Themed \u2018engine performance and condition in a new environmental age\u2019, the roundtable discussion explored how ship owners and engine manufacturers are reacting to current emissions regulations, and what changes they anticipate future regulation will bring. Among the attendees were representatives from MAN Diesel & Turbo, Winterthur Gas & Diesel (WinGD) and five ship owners\/operators: Columbus Ship Management, Hammonia Reederei, John T Essberger, Rickmers Ship Management and Wagenborg Shipping.<\/p>\n
The discussion was chaired by Jakob Buus Petersen, director, Vessel Performance Solutions<\/strong>, who put the topic into clear context. \u201cWhat is it that drives development and innovation, and leads companies\u2019 decisions to invest?\u201d he asked. \u201cIt is what people believe can happen in the next 20 years or so, and that has to be governed to a large extent by regulation.\u201d<\/p>\n Regulation comes in many forms \u2013 particularly when it comes to shipping emissions. Over the past two years the industry has faced the introduction of Emission Control Areas (ECAs) for SOx, from January 2015, and NOx at the beginning of this year. Both have required affected operators to change engine configurations, fuels or operational procedures (and possibly all three). Two future regulatory changes are also looming large: the introduction of a global sulphur cap in 2020 or 2025; and the increasingly stringent energy efficiency requirements of the IMO\u2019s Energy Efficient Design Index (EEDI), intended to curtail CO2 emissions.<\/p>\n ECA experience<\/strong><\/p>\n The most immediate challenge for many shipping companies is sulphur ECA operations \u2013 a challenge that will be extended globally when the worldwide cap is introduced. All the companies at the roundtable had ships operating in the ECAs, and for most the preferred solution was to switch from high-sulphur heavy fuel oil (HFO) to marine diesel oil (MDO) or marine gas oil (MGO) with the required maximum fuel sulphur content of 0.10%.<\/p>\n Fuel switching has caused challenges for engine running, Steve Walker, global marine equipment builder manager, ExxonMobil<\/strong>, reported. \u201cEven when bunkering similar fuel at both ends of a voyage, we would have cases when engines complained for a couple of days \u2013 it was just that there was some fuel mixing and fuels didn\u2019t necessarily fit well together. Our worry with ECAs was that there would be more fuel switching and more of these issues.\u201d<\/p>\n Despite the concerns, for many operators fuel switching when entering and leaving ECAs has been a relatively painless adaptation. But there are still pitfalls to be avoided. Vladimir Shnurkov, fleet manager, Rickmers Ship Management<\/strong>, shared one typical instance. \u201cThere was a case in the US when we changed over fuels in a short time, and we nearly lost power because the MGO was blocked by paraffin wax. So we came to the solution of heating the fuel line to 30-35\u00b0C.\u201d<\/p>\n The difference in viscosity between HFO and MGO is an important consideration when switching. Jan Vinder, promotion manager & customer support, MAN Diesel & Turbo<\/strong>, reported that the engine designer had seen fuel pump seizures in tests where the viscosity of MGO was too low. \u201cThe main thing is to keep MGO above two centistokes,\u201d he said. \u201cWe also recommend testing before you go into the ECA if your fuel equipment is worn. You should install a cooler for operating in hot areas, because if you are on a lower viscosity the temperature outside is 40-50\u00b0C, viscosity can fall below two centistokes. And there could be some instances where you need a chiller, if you are running on really thin oil.\u201d<\/p>\n The challenge of maintaining the correct fuel viscosity for low-sulphur fuels highlights one shortcoming of the ISO 8217 fuel quality standard, noted Iain White, global marketing manager, ExxonMobil <\/strong>\u201cThe specification is written for 1.5cSt to 6.0cSt, but you never really see the high end. And when it comes to the winter and the refineries add pour point depressant, if anything the viscosity goes down. So viscosity can also vary throughout the year.\u201d<\/p>\n Operators also shared experiences of working with ECA fuels \u2013 a range of fuels with low sulphur content and high viscosity, designed to be easier to switch from and to HFO. Kay Th\u00fcrnagel, technical director, Hammonia Reederei<\/strong>, explained that the company\u2019s vessels had been using ExxonMobil Premium HDME 50 \u2013 an ECA category fuel supplied by ExxonMobil \u2013 with no problems. \u201cOur chief engineers also have an on-board kit so that they can test for compatibility before mixing fuels.\u201d<\/p>\n The lower price of oil was noted as a potential obstacle to the uptake of such ECA category fuels. Thomas Geberbauer, fleet manager, Columbus Ship Management <\/strong>noted: \u201cWe did a trial in 2014. It was worth doing to look at an alternative to MGO, but then the fuel price collapsed and the spread between [ECA category fuels] and MGO was not as attractive.\u201d<\/p>\n One factor on which all operators agreed was that increasing sulphur regulation was leading to a more complicated fuel scenario. According to Geberbauer, it is a complexity that has yet to be factored in to vessel design. \u201cShips should be designed to accommodate more fuel treatment,\u201d he said. \u201cToday we see ships designed for one or two fuels \u2013 they need more if you want the flexibility to change. We normally have to use the same bunker line for HFO, MDO and MGO.\u201d<\/p>\n There is a corresponding complexity in cylinder lubricants, Geberbauer added: \u201cFor worldwide trading you can have sulphur levels of all different kinds. But we don\u2019t want to have to use two or three different types of cylinder oil, because it makes it complicated for the people on board. So we would like to see just two kinds of cylinder oil that can cover the full range of fuels on the market today.\u201d<\/p>\n Konrad R\u00e4ss, general manager, combustion systems R&D, WinGD, <\/strong>was able to provide some reassurance on that front. \u201cOur recommendation today says that you can run with just two lubricants: a high base number (BN) oil for higher-sulphur HFO, and a low BN oil for lower sulphur fuels and MGO or ECA category fuel.\u201d Recent tests confirmed the use of BN100 in ECA areas to be harmless provided feed rates are adjusted correctly and engine condition to be closely monitored.<\/p>\n Looking forward to the global sulphur cap, participants were asked whether they would be considering scrubber installations. The lukewarm response suggested that most will prefer to try other options.<\/p>\n A particularly robust rebuttal came from Thomas David, head of newbuildings, John T. Essberger<\/strong>. \u201cIf you want to talk about a truly green scrubber system, you don\u2019t throw the washwater into the sea,\u201d he said. \u201cSo you need a closed loop scrubber, and then a treatment plant, and whatever else. Then to comply with Tier III NOx you need selective catalytic reduction (SCR) or exhaust gas recirculation (EGR). To fit all that equipment you need space, but you cannot build a ship bigger because then you can\u2019t go to certain ports. It\u2019s much easier to say that we will use 0.5% sulphur fuel worldwide.\u201d<\/p>\n Tackling Tier III<\/strong><\/p>\n While ship owners appear to be dealing with SOx restrictions with only minor modifications to engines and fuel systems, the same cannot be said for new limits on NOx emissions. Both compliance options for Tier III NOx regulations require the installation of new equipment \u2013 either SCR or EGR. And they are both pricey; Vinder reports for medium size engines, installation will cost upward of US$1.5 million.<\/p>\n \u201cAt the smaller sizes, we think SCR will be cheaper at first cost,\u201d Vinder told delegates. \u201cBut then there are the other factors, which is why we are offering both solutions.\u201d<\/p>\n One ship operator who knows all about the downside to SCR is Onno Steenweg, superintendent fleet management department, Wagenborg Shipping<\/strong>. Having operated the units for several years, he reports that his crew are always happy to turn them off. \u201cThe SCR works perfectly, but when it is connected to the main engine you can get temperature fluctuations, calcium deposits in the engines, condensation and soot collecting,\u201d he said. \u201cYou have you buy urea, clean the system regularly, and you need cost rebates from port authorities to make it profitable.\u201d<\/p>\n Urea injection and engine temperature can be controlled more accurately in modern systems, Vinder explained. But there is still the potential for cold corrosion to occur while the SCR system heats up, R\u00e4ss noted \u2013 a high operating temperature is needed if the exhaust gas is to be treated properly, and while the system is warming up engine heat is used, potentially reducing in-cylinder temperature.<\/p>\n Although the Tier III market is in its infancy, EGR is the most popular choice for two-stroke engines based on current orders, Vinder notes. But here too there can be engine condition challenges. R\u00e4ss said: \u201cYou have to treat the exhaust gas first, otherwise sulphur-containing exhaust gas blown back into the piston underside can react to sulphuric acid. In the worst case you could corrode piston rod and other components, as well as having sulphuric acid in the crankcase, depending on the condition of the stuffing box.\u201d<\/p>\n With little to separate the alternatives in terms of cost or performance, the choice is very much up to the individual owner, says Vinder. \u201cIt\u2019s a discussion we need to have for each project, whether to use EGR or SCR \u2013 and then whether low-pressure [after turbocharger] or high-pressure SCR. It depends for instance on the initial cost, or whether you have waste heat recovery \u2013 in latter case we think low-pressure SCR is the solution.High pressure SCR is being used for smaller engines, but for big engines [over 40,000kW] you would need very thick materials for high pressure SCR, so it would be a huge reactor.\u201d<\/p>\n The challenges of complying with NOx emissions could become more complicated in the future. Walker noted that both SCR and EGR require more fuel to be used. \u201cIt\u2019s the CO2 element that worries me,\u201d he explained. \u201cIf the EEDI is ratcheted up further, and if the Tier III limits come into effect in more areas, then complying with both regulations could be very challenging.\u201d<\/p>\n It is early days yet for Tier III NOx solutions, and there are engine condition factors to consider for both SCR and EGR. But although the emissions limits are only in force in North American and Caribbean ECAs for now, there is already pressure on ship owners to install the equipment, says Essberger\u2019s David. \u201cWhen you receive a questionnaire from a charter company about what your vessel can do, you know that even if they are not planning to go to the US they want to be prepared in case they want to change the trade.\u201d<\/p>\n Carbon constraints<\/strong><\/p>\n The third element of emissions regulations is the limit on CO2 imposed by the EEDI. Currently in the first five-year phase of gradual CO2 reductions, the EEDI places a limit on the emissions allowable for new vessels. By 2025, newbuilds will need to be 25% more CO2 efficient than ships (of their class) built between 2000 and 2010 \u2013 placing constraints on the installed power of new ships and offering new challenges for engine builders and ship designers.<\/p>\n The difficulties posed for ship owners are clear. Geberbauer from Columbus Ship Management explained: \u201c[Looking at the phase two requirements,] we find that with smaller ships you are not able to reach speeds of 20 knots, or for bigger ships 22 knots. For container or tanker purposes you come up against the limits. So how can you have an operating speed of 14 knots and still be within the EEDI?\u201d<\/p>\n David agrees. \u201cWe put it in our spec that our containerships should meet the 2025 EEDI restrictions as much as possible. For bulk carriers with the new common structural rules [including the added weight of double hulls] it is not easy, nor with tankers.\u201d<\/p>\n The first response from engine designers to the EEDI challenge was to make engines with a longer, slower stroke \u2013 with the resulting increase in in-cylinder pressure exacerbating cold corrosion and necessitating the use of high BN cylinder lubricant. ExxonMobil\u2019s White noted how the re-emergence of cold corrosion in new engine designs had encouraged a greater focus on lubrication.<\/p>\n \u201cWe see the need to lubricate more now on longer-stroke engines, if you have a cold corrosion problem,\u201d said White. \u201cAs operators are doing more monitoring now for cold corrosion and managing feed rate, we also find fuel problems more often \u2013 they might always have been there but now we are finding them. I\u2019d like to know if ship owners are paying attention to the feed rate. Everyone is trying to save money at the moment, but sometimes we still see people using too much, particularly in older engines that do not suffer from cold corrosion.\u201d<\/p>\n Both WinGD and MAN Diesel & Turbo have adapted cooling systems to further combat cold corrosion in their latest two-stroke designs. David provided an insight into how Hammonia was finding the right lubricant conditions for one of these engines.<\/p>\n \u201cWe have new engines from MAN with a cooling system for the engine liners, and we are using BN100 for cold corrosion. But we are still adjusting with a running-in programme, checking the piston underside every two weeks. So far we can see that the cooling system works. We have reached a feed rate of 0.95g\/kWh and it should be possible to reach 0.7g\/kWh. We have done three round trips now and we can see the kind of fuel we are getting, but our chief engineer has not yet done a sweep test.\u201d<\/p>\n Customer driven<\/strong><\/p>\n It is difficult to foretell whether future reductions in CO2 emissions will be met by even longer stroke engines. Vinder explained that MAN is looking closely at future regulations, but is wary of overstretching its partners and customers based on early experiences of so-called ECO vessels.<\/p>\n \u201cA couple of years ago when we were asked by owners about ECO vessels, they said they wanted the greenest ship they could get. And then when we finished putting together prices and so on, they asked for the cheapest solution? So we need to offer something as simple and as cheap as we can make it within the requirements. Going further than the IMO requirements seems not in the customers interest at present.<\/p>\n \u201cWe have also to work together with the shipyard. When we came with long-stroke engines there was big resistance from shipyards, they had to change a lot of things they claimed, So it needs to be a longer term consideration.\u201d<\/p>\n For WinGD, the future development of engines is clearly driven by the demands of their customers \u2013 and that, to a large extent, means their fuel choices. R\u00e4ss explained: \u201cThe two-stroke engine is made to consume all kind of fuels. To improve efficiency one can have a longer strokes, higher pressures and different tunings that come along with different air flow rates through the engine \u2013 nowadays tunings with reduced air flows compared to previous designs further improve efficiency, and that bears quite a high risk of more exhaust gas in the cylinder after exhaust valve closing.<\/p>\n \u201cNothing comes for free. If you want a highly efficient engine tuning you will often find a high amount of trapped exhaust gas remaining in the cylinder increasing risks of cold corrosion which usually requires a higher lube oil consumption, a higher BN or concrete design countermeasures. It also depends on the fuel \u2013 if you burn low-sulphur \u2018gas station\u2019 diesel you will have less cold corrosion problems than when burning high-sulphur fuel.\u201d<\/p>\n High-sulphur fuels are a challenge for new engine designs given the limited amount of air blown through the engine, R\u00e4ss added. \u201cBanning sulphur would make life much easier for the engine designers. But meanwhile we have to work to find additional solutions that can absorb these limits through design changes, including the lubricant which is nowadays seen as component, not commodity.\u201d<\/p>\n Monitoring moves<\/strong><\/p>\n Across all three major emissions areas the emerging challenges to engine condition are complex and formidable. For SOx reduction measures, selecting the right lubricating oil during fuel switching is an evolving science. The impact of Tier III NOx abatement technologies on engine performance will only become clear as more of the SCR and EGR systems reach the market. And increasing constraints on CO2 efficiency will bring further challenges \u2013 in the form of increased potential for cold corrosion if the move toward longer stroke, slower turning engines continues.<\/p>\n Chairman Petersen concluded: \u201cShipping companies will comply with new legislation when required – recently proved with the new sulphur regulation – if the legislation is clear and predictable. It is more difficult to find funding for innovative, fuel saving initiatives: really good business cases have to be put on the table for projects to mature.\u201d<\/p>\n The discussion was also notable for identifying how ship operators felt they could gain a better insight into the condition of their engines. Taking scrapedown analyses can pose challenges when ships are operating at higher speeds, noted Hammonia\u2019s Th\u00fcrnagel. And while testing kits for BN are easy to use they can be expensive, added Geberbauer. Simplifying the tests, and making some of them more affordable, would be a great boost.<\/p>\n New technology might also have a role to play: Perhaps it would be possible to make cylinder lubrication automatic in the future, Steenweg from Wagenborg suggested. Certainly online monitoring of cylinder condition \u2013 either through a database of cases or through engine sensors \u2013 might be a realistic aspiration over the next few years.<\/p>\n In the end though, a crew that is trained to monitor condition \u2013 including physically looking for signs of engine wear \u2013 might still be the best defence. As MAN\u2019s Vinder phrased it: \u201cGet your crew experienced at looking into the engine \u2013 scrapedown analysis is good but it can\u2019t show you everything that is really happening in the cylinder.\u201d<\/p>\n ExxonMobil\u2019s top take-outs<\/strong><\/p>\n Sulphur complexity: <\/strong>With most ship operators choosing to switch fuels when entering sulphur ECAs \u2013 and facing regional sulphur restrictions elsewhere \u2013 individual vessels must now be equipped to handle a range of fuels. Ship owners are seeking vessels designed for this increased flexibility. The key challenges to engine condition are in ensuring fuel compatibility and making sure the correct cylinder oil is in use at the right time.<\/p>\n Scrubber uptake: <\/strong>Few operators have yet committed to installing scrubbers to address current or future fuel sulphur restrictions. This suggests that demand for low-sulphur fuels will continue to rise, particularly when a global sulphur cap is introduced.<\/p>\n Tier III impact: <\/strong>Both solutions for reaching Tier III NOx emissions have a potential impact on engine running: SCR has the potential to cause temperature fluctuations within the engine \u2013 particularly while the system is heating up – while EGR gases, if not properly treated, can reintroduce corrosive sulphur to the cylinders. Modern control technologies from system suppliers and proper sulphur filtration are addressing these issues, but while the NOx abatement technologies are their infancy, careful monitoring of engine condition will be required.<\/p>\n New engine designs: <\/strong>As the EEDI puts further pressure on CO2 emissions, two-stroke engines are expected to continue the trend of using increasingly longer stroke, at even slower speeds. Different engine tunings and adapted air flow can also enhance efficiency. These measures can increase the potential for cold corrosion. Engine designers are adapting cooling systems to address this, and lubricants will also need to evolve to the challenge of future engines.<\/p>\n Cylinder condition monitoring: <\/strong>Ship operators are monitoring cylinder condition more than ever, and are seeking ways to make the testing processes easier for their crews. Innovations including simpler and more affordable test kits, or even online monitoring may bring advantages, but an experienced crew that is able to assess cylinder condition will always be the best defence.<\/p>\n<\/div>\n<\/div>\n","protected":false},"excerpt":{"rendered":" The Motorship and ExxonMobil met several major ship owners in Hamburg last month to share perspectives on the future development of engines and emerging challenges to cylinder condition. The result was an illuminating and far-reaching discussion, of which we are pleased to present highlights in this special report.<\/p>\n","protected":false},"author":8,"featured_media":4103,"comment_status":"closed","ping_status":"closed","sticky":false,"template":"","format":"standard","meta":{"_acf_changed":false,"footnotes":""},"categories":[7],"tags":[],"sponsor":[],"class_list":["post-4102","post","type-post","status-publish","format-standard","has-post-thumbnail","hentry","category-general-news"],"acf":[],"_links":{"self":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/posts\/4102","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/users\/8"}],"replies":[{"embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/comments?post=4102"}],"version-history":[{"count":0,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/posts\/4102\/revisions"}],"wp:featuredmedia":[{"embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/media\/4103"}],"wp:attachment":[{"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/media?parent=4102"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/categories?post=4102"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/tags?post=4102"},{"taxonomy":"sponsor","embeddable":true,"href":"https:\/\/www.motorship.com\/propulsion-and-future-fuels-conference\/wp-json\/wp\/v2\/sponsor?post=4102"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}