VPS, a leading global marine decarbonization advisory services company, has identified a new marine fuel contamination issue in Houston through its fuel testing services. VPS detected significantly high levels of Dicyclopentadiene (DCPD) and associated isomers in VLSFO bunker fuel deliveries in Houston. These chemical contaminants were detected using in-house GC-MS (Gas Chromatography – Mass Spectrometer) analytical methodologies.
In response to this discovery, VPS has issued a Bunker Alert to its customers, specifically referring to fuel deliveries made by a single supplier during the months of March to May 2023. Problems related to these bunkers emerged several weeks after bunkering when the fuel was combusted.
Eleven vessels that used this fuel have reported a loss of power and subsequent loss of propulsion while at sea. These issues resulted from fuel leakage in the ICU (Injection Control Unit) units and the inability of fuel pumps to generate the required fuel pressure. Both the main and auxiliary engines were affected, although failures in auxiliary engines were more commonly reported.
One VPS customer shared their experience with the Houston VLSFO, stating that the first sign of trouble after switching to this fuel was the failure of the fuel pump and fuel injectors in the auxiliary engines. All three auxiliary engines subsequently faced the same issues, leading to a complete blackout and loss of propulsion. The auxiliary engine pumps exhibited significant leakage, and the fuel injectors seized. Both the fuel pumps and fuel injectors required repeated replacement until no spare parts remained.
This customer also reported a significant impact on the purification system caused by this fuel. It was observed that the purifiers were unable to remove the high cat fines present in the fuel under normal engine operating speeds. To maintain the operation of the purifier, the main engines had to run at lower RPMs than usual, reducing fuel consumption and subsequently the purifier feed-rate.
Due to power limitations, the affected vessel had restricted maneuverability as their thrusters could not operate. As a result, the vessel had to switch to LSMGO (Low Sulphur Marine Gas Oil) to safely arrive at the port.
DCPD compounds are unsaturated chemical compounds that can polymerize and oxidize under certain conditions. However, the presence of inhibitors typically found in fuel oil can reduce the rate of this polymerization process. If these compounds begin to polymerize, the fuel becomes sticky and more viscous, causing difficulties for moving components such as fuel pump plungers and fuel injector spindles to operate freely. These effects lead to damage in the fuel injection system and can result in excessive sludge formation over time.
The detected DCPD compounds in this fuel ranged from 3,000 to 7,000 ppm (0.3-0.7%).
Several vessels had been previously alerted by VPS about the potential high-concentration DCPD contamination in their fuel through a “Caution” result from the VPS Chemical Screening service. This highlights the value of VPS’ pre-burn service in providing advance warnings to mitigate such issues.
Source VPS Veritas Petroleum Services