The following article ‘Curing the fuel stability pandemic’ has been written by Ralph Lewis, the CEO of refinery-grade fuel therapy additive producer Newport Fuel Solutions, and has been shared with Singapore bunker publication Manifold Times:
A rash of fuel associated stoppages and delays have ravaged numerous vessels in current months – most from very predictable points relating to the stability of IMO mandated 0.5 p.c sulfur fuels (VLSFO).
Reports from fuel testing laboratories relating to extreme fuel instability of VLSFO-RMG-RMK are unceasing. A steady sequence of alerts by the fuel evaluation firm FOBAS cite instability points with bunkers from Houston, Singapore, Las Palmas, Rotterdam, and Antwerp, amongst different areas.
Veritas Petroleum Services (VPS) has additionally issued quite a few alerts, noting that in May 2020 for instance, 8.8 p.c of samples from European ports have been off spec.
This fuel instability pandemic appears concurrent with the world Covid-19 model, and for good cause.
A serious contributing issue is longer than anticipated fuel storage instances, because of the Covid-19 slowdown in bunker deliveries.
Greatly declining demand for VLSFO-RMG-RMK following the onset of the Covid-19 pandemic resulted in an enormous improve in VLSFO-RMG-RMK storage early on. Stored shares in the Amsterdam/Rotterdam/Antwerp space set a document of 1.74 million mt mid-2020. Singapore storage hit 5 million mt in July 2020. And Fujairah shares soared mid-year as nicely.
As VPS defined, ‘Although longer-term storage of marine fuels is feasible, it will increase the threat of fuel high quality points arising from temperature, stratification, fuel stability….”
This prolonged storage time particularly impacts the very specific nature of VLSFO, which has “a decrease tolerance to long term storage and inside stability,” says Naeem Javid, world operations supervisor of Lloyd’s Register Fuel Oil Bunkering Analysis and Advisory Service.
Of course, many marine fuel therapy corporations have opportunistically touted their respective merchandise as the miracle options. But not so quick. Overcoming a fuel stability difficulty with old skool sludge dispersant chemistry isn’t almost as efficient – a state of affairs some vessel operators are discovering with conventional fuel therapy.
The cause? Chemistries that when labored in heavy fuel oil to carry asphaltenes is suspension – stopping their precipitation as sludge – are wholly ineffective in stopping the wave of chemical interactions that happen when two disparate distillate fuels are blended for VLSFO – leading to speedy fuel high quality degradation.
These reactions can start shortly after the fuel is mixed – points starting to happen only a matter of days following supply. Fuel testing of a pattern inside days of receipt will typically be performed too early for the downside to be detected, as instability reactions are progressive and grow to be a lot worse over time. For this cause, onboard spot testing for compatibility is usually insufficient with VLSFO. Within a couple of days of bunkering the purification system begins to battle.
These chemical reactions from fuel bending have been lengthy recognized and nicely understood by petroleum chemists working at the world’s nice refineries the place fuels are sometimes blended to satisfy regional calls for.
The problem begins with the undeniable fact that fuel chemistry varies vastly in every distillate stream – starting with the supply of the feedstock – the catalysts used for the cracking course of – the course of methodology and the variabilities of time and temperature. On any given day at any refinery globally – the chemistry of a selected distillate stream can range broadly no matter strict management requirements. The consequence? Insoluble are fashioned when chemically incompatible fuels are blended.
To quote a Chevron technical description:
“One nicely established mechanism by which insolubles are fashioned is the acid-catalyzed conversion of phenalenones and indoles to complicated indolyphenalene salts. Phenalenones are fashioned by oxidation of sure reactive olefins. Indoles happen naturally in sure blends. The required natural acid is both current in a mix element or is generated by the oxidation of mercaptans to sulfonic acids.”
And there are further elements. The hydrotreatment of fuels to take away sulfur additionally removes extra unstable, increased fractions that contribute to good ignition high quality in addition to naturally occurring antioxidants. To compensate, refiners sometimes add a cetane enhancement additive identified a 2-ethyl-hexyl-nitrate (2-EHN). Indeed, 2-EHN can increase cetane of an untreated fuel as a lot as eight numbers when added at a extremely aggressive dosage fee.
Yet when these fuels have been first launched in California a long time in the past, fleet operators with centralized fueling techniques started noticing that inside days, fuel filter use started to vastly improve. Chevron investigated and found that 2-EHN over time decomposed and reacted with sure fuel parts to create very excessive molecular weight buildings which not solely elevated fuel filter plugging but additionally resulted in deteriorated ignition high quality.
These chemical interactions, mixed with warmth, oxygen and time, type a recipe for fuel Armageddon – destined to show any wholesome purification system right into a cauldron of sludge stew.
So, what to do?
Simple. In time, refiners found that sure kinds of amine-based anti-oxidant chemistries have been capable of utterly block the chemical reactions which result in the formation of insolubles and better carbon weight molecular buildings which have been inflicting extreme fuel system fouling and compromised ignition high quality.
Taken a step farther – it was additionally found that these chemistries additionally blocked the formation of much less unstable, high-carbon weight buildings which occurred when unsaturated olefinic hydrocarbons would really be a part of collectively into unburnable polymeric chains throughout the combustion course of. In different phrases, it turned out that by blocking this course of, thermal stability of the fuel was vastly improved – offering extra energy per unit of fuel and a discount in unburned hydrocarbons and emissions.
This is exactly why conventional bodily dispersants will predictably fail when a stability downside is the results of chemical reactivity between two fuels. While they might have some restricted profit dispersing a few of the materials that kinds from such reactions – a dispersant is not going to cease the preliminary response or the development of a response – a few of which will be fairly speedy and damaging.
Yet there’s a treatment, time examined to be secure and terribly efficient in stopping the fuel stability contagion.
Among Newport Fuel Solutions marine fuel therapy merchandise are two formulation particularly formulated to cease stability points in marine fuels from the second two fuels are blended. Both include one hundred pc energetic chemistries – the similar utilized by refiners globally to deal with the similar points. And at the moment these merchandise – NP-HFO, and NP-FOT, are on a whole bunch of vessels, utterly stopping slowdowns and stoppages from severely compromised fuel high quality.
These chemistries are formulated with refinery-grade amines which block the undesirable chemical reactions which happen following mixing. Fuel supply techniques stay clear. Sludge and insoluble precipitation are vastly lowered. Icing on the cake is a marked enchancment in thermal stability which supplies enhanced ignition high quality, inhibition of damaging deposits, and reductions in particulates and unburned hydrocarbons.
Unlike aggressive merchandise – Newport doesn’t use any low-cost, petroleum “filler” solvents to “water down” the merchandise for higher profitability. The merchandise include solely one hundred pc energetic substances – the considering is that ship homeowners ought to take pleasure in the similar low therapy prices as world refiners. With no unstable petroleum solvents – the merchandise are additionally deemed non-hazardous – secure for personnel to deal with – secure to retailer on board.
Because these are refinery-grade concentrates, therapy value is much decrease than typical marine fuel components. With a therapy fee of 1 liter per 30 mt, NP-FOT is an natural amide/amine product able to remedying and even reversing fuel stability points. NP-HFO comprises an extra element particularly designed to vastly increase fuel thermal stability – offering higher ignition high quality for deposit management for VLSFO. NP-HFO can also be the selection for vessels with scrubber towers burning typical RMG380 and RMK 380 fuels.
Since January 2020, vessels treating fuel with both of those merchandise have skilled a 99.2 p.c success fee – no fuel system fouling – no stoppages – no constitution rent loss – little question why Newport merchandise are the selection for a lot of of the world’s biggest fleet operators.
Ralph Lewis is the CEO at Newport Fuel Solutions, Inc.
Mr. Lewis served as Technology Transfer and Public Information Specialist with Shell Oil and ultimately, as Vice President Technical with Power Research Inc for over 32 years.
Photo credit score: Manifold Times
Published: 17 May, 2021