WinGD low-speed Engines Licensees Conference 2015 Tier III

Licensees Conference 2015, Interlaken 1 / 18

WinGD low-speed EnginesLicensees Conference 2015

Tier III Programme,Technical Position, Status and Outlook

ABSTRACT

This paper considers IMO Tier III candidatetechnologies and their current development sta-tus in the context of WinGD 2-stroke low-speedengines.

Firstly, fuel related measures and argumentsare addressed. One focus is low sulphur liquidfuel alternatives, but gas as fuel is also brieflymentioned.

Secondly, technologies for the abatement of ox-ides of nitrogen (NOX) will be investigated, fo-cusing on Selective Catalytic Reduction (SCR)and Exhaust Gas Recirculation (EGR).

Besides technical advances, this paper alsohighlights trends detected in the market placeand their potential influence on the direction offurther development.

INTRODUCTION

IMO Marpol 73/78 Annex VI, the InternationalConvention for the Prevention of Pollution fromShips, Regulations 13 and 14 have become re-ality.

Regulation 14 addresses emissions of oxides ofsulphur (SOX). Starting on 1st January 2015, itlimits the maximum sulphur content in marinefuels to 0.1% in Sulphur Emission Control Areas(SECAs). Alternatively, instead of limiting fuelsulphur content, scrubbers can be used to re-duce sulphur in gaseous emissions to less than20 ppm (parts per million).

Furthermore, Regulation 13 governs NOX emis-sions. The global application of the Tier III NOX

regulation in Emission Control Areas (ECAs) asdefined in the NOX Technical Code, IMO Reso-lution MEPC.177 (58) and originally due on 1stJanuary 2016 failed ratification and was de-layed. Nevertheless, the North American Emis-sion Control Area (NECA) will implement theNOX cap as originally planned and as specifiedby the relevant United States Environment Pro-tection Agency (EPA) directive (Regulatory An-nouncement EPA-420-F-10-015).

Over the past decades, scientists have come upwith various means to address the challenge ofreducing SOX and NOX emissions from internalcombustion engines. The measures include al-ternative fuels which aim to avoid those hazard-ous chemical reactions during the combustionprocess which change the composition of exist-ing chemical properties of gases or particulatematter (PM).

Figure 1: Possible combinations of SOx and NOxcontrol technologies.


As an alternative to preventing the formation ofhazardous emissions by primary means, oneapproach is to clean exhaust gases as a sec-ondary measure by removing or converting SOX

or NOX emissions, amongst others, mainly bymeans of exhaust gas scrubbers or SelectiveCatalytic Reduction (SCR).

The technology with the biggest influence onthe design and performance of the 2-strokelow-speed internal combustion engine is Ex-haust Gas Recirculation (EGR), which reducesthe oxygen content in the combustion cycle and,in combination with cooling of the recirculatedexhaust gases, avoids high NOX formation dur-ing the combustion process by limiting peaktemperatures. However, since this primary tech-nology only reduces NOX, additional mainstream scrubbers are required for fuels with sul-phur contents higher than 0.1/ 0.5%.

This paper discusses the current status of thelisted emissions abatement technologies alter-natives with regard to technology acceptanceand proposals from the viewpoint of WinGD.The paper also focusses on alternative fuels,selective SCR and EGR. Unless related to EGRsystem integration onto 2-stroke low-speed en-gines, scrubber technologies are omitted.

In spite of this, it has to be said that the shippingindustry is still in the process of analysing theoverall situation and no clear trends haveemerged as to which approach will prevail.Thus, conclusions and recommendations madehere are temporary judgements that might soonbe overtaken by events.

FUEL ALTERNATIVES

Despite the widespread application of low sul-phur distillate oil (LSDO) to control sulphuremissions, alternative are appearing on themarket in the form of hybrid fuels, biofuels,emulsified fuels and gases. In this chapter ex-perience with these fuels are considered andevaluated.

Low Sulphur Distillate Fuel

LSDO, consisting of Marine Diesel Oil (MDO) orMarine Gas Oil (MGO) is generally accepted to

be the simplest solution to meeting SOX require-ments in ECA areas. The quality of these fuelsis categorised under the ISO8217:2012 stand-ard as Distillate Marine (DM) fuels.

Despite the wide acceptance of LSDO on-boardships, these fuels carry certain risks. Ship’s fuelequipment is traditionally configured to treat andinject residual heavy fuel oil (HFO), with relatedheating and viscosity controls.

That LSDO can be a disadvantage shows dur-ing fuel change-over procedures when enteringSECA areas. If MDO/ MGO is too hot during thetransition from HFO, the distillates’ viscosity willfall too low, with consequent damage to the me-chanical equipment in the fuel system. Obvi-ously, automatic fuel change-over valves cancontrol such a process accurately. However, thehigh cost pressure on shipbuilders leads to thesituation where low price manual change-overvalves are applied, with the consequence thatnot all change-over attempts end successfullywhen a vessel is in service. Although the re-sponsibility for correct fuel change-over proce-dure according regulators and classifications re-quirements lies with the ship designer and ship-builder, WinGD is strongly advocating that auto-matic change-over valves be applied. Consider-ing that additional ECAs are expected, henceincreasing the frequency of change-overs, adeclaration of mandatory automatic changeover valves is under serious consideration.

Further, with modern, highly advanced fuel in-jection equipment, the low viscosity of MDO/MGO is causing increased leakage rates of thefuel used to cool and lubricate injection units, in-jectors and fuel pumps on the main engine andin the fuel supply systems. This leakage fuel isclean and can still be used for combustion inTier III areas, provided it can be contained andre-circulated. Generally, on-board fuel systemsprovide a single tank for collection of both HFOand MGO/MDO leakage from the main engineand returning it to the HFO service tank. Thisprocedure causes a financial loss since thehigher quality distillate is fed into to the lowerquality HFO part of the system. Thus, previouslyleaked LSDO will be burned in a blend with theHFO outside the SECAs. Consequently, itshould be recommended that a split main en-gine fuel leakage collection arrangement isadopted, so that it will become possible to returnclean, high quality LSDO back into the LSDOstorage tank for use in SECAs. At WinGD, fuel


system layout guidelines are updated accord-ingly and will be gradually introduced over theentire portfolio.

In addition, due to their unique design, havingthe injection control element located at the in-jector, a new generation of timed injectionvalves is reducing leakage rates compared totraditional injection systems by avoiding addi-tional leaks at quantity dosing units, like fuelpumps or injection control pistons. At WinGD,these new generation injectors are already ap-plied on all X-engine sizes between 35 and 72cm bore.

Besides technical concerns, the supply ofLSDO could be an issue in future and is an in-

dustry-wide concern. These fuels are increas-ingly demanded not only for shipping but also inemerging markets where regulators are startingto address environmental concerns. They arerequiring land-based engine applications to useUltra Low Sulphur Fuel Oils (ULSFO). Accord-

1 CONCAWE was established in 1963 to carryout research on environmental issues relevantto the oil industry.

ing to a CONCAWE1 study in 2009, an invest-ment of USD 17.5 billion is needed to complywith the additional demand from shipping in Eu-rope alone. This is without considering eitherthe higher demands from shore-based installa-tions and transportation, or from the fast in-creasing demands of the Rest of the World. Asoil majors are naturally not inclined to makesuch high investments, it is presumed that asSECA zones increase, the price differential be-tween HFO and LSDO will increase and affectthe operating costs of vessels trading in thoseSECAs.

Low Sulphur Hybrid Fuels

New residual fuels with sulphur contents lowerthan 0.1% are starting to appear on-boardships. These fuels are claimed to be more costeffective and are therefore increasingly attract-ing customers. The fuels are being marketed bycompanies such as Exxon-Mobile, Chemoil,Shell, SK Energy, BP and Lukeoil, among oth-ers.

The term hybrid fuel refers to fuels categorisedas heavy distillates or HFO based products, of-ten recovered from side-streams in the refiner-ies. Their technical data can be summarised asfollows:

Table 1: Technical Details Hybrid Fuels

S: < 0.1% m/m

Viscosity/ 50°C: 10 – 65 mm2/s

Flashpoint: > 60°C

Density: ~790 – 930kg/m3

Pour Point: +7 ~+25°CFigure 2: W-X62/ 72 FAST injector


Despite the positive aspects of new hybrid fuels,like improved combustion characteristics andlow levels of metals, ash and catalytic fines,WinGD recommends careful planning of theiruse, together with the fuel supplier and the mak-ers of the purifiers and filters. Experience hasshown that these fuels can be very paraffinicwith all related disadvantages like fuel segrega-tion, fuel compatibility issues and required ad-justments to separator plants.

Several Classification Societies like Lloyds

Register (LR) and Det Norske Veritas-German-ischer Lloyd (DNV-GL) have already issued rec-ommendations and guidelines. Due to the factthat hybrid fuels might be blended, the guide-lines address the potential risk of mobilising de-posited asphaltenes in tank and pipe systems.Moreover, compatibility with previously bun-kered HFO fuels can cause flocculation of as-phaltenes and the risk of sludge collecting in fil-ters and purifiers is cited.

At WinGD, the potential risk of fuel injection noz-zle sticking with such fuels is considered high.Therefore, design improvements to the injectionvalves have been initiated and are deployed fornew engine deliveries.

The biggest challenge with hybrid fuels, how-ever, is that they are not standardised under theISO8217:2012 norm. Hence, recommendationsand limitations need to be determined on a caseby case basis. On the one hand, at this momentWinGD does not accept any liability or respon-sibility for engine performance or potential dam-age caused by the use of such fuels. On the

other hand, as this fuel type might indeed be anattractive option for ship owners and operators,WinGD is interested in finding practical solu-tions which enable the controlled use of hybridfuels. In the author’s opinion, this is only possi-ble when the fuel is standardised in the previ-ously mentioned ISO norm.

The following checks are recommended by theindustry before applying hybrid fuels (derivedfrom DNV-GL recommendations) and are gen-erally accepted.

Table 2: Operation Recommendations Hybrid Fuels

1. Compatibility test with previousbunkers

2. Empty & clean settling and servicetanks used for hybrids

3. Clean bunker and transfer system

4. Adapted purifying system

5. Adapted/ separate supply systemto/ from engine.

6. Adapted tank and trace heatingFigure 3: Hybrid Sludge Formation(picture courtesy of DNV-GL)


Biofuels

Bio-derived products and Fatty Acid Methyl Es-ters (FAME) can be found in marine fuels andcan cause a decrease in greenhouse gases andSOX emissions. Most bio-fuel components indiesel are FAME, which derive from a specialchemical treatment of natural plant oils. Thesecomponents are mandatory in automotive andagricultural diesel fuel in some countries. FAMEis specified in ISO 14214 and ASTM D 6751.

FAME has good ignition properties and verygood lubrication and environmental properties,but other more negative properties of FAME areequally well known. These are:

• Possible oxidation and thus long-termstorage problems.

• A chemical attraction to water and anutrient for microbial growth.

• Unsatisfactory low temperature proper-ties.

• FAME deposits particles on exposedsurfaces, including filter elements.

Where FAME is used as a fuel, it should be en-sured that the on-board storage, handling, treat-ment, service and machinery systems are com-patible and suitable for handling the product.

WinGD is running endurance tests with FAMEfuels on injection test rigs to determine their longterm effect on fuel injection equipment. So farno conclusive results are available.

Emulsified Fuels

Unlike the previously mentioned fuels whichmainly address SOX emissions, emulsified fuelsare a candidate technology for reducing NOX

emissions.

Emulsified Fuels can be categorised as “water-in-fuel” and “fuel-in-water” types. While the wa-ter-in-fuel systems mixes the emulsion on boardship, the fuel-in-water mixtures are conditionedonshore in specialised plants.

Water-in-fuel emulsions have been under testsince the early 1980s when it was claimed, thatwith an homogenous mixture, fuel consumptioncould be further reduced. Nowadays the focusis more on reducing NOX exhaust gas emis-

sions. The evaporation of the water detracts en-ergy from the combustion of the fuel, hence low-ering the combustion process temperature,which in turn reduces NOX formation.

The challenges with the water-in-fuel emulsionsare to achieve an homogenous mixture that re-mains stable until injected and during circulationthrough fuel pumps. The standard viscosity con-trol and related heating temperature might influ-ence such emulsions in such a way that the wa-ter might start to boil, with related negative ef-fects.

Tests started on WinGD’s RTX research en-gines showed that although the emulsion is sta-ble over long periods it is not easy to handle. Inorder to have an injection viscosity of 13-20 cSt,the emulsified fuel has to be reheated to tem-peratures over 100°C after the mixing of theHFO and water. As stated previously, thesetemperatures involve a certain danger in caseswhere pressure drops very fast to below vapourpressure and water vapour expands, e.g. indrain and leakage pipes. The same testsshowed that NOX reduction potential is very lim-ited without fuel penalties and will not be suffi-cient to reach Tier III levels. Hence, other tech-nologies need to be combined and will add com-plexity and cost to the system.

More promising are fuel-in-water technologies,in which fuel is added to water with the help ofadditives that enable an homogenous, stablemixture. Temperatures are kept below boilingpoint, hence there is a relatively low risk of va-porizing.

With such fuels, WinGD has been able to attainNOX reductions of up to 50 %, and more mightbe possible with further optimisation. Obviously,this is still not achieving the 80% reduction re-quired under IMO Tier III, but the method seemsto have higher potential than water-in-fuel mix-tures.

With both type of emulsion fuels, the challengecentres on the reliability for engine components.In order to avoid increased wear and tear, it isprobably necessary to equip an engine with dif-ferent injection equipment materials. Similarly,the effect on combustion chamber componentscannot be ignored. Higher humidity concentra-tions in the cylinder environment caused by thewater in the fuel, is likely to increase condensa-tion on liner walls at temperatures below the


dew point. The condensate will react with sul-phites from the base fuel and might form harm-ful and aggressive sulphuric acid (H2SO4 ).

At WinGD, both options are under continuoustest and technologies under further develop-ment. Some approaches do have positive sig-nals and might become viable options in future.However, the technology and availability of thesystems and fuels does not yet seem matureenough to employ it on wide range of vessels inoperation.

Liquid Natural Gas

A lot of discussion has centred on Liquefied Nat-ural Gas (LNG) as a fuel. Obviously LNG candeal with SOX limitations, merely by its naturalchemical composition. Hence no othermeasures will be required to reduce SOX levelsto the 20 ppm prescribed in Regulation 14 otherthan applying this gaseous fossil fuel. Existingliquid fuel engines cannot, however, operate onLNG unless they are converted, with conse-quent investment costs. Further, an on-boardstorage and transfer plant needs to be installedand requires both space and energy. Hence, atWinGD we conclude that it is likely that thesegaseous fuel systems will only be applied onnew buildings and will only as an exception beseen as a measure to meet SOX requirementsfor existing engine installations.

For new buildings however, WinGD is clearlypromoting the Dual-Fuel (DF) solution, involvingswitching between liquid and gaseous fuels asa viable solution to meet not only SOX emissionslimits, but also by applying the lean burn usingthe Otto combustion cycle to meet Tier III NOX

emission limits in ECAs. The detailed functionsand applied technologies, with all their ad-vantages and disadvantages, is explored in aseparate conference paper and will not be ex-amined further here. The LP-DF application is aparticularly attractive solution when vessels aredeployed mainly in ECAs, as no further SOX andNOX abatement is required for compliance withlegislation.

SELECTIVE CATALYTIC REDUCTION

General Assessment

Selective Catalytic Reduction (SCR) installa-tions have been around for a considerable timeand the technology has been applied to 2-strokelow-speed engines since the 1980s. It is gener-ally agreed to be a mature, well understoodabatement method which causes few issueswhen operated properly. Typically, the systemsconsist of:

· Urea storage and transfer system· Engine load dependant urea dosing· Mixing arrangement with urea injection· Reactor with catalytic elements· Soot blowing system· Controls

The urea dosing system delivers an aqueous 40% urea solution as the reducing agent into themixing duct where it evaporates and releasesammonia (NH3). This ammonia then reacts onthe active catalytic element substrate, convert-ing the NOX and ammonia into nitrogen and wa-ter (vapour), as shown in Figure 4.


SCR systems are installed on numerous 4-stroke marine engine installations and can cur-rently be considered the industry standard forNOX abatement. However, for 2-stroke applica-tions, only a few owners have taken the decisionto install an SCR system. Incentives weremostly driven by NOX tax regulations, NOxfunds for territorial waters or voluntary incentiveschemes.

Integrated SCR applications also offer ship op-erators a fuel reduction benefit, since the enginecan be tuned for optimised fuel consumption,with the SCR system compensating for the in-crease in raw NOX after the cylinders. This fuelsaving benefit can be achieved simply by opti-mising engine parameters without installingmore complex turbocharger strategies or in-creasing firing pressures, as applied on EGRengines. In this tuning flexibility aspect,WinGD’s electronically controlled common-railengines offer full flexibility and are superior toother technical approaches presented to themarket.

Compared with other NOX abatement technolo-gies, the SCR solution is rather simple, involveslittle equipment and incurs low installation andoperating costs. However, the urea is a con-sumable which has to be taken into account inOpex calculations and should be set against po-tential fuel saving scenarios.

On low-speed 2-stroke engines, SCR is, on theone hand, applied at the low-pressure (LP) side,downstream of the turbocharger turbine. Froman engine point of view this is the simplest ap-proach, as it does not influence the design andoperation of the engine since the exhaust gasesare cleaned afterwards. This principle is appliedin most on- and off- highway applications andon 4-stroke marine engines with SCR. In tech-nical application terms, the industry refers toLP-SCR systems in this case. A detailed explo-ration of the LP-SCR in the view of WinGD canbe found in the following chapter.

Due to high thermal efficiency, exhaust gastemperatures after the turbocharger turbine ona 2-stroke low-speed engine are rather low andbelow the optimal operating temperature rangefor the ideal chemical reaction. Hence, even inearly applications, designers started to placethe SCR reactor on the high-pressure side, be-fore the turbine, where temperatures are con-siderably higher. The industry commonly refersto HP-SCR applications in this case. A detailedexploration of HP-SCR in the view of WinGDcan be found in the chapter HP-SCR.

One of the biggest advantages of SCR technol-ogy is its wide supplier base. Shipbuilders anddesigners can choose not only from various es-tablished suppliers but also new market en-trants. This puts price pressure on the supplyside and makes Capex more attractive. How-ever, during recent months, we have started to

Figure 4: SCR principle; the same on HP and LP applications


detect that the prime contractor for SCR sys-tems is not the shipyard or related ship design-ers, but seems to be the engine builders, whosupply an entire IMO Tier III compliant package.Hence, SCR suppliers tackling the maritimemarket should focus on the engine builder.

Consequently, SCR solutions represent a busi-ness opportunity for engine builders. At WinGDthe belief is that once the major engine buildershave standardised their IMO Tier III offerings,there will be a decline in the numbers of activeplayers trying to sell SCR systems to thelow-speed 2-stroke market.

LP-SCR

Besides maturity and availability, LP-SCR offersseveral other advantages. It is quite a simplesystem which, in case of issues, can be by-passed without affecting engine performance orcausing prime mover downtime.

The reactors can be flexibly arranged in a hori-zontal or vertical layout inside or outside the en-gine room. Particularly on vessels that have ac-commodation and funnels located at the stern,there is the option of placing an LP-SCR abovedeck in a funnel housing that is slightly wider orlonger. The SCR can also be placed betweenmooring winches and the funnel in a horizontalarrangement, requiring only minor modificationsto vessel design.

With its long development pedigree, in alow-pressure application the reactor housingcan be light and maintenance access to the cat-alysts remains simple. Especially with horizon-tal applications on deck, catalyst layers can bereplaced using a deck derrick crane. Such LP-SCR deck arrangements are also one of themost viable NOX abatement retrofits available.

Compared to HP-SCR or EGR application, de-scribed later, LP-SCR offers a clear advantageon multi turbocharger main engine installations.Since the system is placed downstream of theturbochargers, it will not influence their balanc-ing and control. Hence, complicated control sys-tems and algorithms are not needed and theSCR system is simply put into the exhauststream when required. If control regimes are ap-plied, they could be used to operate only a partstream to the reactor on high powered enginesrunning at low loads.

Suppliers have come up with combined solu-tions for SCR reactors and exhaust gas boilers.The combination of exhaust gas economisersand SCR functions in a single housing has a sig-nificant benefit in terms of installation space re-quirements, which is one of the biggest down-sides of LP-SCR systems. Additionally, such ar-rangements reduce the pressure drop over thesystem.

As well as simplicity, shipowners also have toconsider their exact operation pattern whenconsidering LP-SCRs. These patterns defineadditional technical measures that might be re-quired to achieve satisfactory performance fromthe installation.

Due to the high thermal efficiency of low-speed2-stroke engines, temperatures at the reactorinlet are lower than the optimum range neededfor an ideal chemical reaction. Measures to in-crease reactor inlet temperatures can be partlyachieved via the main engine by artificially in-creasing exhaust temperature after the cylin-ders.

One strategy is to reduce turbocharger turbineefficiency using a proportional by-pass valvethat diverts the hot exhaust gases past the tur-bine. With a by-passed turbine, the air-flowthrough the cylinder is reduced.

With the cyclic scavenging of the cylinder theamount of residual gas will increase and thus

Figure 5: Horizontal arrangement of a LP-SCR reac-tor (picture courtesy of Doosan)


the combustion process temperature level willincrease. Obviously, this approach is simple butincludes the drawback of increased fuel con-sumption, slightly increased raw NOX emissionsand, under certain circumstances, an increasedrisk of liner/piston ring cold corrosion due to theresidual gas.

At WinGD these circumstances were recog-nised and the newest common-rail engines nowoffer a potential alternative technology, featur-ing timed injection valves, as introduced in thechapter “FUEL ALTERNATIVES”. A quick act-ing valve enables injection patterns that allow,together with flexible exhaust valve timings, tocontrol the exhaust gas temperatures in a mon-itored approach.

In this way the catalyst can work in an ideal tem-perature range for the chemical reaction withoutadding much extra heat from auxiliary burners.Currently WinGD is developing and optimisingthis adaptive injection technology and validationtests will be started soon.

Auxilary burners however are still needed forthe application of LP-SCR. They have the func-tion of increasing the temperature of the ex-haust gas to a level where the urea can vaporiseefficiently over a short distance before forminga homogenous ammonia gas mixture at thestatic mixer. Besides increasing the engine’sexhaust gas temperature in case it is too low,burners can also pre-heat the catalyst to its op-erating temperature while the vessel is still atthe quay preparing to depart.

Another useful function is the regeneration ofthe catalyst substrates. Over a certain operatingtime and temperature, condensation forms atthe substrate inlets, diminishing the reductionrate of the reactor and increasing back-pres-sure. Another mechanism of deposit formationis an undesirable parallel reaction where sul-phur dioxide is oxidised to sulphur trioxide(SO3), which can react with ammonia to formammonium sulphate and bisulphate (ABS).

The deposited layers on the catalysts reducetheir effective area, NOX conversion is reducedand more ammonia will slip past the catalyst.The substrates can be regenerated by applyingthe burner to heat the catalysts and burn off theABS layer. The soot resulting from this regener-ation function is blown off to the normal exhaust

2 IACCSEA - The International Association forCatalytic Control of Ship Emissions to Air

stream while the SCR system is by-passed (inTier II mode).

Contrary to a white paper published in Decem-ber 2012 by IACCSEA2 with most major SCRsuppliers contributing, WinGD sees the LP-SCRas an attractive option in terms of Capex. In itspaper the IACCSEA proposes costs of an SCRinstallation in the range of 25 – 62 €/kW of en-gine power. Additionally, they claim that theburner will contribute to making the LP-SCRroute a higher investment than HP-SCR.

While the price range given is still valid today, ithas become obvious that an LP-SCR systemstill has advantages when taking into accountthe necessary engine modifications and the pro-ject-specific piping and control interface adapta-tions, which result in additional engineering

Figure 6: Tier III package; including main engineand LP-SCR system with burner arrangement. (pic-ture courtesy of Doosan)


work and manufacturing costs for the HP-SCRarrangement on the engine.

At WinGD the view is that, based on equalboundary conditions, a Tier III package with en-gine and LP-SCR involves lower Capex com-pared to the HP-SCR solution.

Based on technical maturity, the previously dis-cussed pros and cons of the system and theanalysis of structured market feedback, WinGDhas decided to fully support LP-SCR installa-tions and to make them operational.

An LP-SCR interface specification has beendrafted and is currently under validation withLP-SCR system providers. In this interface,WinGD provides:

· Active exhaust gas temperature controlwithin the engine’s physical limits.

· Active Tier II/ Tier III switching for opti-mised performance in each mode.

· An integrated engine control interfaceproviding high flexibility in additionalcontrol functions and monitoring.

· Concepts for the entire engine portfolioincluding all cylinder and turbochargernumbers.

· Publishing engine performance dataand guarantees for LP-SCR operation(GTD).

The preliminary interface specification is availa-ble and now needs confirmation from the firstinstallations in service. As the interface specifi-cation is a lean, simple, derived version of theHP-SCR interface specification which has beentested successfully at sea on pilot installations,no major challenges are foreseen.

It is expected that the approved LP-SCR inter-face specification, validated on an operatingsystem, will become available in the drawingsystem in Q4 2015. The impact on engine per-formance has already been released with anupdate to the GTD programme.

HP-SCR

The HP-SCR reactor is an integrated part of theengine’s system and has thus received high at-tention from WinGD. As the reactor is placedbefore the turbine, it influences turbochargerperformance and, as a consequence, engine

performance. Additional flap valves and by-pass lines must be installed on the engine andrequire design changes to the engine’s basicstructure.

Provided that all boundary conditions such asthe fuel and catalyst used are the same, HP-SCR requires a reduced catalyst volume, by afactor of approximately three, compared to anLP-SCR application. This is due to the highergas density under higher pressure and thehigher temperature of the exhaust gases.

The HP-SCR system can be prepared for MGOand HFO. There is a potential to reduce the re-actor size if a 0.1 % S distillate is used as thedesign fuel. With MGO catalysts can have ahigher density due to lower soot and ash emis-sions forming during combustion. The vana-dium content of HFO also has to be considered,since vanadium is part of the substrate whichaccommodates the chemical reaction.

When limiting HP-SCR application to 0.1% sul-phur fuels, as applied in ECA areas, the reactorcan be optimised for distillate fuel operation thathas zero or only limited vanadium content andlow soot and ash formation during combustion.The catalysts’ density, designated in “cells persquare inch” (CPSI), is selected higher and thereactor becomes more compact. This compactsizing, together with sufficient exhaust gas tem-perature for an ideal chemical reaction, are theprime advantages of the HP-SCR solution.

Low-speed 2-stroke engines designed byWinGD accommodate the application of HP-

Figure 7: W6X72 with an HP-SCR interface, showingthe axial TC inlet and T-connection.


SCR by having generally higher exhaust gastemperatures than other 2-stroke engine prod-ucts on the market. This high temperature isonly possible by the application of efficientlybore-cooled combustion chamber componentsin combination with an optimised cylinder scav-enging concept. These are the two factors inwhich WinGD products are differentiated in theirdesign.

The above mentioned scavenging concept, in-cluding high compressor pressure ratios at theturbochargers and higher auxiliary blower ca-pacities, is already applied on Tier II engines.With this scavenging approach, WinGD has notso far detected a need to improve gas exchangeto cope with transient engine load conditionswhile in Tier III HP-SCR mode.

Detailing the transient mode issue, the chal-lenges with the HP-SCR application are, on theone hand, related to the reactor fouling. Foul-ing and Δp will not be an issue, provided tem-perature management is adequate. On theother hand, the catalyst elements have a sig-nificant thermal capacity which absorbs ex-haust energy when starting and loading up theengine. In such transient conditions, the turbo-charger is affected and starts to lack exhaustenergy. As a consequence, the compressorwill reduce the fresh air supply into the scav-enge space and scavenge air limiters mightbecome active.

With the modern generation of common-rail en-gines, an automated detection algorithm for fuelused is already implemented. With this algo-rithm in the background, the minimum requiredoperating temperature of the SCR, according tothe figure 8 below can be calculated (shown foratmospheric pressure).

At low engine loads with a Tier II tuned engine,the available exhaust gas heat after the cylinder

is insufficient to reach the ideal reaction temper-ature in the SCR reactor, hence turbine by-passvalves are applied to raise the overall level, asdescribed in the Chapter “LP-SCR”. WhenMGO is used instead of HFO, the target temper-ature can be lower, hence a lower or zero tur-bine by-pass ratio is required. This gives a fuelconsumption benefit when operating in Tier IIImode.

Another viable measure for controlling catalystinlet temperatures without endangering enginereliability are specific injection patterns, as nowpossible on the new X-engine generation. Thismethodology was described in the Chapter “LP-SCR” and is applicable on the X-35 to X-72 boreengines.

As required by Classification Societies and ap-plied with LP-SCR, the HP-SCR solution alsorequires an exhaust gas by-pass in Tier II modeor when the SCR system fails. Unlike LP-SCR,with HP-SCR the control valve arrangementsand related control strategies are fully in the re-sponsibility of WinGD as the engine designer.This is reflected in the higher degree of integra-tion into the engine design compared with LP-SCR.

This high degree of integration was the reasonwhy WinGD explored SCR technology further.On the one hand, a single turbocharger enginewas equipped with WinGD’s own HP-SCR de-sign. On the other hand, multi-turbocharger in-stallations are now under preparation for a sim-ilar field test. Here, the aim is not to become anHP-SCR supplier, but merely to establish thepotential for further engine concept optimisa-tion, taking into account the entire Tier III pack-age. As this technology is still applied only rarelyon low-speed 2-stroke applications, WinGD ex-pects some major technology steps in a rather

Figure 8: Minimum temperature for long term opera-tion, below blue line increased risk of ABS formation.(Graph courtesy of IACCSEA)

Figure 9: WinGD pilot SCR on CMD test bed


short time and wants to be prepared for thesedevelopments.

At the beginning of 2015, WinGD was able todemonstrate its own HP-SCR system to thepublic at CSSC-MES Diesel Co., Ltd. (CMD) inShanghai, China. The pilot system was the re-sult of a two-year cooperation with HudongHeavy Machinery (HHM) and an expert team atWinGD in Winterthur, Switzerland. While the in-itial technical backbone of the SCR system wasderived from standard 4-stroke SCR systemsalready on the market, a lot of new knowledgeand expertise was created and exchanged dur-ing this project. The project now serves as a ba-sis for further collaborations between the com-panies, with continuously improving skills andexpertise.

The pilot application is on a 5RT-flex58T-D V2engine in a 22 kDWT Multi-Purpose Vessel(MPV). The owners operate the SCR as fre-quently as possible in order to gain experienceand clock operating hours. These endurancetests will show if the specifications of the cata-lysts and the scaling of the reactor are correctfor the given target of 10,000 running hours inTier III operating mode. It will also show whetherthe applied measures for reactor inlet tempera-ture control will have any unexpected long termeffects on the engine.

The pilot reactor was designed for HFO with anexpected operation time of 10,000 runninghours. Hence, for this installation reactor sizingwas rather big. The system employs a catalystwhich is used as standard supply for WärtsiläLP-SCR applications, but on the high-pressureside. The reason to employ such a catalyst isthat sufficient long term experience exists withit, which avoids surprises in the early stages.

The urea dosing equipment is also a standardcomponent from the market. Urea injection noz-zles, static mixers and soot blowing needed tobe adapted to the high-pressure application andwere hence specially designed.

The test at CMD was commenced accordingscheme A, which means that the engine andSCR system were fully assembled on the testbed. Tier III compliance was demonstrated sev-eral times and confirmed by the attendant rep-resentative from Lloyds Register.

Besides meeting Tier III requirements, the test-bed trials also showed that the promised fuel

consumption values can be achieved. The exo-thermic reaction of the ammonia on the cata-lyst’s substrate actually boosts the turbineslightly, which ensures that fuel consumption inTier III does not increase compared to Tier II.

WinGD has invested considerable time and ef-fort into the development of its own HP-SCRsystem, mainly to understand the technical de-tails and challenges. In future, this knowledgewill be further expanded and used for continu-ously optimising the technology of the SCR sys-tem integrated onto a low-speed 2-stroke en-gine. The expertise and understanding gainedis currently being utilised to develop a multi-tur-bocharger SCR application that needs furtherintegration into the engine’s total system.

The challenges of the multi-turbocharger HP-SCR application are with the load balancing ofthe individual turbochargers and the use of evenbigger reactors, based on the relevant enginepower. These larger reactors absorb still moreheat before the turbocharger and the previouslymentioned issues will become more acute.

To counteract these limitations, WinGD is con-tinuously working on optimising cylinder scav-enging strategies and injection patterns, utilis-ing the great flexibility of the common-rail sys-tem applied on the WinGD engines.

Further investigations include cascading reactorsolutions and fully integrated control strategies,allowing closed-loop reactor temperature con-trol, urea dosing and acceleration boosts incase of high thermal inertia caused by the reac-tor. Such a strategy could include isolating tur-bochargers at low load to have more boost effi-ciency from the turbochargers remaining in op-eration. The effect is the same as already ap-

Figure 10: Measured NOx values with pilot HP-SCRat the defined IMO points


plied in turbocharger cut-out solutions on ves-sels in service, or as applied on EGR engines inorder to compensate for fuel penalties. Such op-timising strategies will make the application ofSCR on a large bore engine an attractive alter-native in terms of even lower fuel consumption.

As a consequence, studies of a large enginewith three turbochargers and with an HP-SCRinstallation are well advanced and details will bepublished soon. Also with this arrangement, theshort term target is to have a pilot running togain long term experience. WinGD is positivethat this pilot installation can be announcedsoon.

WinGD has invested in building extensiveknowledge of SCR technology and now sharesthis knowledge in detailed interface documenta-tion. The control interface specification for inte-grating an HP-SCR system with the reactor lo-cated off-engine has been finalised and is avail-able, as is a requirement specification docu-mentation for the reactor itself.

As well as recommendations for sizing and ar-rangement options, this document gives enginerelated limitations and process data. Anotherdocument available is a piping and installationguideline, which guides the ship designersthrough reactor and piping arrangements in theship’s hull.

The Interface Specification, which is now avail-able, was prepared with the utmost attentionand care. It incorporates knowledge from sev-eral years of specific developments and is re-garded as having a good, advanced status witha high technical standard.

Economiser By-Pass Requirement

In recent months, there has been frequent dis-cussion on the requirement to implement an ex-haust economiser by-pass line with SCR instal-lations.

In the case of insufficient matching of the SCRsystem to the engine exhaust gas flow, there ex-ists an increased risk of ABS formation. Besidesthe existing chemical components in the ex-haust gases, downstream formation of ABS af-ter the reactor is mainly temperature depend-ent, being a form of condensation. ABS collectsas a deposit layer downstream at the exhausteconomiser inlet where it starts to block gas-ways. This leads to rapidly increasing exhaustgas back-pressures and reduced economiserefficiency. Increased back-pressures due to theeconomiser will reduce engine efficiency be-cause of reduced expansion over the turbine.This, again, will have the effect that temperaturelevels are generally increased. Hence, theblocking of the economiser by deposit layerscauses as a consequence hotter exhaustgases, which in turn are able to remove/burn offsome of the ABS condensate. The system thenreaches a state of equilibrium and stabilises.

Due to the higher sulphur content, it is likely thatABS formation will be more pronounced in anHFO application, but also to a lesser extent inMGO applications, unless Ultra Low SulphurFuel Oils (ULSFO) with a specified sulphur con-tent of 10 – 50ppm are used.

So far, for the many SCR installations applied inthe marine industry, economiser by-pass pipeswere not requested, either by authorities or byexperts. Many of these installations operate theSCR permanently and need the energy from theeconomiser in parallel. To now introduce by-pass as a requirement for Tier III SCR opera-tions on low-speed 2-stroke represents a funda-mental change of approach.

WinGD believes that with correct matching ofthe catalyst substrate, integrated temperaturecontrol and urea dosing for the reactor and pos-sible regeneration mode, an economiser by-pass is not needed. This has been shown in themany existing applications. The availability ofsuch experience is one of the advantages of ap-plying a mature technology like SCR.

With proper monitoring of SCR conditions, ei-ther by a Continuous Emissions Monitoring Sys-tem (CEMS), recording for example ammonia

Figure 111 Multi TC arrangement with collector pipe


slip (NH3 sensor), or by frequent visual inspec-tions of the catalyst layers, the risk of by-prod-ucts such as ABS condensate layers can be re-duced to a minimum. Thus, reliable system op-eration is guaranteed and a need for eco-by-pass is not foreseen.

EXHAUST GAS RECIRCULATION

Exhaust Gas recirculation is a primary technol-ogy directly affecting combustion in the cylinder.Exhaust gas is recirculated in to the cylinder bya blower or auxiliary turbine. As the exhaust gasconsists of harmful components like SOX, sootand particulate matter, efficient cleaning ofthese gases is mandatory. Further, since highcombustion temperatures would benefit NOX

formation, the recirculated exhaust gas needsadditional cooling, which represents a consider-able loss of heat energy. In the case of gascleaning or cooling failures, EGR carries thehighest risk of engine damage of all the candi-date technologies.

In general, there are three feasible ways of ap-plying exhaust gas recirculation on a diesel en-gine. These technologies are widely researchedand applied on engines in on- and off- highwayapplications burning low and ultra-low sulphurfuel oils. The technologies are:

- High-pressure EGR (HP-EGR); ex-haust gas is re-circulated outside thecylinder, taken from before turbine,cleaned, cooled and then blown intothe scavenge air after the compressor.This solution is typically applied onsmaller diesel engines.

- Low-pressure EGR (LP-EGR); exhaustgas is taken after the turbine, cleaned,cooled and blown in before compres-sor. This technology is not applied onsmall engines but is feasible forlow-speed 2-stroke applications.

- Internal EGR; exhaust gas is retainedin the cylinder during scavenging.Commonly applied on smaller enginesfor lower EGR rates, often in combina-tion with a secondary SCR catalyst.

High-Pressure Exhaust Gas Recirculation

At WinGD, the first test on high-pressure ex-haust gas re-circulation was carried out in 1993.Already then it was clear the technology can re-duce NOX formation. With EGR the oxygen con-tent of the air available for combustion is re-duced. This leads to a slower combustion pro-cess, reducing the temperatures peaks that fa-vour NOX formation but, likewise related to theslower heat release, also reducing combustionfuel efficiency. The lessons learned at that timegenerated the knowledge that EGR is a viabletechnology to reduce NOX, but comes with aconsiderable fuel penalty. Moreover, issueswith failing water supply to wet scrubbers wereobserved, causing the harmful components topass to the cylinders and corrode them, and onthe way also attacking coolers and the down-stream EGR blowers. Hence, the technologywas rated high risk and put aside.

It reappeared however with the IMO Tier III dis-cussions and in the new millennium it was pos-sible to prove on a lab installation in Winterthur

that IMO Tier III levels can be achieved with HP-EGR.

Regardless of the risk of internal engine dam-age in the case of scrubber failures, applied wetscrubbers produce scrubber water that needsneutralisation by caustic soda. This water’s af-tertreatment causes additional sludge which

Figure 12: principle sketch of a HP-EGR


needs to be removed from the ship. Obviouslythe amount of caustic soda needed and hencestorage capacity and Opex, and the amount ofsludge formation depends on the fuel used(HFO vs. MGO) and the period in Tier III areas.

When ULSFO is applied, however, the claim re-garding potentially severe engine damage thenbecomes void, as SOX only exists in negligiblequantities in the exhaust gases. This is why theon- and off-highway industry can apply EGR asone of their main technologies for compliancewith EURO 6, for example. Obviously, in caseULSFO also becomes available to the maritimeindustry, which seems to be the case in NorthAmerica, the arguments against sulphuric acidformation and its effects on engine componentsis no longer valid and EGR becomes a viablesolution for Tier III compliance.

Another argument against an HP-EGR systemis the required cooling of the recirculated gas.To attain IMO Tier III levels, 40% of the exhaustgas mass flow needs to be recirculated into thecylinder. As this gas is taken from before the tur-bine, temperatures are significantly high andneed to be reduced to scavenge air levels. Thisabsorbs a considerable amount of heat energy,which then needs then to be re-cooled in thecentral cooling system aboard ship. Thus, thecooling capacity of the EGR coolers, combinedwith the wet scrubbers, is an energy loss to betaken into account in a vessel’s total fuel con-sumption balance.

Another variable with HP-EGR applications onthe engine is sizing. Where a system is de-signed for HFO, the scavenge trunk with the un-derslung receiver will require considerably morespace due to the scrubbers, coolers and blow-ers which need to be applied. This might, con-flict with slim aft-ship designs that are optimisedfor high propeller efficiency. Where the sameship is specified for ULSFO, no major changeswill be needed to the scavenge trunk.

The top structure of the engine is, however, in-fluenced, particularly in the case of multi-turbo-charger HP-EGR application. The additionalweight on the top of the engine with additional,smaller turbochargers for EGR operation has aconsiderable influence on engine design. Thewhole structure needs re-enforcement and al-ternative cylinder block materials need to beconsidered.

With the HP-EGR system, blowers and turbinesand generally all material exposed to SOX in the

re-circulated exhaust gas, need to be made ei-ther from stainless or coated materials. This ismore pronounced for an HFO installation thanfor an MGO installation. Also, scrubbers usedwith MGO will be smaller and the system slightlysimpler. However, all these factors result in ra-ther higher Capex for an HP-EGR system.

On the other hand, investment in more enginedesign margin has the advantage that themeasures applied to enable HP-EGR, and con-trol fuel consumption in EGR mode, can be uti-lised in Tier II mode. A higher maximum cylinderpressure used to limit the Tier III fuel consump-tion penalty has the same effect in Tier II, henceTier II consumption is reduced. Moreover, thedifferent sizes of turbochargers which are fun-damental to EGR, can applied sequentially inTier II, further adding to the fuel consumptionbenefit at lower loads. Both these fuel consump-tion reduction measures are, however, funda-mental technology that can be applied to any 2-stroke engine to achieve the same result.Hence an SCR installation equipped with se-quential turbocharging and high cylinder pres-sures will also benefit of higher combustion effi-ciency.

Considering all the above, with a wide under-standing of advantages and disadvantages,WinGD is investing further in HP-EGR technol-ogy development. There is a sound market po-tential, with shipyards and shipowners signal-ling interest, and the technology is continuouslyadvancing. We are convinced that EGR will be-come a technology applied to specific types ofvessel, like ultra large container vessels (ULCV)and small vessels of less than around 75,000DWT. For both vessel types space for SCR re-actors is very limited and if MGO fuel is agreed,HP-EGR technology becomes a viable alterna-tive.

At WinGD, the validation testing of scrubbersystems for serial application is in full progress.As a next step, it is planned to equip one of thelab engines for a full scale EGR test, probablyincluding an endurance trial before the systemis launched to a pilot application. The target isto have a pilot vessel equipped with a WinGDHP-EGR system by 2017.


Low-Pressure Exhaust Gas Recirculation

A good alternative to HP-EGR, is LP-EGR. Withthis technology exhaust gas is recirculated,cleaned and cooled after the turbine and beforethe compressor, i.e. at the low-pressure side ofgas exchange.

This approach has several advantages. In-stalled equipment does not have to be designedfor up to 5 bar absolute pressure. As the ex-haust gas is taken after the turbine, its temper-ature is considerably lower than before the tur-bine and it needs less cooling. Many scrubberdesigns and applications exist from the chemi-cal process and heating industries for this typeof low-pressure installations, thus there is muchexperience and the technology is mature.

As with LP-SCR, LP-EGR has also larger spacerequirements. Again, if MGO fuel is specified,this argument is not as pronounced as withHFO. Consequently, LP-EGR suppliers, like LP-SCR suppliers, currently offer their systems forMGO only.

At WinGD, extensive tests with LP-EGR sys-tems and components were carried out from2011 to 2013. Again, they clearly showed thatTier III NOX levels can be achieved with thistechnology as well. Challenges experiencedwere sludge formation in the scrubbers withhigh sulphur HFOs. Also of concern was thespace required for the whole installation on therather moderately powered test engine. Argu-ments regarding higher fuel consumption inEGR mode and energy loss through exhaustgas cooling are also as valid for LP-EGR as theyare for HP-EGR and measures to reduce fuelconsumption with LP-EGR are also required.

Despite being a proven technology in the pro-cess industry, the LP-EGR approach on alow-speed 2-stroke engine needs to be vali-dated. The first pilot installations should be inservice by the time this paper is issued. Regard-less of all the counter-arguments, it seems thatsuppliers to the industry have responded to find-ings and more compact LP-EGR systems willbecome available.

Based on accumulated experience with test in-stallations, WinGD is supporting further testingwith LP-EGR systems and will also accommo-date the required adaptations to the engine de-sign. As with LP-SCR, LP-EGR is seen as athird party offering which needs a rather simple

interface to the engine. However, as EGR di-rectly affects internal combustion, individualagreements defining quality standards and lia-bilities need to be reached with potential suppli-ers before it can be commercialised on WinGDengines.

Internal Exhaust Gas Recirculation

The high internal EGR rates needed to complywith strict emissions limits are used only onhigh-speed experimental engines. A relativelyhigh boost pressure will be needed to compen-sate for the negative impact of internal EGR, i.e.more compression work has to be done beforethe cylinder in order to stay within desired com-pression and combustion temperatures. Thiscan be achieved with two-stage turbocharging,for example.

Of all the EGR approaches, internal EGR hasthe lowest number of components exposed tofouling from the exhaust gases.

Due to the required residual gas quantityneeded to achieve high EGR rates, combustionstarting temperatures are considerably in-creased. This leads to higher NOX formation,which has then to be compensated by even fur-ther oxygen reduction, hence leading to a fur-ther increase in the EGR rate. It remains to beseen if internal EGR is a technology that canachieve IMO Tier III levels on its own. With ex-haust gas re-circulation rates higher than 40% itseems difficult to achieve this goal in reasona-ble terms.

However, if the combustion temperature can becontrolled and the residual gases remain in ar-eas in the cylinder where they cannot condenseon component surfaces, the technology is via-ble and can, at least partly, contribute to achiev-ing lower NOX levels.

At WinGD, intense investigations in the area ofinternal EGR were carried out in the years be-tween 2002 and 2007. In order to control peaktemperatures during combustion, water spraywas directly injected into the combustion cham-ber. This worked well with distillate fuels and thetechnology also showed potential with HFO.

The experience gained in such an investigationled to the decision to introduce a small rate ofinternal EGR with the introduction of the Tier IIengines in 2011. Hence, every Tier II tuned


WinGD engine design has an internal EGRfunction. This is achieved by exact timing of theexhaust valve, which is controlled according tothe scavenge air pressure and engine speed,hence roughly entrapping the same amount ofair at the same load point. To maintain the com-bustion process temperature as low as possi-ble, and therefore avoid NOX formation, thebore-cooled cylinder components were furtheroptimised.

More decisive for efficient Tier II engines, how-ever, is the application of an extreme Miller Cy-cle. With this technology, the pressure ratio andefficiency of the turbochargers are increased,which allows a further delay in the closing of theexhaust valve without losing total engine effi-ciency.

Considering that the high boost pressureneeded for Miller is already applied and that, intheory, the internal EGR rate can be readily in-creased, this technology might become a bigcontributor to IMO Tier III emissions compliancein future.

The technology has its biggest potential whenapplied with other candidate technologies. Aninternal EGR system that can further reduceraw NOX from the cylinder at the same fuel effi-ciency and, without major changes to the en-gine can, for example, help to reduce the size ofan SCR installation considerably. In the mean-time, such strategies are commonly applied inEURO 6 on-highway applications and couldserve as technology examples.

However, the fuel used for marine applicationsmust be seriously considered. In the case ofhigher sulphur content, internal EGR mightcause corrosive attack to the combustion cham-ber components, as with the other EGR technol-ogies. Hence, it again seems better to limit in-creases in internal EGR rates to MGO fuelsonly.

One possible measure to avoid corrosive attackto components with EGR is to avoid condensa-tion on the components’ surface. Hence alow-speed 2-stroke engine liner will in future notonly be cooled, but conditioned. This means,that twin circuit cylinder cooling systems mightbecome standard.

WinGD is continuously exploring possibilities toincrease internal EGR rates and, in combina-tion, further optimising the cylinder scavengingstrategy. Lessons learned from these efforts are

continuously being applied to IMO Tier II andTier III tuned engines. Thus, internal EGR isconsidered an important technology and it willprevail on WinGD engines for a long time,whichever IMO tuning is applied.

CONCLUSION

At WinGD, several of the candidate IMO Tier IIItechnologies are now approved and applied inthe field. In order to control SOX emissions, lowsulphur distillate oils (LSDO) are in the lead, butthe DF technology also fulfils this requirement.The hybrid fuels now appearing on the marketare being validated and more guidelines are ex-pected soon. However, a first requirement is tostandardise such hybrid fuels.

With regard to NOX abatement technologies,WinGD considers SCR solutions to be matureand safe. The solutions can be a simple LP-SCR application or a more complex HP-SCRapplication before the turbocharger turbine. Forboth solutions, WinGD considers the technol-ogy mature and widely proven enough to applyit on the entire engine portfolio, regardless ofcylinder count or numbers of turbochargers. Amulti-turbocharger pilot installation is now pro-gressing and a running engine is expectedwithin 2016.

In terms of EGR, WinGD is well advanced withinternal EGR approaches and considers them acore competency. For LP-EGR systems,WinGD is open to the integration of third partiessupplying these systems, provided a strict qual-ity and liability regime is in place. HP-EGR isseen as a viable technology and a further devel-opment driver. A full-scale engine test isplanned for 2016 and the first pilot installation isexpected to follow.


BIBLIOGRAPHY

IACCSEA. (2012). The Technological andEconomical Viability of SelectiveCatalytic Reduction for Ships.

Lloyds Register Marine. (2015). Your options foremmisions compliance; Guidance forshipowners and operators on theAnnex VI SOX and NOX regulations.London.

MHI-MME. (2015, May 18). The World's FirstConfirmation of IMO NOX Tier IIIRegulation using Low Pressure EGRsystem. Retrieved from MitsubishiHeavy Industries, Marine Machinery &Engine Co., Ltd.: http://www.mhi-mme.com/news/0038.html

Millius, J. (2015). Change from HFO to LowSulphur Fuel: Basics and Experience's.The Green Ship TechnologyConference (pp. 8-9). Copenhagen:DNV-GL.

AUTHOR

Dominik SchneiterGeneral ManagerIMO Tier III ProgrammeProduct [email protected]

Documents

WinGD low-speed Engines Licensees Conference 2015 Tier III