, has developed to the extent that other ship types, like Ro-Ro and smaller ferryboats use LNG as the fuel.
In 2010, DNV presented the LNG fuelled container ship, the “Quantum”. The “Quantum” concept introduces a number of innovative solutions to increase efficiency and reduce the environmental impact of container ship operation. The machinery arrangement is based on electric propulsion and dual fuel gensets. With the recent technology development, MAN Diesel & Turbo now manufactures both dual fuel medium speed engines, and low speed MAN B&W LNG-burning ME-GI type engines offering propulsion power with reduced emissions.
The development of the ME-GI engine has made it possible to install a simple, yet unique propulsion power solution, with total system efficiency similar to conventional vessels, but with reduced emi s-sions. Hence, the further development of the DNV “Quantum” project with a single propulsion line, using an ME-GI main engine as the power source, is a natural and obvious progression for future container ship designs to obtain a reliable, energy efficient, and emission-friendly LNG solution.
As a result of recent market trends, it was decided to increase the ship size from the 6000teu range to the 9000teu range. With the new Panama Canal, this ship size is appropriate for the Asia-US trade through the Panama Canal. The hull form and arrangement has, consequently, been modified and optimised for the new machinery arrangement, ship size and trade.
The ME-GI engine will fulfil IMO Tier III NOx levels when combined with the exhaust gas
recirculation (EGR) technology. A technology developed by MAN Diesel & Turbo for the complete low speed B&W engine programme for compliance with IMO Tier III NOx emission regulations.
Then DNV introduced the “Triality”, a new crude oil tanker concept fuelled by LNG, and that has a hull that removes the need for ballast water and recovers hundreds of tons of cargo vapours on each voyage. The new concept tanker has two high pressure dual fuel slow speed main engines fuelled by LNG, with marine gas oil as pilot fuel. The “Triality” (Fig. 1) will have twin high pressure dual fuel two-stroke main engines using MGO as pilot fuel, low pressure dual fuel generator engines using MGO as pilot fuel and a triple fuel boiler that can burn natural gas, MGO and Volatile Organic Compounds (VOCs).
Fig. 1. The “Triality” [2] Rys. 1. „Triality” [2]
Two IMO type C pressure tanks capable of holding 13 500 m3 LNG, enough for 25 000 nm of
operation, are located on the deck in front of the superstructure. The generators are dual fuel (LNG and marine gas oil) while the auxiliary boilers producing steam for the cargo oil pumps operate on recovered cargo vapours.
Concerns
Using LNG as a fuel in shipping has been met by growing concerns that there is a patchy approach to research and applied rules that is leading to potential challenges being ignored, leaving many wondering whether or not to invest. Research into bunkering procedures and fuel feed into ships engines are two areas where there is still a need for further analysis. There appears to be assumptions over bunker loading conditions, safety criteria and the feed into the engines that may be being over-looked, commented Andrew Alderson, consultant at ship designers Hart Fenton.
With regards to the IGC code, the rules on how gas carriers can store, handle and use gas as a fuel, is currently being revised at the same time that a set of interim guidelines on the use of LNG as a fuel,
known as the IGF code, in other vessels is being developed and solidified. There are contradictions
between these two sets of codes that need to be resolved to give reassurance to owners that their
ships in the future will be fully compliant. The
main conflict is the way LNG is transported when stored as a cargo or as a fuel, even though it is the
same hydrocarbon liquid with the same properties. Impacting on design, if the LNG is a cargo it can’t be stored under the accommodation, whereas if the LNG is used as fuel it can be located under the
accommodation, such as the DNV “Quantum
9000” (Fig. 2) design which has two large p res-surised tanks under the accommodation block of a container vessel.
Fig. 2. The “Quantum 9000” – LNG stored under the accommodation [2]
Rys. 2. Statek „Quantum 9000” – LNG pod powierzchnią mieszkalną [2]
The IMO has brought together the two corre
s-pondent groups working on these two codes to ensure these discrepancies are ironed out. As a result, the deadline for confirming the IGF code
has been pushed back two years to 2014, adding even more uncertainty to owners eyeing LNG as a solution for the 2015 Emission Control Area
(ECAs) emission deadline.
Many owners cite the lack of infrastructure as an
obstacle, although according to gas suppliers, this is one that can be dealt with fairly quickly. A number of companies are actively addressing this issue, including port authorities, gas and utility co mpa-nies, LNG terminals and ship operators, who are all
looking at the logistical chain for LNG bunkering that is suitable and economic. Another concern is necessary qualification of the crew members involved in LNG bunkering for which fail safe procedures and equipment are required for routine operations.
The infrastructure
Looking to the immediate future, the main application of LNG as a fuel would be in the short-sea and ferry sector in the ECAs, where gas is widely available and where there are immediate pressures with regards to SOx and NOx compliance.
But for LNG to be a competitive fuel, there needs to be an appropriate LNG infrastructure.
Norway has led the way in its use of LNG as a bunker, and as a result interest has spread to Sweden and Denmark where various projects are underway. The Danish Maritime Authority is looking at how LNG infrastructure can be developed, should owners opt for LNG as a fuel, as Fjord Lines is on course to have its two new ferries built with dual fuel engines and have type C LNG tanks installed, while Viking Line has signed up STX Finland and Wärtsilä to build a cruise ferry to run between Stockholm and Turku.
This interest in gas power has also popped up in South America, where Buquebus has bought a high-speed ferry to run off a gas turbine engine. Capable of over 50 kts, the vessel will operate on the River Plate. Apart from the last project, all the other vessels being built or in operation have received some sort of financial incentive to get owners to make the extra capital investment, but these will not always be available.
One method of developing the LNG infra-structure is to have floating re-gas stations. The concept, such as the “Energy-Bridge” vessels, has been applied at the Northeast Gateway near Boston, Massachusetts, and the Gulf Gateway off the Louisiana coast, where gas is discharged into offshore submerged buoy installations. A variation, labelled “Gas Port” where conventional vessels undertake a ship-to-ship discharge into a docked Energy-Bridge unit, has been put into place at Mina Al-Ahmadi in Kuwait, the River Tees in the UK and Bahia Blanca in Argentina. And an Excelerate project in Argentina, at Escobar near Buenos Aires, is expected online in mid-2011.
Golar LNG owns and charters out floating storage and regasification units to Petrobras and Dubai Supply Authority. Petrobras has chartered in Golar Spirit and Golar Winter, under 10-year time charters, which are moored at Pecem in north-eastern Brazil and Guananbara near Rio de Janiero, respectively. There are a number of other projects like this worldwide.
The market
Another determining factor to using LNG is the price. Analysts have been reporting for a number of months that while gas prices may rise, they will not do so to the same extent as crude oil. There are three distinct gas prices: North America, the cheapest, Europe and then Asia, particularly Japan, the most expensive, but these prices will merge at
some point and form one global market price which will be independent of crude prices.
Gas prices have decoupled from crude oil prices in bunker, as although gas is an alternative to crude, you need a specially designed vessel to be able to run on LNG, and as there are not that many LNG
vessels at the moment, LNG as a fuel becomes
inelastic.
Japan is the world’s biggest buyer of LNG, but the recent natural disaster that hit Japan saw LNG prices jump as dealers braced themselves for the huge demand expected to replace large amounts of nuclear power capacity that was knocked out in the earthquake and tsunami. The cost of UK LNG delivered in one month increasing 7.7% in a matter of days, with contracts traded as high as 64.5p per therm, a two-year high.
According to CRISIL Research, the incremental gas demand is likely to push up spot LNG prices from around US$9/MBtu to US$13–14/MBtu in the next 3 months. Germany’s recent decision to shut seven atomic power reactors (7.4 GW) for 3 months in the wake of the Japanese crisis and the resultant increase in gas demand would drive a rise in prices in the short term. Spot LNG prices are rising due to tight availability, and CRISIL expects the 40%
substitution with gas-based power capacities to boost gas demand by 6–8 Mt p/a.
Projects
BV has forecasted that LNG projects could be worth $7Bn by 2017, as there are perhaps 20–25 such projects under discussion around the world, with BV involved in 14 of them. However, owners are delaying such investment until the LNG supply
in the ports is secured, plus shipowners are demanding security that the price of LNG would be lower than that of bunker oil in the future as well.
Golar LNG has ordered four LNG carriers worth
around $800M from South Korean shipbuilder Samsung Heavy Industries with options for four more, with delivery for the first four in 2013/2014. Golar said fuel costs will be reduced because the vessels will have dual-fuel Diesel-electric engines rather than steam turbines.
Spot rates for LNG carriers are around $80 000 per day and FSRUs can earn around $125 000 per day. But spot rates for LNG carriers should reach
$100 000 per day before the onset of the northern hemisphere summer months, further boosted by Japan’s extra demands. Although there is an imme-diate impact on rates, the excess of LNG in the market will stem rates soaring over the long term.
Conclusions
As DNV CEO Henrik O. Madsen, said: “I am convinced that gas will become the dominant fuel for merchant ships. By 2020, the majority of owners will order ships that can operate on LNG”. When it comes to the additional cost of building a vessel like the “Triality” and the reduced cost of
operating it, he concludes: “It is possible to develop an environmentally superior ship and be profitable at the same time. Our best estimate is an additional capital expenditure of 10–15% for a “Triality” VLCC newbuilding compared to a traditional VLCC. Even with this extra cost included, we estimate a reduced life cycle cost equal to 25% of the newbuilding cost for a traditional VLCC.”
However, LNG propulsion will not take off just because it is less malignant, it will only do so when the economics stack up. Experts predict, this is on its way to happening. Natural gas reserves are greater than crude oil and its price is lower.
References
1. Pounder’s marine Diesel engines and gas turbines. Elsevier, 2009.
2. LNG – going for gas. MER, May 2011, 38–41.
3. FFOOKS R.: Natural Gas by Sea. Gentry Books, London
1979.
4. WOOLCOTT T.W.V.: Liquified Petroleum Gas Tanker
Practice. Brown, Son & Ferguson, Nautical Publishers, Glasgow 1987.
The paper was published by financial supporting of West Pomeranian Province Fig. 3. The „Triality” engine room layout [2]
Rys. 3. Układ siłowni „Triality” [2]
Engine room MGO
MAN ME-GI Gas room
LN G ta nk LN G ta nk MGO VOC Boilers Auxiliary MGO Low pressure LNG High pressure LNG MP pres sure s pum p
