SGMF - Gas as a Marine Fuel - An Introductory Guide (1)

commercial safety technical environmentalVersion 1.0, September 2014 Acknowledgements © Society for Gas as a SGMF would like to thank the Marine Fuel, 2014 following organisations for use of images contained in All rights reserved. No part this publication: of this publication may AGA be reproduced, stored L.E.Larsen, Marine Traffic.com in a retrieval system, or MannTek transmitted in any form or Penguin Energy Consultants by any means, electronic, Tarbit AB mechanical, photocopying, Tuxan Consulting Ltd recording or otherwise, USMRC without the prior permission of the Society for Gas as a Marine Fuel. While the advice given in the “gas as a marine fuel – an introductory guide” has been developed using the best currently available information, it is intended solely as guidance to be used at the owner’s own risk. Introduction environmental Natural gas as a marine fuel Increasing concern over the distances. It has been impact of human activities produced and transported on our environment is internationally in bulk for encouraging the maritime 50 years. The gas-as-fuel transport industry to move industry builds on this towards using natural expertise – but the bulk trade technical gas on board ships as a and the gas-as-fuel business prime source of energy for differ in significant ways. propulsion and electricity This guide to gas as a generation. This trend is marine fuel – an overview being reinforced by national of these variations and their and international regulation, implications – is the first led by the International of many documents that Maritime Organisation (IMO), the Society for Gas as a with its Emission Control Marine Fuel (SGMF) plans to Areas (ECAs). publish. The society is a non- governmental organisation safety The use of natural gas as a (NGO) established to fuel is one way of complying promote safety and industry with the increasingly strict best practice in the use of regime governing emissions gas as a marine fuel. This of harmful atmospheric initial high-level document pollutants, such as nitrogen will link to more technically oxides (NOx) and sulphur and commercially rigorous oxides (SOx), and reduces guidelines aimed at assisting the carbon footprint of ship the emerging gas-as-fuel operations. Liquefied natural industry to develop, with commercial gas (LNG) is the most cost- safety as the paramount effective way of transporting concern. natural gas over very long 1 Introduction What is LNG? to trace levels during production Liquefied natural gas, or LNG, is natural gas that has Physical properties been cooled sufficiently to condense into a liquid. At LNG, a colourless and atmospheric pressure, this odourless liquid, burns only happens at a temperature when in its vapour state. Its of -162°C (-260ºF). As the very low temperature means natural gas condenses, that at ambient temperature about 600 volumes of the liquid is always boiling gas become one volume and creating vapour. of liquid. This makes it The vapour is heavier commercially feasible to than air until it warms to transport large volumes about -110°C. The vapour is of gas in a ship. The LNG colourless but can be seen is generally regasified by as it mixes with air because heating at its destination water vapour in the air is before being fed into a condensed by the coldness pipeline grid. of the warming natural gas. The result is a white cloud. LNG is a mixture of hydrocarbons, How is LNG made and predominately methane where does it come from? (80 – 95%). Other significant components include other LNG is produced using a alkanes – ethane, propane physical process: natural gas and butane. Nitrogen may is compressed to 50 – 80 also be present at levels up times atmospheric pressure to 1%. All the more complex and then cooled from hydrocarbons, along with ambient temperature until it carbon dioxide and sulphur liquefies. compounds, are removed 2 environmental The scale and cryogenic LNG industry overview temperatures involved make LNG production Some 237 million tonnes of much more difficult than the LNG were traded worldwide underlying physics would in 2013. Japan was by far the suggest. Liquefaction plants biggest importer (88 million are frequently valued in tonnes) followed by South billions, or tens of billions, Korea (40 million tonnes) of US dollars, require and China (19 million tonnes). technical several hundred megawatts Virtually all the LNG produced of electricity generation was used for electricity capacity (a megawatt (MW) generation, industrial and of electricity is sufficient to commercial gas use, and by power 500 - 1000 European residential customers. homes), and can occupy an area of up to 1.5 km2. Statistics show that about 5 million tonnes per year of As of mid-2014, 18 countries LNG is transported by road were producing LNG in tanker from bulk import bulk, with another eight terminals and small LNG safety producing smaller quantities producers around the world. for domestic consumption. Road transportation is most According to the LNG common in China, Spain, importers group GIIGNL, Turkey and the USA. Most the biggest producers in of this LNG is consumed 2013 were Qatar (78 million by large industrial users tonnes), Malaysia (25 million and power plants that do tonnes) and Australia (22 not have access to a gas million tonnes). pipeline network. commercial The use of LNG as a fuel has expanded significantly in recent years but volumes 3 The gas-fuelled shipping fleet is also expanding rapidly.are still relatively small. while Australian miners and American shale gas/ oil producers are replacing diesel with LNG. 4 . Most transportation fuel is used by heavy-duty trucks or to fast-fill cars with compressed natural gas. particularly in Scandinavia. Using LNG to fuel railway locomotives is being trialled in the USA and Canada. Bulk international LNG trade during 2013 with the arrows showing direction of flow and their size showing the scale of the trade. 5%.000 times as reductions in nitrogen oxide much sulphur as road fuel. However. is working to reduce emissions of sulphur and commercial particulate matter worldwide by 2020 or 2025. These and in 2011. controls and regulates many aspects of the global shipping business. but technical So. implemented oxide pollution. other pollutants damage the environment in several ways (see page 6). The timescale will depend on 5 5 . emissions worldwide. to world commerce. IMO.7% of world carbon engine size and speed. some ship fuels MARPOL also requires contain 10. through its marine pollution protocol (MARPOL). making it essential now to 0. it limits worldwide are based causes 14% of the sulphur on Tier II limits. while shipping accounts these limits depend on for only 2. a United Nations body.Environmental environmental Why should I use gas? whether worldwide refining capacity is sufficient to allow Shipping is the most efficient the reduction in sulphur way to move most goods content in fuels from 3. The dioxide (CO2) emissions.5% globally. IMO regulations for emissions reduction safety The International Maritime Organisation (IMO). 6 . Carbon Dioxide (CO2) Carbon dioxide is a greenhouse gas. a contributor to global warming. This is called methane slip. SOx combines with water to form “acid rain”. primarily. which acidifies oceans and damages plant life. two-stroke and four-stroke. Losses of methane can occur in four-stroke engines as fuel gas is pre-mixed outside the cylinders and then injected at low pressure. and in heart disease.Sulphur Oxides (SOx) SOx is a mixture of sulphur dioxide (SO2) and sulphur trioxide (SO3) which quickly converts to sulphuric acid (H2SO4) in the presence of water. Particulates are the deadliest form of air pollution because they penetrate deep into the lungs and blood and can cause cancer. There are two broad types of engine. It is also a primary constituent of smog and contributes to the formation of atmospheric ozone. The main focus on CO2 reduction has been through improving the efficiency of engines and ships. Particulate Matter (PM) Particulate matter consists of particles of soot or smoke resulting from the burning of. such as asthma. It is considered to be a major health hazard. Nitrogen Oxides (NOx) NOx consists of nitric oxide (NO) and nitrogen dioxide (NO2). heavier oils. The latter is solid and ends up in the particulate matter (see below). NOx with water can form corrosive acids and has a role in lung diseases. CO2 emission benchmarking across ship type and age is covered by the IMO’s Energy Efficiency Design Index (EEDI) and Ship Energy Efficiency Management Plan (SEEMP) regulations. Methane (CH4) Methane is a greenhouse gas with a 100-year global warming factor of 25 compared with the 1 of CO2. MDO is also used by inland waterway better than HFO on PM. An Emission Control Area (ECA) is an area in which NOx emissions are very the emission limits for SOx dependent on engine load (sulphur oxides) and NOx commercial and technology. the amount of sulphur in MDO. MDO and What is an Emission HFO would need scrubber Control Area? technology to comply with ECA limits. LNG sulphur levels are therefore 1/875th of current LNG produces minimal heavy fuel oil (HFO) limits and quantities of particulate 1/25th of future ECA limits. Using LNG 1% sulphur and marine gas reduces PM emissions oil (MGO) 0. In matter but dual-fuel engines comparison marine diesel using LNG and diesel will oil (MDO) contains about create PM. This calculates to fuelled engines. mass. EN compared with HFO engines safety 590 diesel (road fuel diesel by about 90%.004% of sulphur by engines may also need SCR. None of (nitrogen oxides) are lowered the oil-fuelled options are to reduce their impacts on able to meet Tier III limits health and the environment. 7 . Oil-fired systems will the fuel. Some LNG about 0. environmental Emissions levels of fuels unaided. vessels in Europe) has only 0. HFO has NOx levels marginally higher than. Typical (SCR) technology or Exhaust sulphur specifications in Gas Recirculation (EGR) to LNG are less than 30 parts reduce NOx emissions to technical per million (ppm) of total levels comparable with LNG- sulphur.1% sulphur. The gas used for need to be equipped with LNG production is cleaned Selective Catalytic Reduction prior to liquefaction.001% of sulphur. but SOx emissions depend on generally comparable with. S.1% by the 1st January 2015. Hawaiian Islands U. Caribbean Islands (Puerto Rico Map of Emission Control Areas. Sea (since 2006) followed by ECAs have been proposed the North Sea (2007). mass) and will lowered to 0. for many other areas but are yet to be fully defined. East Coast Baltic North Sea 8 . The first was the Baltic of sulphur in diesel fuels.0% (by 2014. III limits within ECAs from 2016. Germany. Netherlands and Switzerland) already There also exist Sulphur effectively operates as an Emissions Control Areas SECA. Inland waterway traffic in Similarly NOX will be set at Tier western Europe (Belgium. certain timescale for A smaller ECA around the US implementation. West Coast U. Environmental Within an ECA the maximum and the US Virgin Islands) allowed sulphur content in came into force in January ship fuel today is 1. The first complete ECA is the accepted or have any North American ECA (2013). with a limit of 10 ppm (SECAs).S. until it has the right MGO amount of fuel on board with the correct Marine Gas Oil (MGO) and sulphur content Marine Diesel oil (MDO) safety can be used in many • A vessel being detained existing ship engines that in its next port of call if have traditionally operated the results of sampling on heavy fuel oil (HFO). 9 . or a switch to a allowed to leave port variety of other fuels. not specific about how this Various penalty regimes should be achieved. MGO commercial generally comprises lighter hydrocarbons and is more likely to meet ECA limitations. installation of • A vessel not being scrubbers. come in late MDO tends to create more • Fines based on what particulate matter and a ship could earn on potentially SOx – so would cargo / fuel costs need careful specification   to ensure compliance with ECA limits. So have been suggested. Three options are • Large fines generally regarded as the main alternatives: a switch • Prison sentences to MGO. there are various options for technical including: meeting the tighter emissions limits. environmental How will ECAs be Are there alternative regulated? options? Each country implements ECA regulations specify that the IMO rules under its own NOx and SOx emissions laws and will enforce the law must be reduced but are through national procedures. The cost of long term. Scrubbers hydrogen seen by many as can be fitted to the engine the fuel of the future in the exhaust system. and used in fuel cells to generate the space requirements and electricity. replacement option on a technical basis. Hydrogen can be installation is significant. A move towards electric propulsion using Scrubbers usually remove traditional engines as power only SOx. It is widely available on marine discharges from as it is a petrochemical scrubber systems. Disposal 10 . which can then be weight of the equipment will used to drive ship propulsion also need to be considered. Therefore centres and may be very MGO may be a direct expensive. However. be an issue. Disposal at sea would lead to acidification Methanol is gaining some – so many European port popularity as an alternative states are imposing limits fuel. Disposal of the generators is already under waste products may also way.Environmental Again. fitted to most vessels to Scrubbing comply with Tier III limits. with is not reduced. CO2 production are under consideration. systems. then treat the exhaust gases to reduce SOx and NOx Alternative fuels emissions to comply with A variety of alternative fuels the limits. Additional NOx abatement it costs substantially more technology will need to be than HFO. This uses a catalytic process (SCR) Ships may continue to burn based on injecting urea into HFO in their engines if they the exhaust gas. the exact specification onshore is allowed only at a requires careful analysis limited number of specialist before purchase. commercial 11 . and to tanks.2 MJ/m3. so extra is operating in Brazil. A few (CNG)? ferries are trialling methanol on the Scandinavian/Baltic Compressed natural gas has trades. It is also used in Why can’t I just use a limited way as an engine compressed natural gas fuel (“wood alcohol”). is miscible with water. This means that CNG vessels will have to have large fuel tanks or short distances between refuelling. However. as a road transportation and has a low energy fuel and more recently for content per unit volume ships. environmental feedstock. A CNG-fuelled ferry technical (energy density). CNG stored if it is available at very low at 250 times atmospheric cost. pressure has an energy density of only about 9 Liquid ethane carriers are million Joules/cubic meter also going to use ethane as (MJ/m3). Methanol is only seen a lesser extent LNG. is its as interesting for bunker fuel energy density. just as some bulk LNG twice as good as CNG at carriers use natural gas. Petroleum safety fuels remain better at about 35 – 40 MJ/m3. it is highly been used for many years toxic. The space is needed for fuel problem with CNG. 22. LNG is more than fuel. China has two the EU are Denmark and LNG-fuelled tugs in service Sweden but other countries 12 . The first vessel very active in putting systems entered service in 2000 in place to enable LNG to and by the end of 2013 be used as a marine fuel. However. with LNG-fuelled vessels are yet in a particular emphasis on service but ten vessels are on the SECAs in the Baltic Sea order in the USA and another and the North Sea/English three in Canada. Many more Channel. will follow. Far East Most of the gas-fuelled vessels in service are in Japan and China are both Norway. No LNG as a marine fuel. Belgium. the Norwegian fleet had However. with 28 that this region looks set member states. Germany Interest in the use of LNG and France – are also as a bunker fuel is growing involved or have ordered rapidly. but also in Canada. Europe US / Canada Norway.Technical Who is doing it? – including the Netherlands. The the last 18 months means European Union (EU). the country that North America started later pioneered the technology. short-sea trades. vessels. it is South Korea increased to more than 30 that has built the first vessel. It is in service in Incheon The lead nations within harbour. Finland. continues to push forward the amount of activity over with more vessels. than Europe. not just in ECAs but vessels for their coastal or around the world. is attempting to overtake Europe very to develop a co-ordinated quickly – primarily in the approach to the use of USA. later this year. The gas- None of these vessels operate in ECA zones. to operate in Tokyo its 26-ship fleet to LNG Bay. one of the Big fuelled. Three national oil and gas high-speed ferry entered companies. and Uruguay. Brazil has a many inland waterway CNG ferry in operation. and has ordered service in 2013. with national oil and gas company Pertamina. gas turbine-driven. vessels. Gas-fuelled ships in service and under construction. Japan looks set to Indonesian ferry owner Pelni order its first LNG-fuelled is examining converting vessel. safety safety 70 60 s p i sh50 Other (order) d le l PSV (order) e 40 u f Ferry (order) asg f 30 Other Ships o r e PSV b20 m u Ferry N commercial commercial 10 0 Norway Other Europe US/Canada Rest of World 13 . environmental environmental with CNOOC. technical technical Rest of the world Australia is close to ordering Probably the world’s most its first gas-fuelled ferry to advanced LNG-fuelled ship run between Melbourne and operates between Argentina Tasmania. product tankers and general cargo ships. A variety of other ship types are in service. They account for 21 out of 41 (51%) of the vessels in operation and 10 out of 38 (26%) of the vessels on order. tugs. Offshore support vessels (OSVs) make up the second- largest contingent at 29% and 18% respectively. including marine patrol vessels.Technical LNG-fuelled fleet Car ferries currently (mid 2014) make up most of the LNG-fuelled fleet. Gas-fuelled Ferry 14 . but also for ferry vessel called Seagas that operations on the west coast provides LNG fuel. to have at least one LNG bunkering port in each member state. Coastal port 15 . environmental LNG bunkering facilities LNG infrastructure will be completed by 2020 and for LNG is available for inland ports by 2025. Elsewhere in Asia. Oslo and Risavika/Stavanger. Karmøy. vessels that are compatible Singapore. LNG bunkering in the port of Incheon and is looking safety All these ports are able to at a second facility at offer LNG to prequalified Busan. EU policy is facilities. Spain. Norway. About 10% of European coastal and inland ports will be included. UK are considering where LNG can also be bunkered to locate LNG bunkering at the Norwegian ports of facilities. a total commercial of 139 ports. Sweden and the Stockholm and Zeebrugge. Finland. Rotterdam. Japan and China with the LNG-loading are looking at LNG bunkering infrastructure. however in Bergen America. mostly in the Gulf there is a dedicated terminal of Mexico and around the and Stockholm has a bunker Great Lakes. Ports in Finland. Florø. In There are several ports most cases this is by road under development in North tanker. Germany. technical Bergen. Amsterdam. To date marine fuel use in the Denmark. European ports of Antwerp. France. Estonia. Italy and Spain have South Korea is able to offer also loaded LNG as bunker. DNV GL’s latest constrained for its traditional forecast (2014) appears to business model over this extrapolate from recent period.200 vessels by as a marine fuel has arrived. Wood Mackenzie. of LNG by 2030. CERA and This would be an average Total – predict 20 – 30 mtpa of about 150 ships per year. when such as BG Group are the IMO is proposing to already suggesting that the impose worldwide sulphur LNG business will be supply- reductions.000 ships by 2025. This would significantly more than the require about a 10% growth 14 ships delivered in 2013 (20% for the most optimistic and the 22 ships expected in scenario) in today’s LNG 2014. Lloyds forecasts are significantly Register provided a detailed less optimistic than the review of the potential DNV GL fuel forecasts.Technical Projections for the future higher gas-fuelled ship numbers early. Its commercial commentators optimistic scenario predicted – including Poten & Partners. Most of the growth in production just for fuel use. bulk LNG yet there is little alignment business. Most of these between them. what we have yet to see is how large the industry will Other commentators have grow to and how quickly. growing to There is no question that LNG a total of 3. about 2. looked at the overall size of the fuel market and at how The industry has made gas-fuelled ships would several forecasts but as impact the global. the Lloyds Register scenario LNG industry commentators takes place after 2020. 2025. deliveries and so predicts 16 . Most growth scenarios in 2012. 285 (86). An interim set of rules is currently in place under MSC. The IGF Code is currently being finalised and is expected to be released in the next version safety of SOLAS (Safety Of Life At Sea) in 2017. This section discusses the general principles of ship design influenced by the IGF Code. 17 . The requirements for an LNG-fuelled ship are technical currently being developed by IMO under the International Code of Safety for Ships using Gases or other Low Flashpoint Fuels (IGF Code). environmental What does a LNG-fuelled ship look like? The fuel storage and use systems on a LNG-fuelled vessel differ to those on a conventional oil-fuelled ship. Specialist consultancies and classification societies will be able to provide more specific commercial advice. • Redundancy of fuel systems to ensure that LNG storage the vessel can continue to navigate if one The IGF Code is specifically system is damaged concerned with monitoring or fails the conditions within the tank (temperature and pressure).Technical Ship design The factors to be considered Most discussion currently during ship design are: surrounds the location of the LNG storage tanks and how • Protection of the LNG far these need to be sited storage tank and LNG/ from the outer hull to avoid gas pipework from damage. Type C tanks have damage through particular issues as their collisions with other cylindrical shape is not easily vessels and/or cargo or accommodated in a space- by dropped objects efficient way in many parts of the hull. as well as boil-off • Safety systems that gas management systems provide a safe shut. • Minimisation of any providing pressure-relief hazards provided by systems to dispose of the use of gas as fuel gas safely in emergency scenarios. to control tank pressure down of hazardous during normal operations systems and removal and to ensure that leaks of their inventories to are minimised by pipework prevent the build-up design and/or by providing of potentially explosive specific protection for a ship’s atmospheres structural elements. 18 . both LNG or layout between the LNG gas. must be detected and supply and the engines. the LNG storage tank or any other significant volume of LNG. LNG contained. leaks. If the pipes start to warm. safety m/t Bit Viking with two 500m3 Type C tanks commercial 19 . pressure-relief valves must be provided to allow vapour to escape. This is typically is very cold so the pipework achieved by using a pipe- (up to the point where the in-pipe (or duct) system with LNG is evaporated) must be the LNG running through technical allowed to contract without the inner pipe and a leak damage as it cools. Valves detection system provided in must be included to isolate the outer pipe. environmental Ship fuel systems The code provides specific As with the LNG storage advice on pipe design and tanks. and fuel systems should be each with its own fuel system capable of being monitored. fuel supply system.Technical Redundancy of the fuel Control systems system is considered essential. an automatic monitoring systems should fuel changeover system have their own dedicated is required. The (ESD) system is required. – with a vessel needing to continue to operate with the An Emergency Shut-Down failure of one engine. multi-fuel ventilation systems. The code covers gas-only pressures and temperatures. each should be capable of being in a separate machinery triggered manually from space. Power generation & Suitable instrumentation propulsion should be provided to monitor tank levels. and automatically by specific occurrences. Safety engines. from outside any potentially gas containing space. engines. LNG tanks based on multiple LNG tanks. dual-fuel gas to review the operation of and oil engines. This is preferably The engines. detect the escape of gases gas turbines and fuel cells. is the preferred option multiple locations on the ship in the code. providing fuel to multiple controlled and shut down engines.and multi-fuel gas detection. 20 . for example For dual. or – in the worst case – the Redundancy is the key issue outbreak of fires. and to engines (such as methanol). It use of multiple engines. which must and independent control operate on the failure of one systems. A ship-to-shore (or bunker vessel) communication system with ESD linkage is recommended. environmental Bunkering facility The bunkering system should be on an open deck with plenty of natural ventilation. safety commercial Hose connected to ship’s bunkering manifold 21 . If this is not possible. forced ventilation will be required. Spill management and the technical need to protect the ship’s steel structures are also highlighted. Small terminals transfer system. bunkering will take place using pumps. are similar to road tankers and most bunker vessels as Bunkering options LNG terminal Road tanker Bunker vessel LNG Container 22 . will require the ship needing fuel to sail look like? to the LNG terminal. This type of LNG terminals terminal will be supplied by large LNG tankers and will LNG terminals can transfer often be the supply source LNG to ships directly without for road tankers and bunker using any intermediate vessels. Large terminals will have storage There are four different tanks that operate at options for refuelling an atmospheric pressure and LNG-powered vessel. This.Technical What does a bunkering system however. safety amount of LNG that can be inside a container-shaped stored on a bunker vessel. which can be moored alongside ships Containerised LNG anywhere in a port. by dedicated 40 foot container sizes and LNG pumps. trucks rather than custom- built road tankers. LNG road tankers are limited LNG could be provided and by weight through road stored by such “cassette”- commercial transport legislation so type cell systems. Road trucks For gas as a marine fuel. They will end of the LNG transfer receive LNG either from LNG market. if high speeds within standard 20 foot and are required. depending LNG can be transferred from on the LNG volume required bunker vessels or even small and the piping arrangement. Emptying a single carriers or manufacture it road tanker can be achieved themselves. Many road so one bunker vessel may transport operations now use be able to service more than LNG containers on flat-bed one ship. Multiple road Bunker vessels tankers can be unloaded technical simultaneously. the ship and typically takes about an hour. LNG transfer using a pressure differential will normally be by pressure between the tanker and differential. Whole bunkering via a road tanker containers would be lifted 23 . environmental they use pressurised tanks typically serves the smaller to store their LNG. There are no comprise a Type C LNG tank. physical restrictions on the similar to a road tanker. steel frame. LNG carriers. Transfer of LNG can be by pressure LNG tanks can be provided difference or. 24 . technology are that it is not Empty tanks would be space-efficient. a transfer operability but take up very system that connects this large amounts of space. to the tank on the ship that It is therefore difficult to is to be filled. This barriers supported by the is very attractive for the LNG strong hull structure via bunkering process as it load-bearing insulation avoids venting any cold gas. The tanks have Most of these tanks have internal strengthening and operated successfully on LNG structural systems which carriers operating in the bulk make them very robust but international LNG business. located within the hull. pressure vessels whose internal pressure may be Membrane containment increased to several times systems use thin metallic atmospheric pressure. hull shapes.Technical or driven on board and The disadvantages of this connected to the fuel system. free-standing. ships adopting this tank technology. Bunkering system components The iconic. and is relatively expensive. Moss Rosenberg spheres The bunkering system are extremely robust in consists of an LNG tank to terms of strength and hold the LNG. particularly if disconnected and removed. also expensive and relatively IMO Type C tanks are heavy. Self-supporting LNG Storage tanks Prismatic type B (SPB) tanks are effectively cuboid in A variety of LNG storage shape and can be designed tanks are (or will be) to fit comfortably within most available to hold LNG. and a control envisage any LNG-fuelled system to enable the transfer. and therefore requires a duplicate “secondary barrier” to protect the hull in case of failure of the primary membrane. The membrane is subject to deflection loads as the hull moves. safety LNG bunker transfer system The LNG bunker transfer system consists of valves. environmental arrangements. Membrane tanks can be technical made into any shape so can be used space efficiently within a hull. a flexible piping system. However. the membrane is thin and can be damaged by “sloshing”. safety valves and a connector system to the ship’s pipework and control system. waves generated within the LNG tank by ship movement. commercial 25 . The shape of the tank and the strength of the insulation needs careful consideration to avoid sloshing issues. used in almost all liquefaction plants and import terminals. The swivel allows movement in one or two dimensions. As the pipes are rigid. a hose made from a stainless steel inner pipe.Technical Flexible piping system There are two options for flexible piping: firstly. Flexible hose Flexible hoses have been used for many years to unload LNG road tankers into small onshore tanks and more recently to transfer bulk LNG cargoes between ships and floating terminals. hard arms are more robust than flexible pipes and have potentially better safety Hard arms 26 . hard arms that consist of lengths of pipe linked together by an articulated joint called a swivel. and. They are also increasingly popular for loading LNG road tankers. layers of insulation and an external armour. secondly. meaning that two swivels are required. Hard arms are the workhorse of the bulk LNG industry. An ERC consists of two valves that Emergency release coupler close automatically in an emergency shut-down to monitor the filling process scenario. That said. Control systems commercial Best practice is to connect the two LNG tanks and control systems to allow each side 27 . with the only spillage being the small amount of LNG trapped between the two valves. allowing filling or over-pressurisation separation of the two vessels – developing. environmental performance. Emergency release coupling technical Emergency release couplers (ERCs) have been introduced to limit – indeed almost eliminate – LNG spills should the system need to be disconnected in an emergency. Between the two and prevent any hazardous safety valves is a coupler that scenarios – such as over- can break away. the continuous movement of the swivels during bunkering may lead to maintenance and component lifetime issues. over the ship. and the pressure bunkering. The master is environmental and maritime acting on behalf of and in requirements. the transfer process the LNG. The PIC will also The master of the vessel to be responsible for complying be fuelled retains control with any local safety.Technical Bunkering process the seller of the LNG. The PIC is stakeholders and has several responsible for the safety of stages. the right to terminate the process. In most scenarios the PIC will act on behalf of 28 . is in control of the transfer of LNG. the LNG supply and transfer equipment. If. The master must also The choice of filling method ensure that the LNG transfer will depend on many factors. The bunkering process is summarised in the flow The Person In Charge (PIC) diagram on the right. at any the interests of the buyer of stage. LNG that will be bunkered. the temperatures requirements do not continue of both LNG volumes. the master has ratings of the LNG tanks. the PIC should quantity and quality of the terminate the transfer. process is safe and that including: the compositions environmental impacts are of the LNG in the tank and the minimised. In this capacity the PIC will provide Bunkering an LNG-fuelled the correct amount and vessel involves many quality of LNG. If these basic LNG fuel. In this capacity the fails to comply with the local master must approve the regulations. the to be met at any time during filling rate. environmental Flow diagram of a typical bunkering process technical safety commercial 29 . Stainless steel and impacts than marine oils. This is called a the physical obstructions in Rapid Phase Transition (RPT). If the Spills of cryogenic fluids onto LNG leak is larger than the water lead to very rapid rate of vaporisation can boiling of the LNG. one benefit of must be protected against LNG’s cryogenic nature is accidental LNG spills using that it will start to vaporise drip trays and/or water on contact with air. ground curtains. aluminium do not become brittle so are normally used Almost all LNG-based safety for cryogenic pipework and incidents will start with a valves. fracture – so areas at risk However. into the atmosphere. Carbon steels or water. the circumstances the expansion LNG will form a pool that caused by the rapid boiling may stay in one place or can create a low energy spread out. In unusual immediately dissipate. spill of LNG or an escape of cold gas. its vicinity and the degree of movement of the vessel involved.Safety Is LNG safe? Handling cryogenic liquids The cryogenic nature of LNG Extremely low temperatures introduces new hazards that will cause standard ship differ to those of conventional steel to become brittle and oil-based marine fuels. depending on blast wave. This means that used for shipbuilding start LNG spills tend to leave to become brittle below fewer lasting environmental -20°C. This gas may disperse to vaporise and disperse. 30 . particularly onto water. structures of quaysides are the LNG may vaporise very unlikely to cause damage quickly and become a cold but may take some time gas. For very small LNG Spills on earth or the concrete spills. Wherever the gas cloud is highly dependent ignites. the gas will rapidly on prevailing weather burn back to the leak source. there technical therefore decreases and the is potential for a fire to start gas becomes more buoyant. If LNG spills starts to warm. flammable. Its density and starts to evaporate. Natural gas ignites only becomes lighter than air and in mixtures of between about starts to rise. if an ignition source is close At about -110°C the cold gas by. which is why LNG As it spreads. it should safely and so leaks will roll down disperse in the atmosphere. conditions. and along a deck or water surface. They are usually very Fires & firefighting apparent as the cold gas condenses water vapour in Vapour from boiling LNG is the air to form a white cloud. the cold gas is used as a fuel. The direction 5% and 14% by volume in and speed of gas dispersion air. environmental Cold gas is heavier than air not ignite. If the gas does where it will continue to burn safety Dense white cloud formed by vaporising a liquefied gas (nitrogen commercial in this case) spreading over water 31 . During and to prevent a hazardous after construction some scenario escalating into an safety improvements may actual safety incident.Safety until it is extinguished or all regarded in the marine and the LNG has combusted. The bulk LNG industry has a good safety record. These factors The greatest benefits of combine to minimise safety analysis are at accidents. incidents and the design stage. solid construction Designing in safety and stringent operational practices. LNG facilities and LNG carriers are 32 . no longer be possible at reasonable cost. hydrocarbon industries as In very specific circumstances best practice. overall attention to detail in design. be so violent that a form of robust safety systems and explosion can occur. This view is the ignition of a fire may based on their high-quality. is when most proposed safety improvements Multiple layers of protective can be accommodated measures are implemented relatively easily. as well as high standards of training and operational procedures. having developed very rigorous design guidelines for both ships and shore facilities. for example Layers of if they require the altering or protection moving of major systems or principles hull components. which product releases. It uses the same leaks. Some is unlikely. commercial need to be credible. which 33 . probabilities or frequencies The size of safety zones to the chance of an event can be calculated by one occurring. The safety of two generally accepted distances generated are systems. community. Safety distances here can be small to very The maritime industry small. Safety distances are The alternative –probabilistic designed to keep ignition – approach predominates technical sources away from the in many onshore LNG LNG and any potential facilities. The weakness of this has generally used a method is the ability of the deterministic approach. These scenarios hazard scenarios. such as collisions. while simultaneously consequence calculations minimising the potential for as the deterministic scenarios that could lead to method but also assigns damage. hazard assessor to source in which distances are appropriate frequency data calculated for certain failure and independently assess scenarios. of perhaps exclusion zones up to 100 metres or more. environmental Simultaneous failure of is normally where the multiple layers of protection arguments begin. supposedly credible scenarios may lead to large Safety distances and safety distances. The choice will examined on the maximum usually be at the discretion of risk to an individual worker/ safety the local regulator and may member of the public and also depend on the type of the societal risk to the wider bunkering being used. design work is safe while operation and maintenance. on individual exceeds their requirements. others will be carried out 34 . and on the whole Risk assessment is normally bunkering process.Safety Probablistic risk-based assessment Risk assessment Risk assessments will to demonstrate to the local need to be carried out and/or national authorities on equipment and that the design meets or components. vessels. Some carried out during the design risk assessments will be and planning phases – performed to ensure that addressing construction. the understand all the hazards use of different bunkering involved. mal-operations and the impact of the effects of poor Any work also needs to performance is quantified – be seen in the context of is particularly appropriate. This may be a be placed on non-routine new vessel to be fuelled operations. Alongside risk Risk Assessment! A HAZard assessment. 35 . environmental The results of such risk Safety management systems assessments must be incorporated into Management systems and the operational and procedures must reinforce maintenance procedures staff behaviours around the as appropriate. it needs or cause safety concerns safety to be repeated every time for other tasks/workers. the whole plant or vessel – to ensure that one task Risk assessment is not a does not interfere with one-off process. something significant Particular emphasis should changes. Full risk implementation of safety assessment consists of much to ensure that policies are more than just a Quantitative effective. Modifications should go through a risk assessment commercial process before being authorised. the use of technical and OPerability (HAZOP) safety manuals. where it may (if substantially different not be straightforward to from others fuelled). appropriate study – in which each major working procedures/ equipment component is practices and training are examined for a variety of crucial. and/or changes in operating procedures. equipment. The offsite emergency response plan aims to handle the consequences 36 . for example the incident. There is nothing in the Generally there should be regulations forbidding two levels in an emergency simultaneous operations. the most risk assessments and safety appropriate response clicks management systems. The second dropping of a container level looks after the wider on the bunker vessel. operations will be allowed Planning therefore should will be for the port authority consider all possible and/or the safety regulator eventualities. For The site emergency response example. in.Safety Will simultaneous How do I plan for operations be allowed? emergencies? Whether simultaneous Accidents can happen. vehicle engines. The first level looks but they introduce additional after the site of a potential hazards. plan. on the basis of worst happens. the consequences of an incident being greater. The ignition sources because of purpose of this is to handle their mobile phones and/or the immediate hazard. so that if the to decide. controlling and extinguishing any fire and treating any injured people. passengers are would probably involve likely to be more vulnerable the bunker company/ during boarding and also facility owner and fire and represent multiple potential ambulance authorities. or community. and ambulances treating Both the bunker supplier and simulated casualties. Typically the needs to be tested at least police are the main agency annually. to full-blown simulated Dealing effectively with emergencies. 37 . Fire and ambulance authorities are very good at fighting normal fires and attending a range of accidents. Tests can range and the local authority from desk-top exercises will need to be involved. Supporting the training of key members of the emergency services and commercial regular visits and drills to familiarise first responders are strongly recommended. with fire media interest is an appliances in attendance technical important part of this activity. environmental of an event for the wider The emergency plan community. involving only senior staff particularly if a public from the emergency services evacuation is required. an LNG spill is not a normal accident safety and the bunkerer – especially in the case of a terminal – is likely to have more experience and knowledge in LNG fire-fighting and first aid than the emergency services. This can be a cause of conflict. the ship owner should be involved. However. It is probably not Training for mariners possible to train everyone in everything but the basic Gas-as-fuel training for mental model between the mariners will come under two parties should be shared the International Maritime to enable understanding. only infrequently (every • Basic training of all several days or weeks). Organisation’s (IMO’s) Communication and Standards of Training and co-ordination are key Watchkeeping Committee to successful and safe (STCW). This bunker vessel. The shipping rules and IMO two crews need to work training systems. The and equipment.Safety What training is required? There is concern over “regulatory clash”. A four-level system is bunkering. together so both must be trained. The ship may bunker regulations. the Working together mismatch of onshore rules (frequently competence- Bunkering is a two-stage based but with criteria set by process – one party operators and approved by supplying the fuel and regulators) with prescriptive the other receiving it. The crew on a gas-fuelled quality of the receiving vessel vessel about the safety and training of its crew are issues of natural gas key to safe bunkering. 38 . terminal or is expected to be the road tanker staff would be responsibility of ship bunkering every day and owners and managers probably many times each and outside of STCW day. anticipated: The main risks are thought • Familiarisation of the to be associated with the crew with the ship ship being fuelled. transfer in the hazards of LNG and and engine operation. cargo in bulk. vessel. of view. The existing • Equipment specific training requirements of training. based on liquefaction plants to provide their actual roles within the training for their employees gas/LNG storage. probably from STCW under the IGC Code the vendors. including training courses. bunker vessels fuelling system and are considered to be LNG technical the LNG-bunkering carriers as they transport LNG process. rather than the ship. simulator 39 40 . • Advanced training Training for bunker for all officers and vessel staff engineering crew involved in the From a regulatory point operation of the gas. DNV GL has suggested an safety alternative approach for Training for terminal staff the advanced training that would involve separating It is normally a legal out different learning requirement for LNG requirements for deck and import terminals and small engineering staff. Some elements of the IGF code. for the would therefore apply to actual systems used on bunker vessels. commercial A variety of training methods are proposed. the company’s operating and maintenance procedures. This too would any system proposed under lie outside the STCW IGF. environmental and how these should training and experience on be dealt with on the operating (or training) ships. code training process may also apply. Good practice appears to be a one-day course. tanker-specific training (“learning to think”)as there are many different types of road tanker. such as actually filling an LNG road tanker (to “demonstrate competence”). Maritime simulator training facility in the US 40 . with the programme including: class-room training to understand processes.Safety Training for road tanker operators All road tanker drivers need training – but there is no industry standard or commonality as to what the training should be. and practical training. where sourced from. typically in options. types of LNG trading.) compositions of the LNG and The price of gas varies by the oil. is commensurate with other Gas and LNG are sold on international gas trading an energy basis. there are the cost of producing and the smaller local producers distributing LNG at small that produce LNG for local scale. Firstly. They also depend on location. Secondly. country and within countries. in which LNG customers. from country to engine type and efficiency. often over very would probably be based long distances. because they the most common unit is depend on the precise a million Btu.Commercial environmental How much does LNG cost? There are essentially two bunker (see diagram). of LNG bunker with oil a Btu is about 4 calories. LNG bunker prices to another. LNG would will depend on which of compete with this price but these models is used and would need to show that where in the world it is the upstream profit. or MMBtu. (Because a Btu is a very Comparing the economics small measure of energy. safety British thermal units (Btu). is difficult. the gas market moves from one country price. in large LNG on the market gas price plus technical carriers. most of the risk is taken. Bulk. The price of LNG supplied. internationally markets. Build-up of LNG bunker prices commercial The price of LNG as bunker needs to be built up from the gas well to the LNG 41 42 . The main reference price there is the international will be the cost of gas to bulk trade. Gas Fields (on or off shore) 42 Gas Treatment Bulk LNG Liquefaction If price insufficient Terminal Cargo diverted Gas Market Price Minus Bulk LNG Shipping Bulk LNG Shipping Alternative Gas Bulk LNG Import Gas Transmission Market Price Terminal System Commercial Gas Market Price Small LNG Liquefier Gas Market Price Plus Small LNG ships LNG Road Transport Bunker Price Containerised LNG Bunker Vessel Bunkering Terminal Quayside Bunkering Bunkering . at the Dutch equivalent. environmental The corresponding prices for oil after conversion to energy terms (as of June 2014) US$ / mmBTU Europe US Far East (Rotterdam) (Houston) (Tokyo) HFO 14 . LNG As LNG contracts are delivered to a ship as fuel is generally based on traded expected to cost less than oil and/or gas references. It is comparable with HFO.15 16 .16 Over the long term.22 technical Natural Gas 7-8 4-5 15 . easy to envisage USA LNG bunker sales contracts being LNG contracts normally based on the price of gas at include some form of price Henry Hub and European safety indexation.24 21 .17 MDO 20 .15 14 . depending on Crude Cocktail (JCC) price how it is indexed. used in price-formation mechanisms – usually The oil equivalents include Henry Hub in the USA or the the price of oil from Brent National Balancing Point (an oil field in the UK sector (NBP) in the UK. The price of of the North Sea). West the LNG therefore generally Texas Intermediate (WTI) commercial rises and falls in line with oil in the USA. in Asia (also referred to as 43 .21 23 . Historically this bunker prices being based has been against an oil or a on either NBP prices or those basket of oils. MDO and to be generally they can be hedged. the gas indices are being Title Transfer Facility (TTF). Increasingly. and the Japan or gas prices. there is no definite answer as yet. models with relatively minor Over many days or weeks modifications. It well covered by existing consists of the most volatile commercial practices. exist but companies and specialist energy lawyers As BOG is generated. However.Commercial the Japan Customs-cleared On the LNG delivery side Crude price). the should be confident of composition (or quality) of the continuation of these the LNG gradually changes. One of the purchase LNG from a bulk technical committees of importer or local liquefaction the European Sustainable company. significant changes in 44 . LNG. Secondly. Any truck operators. So alignment should Firstly. the bunkerer has to be possible. normally Many different models nitrogen and methane. In between LNG supply and ship bunkering Differences between may be some form of LNG & oils delivery contract to cover the costs incurred by third LNG differs from oils in that it parties. existing oil What commercial bunkering contracts – and agreements will I need? Bunker Delivery Notices (BDNs) – are not dissimilar There are two operations to the documentation used that need to happen for LNG in the bulk transportation of bunkering to take place. components. for example road is an evaporating liquid. bunkerer. the Shipping Forum is ship owner/operator has to developing a standardised purchase LNG fuel from the LNG BDN. heat ingress boils off some of the LNG to create what is The LNG supply side is called Boil-Off Gas (BOG). The density to a certain extent LNG commercial is calculated from a LNG road trucking. the bunker be used on a bunker vessel) and may have a vessel. in the custody transfer system and so require only Quantity measurement occasional cross-checking and calibration. preferably at need to be made for cargo the same time. rate of bunkering and measuring instrument. Therefore laborious measurement and safety two flows potentially need to corrections are normally be measured. but otherwise temperature and pressure. and the transfer. LNG importers’ group GIIGNL BOG may be generated provides detailed guidance during bunkering. LNG in bulk has always been measured by recording The alternative from the tank levels before and after LNG road fuel market. Sampling is calculated. bulk LNG industry this BOG is returned to the supplier A similar method could (for example. environmental composition can occur. The composition of the LNG. both the liquid performed by computers LNG and the gaseous BOG. is to use a sample taken at the same mass measurement device. and from calibration Depending on the LNG tank of the tanks and the type. In the on this method. volume and the density the This is called “aging” or mass of LNG transferred “weathering”. The apparently financial value. within a few hours. list and trim of the LNG technical tanker. To ensure for quality measurement accuracy – this type of LNG therefore needs to take custody transfer is accurate place close to the time of to ±1% – many corrections LNG bunkering. time and using this known Road tankers are frequently 45 . the density and the calorific Coriolis meters are the value of the LNG. Sampling & quality calculation The largest inaccuracy in traditional LNG custody transfer systems stems not from the flow measurement but from the calculation of the density. This pump with a totaliser system analysis is used to calculate based on a mass flow meter.Commercial loaded on weighbridges to Vaporisation must be very accurately determine the fast to prevent volatile mass of LNG transferred. As with oil. The density is calculated accurately from a composition. normal technology choice. a sample of LNG must be taken from the transfer pipe as close as possible to the manifold. components leaving Filling LNG-fuelled trucks prematurely and to ensure uses a system similar to a that no residual components petrol/gasoline or diesel are left as liquid. the difficult stage is sampling for the composition. the sample must be vaporised to analyse the composition of the resulting gas in a chromatograph. Unlike oil. 46 . gas samples need to be kept in case of appeal by one party against another. As with oil. sgmf. London. all the players Email: along the gas supply chain office@sgmf. Society for Gas as a Marine Fuel Twitter: @sgmf2014 47 .The Society for Gas as a Contact Us Marine Fuel (SGMF) was established to promote Address: best practice in the use of 50 Liverpool Street. UK society’s ultimate goal is to develop and produce Telephone: definitive guidelines so +44 (0) 20 3637 1455 that the process of using gas as a marine fuel can Website: be undertaken safely and www.info consistently worldwide.info will be able to realise the benefits that stem from its LinkedIn: use. In this way. The EC2M 7PY. gas as a marine fuel.