- Presence of Styrene, Indene, and DCPD in fuel is a risk to ships.
- Viswa Lab defends accusations of false alarms by providing proof about these risks.
- Only one like Styrene even at high levels of 2000 ppm in fuel is safe.
- Combination of Styrene, Indene & DCPD above 100 ppm each causes problems.
- Impure liquid polymerises over time and blocks pump plunger and barrel.
What is the problem?
Some of the members of the supplier community refuse to accept that the presence of Styrene, Indene, and DCPD can cause any problem in fuel engine. Their argument has been that for years these substances have been present in bunker fuel without any deleterious effects. Viswa Lab itself has been bombarded with strong accusations of unnecessarily raising unjustified alarms states their technical report from 29th November.
What are the arguments made?
According to Viswa Lab, the presence of just one substance such as Styrene alone, even at very high levels, say, 2000 ppm does not create any problems. It is a combination of Styrene, Indene & DCPD above 100 ppm each that causes problems.
Process of contaminant detection
The empirical conclusions drawn by Viswa Lab (VL) are based on a process equivalent to “Reverse Engineering”. Customers report problems and VL carries out detailed analysis including testing by Gas Chromatography-Mass Spectrometry (GCMS) to identify the presence of a contaminant or a group of contaminants which can be correlated to the problems. The supplier community has demanded a proof. Viswa Lab has countered that empirical conclusions are scientific even though they lack direct proof.
A sample captured in a photograph provides as near a proof as could be asked for. This sample represents the drain from an ethylene cracker. The contents have been tested and they show the presence of Styrene, DCPD, Indene. It can be seen from Pic 1 that there is the drain in a liquid flowing matrix and also a precipitate which has solidified (Pic 2).
The liquid over a period of time solidifies which can be called polymerizing. In liquid form, it may be monomers, dimers, and trimers but with the passage of time they form polymers which tend to freeze into a solid.
How is the plunger affected?
This is exactly what happens in a fuel pump plunger and barrel. The gap between the plunger and barrel is about 8 microns. The substance in the bottle is added to the bunker fuel as a cutter stock. It helps the refinery or petrochemical plant to get rid of waste drain and it helps the bunker fuel suppliers to use this as a low‐cost cutter stock. What happens subsequently is a matter of time.
Where is the risk?
The liquid solidifies, polymerize and suddenly the plunger is frozen in the barrel. The main engine comes to a stop. Ship staff goes crazy trying to find a solution. The navigators up on the bridge are also panicking because the ship starts to drift since there is no power. In a heavy traffic area, this is a prime risk of serious accident.
Why is it a risk to ships?
Ship staff desperately remove the plunger barrel, clean the surfaces and fit it back. In many cases with luck on their side, the fuel pumps start functioning. However, if the adhesion of the plunger in the barrel is very strong, it is not possible to remove the plunger from the barrel, the only alternative is to change the fuel pump. In many cases, ships may not have a full set of fuel pumps as spare to change.
How to test for the impurity?
Viswa lab urges the reader to ensure that this substance is viewed. When the liquid substance is dabbed between two fingers say the thumb and forefinger after some time the liquid solidifies, and the two fingers are stuck together. This is exactly what happens in the fuel pump.
One could not ask for a better proof than this.
The main point to remember is these substances have no business to be present in the bunker fuel.
How much or how little is not the issue.
Pic 1. Ethylene cracker stream in liquid form
Pic 2. Closer look at the polymerized products
Pic 3. Polymerized products
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