Trifecta of challenges

(Article originally published in the March/April 2023 edition.)

Bulk carriers, box ships, cruise ships and workboats all have one thing in common: they need reliable propulsion to get from port to port. Regardless of what they’re hauling, towing or pushing, every conventional boat needs a well-functioning engine with the right lubricants and fuels to make the trip.

A thin layer of lubricant, often less than a thousandth of an inch thick, is all that keeps engine components from rubbing. Any defects in lubricant performance will show up later in the form of accelerated engine wear and increased maintenance costs.

The additive package of the lubricant has to be the right one to do this job well. Lubricity must be high enough to prevent wear. The base number must match the sulfur content of the fuel and the formula must have enough detergency to clean the inevitable soot from burnt residual fuel oil.

The industry solved this trifecta of challenges for high-sulfur heavy fuel oil many decades ago. Higher base number (BN) lubricants have additional additives to neutralize the acids produced by burning sulphurous fuel in a two-stroke engine. As a happy coincidence, these additives also provide excellent detergency, solving two problems in one step.

transition

This formula served the maritime trade well from the 1950s until the 2020s, when the IMO began mandating the use of very low sulfur fuel oil (VLSFO). The transition forced ship operators to switch to lower base number lubricants to match the new low-sulfur fuel, but with a catch. These oils also had less detergency, and shipowners quickly discovered that this resulted in large carbon deposits and excessive wear on modern high-pressure two-strokes, specifically the popular MAN Mark 9 and 10 rigs.

“This will have implications for cylinder oil selection in the future, as detergency is more important than acid neutralizing ability,” says Milind Phadke, vice president of Energy at lubricants consultancy Kline Group.

In mid-2022, after two years of R&D and field testing, most major lubricant suppliers released new 40 BN oils that decouple detergency from the base number. Gulf Oil’s GulfSea Cylcare XP 5040X, Shell’s Alexia 40 XC, Chevron’s Taro Ultra Advanced 40 and ExxonMobil’s MobilGard 540 AC rival BN 100 oils for maintaining cleanliness in both modern and high weather efficiency, while providing the required basic BN 40 number. for VLSFO.

The decoupling of detergency and base number may also give these new lubricants an advantage in the green transition: many are also dual-rated for use with other low-sulfur fuels such as LNG and methanol, which will play a leading role in the decarbonisation of the industry.

Methanol is the green fuel of choice for Maersk Line, which has ordered 19 container ships with dual-fuel methanol engines, including six ultra-large container ships with a capacity of 17,000 TEU each. Just like any other boat with a two stroke diesel, these boats will need proper lubrication and low BN oils are ready and available to provide it.

Lubricating oil monitoring

With all these changes in the fuel market, lube oil control is more important than ever and the lube industry is responding with sophisticated digital solutions.

ExxonMobil moved ahead of the pack last year through a partnership with Palantir, an analytics provider for big-name clients including IBM, HD Hyundai and the US Navy. Exxon is adding the capabilities of Palantir’s Foundry digital platform to its Mobil Serv cylinder condition monitoring service, which enables on-board scraping oil analysis to quickly identify lubrication problems.

The goal is to use Palantir’s advanced analytics to protect engines from premature wear by detecting problems early. Vessel managers will also be able to compare their vessels’ performance with (fully anonymized) data from other vessels in the ExxonMobil database. At the same time, data tools will aid ExxonMobil’s R&D efforts by providing hidden clues about lubricant performance.

“We can now take full advantage of the big data we’ve gathered in our experience to develop and deploy even more powerful data-driven insights when and where they’re needed,” says Ioannis Chatzakis, director of ExxonMobil’s global marine technology program. “Vessel operators will be able to use this data for their own analysis within the platform and connect to existing vessel management platforms.”

Shell’s LubeMonitor condition monitoring service has also been digitized with an app-based one-stop shop for lubrication data. The LubeMonitor app allows engineers and ship managers to store all relevant information, including photos and measurements from engine inspections, lab test results and technical advice from Shell’s LubeAnalyst service advisors.

This reduces the user’s workload of moving from one system to another for each function and report. It allows operators to easily compare their vessels with benchmarks, from the fleet level down to individual engine cylinders. To maximize ease of access, the application is available over the Internet, on Apple iOS and Android operating systems, as well as in offline registration formats.

Chevron takes a traditional approach to lubrication monitoring with its FAST (Fluid Analysis and Trending Service) program laboratory analysis network. Chevron uses well-equipped, ISO-certified laboratories in Antwerp and Shanghai to quickly analyze marine lubricant samples and provide customized information to its customers. The changeover is fast, as the name suggests, and the resulting reports are published on an online portal for ship managers to access at their convenience.

For boat operators who want even faster and more up-to-date information on the health of their engines and lubricants, the Chevron FAST OnBoard Test Kit allows engineers to perform do-it-yourself tests in the field. This identifies changes at the earliest possible stage, enables engineers to make changes and interventions immediately and fosters a culture of hands-on monitoring in the engine room.

Unburnt fuel

Modern marine diesel engines are very efficient, but even the best engines leave some fuel unburned.

Under low-load conditions when the engine is below its designed operating temperature, incomplete combustion can account for more than two percent of the injected fuel, according to emissions control company SailPlan. This represents a cost to the operator in the form of wasted fuel and increased wear and tear. Emissions of half-burnt fuel (PM and PAH) also pose a health hazard to coastal populations.

Fuel additives can help by improving the combustion properties of the fuel, reducing carcinogenic emissions and potentially saving opex at the same time. After all, fuel costs money, and unburned fuel is money that escapes the stack.

UK-based SulNOx Group specializes in fuel additives that promote complete combustion. Their LR-certified SulNOxEco fuel conditioner is a bio-based additive for diesel and MGO, improving both lubricity and fuel efficiency. The additives, designed by specialty chemical giant Nouryon, create an emulsion that allows the water in the fuel to mix completely, increasing the total oxygen content of the fuel.

This improves combustion efficiency and lowers combustion temperature, which helps reduce NOx formation. It can also reduce particulate emissions by up to 60 percent while delivering eight to ten percent fuel savings. This is a simple way for shipowners to improve their Carbon Intensity Indicator (CII) rating, according to SulNOx.

“A lot of shipowners are talking about having to slow down ships to comply [with CII]which obviously comes at a huge commercial cost,” says SulNOx CEO Ben Richardson. “However, with the proven improvements in fuel efficiency, power and torque from using SulNOx in fuels, we offer immediate and ecological solutions”.

Current users trialling SulNOx products include OSV operator Caspian Marine Services (CMS) and Norwegian shipowner Myklebusthaug Management, among others. Myklebusthaug is particularly interested in SulNOx’s ability to reduce NOx emissions, which are taxed in Norwegian waters. Norway’s NOx tax of $2.30 per kilo is based on a combination of fuel consumption and engine performance measures, and is high enough to incentivize operators to put controls in place.

Mykelbusthaug will test SulNOx fuel additives aboard two vessels and evaluate the effects.

UK supplier FAST (no relation to Chevron) has a long history in road fuel additives and is also seeing growing interest in its marine formulations. Its Exocet brand of fuel additives is designed to solve a number of common fuel problems such as microbial growth in fuel tanks and water contamination in fuel.

FAST’s Exocet Marine Fuel Conditioner is a multi-functional additive for inland and coastal marine diesel engines running on distillate fuel. According to FAST, it inhibits fuel tank sludge formation, prevents microbial growth, promotes a clean fuel system and inhibits injector fouling. One gallon of conditioner treats about 2,000 liters of fuel, and a version formulated for heavy fuel oil is available.

The company also offers a specific formulation designed to restore diesel engine power by cleaning injectors, as well as a universal antimicrobial treatment to treat or prevent the growth of “bugs” in fuel tanks.

saving money

These additives help vessel operators solve a wide range of operational and compliance challenges, from exhaust pollutants to fuel, sludge, coke and tank deposit incompatibilities. In many cases, this is cheaper than trying to make the same changes by altering boat speed or engine settings.

Addressing specific problems with additive treatment can get a boat back into service without extended downtime, and a routine conditioning regimen can prevent problems from occurring in the first place.

The views expressed here are those of the author and not necessarily those of The Maritime Executive.