Additives have a big role to play in the development of 2020-compliant fuel, enabling the sector to better deal with the complications presented by a low-sulphur future, writes Selwyn Parker
With the 2020 sulphur cap becoming a not-so-distant concern, Japanese container shipping giant, Ocean Network Express (ONE), has engaged fuel treatment specialist Innospec to develop the cleanest possible fuel for its requirements.
The marine division of Innospec, a specialist in fuel additives, will be treating many tonnes of fuel in a trial involving more than 60 of ONE’s vessels. Rival container groups will be watching the exercise closely. With a total fleet of 240 vessels and a capacity of approximately 1.44M TEU, the group boasts the sixth-biggest fleet in the world and, like its rivals, has much to gain from cleaner and more efficient fuel.
The trial is taking place as operators of container ships, tankers, cruise ships, ferries, tugs and offshore support vessels search for the best ways to meet the new standards that mandate 0.5% sulphur emissions. Although undoubtedly good for the planet, the regulations are putting the world’s shipping fleet and the fuel industry under unprecedented pressure.
With time running out, some experts are even predicting the end of heavy fuel oil (HFO), the default energy of the fleet for nigh on a century. These assumptions are based on the relative lack of interest to date in scrubbers, that are designed to clean up emissions in the exhaust system. According to industry sources, the total number of scrubbers already installed and on order is just 500, far below earlier expectations. And looking ahead to 2020, Shell Marine estimates that fewer than 2,000 ships will be fitted with scrubbers that will allow them to continue running on high sulphur fuel oil (HSFO).
That means the long-term future for HFO looks dim. “The reality is that we are looking at a distillate future,” predicts Innospec.
Spanish ferry group Balearia would certainly agree with that conclusion. The company announced in late July that it will be investing €60M (US$70M) in switching five of its ferries over to natural gas-powered engines. The two-year exercise is estimated to reduce CO2 emissions by more than 45,000 tonnes and NOx emissions by more than 4,400 tonnes, while eliminating all sulphur and particle emissions.
Balearia Ferries will spend US$70M on gas-powered engines
In addition, in February 2019, Balearia will launch the first of two low-emission smart ships. “Balearia expects to have nine ships sailing with this energy within three years,” announced chairman Adolfo Utor.
As with other conversions to gas power, Balearia’s project crucially depends on the skill and knowledge of the oil companies. In the ferry group’s case, Spain’s Gas Natural Fenosa has developed the 2020-compliant fuel and has signed a 10-year supply contract.
In addition to fuels, there is also an unprecedented amount of work going into lubricants. Shell Marine has designed its entire portfolio of lubricants to meet the incoming standards. The oil giant is also trialling a new cylinder oil, due to be launched in 2019 as demand grows for lubricants fit for the new era. “Shell Marine’s expectation is that 90% or more of the shipping fleet will switch to fuels with a sulphur level of 0.5% in the run-up to January 2020,” said global technical manager Sara Lawrence. “This will be a mixture of very low sulphur fuel oil and distillate fuels.”
Not to be outdone, ExxonMobil has developed Mobilgard 525, a high-quality cylinder oil for vessels operating on fuel oil with 0.10% sulphur content.
Additives in the mix
The production of higher quality fuel also requires the application of advanced science in terms of distillate additives. Shipping companies of all types want improved lubricity. They also want cleaner fuels that reduce the fouling of injectors, a regular bugbear in the engineroom. To reduce fuel waste, they want more efficient combustion. In the interests of easier maintenance and longer-lasting engines, they also want less corrosion, another area where additives offer sustainable solutions. And everybody wants more stable fuel that retains its properties even under long-term storage.
"Additives can be used to stabilise distillate fuel that has been stored onboard for long periods, an important consideration in “fuel-switching” – when a vessel changes to cleaner fuels in low-emission zones"
Additives have an important role to play – if they work. As Lubrizol Industrial Fuels’ technology manager Jim Bush and product manager Scott Hace explained in a paper titled The truth about marine fuel additives, “over the years fuel additives have developed a questionable reputation in the shipping industry, due to the actions of a few unscrupulous suppliers.”
Thankfully, this concern appears to be a thing of the past, and the additives industry is toiling along with the rest of the fuel sector to deal with the complications presented by a low-sulphur future. “Treatment with lubricity-improving additives is sometimes required for fuels which have been severely hydro-treated to produce ultra-low sulphur diesel,” noted the paper’s authors.
Additives can be used to stabilise distillate fuel that has been stored onboard for long periods, an important consideration in “fuel-switching” – when a vessel changes to cleaner fuels in low-emission zones. Additives also play a key role in improving fuel combustion, which not only makes for more economical voyages but also reduces the build-up of soot, a constant concern in enginerooms because it presents a fire hazard. Finally, metal-based additives can neutralise the accumulation of corrosion-causing acid created by high-sulphur fuels.
The perennial problem of tank sludge is also coming to a head as the low-sulphur deadline nears. The muck from HFO accumulates in fuel storage tanks, fuel lines and injection gun systems, sometimes over years. It is not possible to pour 2020-compliant fuels on top of the sludge because it breaks up the residues, which then work their way through the main engines and auxiliary power systems, causing blockages in filters and purifiers.
So how to get rid of it when ships switch over to non-HFO or cleaner HFO fuels? Until recently, the only way was to take the ship out of action while the tanks were cleaned in an expensive and time-consuming exercise. However, Innospec has developed a product that it claims allows the tanks to be cleaned while the vessel is under way.
This could have a huge impact on costs and fleet management, allowing engines to practically clean themselves during operation.
The pursuit of the right treatments and additives is endless, with experiments going on constantly in the background. In early 2017 at its Marine and Power Innovation Centre in Hamburg, Shell tested the properties of an Innospec product, Octamar Complete, designed to improve specific fuel oil consumption (SFOC), stability and emissions. According to the company, the results showed an average SFOC reduction of 1.6% across the power range and a maximum reduction off 2.2% at half load. Furthermore, the product was able to reduce the emission of particulate matter by 60%.
The problem of supply
One of the main underrated challenges is that of supply. How much of each kind of oil and lubricant will the world’s shipping fleet require? It is a complex issue that goes right back to the refineries. Shell Marine anticipates up to 3M b/d of HSFO will be displaced by low-sulphur fuels, which clearly involves huge adjustments in supply.
It has already implemented most of its two-stroke portfolio and is working on the rest, but there are many kinds of oils to consider. The company has recently upgraded its four-stroke crankcase lubricants – Shell Gadinia and Shell Argina – noting in a technical paper titled Shell Marine prepares for more cylinder oil uncertainties, that “The new oils have been optimised to deal with the faster viscosity increase and the base-number depletion experienced by oils in modern medium-speed engines.”
Similarly, ExxonMobil has come up with Premium HDME 50 that meets all the low-sulphur regulations. “[It] has no residual material, which leads to cleaner engines without cat fines,” the company reports. ExxonMobil also claims excellent ignition quality for the fuel.
Commonly shortened to “cat fines”, catalytic fines are tiny particles about the diameter of a single human hair. Created by the catalytic cracking process employed in refineries, they are composed of aluminium and silica, which are elements used in the process. Some of the particles are carried over into the residual oil via the slurry oil.
Nearly as hard as diamonds, cat fines can cause a lot of mechanical damage despite their microscopic size. Measured on the Mohs scale of mineral hardness used by scientists, they are nearly twice as hard as the iron and steel used in engines. And unfortunately, they are becoming more prevalent in fuel because they are produced as a side effect of low sulphur fuels.
Two-stroke engines are the biggest victims. As Wilhelmsen reported in an early 2018 study entitled Between a rock and a hard place – catalytic fines in fuel “The damage caused by catalytic fines is almost exclusively seen in two-stroke engines.” In fact, some two-strokes have been put out of action in less than 100 hours by this issue. Rough weather tends to bring the contaminants into play because they get shaken free from the sediment in the bottom of fuel tanks.
An exhaustive study last year by ExxonMobil, titled Explore the outlook for energy – a view to 2040, which looked at more than 400,000 oil samples revealed that 43% of vessels had enough of these impurities in their fuel to trigger serious engine damage and even catastrophic failure.
Lloyds Register’s Fuel Oil Bunkering and Advisory Service (FOBAS) also identified “significant problems” with catalytic fines in bunker fuels. In samples taken at Fujairah bunkering port in the United Arab Emirates, the levels of these contaminants ranged from 75 milligrams per kilo to 139 milligrams per kilo.
In the above-mentioned report, Wilhelmsen cited the Viswa Lab, the fuel analysis specialists, which earlier this year issued a warning for ARA regions after detecting high concentrations of cat finds in bunker fuel. “These trends are alarming,” warned Wilhelmsen. “If the quality of fuels during bunkering and onboard use is not proactively monitored, this can lead to significant main and auxiliary engine damage and repair costs.”
Four-stroke engines are less sensitive to the issue, partly because their splash-type lubrication washes away most of the cat fines.
On the bright side there are ways of beating cat fines and other fuel impurities. Purifiers are one option, although Viswa Lab has found that the efficiency of purifiers can vary wildly, from 20% to 60% depending on type. Another method is generally described as condition monitoring. Wilhelmsen business manager for water and oil solutions Sachin Gupta described condition monitoring as “a pre-emptive way of carrying out maintenance.” Likening it to going to a gym to stay in shape, he said: “Condition monitoring is carrying out spot checks regularly – daily or weekly – so that ship operators, managers or crew can understand their machines so well that they anticipate problems before they arrive.”
And, fuel being of prime importance, he recommended regular testing of fuels and lubricants so that any impurities or other problems are detected. Wilhelmsen, for example, has a range of test kits that enable crews to carry out spot checks on fuels during bunkering. “You have a quick answer. It takes 15 minutes,” said Mr. Gupta.
One such kit, the Unitor, designed for onboard testing (rather than in a lab) analyses the cat fines content down to 20 particles per million. It can also be used to check the efficiency of the filtration system. Like similar products, the point of Unitor is to assess the integrity of the fuel before it gets into the system.
“If the quality of fuels during bunkering and onboard use is not proactively monitored, this can lead to significant main and auxiliary engine damage and repair costs”
Fuel quality issues
As the 2020 deadline approaches, the variable quality of fuel remains a pressing issue. However, ship-to-shore connectivity and sensor-based analytics are helping ensure the integrity of the fuel.
Several oil companies have devised proprietary systems, such as Shell Marine with LubeMonitor, which detect deteriorations in the condition of cylinders and feed the data to Shell’s on-shore team for analysis. As the company explained, ship operators ignore such aids at their peril: “Even companies grappling with the cost of the Energy Efficiency Design Index, Shipping Monitoring Reporting and Verification, CO2 and ballast water management systems will concede that one lesson learned from engine cold corrosion has been that saving on cylinder oil technical services can prove a false economy.”
One company that has adopted Shell’s advice is maritime contractor Van Oord. In June the Rotterdam-based group signed a five-year contract with the oil giant to handle lubrication for its fleet. “We are involved in dredging, oil and gas infrastructure, and offshore wind projects around the world,” explained staff director of the ship management department Jaap de Jong. “We must have 100% reliability wherever our vessels are operating.”
That is why laboratories around the world are working at peak capacity to create fuels and lubricants that are not only friendly to the environment but also to the engine.
A new ‘wonder fuel’ out of Japan
The imminent low-sulphur regulations have sparked Japan’s Oshima Shipbuilding and other partners to explore the development of a new virtually emissions-free, reasonably priced fuel based on cycle oil. According to Oshima and classification society DNV GL, the fuel would meet the 0.5% sulphur cap without the need for scrubbers or other expensive and space-consuming equipment. For good measure, it is said to be highly combustible.
Known as Super Eco Fuel, it is a compound of different liquids. Oshima Shipbuilding said it comprises light cycle oil (LCO), which is a secondary refinery product, gas-to-liquid (GTL) made from natural gas, and finally plain water. Each component of the mix contributes something to the result. LCO has a low sulphur content but is hard to ignite, while GTL contains almost no sulphur or other impurities, ignites easily and delivers a complete combustion process. The fuel, which is mixed on board, can be used in existing engines without the need for time-consuming retrofits.
“In addition the specific fuel oil consumption is slightly lower,” said Oshima. “CO2 emissions and soot formation are reduced as well.” According to DNV GL, this potential wonder fuel will cost more than standard HFO but less than other low-sulphur fuels.
However, it is still early days. The fuel is being trialled in Japan and the results are being collated. “Preliminary tests of the fuel characteristics, engine performance and reliability have yielded satisfactory results,” DNV GL reports.
The biggest challenges will be availability. But so far DNV GL is impressed by the potential. “I am excited about Super Eco Fuel,” said DNV GL expert Adam Larsson, discipline leader in hydrodynamics and stability, who has been working with Oshima on a new kind of general cargo carrier. “[That is] provided there is sufficient availability of bunkering. Also, the technical feasibility of engine performance has to be assured. But it may have significant potential as a marine fuel.”
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