The following article was written by Ralph Lewis, the CEO of refinery-grade fuel treatment additive manufacturer Newport Fuel Solutions; it was recently shared with Singapore bunker publication Manifold Times:

As the IMO continues to plan and implement directives for improved vessel efficiency, targeting progressive CO2 reductions, and mandating new directives such as EEXI, fuel additive manufactures are increasingly touting products with claims of remarkable efficiency improvements and reductions in emissions.

Yet with these promises, combined with those of hull coating companies, engine management software developers, propeller manufactures and the like, the combined efficiency improvements should make fuel almost free of charge, if all are to be believed! 

Increasing Pmax 

The reality is that no additive can change the BTU content or inherent energy value of any fuel. Yet it is possible to achieve a very slight improvement in inherent efficiency with changes in the thermal stability of the fuel. Man Diesel and Wartsila calculate that for every bar increase in pmax, a 0.25 percent improvement in fuel efficiency is achieved. 

So a few years ago we did some studies on the chemistries of NP-HFO and NP-FOT. Depending on the engine, application of the chemistry provided a result ranging from 3-to-5 bars increase in pmax– indicating a fuel efficiency improvement of 0.75 to 1.25 %! 

Is such a slight improvement in efficiency noticeable at sea? Highly unlikely owing to a wide range of sailing conditions affecting vessel efficiency – load, wind speed, sea conditions, ambient air temperature, engine speed, among many others. 

Yet even just a slight change in engine efficiency is reflected in engine condition long-term, an easily measurable parameter.

Thermal Stability 

The key to this slight improvement is improved thermal stability of the fuel. Newport products contain complex amine chemistries refiners apply globally to improve both thermal and physical stability of blended fuels, automotive fuels, and aircraft fuels. These amines are routinely applied to jet fuels to prevent carbon deposit accumulations on jet engine turbine blades. In fact, the focus on thermal stability research for aircraft fuels has been extensive over the decades. After all, it would not do to have an engine failure at 35,000 feet altitude. 

The same holds true for the automotive side. Most government agencies regulating automotive fuels globally now mandate the use polyether amine type additives – design to prevent deposits and keep fuel delivery systems clean to minimize unburned hydrocarbon and particulate emissions. Today thermal stability technology is universally applied and the effect has been dramatic – reducing unburned hydrocarbon emissions from vehicles an amazing 97 percent in the United States since the 1980s. 

To keep it simple, thermal stability refers to the extent to which a fuel, when heated, produces unburnable carbon mass. Fuels with poor or compromised thermal stability will suffer a slight loss in combustion efficiency and will produce more unburned hydrocarbon deposits and particulates than will fuels with greater thermal stability. Multiple factors affect this characteristic – primarily metallic presence – amount of olefinic unsaturated hydrocarbons, and even the chemical reactions which take place when two or more fuels are blended. 

Again, this effect has been the subject of decades of research and much of this can be discovered in the papers published by the International Association of Fuel Stability and Handling, of which Newport Fuel Solutions is a member. 

Some marine fuel treatment makers seem to conflate these two characteristics of thermal and physical stability. A stand-alone dispersant chemistry – of which there are many – does not, for example, improve thermal stability. The two are quite different. Any additive maker claiming thermal stability for a treatment should provide evidence that the formula contains a significant percentage of amine-based antioxidants.

Physical Stability 

There is one additional factor which affects efficiency – physical stability. Pre 2020 fuels and even today’s modern blended fuels produce some measure of physical sludge. In time, this material begins to affect fuel delivery systems. Combined with the effect of compromised thermal stability, fuel injection systems – injector apertures – needle valves progressively become fouled and spray patterns disrupted. The engine makers original design parameters for optimal efficiency is degraded. Fuel efficiency loss over time can be significant. 

The key to preventing sludge – consisting of asphaltenes, gums, resins, chemical contaminants – is through the application of a highly effective detergent dispersant chemistry. In addition to the refinery-grade amine chemistry therein, NP-HFO and NPFOT have a proven, highly effective tall oil fatty dispersant which physically penetrates the fuel on a molecular basis and separates and disperses these materials evenly throughout the fuel mixture in what is defined as a colloidal suspension. Fuel delivery systems remain deposit free. Injector spray patterns remain optimal. 

Enhancing both thermal and physical stability is key to optimum fuel efficiency - especially critical considering the highly variable and uncertain nature of today’s blended marine fuels. 

And unlike our competitive products, NP-HFO and NP-FOT contain only 100 percent active, refinery-grade components – no cheap petroleum solvent fillers. As highly concentrated products, this makes cost of treatment per metric ton the most competitive in our industry. This also classifies them as nondangerous – safe for shipboard handling and storage. 

NP-HFO and NP FOT are very similar in function. Increase in thermal stability with NP-HFO is slightly higher than with NPFOT, but both products have proven highly effective improving and maintaining vessel efficiencies over the years. 

EEXI – Slow Steaming 

Among the EEXI recommendations – slow steaming is the predominate one - back in the picture as a way to dramatically reduce CO2 emissions. Yet there is a trade-off. At reduced operating speeds, marine engines can be expected to produce higher levels of particulate and unburned hydrocarbon emissions per unit of energy produced. This has always been clearly evident with observation of increased carbon deposits on engine components on two-stroke engines operating at reduced speeds for prolonged periods. 

But this does not have to be. With improved thermal stability of the fuel even at reduced speeds – these deposits are greatly inhibited by Newport products. We know. Our clients simply never experience any excessive deposits under these operating conditions. Rather, engine condition – piston crowns, exhaust valves – turbocharger blades, remained remarkably deposit free at reduced engine speeds over prolonged sailings.

Fuel Treatment Pitfalls 

Newport chemistry is the same refiners have depended on globally for decades - time proven and effective. In comparison, many manufacturers of so-called “combustion improvers” or combustion catalysts” rely on highly questionable components, which in some cases, have long-term negative effects. 

These “catalysts” are needlessly drowned in a high percentage of inexpensive petroleum solvents by products like naphtha, naphthalene, hydro-treated distillate and the like which make up as much as 70 percent of the additive. The safety data sheets are telling – listing these components by chemical abstract number (CAS), percent content, and with the appropriate warnings for storage and handling. 

A common combustion improver decades ago was iron-based ferrocene. In the steam turbine days additives containing ferrocene were used to inhibit some measure of particulate emissions while providing a slight increase in combustion. Even in a two-stroke marine engine, some data indicates that ferrocene application will provide a slight improvement in pmax. 

But there is a downside. Post combustion deposits of ferrocene have been observed visually as a thin later of a red-colored iron oxide film on piston crowns and exhaust valves. In time, this material will accelerate wear on areas it touches. 

This capability to “polish” metal surfaces is well known to jewelers and goldsmiths – who use iron oxide impregnated cloths to polish and shine their works – referring to the material as “jewelers rouge”. Some engine makers refuse to issue a No Objection letter for any marine fuel additive containing ferrocene, or for that matter, other metallic materials often seen in marine fuel additives, including magnesium and manganese. 

Lowest Fuel Treatment Cost 

NP-HFO and NP-FOT contain no metals and no cheap petroleum solvent fillers. With a 100 percent concentration of refinery-grade additives, dosage rates provide the lowest treatment cost per metric ton in the maritime industry. Our business is wholly focused on making yours much safer, secure and profitable.

Photo credit: Chris Pagan on Unsplash
Published: 25 July, 2022