Staying aheadin SOx complianceA guide to SOx abatement alternatives, scrubbers and suppliers

Think aheadStarting in 2020, all vessels must comply withglobal sulphur limits established in MARPOLAnnex VI. Making the right compliancechoices now can keep you a step ahead.Alfa LavalPureSOxThechoiceof supplierOther global supplier solutionLocal supplier solutionInstall a scrubberThecommercialdecisionSwitch to low-sulphur fuelSwitch to LNGMARPOL Annex VI2Staying ahead in SOx compliance

ContentsIntroduction4–5The commercial decision6 –17The choice of scrubber18 – 29The choice of scrubber supplier30 – 41PureSOx from Alfa Laval42 – 71Scrubber supplier selection guide72 – 75Scrubber supplier checklist76 – 77For further information78Contact Alfa Laval79Staying ahead in SOx compliance3

Don’t just complyEnvironmental legislation is having an acute effect ontoday’s marine industry. For ship owners and shipoperators, it is an additional constraint on an alreadydifficult business – especially when it forces a changein the equipment on board.With respect to equipment, however, the regulation ofsulphur emissions by MARPOL Annex VI is somewhatdifferent. While all vessels must comply, there aremultiple strategies available for doing so. This booklet’sfirst aim is to help you understand them.Its further aim is to explore one of those strategies– SOx scrubbers – in detail. Scrubbers are becominga familiar presence in the marine industry, as theyprovide an excellent balance of compliance security andoperating economy. Yet scrubber solutions are far fromthe same. The technology and supplier you choose canmake the difference between bare-minimum complianceand truly staying ahead.4Staying ahead in SOx compliance

– be a step aheadAlfa Laval’s own capabilities and an overview ofthe Alfa Laval PureSOx system are presented ina separate chapter.The final pages include a convenient guide and checklistto assist you in supplier evaluations, as well as a listof resources for further reading. With this booklet inhand, you will be able to make informed and confidentdecisions that keep you at the forefront.Best regards,Erik HavemanSales DirectorExhaust Gas CleaningAlfa LavalStaying ahead in SOx compliance5

6Staying ahead in SOx compliance

The commercialdecisionEmission limits are having a strongeffect on the marine industry as shipowners and ship operators choosedifferent strategies for compliance.Your own choice can be one that putsyou at the mercy of higher fuel prices, orone that retains your competitive power.Staying ahead in SOx compliance7

Emission Control Areas (ECAs)Global sulphur capMARPOL Annex VI and SOx limitsVessel emissions – including thoserelated to sulphur – are governed by MARPOL Annex VI, which firstentered into force in May 2005. IMOhas adopted subsequent revisionsof Annex VI to progressively reducethe maximum allowed sulphurcontent of marine fuels.8Staying ahead in SOx complianceHowever, IMO has also approvedthe use of higher-sulphur fuels withexhaust gas scrubbers that removea corresponding amount of sulphuroxides, or SOx. This is referred to asan “equivalence” in IMO terminology.SOx is a collective term for sulphurdioxide (SO2) and sulphur trioxide

As of January 2015,the limit applicablein ECAs is0.1% SAs of January 2020, theglobal limit applicableoutside of ECAs is0.5% S(SO3). Hazardous to the environmentand to human health, SOx is pro duced during the combustion of fuel,along with harmful particulate matter(PM) in the form of soot and ash.Additional PM is formed when theSOx reaches the atmosphere andforms small aerosol compounds,which is the reason why SOx andPM fall under the same headingin Annex VI.The higher the fuel sulphur content,the greater the SOx content in theexhaust gas and the level of PMformation.Staying ahead in SOx compliance9

The global cap and ECAsMARPOL Annex VI establishes theregulation of a global sulphur cap,as well as stricter regulation inEmission Control Areas (ECAs).As of January 2020, the existingglobal cap will be reduced from3.5%S to 0.5%S. This was decidedby the IMO Marine EnvironmentProtection Committee (MEPC) inOctober 2016.10Staying ahead in SOx complianceThe sulphur limit in ECAs, applicablesince January 2015, is 0.1%S. Anyparty to MARPOL Annex VI canapply to become an ECA, with thetime from application to enforcement taking about 18 months.It is also worth noting that there areports around the world that havechosen to establish their ownsulphur limits outside of those setby MARPOL Annex VI. In somecases, these limits are stricter thanthe global cap.

What choices does the legislation imply?Needless to say, the heavy fuel oil(HFO) in popular use today has asulphur content well above the limitsestablished in MARPOL Annex VI– at present the world average is2.4%S. With this in mind, currentregulations leave you as a shipowner or operator with three basicoptions going forward:This list is deceptively simple,however. Each of the choices hasmajor implications, both for yourease of doing business and for yourshort-term and long-term profitability. These implications are exploredin the following sections. Switch to liquefied natural gas(LNG) or another liquefied gas Switch to a low-sulphur fuel Install a SOx scrubber andcontinue using HFOStaying ahead in SOx compliance11

Switching to LNGIn emission terms, using LNG ratherthan HFO is an elegant solution.Because LNG contains absolutelyno sulphur, it eliminates the problemof SOx altogether. The issue lies notin the result, but rather in thecomplexity of making the change.LNG will put you in compliance withMARPOL Annex VI, but in order torun on LNG with an existing vessel,you will need a retrofit that iscomplicated and expensive. Not allengines can be modified for LNGuse, and cargo or passenger spacemay have to be reduced in order to12Staying ahead in SOx complianceaccommodate the much larger fueltanks. As a result, LNG is an optionmost feasible for newbuilds.At present, the prospects forLNG remain somewhat uncertain.The LNG infrastructure is stillunderdeveloped, even as LNG isbeing selected for an increasingrange of newbuilds. LNG willundoubtedly continue to grow, andmost likely it will be a significantfuel by 2030. Nonetheless, its costdevelopment and availability aredifficult to project.

Switching to a low-sulphur fuelBy far the easiest choice is to operateon a distillate fuel like MGO ratherthan HFO. This will be an interimchoice for some while evaluatingother options, whereas for others itwill be a long-term strategy.The choice is not entirely problemfree, due to the differences inproper ties between low-sulphurfuels and HFO. It may be necessaryto replace older pumps and otherequipment to prevent leakage andsticking, or to invest in a moremodern booster system designed tohandle change over between fuels ofdifferent temperatures and viscosities. Without proper automationand cooling, the fuel changeoverprocess becomes difficult andhazardous, which may lead tocritical engine stops.The financial implications ofchoosing a low-sulphur fuel willdepend in part on whether you viewit as a temporary solution or as apermanent route to compliance.Since the cost of low-sulphur fuelsis higher than that of HFO, significant usage will increase your fuelcosts – thus changing the conditions for your business.In short, switching to low-sulphurfuels involves a small initial investment and requires little immediatethought. It will, however, reduce yourlong-term competitive power. If yourcompetitors continue operating onHFO, your own choice of fuel maygive them a chance to pull ahead.Staying ahead in SOx compliance13

Installing a SOx scrubberAs previously described, IMO hasapproved the use of higher-sulphurfuels with exhaust gas scrubbers,globally and in ECAs, so long as thescrubbers remove an amount ofSOx equivalent to the MARPOLAnnex VI requirements. The abilityof scrubbers to do this has beenfirmly demonstrated.A SOx scrubber is a substantialinvestment requiring a significantspace on board, as well as a numberof weeks to retrofit. However, witha SOx scrubber installed you cancontinue operating on HFO, enjoyingthe best possible fuel economy.Regardless whether you need tocomply with the global sulphur capor stricter ECA limits, your fuelsavings will be measurable – andsubstantial.14Staying ahead in SOx complianceCompared to competitors who relyon low-sulphur fuel, you will have along-term cost advantage that canbe used to reduce your prices orto increase your operating profits.Scrubbers are simple in principleand have been used in industrialapplications for many years.Though they must be optimized foruse at sea, they are proven in themarine environment and have beenan integral component of inert gasproduction systems for decades.What matters most is not yourchoice of an open-loop, closedloop or hybrid scrubber arrangement, but rather the choice of anexperienced scrubber supplier.

Will the fuel market change?Fuel economy is the incentive forusing anything other than lowsulphur fuels to comply withMARPOL Annex VI. So long asthere are cheaper fuel alternatives,those alternatives will have a strongbusiness case.Of course, the future price of agiven fuel is difficult to predict. Theprice of LNG, for example, mightbecome lower as the LNG infrastructure expands. Likewise, no onecan anticipate the exact price oflow-sulphur fuels and HFO in thecoming years.However, a continued difference inprice between low-sulphur fuels andHFO is likely. So long as it remainsin common use worldwide, a residualfuel like HFO will always be a cheaperalternative. This price differential iswhat justifies the installation of ascrubber – and its size determinesyour time to payback and profit.One thing is certain: the sooner youchoose a scrubber, the greater yourpotential long-term savings will be.Staying ahead in SOx compliance15

Does your business modelmake a difference?Installing a SOx scrubber lets you continue usingHFO, which means fuel cost savings. Directlyor indirectly, those savings can be used tostrengthen your business – no matter what yourbusiness model.For owner-operatorsIf you both own and operateyour vessel, you pay for yourown fuel. This makes the casefor installing a scrubberrelatively simple. You savemoney by purchasing HFOrather than a low-sulphur fuel,which is money you canreinvest in your business orpocket as profit.For owners of charteredvesselsIf you charter your vesselto others, it is usually the16Staying ahead in SOx compliancecompany operating the vesselthat pays for the fuel. However,a scrubber will let you offer astronger business case thancompetitors reliant on moreexpensive fuels. Those whocharter your vessel will be ableto keep their own prices down,which will allow them to gainbusiness over other shippers.Already, there are exampleswhere the projected differencebetween HFO and low-sulphurfuels is tipping the competitivebalance in contract negotiations.

The time to choose is nowA “wait-and-see” approach to SOxabatement – in the hopes of a dropin low-sulphur fuel prices or a suddenimprovement in the LNG infrastructure – is no doubt an option. What iscertain, however, is that choosing toinvest in a SOx scrubber meansimmediate payback in terms offuel-related operating costs.The longer you delay your choice,the more difficult it may be toimplement when you make it. Inaddition to MARPOL Annex VI,other environmental regulations arenecessitating new equipment onboard. Shipyard availability, as wellas the number of suppliers who candeliver a scrubber on time, may thusbe limited in the future.By delaying your decision, you maybe committing to expensive fuel fora long time to come.Staying ahead in SOx compliance17

The choice ofscrubberChoosing a scrubber is the economicalway to meet SOx emission limits. But thechoice is a long-term one, and there aredifferences between scrubber solutions.Your priorities and sailing profile are bothimportant to consider.18Staying ahead in SOx compliance

Staying ahead in SOx compliance19

Scrubbers at seaScrubbers are emission controldevices that remove unwanted SOxand particulates from exhaust gas,preventing them from entering theatmosphere. In most cases, assuggested by the name, the pollutants are literally “washed” out ofthe exhaust gas.While scrubbers have a longerhistory of use in industrial applications on land, they are not new to themarine industry.20Staying ahead in SOx complianceFor example, they are an integralcomponent of inert gas productionsystems, which generate cargostabilizing inert gas for oil andchemical tankers and inert gas forgas freeing of LNG cargo tanks.While scrubbers have a longerhistory of use in industrial applications on land, they are not new to themarine industry.

Scrubber typesTwo general categories of scrubberexist: wet and dry. Both have beenshown to meet the requirementsof MARPOL Annex VI, but wetscrubbers remain the dominanttype within the marine industry.Wet scrubbersWet scrubbers wash the exhaustgas stream by forcing it into contactwith a liquid. In the case of marineSOx scrubbers, this liquid may bethe readily available seawater, whichis naturally alkaline, or desalinatedcirculation water mixed with analkaline additive (usually causticsoda). The SOx compounds areabsorbed and converted intoharmless substances, while much ofthe particulate matter is trapped inthe liquid and thereby preventedfrom entering the atmosphere.Dry scrubbersDry scrubbers force the exhaust gasthrough a dry bed of granulatedcalcium hydroxide. Although simpleto install and operate, they are lesscommon in the marine industry. Thisis partly due to their high rate ofgranulate consumption, which mayapproach 20 tonnes per day for a 20MW engine.* In addition to the freshgranulate, the used granulate mustbe stored on board prior to onshoredisposal, which means considerableweight and large space requirements.* Source: “Understanding exhaust gastreatment systems: guidance for shipownersand operators”, Lloyd’s Register, June 2012.Staying ahead in SOx compliance21

Scrubber compliance schemesScrubbers are an IMO-approvedequivalent to low-sulphur fuels incomplying with MARPOL Annex VI.Their compliance can be demonstrated according to two schemes:Scheme AThe performance of the installedscrubber system is initially verifiedand certified. This is followed byperiodic surveys, which can involvethe use of a continuous exhaust gasmonitoring system. If a monitoringsystem is not installed, daily spotchecks are recommended.22Staying ahead in SOx complianceScheme BThe performance of the installedscrubber system is not verified.Instead, emissions are continuouslymonitored to show that the systemis in compliance. Daily checks ofkey operating parameters are alsorequired, although as these are apart of the control system, they aremonitored continuously in practice.Since emission checks are requiredwith either scheme, most vesselsopt for Scheme B in order to avoidthe added expense of certification.However, continuous monitoringplaces high requirements onsensors, instrumentation and datastorage systems, which musttherefore be robust and reliable.

The environmentalimpact of scrubbersMarine SOx scrubbers are generally of the “wet”type. This means they scrub the exhaust gas eitherwith seawater or with desalinated circulation waterwith an alkaline additive. In the process, the SOxis first dissolved and ionized, then oxidized intosulphates. Sulphates are a natural part of bothseawater and aquatic organisms, which meansthey are harmless to the environment.In closed-loop operation, thewater is recirculated and thecompounds accumulated init are removed by a watercleaning unit. This forms asludge that is deposited onshore like any other vesselsludge, while only clean waterand sulphate salts with aneutral pH value go overboard.In terms of energy and CO2footprint, the use of SOxscrubbers has advantagesover distillates in a globalperspective. At the refinery,the desulphurization of HFOis a very energy-intensiveprocess that increases CO2production substantially.Staying ahead in SOx compliance23

Operating arrangementsWet SOx scrubber systems can beconfigured in three differentoperating arrangements. They canbe prepared for open-loop scrubbing with seawater, for closed-loopscrubbing with circulation water oras hybrid systems, capable ofoperating with either seawater orcirculation water.Open-loop scrubbingA scrubber in an open-loop arrangement scrubs the exhaust gasdirectly with sea water, which isthen legally discharged back intothe sea.This involves the least amount ofequipment, which means a lowerinvestment cost and simplerinstallation. Likewise, it means thelowest possible operating cost,since there are no consumables.However, an open-loop scrubbersystem may not perform adequatelyin low-alkalinity waters, such asthe northern waters of the BalticSea (see fact box on page 27). Inaddition, its use may be limitedby local discharge legislation.Closed-loop scrubbingThe performance and dischargeissues associated with open-loopscrubbing are avoided with aclosed-loop arrangement. Inclosed-loop scrubbing, thescrubber water is dosed with analkaline additive (usually causticsoda) and recirculated. Becauserecirculation leads to a build-up24Staying ahead in SOx complianceof impurities and diminishedscrubbing effect, a portion of thecirculation water (bleed-off stream) isperiodically cleaned, discharged andreplaced with desalinated waterto retain capacity.Because an additive controls thewater alkalinity within the scrubber,the seawater alkalinity is irrelevant.Moreover, discharge into the seacan be avoided altogether for longperiods of time. The drawbacks areadditional equipment, which includesthe water cleaning unit, and a higheroperating cost due to the need fordesalinated water and additive.Hybrid scrubbingA hybrid arrangement offers an idealcompromise between the costefficiency of open-loop scrubbingand the operational security ofclosed-loop scrubbing. In a hybridscrubber system, both open-loopand closed-loop modes are available,ideally at the push of a button.Simply put, a hybrid systemoperates in open-loop modewhenever possible, which reducesits operating costs. Wheneverdemanded, it can nonethelessswitch into closed-loop mode.This allows continued operationon HFO while respecting localopposition to open-loop waterdischarge, or in compliance withlocal regulations that forbidthe discharge of wash wateraltogether.

Alkalinity and the Baltic SeaSeawater alkalinity has a proportional effect on ascrubber’s cleaning ability. The lower the alkalinity,the lower the cleaning capacity. In the Baltic Sea,the alkalinity of the water gets lower as you sailnorthward.How far north you can sailbefore open-loop scrubbingbecomes ineffective dependson the time of year, but alsoon the size of your system.Increasing your scrubbersize will extend its seawaterrange, thus reducing yourconsumption of desalinatedwater and alkaline additive.But this must be weighedagainst the added equipmentand installation cost.In general, extending sea wateroperation pays off if you sail inthe Baltic Sea on a regular basis.Staying ahead in SOx compliance25

26Staying ahead in SOx compliance

Scrubber designsThe main component of a wet SOxscrubber system is the scrubberitself. Different scrubber designs arepossible, with different placementsof the jet and absorber sections.Their characteristics must beweighed against the design of thevessel as a whole.Split designsMost wet SOx scrubbers have asplit design, which means that thejet and absorber sections arephysically independent from oneanother. The absorber section formsthe main bulk, while the jet sectionis a smaller additional unit.Because it has two vertical sections,a split design has a larger footprint.Yet it is also the simplest design. Theconnection between the sectionsforms a natural water trap thatprotects the engine from waterbackflow, and fewer additionalcomponents are needed in the lowerpart of the vessel.Inline designsScrubbers can also be built with aninline design, in which the absorbersection is placed directly atop thejet section. In other words, the twosections are integrated without anyintermediate connection.This is especially appealing forvessels with difficult space constraints or stability issues, such ascruise ships and RoPax vessels.However, an inline design is not onlytaller, but also more complex. Forexample, careful attention must bepaid to creating a safe water trap inorder to protect the engine. Moreover, the scrubber will experiencegreater material stresses, as it willbe cooled and heated with everystart and stop.Staying ahead in SOx compliance27

Configuration criteriaConfiguring a SOx scrubber is acomplex process. The choice ofoperating arrangement and scrubber design depends on both yourvessel’s sailing profile and itsphysical constraints.Choosing anoperating arrangementWhile the lower initial investment ofan open-loop arrangement istempting, there are good reasonsfor considering a closed-loop orhybrid arrangement. One is theamount of time you spend inlow-alkalinity waters like the BalticSea (see fact box on page 27).The other is the ability to use thescrubber in areas where open-loopdischarge – or even any discharge– is discouraged or prohibited.In some US states, zero-dischargeregulations have already takeneffect. Similar laws are beingconsidered for heavily traffickedports in Europe. If the latter becomea reality, there is a good chance thatyou will need the ability to operateyour SOx scrubber in a closed loop.28Staying ahead in SOx complianceDepending on your requirementsand your supplier’s capabilities,it may be possible to install anopen-loop scrubber system thatis prepared for later conversionto a hybrid version. Your suppliermay also be able to reduce costand space requirements by supplying a multiple-inlet scrubbersystem, which will allow onescrubber to handle exhaust gasfrom several sources.Choosing a scrubber designWhen it comes to the scrubber itself,it is important to remember that thescrubber’s design affects the systemas a whole. Not all components areplaced within the ship’s funnel.While an inline design demands lessspace for a single scrubber, it doesinvolve additional considerations. Sowhile it can solve challenging spaceand stability issues on certainvessels, an inline design should notbe seen as a default. Even on cruiseships and RoPax vessels, a splitdesign may prove to be the betterchoice.

Scrubber optimization and vital equipmentAs mentioned previously, scrubbersare simple in principle and proven towork at sea. However, it takesconsiderable knowledge to optimizetheir function – especially in themarine environment. Only a handfulof suppliers have the breadth andexperience required, as will bediscussed later in more detail.Besides the overall optimization ofyour SOx scrubber system, thereare individual equipment aspectsthat are vital to consider. One ofthese is the quality and robustnessof the sensors and data systemsused to verify compliance. To putthe matter bluntly: if you cannotprove your compliance, you arenot in compliance.Another critical aspect is the watercleaning equipment used in aclosed-loop arrangement or by ahybrid system operating in closedloop mode. Here there is nosubstitute for a centrifugal separator,which contributes to a compactinstallation and is more reliable thanother existing alternatives. In roughseas, a centrifugal separator is theonly solution that will remainunaffected by pitch and roll.Staying ahead in SOx compliance29

The choice ofscrubbersupplierFor smooth installation and reliablecompliance, you need not only the rightscrubber system, but also the rightsupplier. Your supplier’s capabilities– and ability to work with others – havea profound effect on the end result.30Staying ahead in SOx compliance

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Scrubbers from local suppliersThere is naturally no requirementthat you purchase your SOxscrubber from a global or even alarge supplier. As long as yourscrubber complies reliably withMARPOL Annex VI, it can be builtby virtually anyone. Certainly thereare many suppliers, including localsuppliers without a marine background, who are eager to enterthe market.It is important to remember,however, that these suppliers havelittle experience with class rulesand marine regulations. Likewise,they are limited in the assurancesthey can offer.On the equipment side, localsuppliers may lack specific experience and developmental resources,especially when it comes to watercleaning. A local supplier who32Staying ahead in SOx compliancewishes to create a reliable watercleaning unit, let alone a completescrubber system involving manytypes of equipment, faces a steeplearning curve.On the delivery side, local suppliersmay lack the manufacturing andlogistical infrastructure to deliveron time. If your supplier is unableto equip your shipyard during thescheduled slot, you will incur a greatdeal of additional expense.Finally, local suppliers can offeronly a limited scope of service. Ifyour scrubber cannot perform asrequired by law, you may be subjectto fines or stuck in port while waitingfor parts or repairs. At the very least,you may be forced to switch to alow-sulphur fuel – which woulddefeat the purpose of yourinvestment.

Scrubbers from global suppliersIf you purchase your SOx scrubberfrom a global supplier, you canplace higher expectations on itsperformance, its reliability and thedegree of support that follows withit. As there are a number of majoractors providing scrubbers to themarine industry, all with solutionsthat are compliant with MARPOLAnnex VI, there is an ample rangeof more secure choices.These suppliers have a muchbroader base of experience, if notwith scrubbers specifically than atleast with the supply of large-scalemarine solutions. With their moresubstantial resources, they will bebetter equipped to help you selecta scrubber and adapt it to yourspecific vessel – and to support itin years to come.Nevertheless, there are importantdifferences even among globalsuppliers. Some have a great dealof marine background, but littledirect experience with scrubbers.Some have supplied scrubbers forauxiliary engines, but lack experience with main engines, which havegreater safety requirements, higherpower and a higher variable load.Even among global organizations,there are substantial differences inthe extent of their networks and thespeed with which they can delivera scrubber or provide service for it.The remaining sections of thischapter highlight key points toconsider in evaluating any supplier,local or global.Staying ahead in SOx compliance33

Access to core expertiseAs previously discussed, scrubbersas a whole are not new to themarine industry. However, the baseof long-term experience withscrubbers is limited to a handfulof marine suppliers.Even suppliers who have donesignificant work with scrubbersmay lack in-house access to keyequipment expertise. This isespecially true when it comes towater cleaning, which is a criticalfunction in both closed-loop andhybrid configurations.For a company with limited experience in separation, the path to ascrubber-optimized water cleaningunit may be long and difficult.34Staying ahead in SOx complianceAlso important to consider is asupplier’s ability to integrate thescrubber into the vessel as a whole– which includes integration withvessel control systems. Key operations should offer “one-button”simplicity, operating transitionsshould be automated and engineoperation should be kept independent from the scrubber’s. A supplierwho has worked with a broaderrange of marine equipment mayhave stronger abilities in this regard.

Reference breadthReferences are critical in evaluatingany technology, but especiallywhen that technology is is used forlegislative compliance. Some of theSOx scrubbers available today arelargely untested in real-life marineoperation. Others are proven, butonly within a limited operating range.For example, they may be in usewith auxiliary engines but not mainengines.A supplier’s reference list shouldbe not only long, but also comprehensive. Ideally, it should reflectcompatibility with engines from allmajor manufacturers, as well as agood balance of installationscovering both main and auxiliaryengines – from single-engineinstallations of a few MW tomultiple-en gine installations largerthan 60 MW.It can also be important to make surea supplier is familiar with the rangeof regulations facing vessels operating in different regions. For example,some technologies can ensurecompliance with the global sulphurcap, but may be unsuitable for stricterlimits in ECAs and vice versa.Another assurance to look for isthe presence of repeat orders,especially from customers whohave had their scrubbers in use.The decision to purchase again,based on successful operation atsea, is a definitive seal of approval.Staying ahead in SOx compliance35

Referenced technologiesA supplier’s reference list cannotalways be taken at face value.Rather, it must be examinedcritically. The simple reason is thatmost supplier reference listscomprise a range of differenttechnological platforms.Many suppliers have begun workingwith one scrubber technology, thenhave switched to another when thefirst proved difficult to implement oroptimize. Others have developedan in-house technology for openloop systems, for example, buthave purchased another externallyfor closed-loop systems. As playershave entered and left the market,technologies have frequently beenabandoned or switched hands.The longer a supplier has ownedand optimized its technology, thestronger that technology is likelyto be. If all of a supplier’s SOxscrubber installations – includingtrial installations – are still operatingto the customer’s satisfaction,it is an indication of a soundtechnological foundation andongoing optimization.36Staying ahead in SOx compliance

– SOx scrubbers – in detail. Scrubbers are becoming a familiar presence in the marine industry, as they provide an excellent balance of compliance security and operating economy. Yet scrubber solutions are far from the same. The technology and supplier you choose can make the difference between bare-min