DESMI Octopus LSFO skimmer delivers promising recovery performance in IMAROS 2 test

DESMI Ro-Clean is part of the EU IMAROS 2 project to increase responder readiness for LSFO spills. Results indicate that our new unique Octopus LSFO brush skimmer delivers much better recovery performance than equipment designed for HFOs or other oil types.

The IMO 2020 sulphur cap has slashed sulphur oxide emissions to the atmosphere by 70% since coming into force in 2020, replacing heavy fuel oils (HFOs) with low-sulphur fuel oils (LSFOs). But while LSFOs contribute to a cleaner atmosphere, they cause problems in our oceans: They behave very differently than HFOs and other oil types when spilled at sea, and traditional skimmers including conventional cylindrical brush banks very often are not effective at recovering LSFOs.

Several LSFOs have high pour points, causing them to solidify and break up in chill seawater because their viscosity increases, and their structure changes dramatically. Since they have very poor adhesion, a layer of water is formed between traditional skimmer brushes and the oil emulsion which prevents oil recovery. In addition, LSFOs have limited flowability, making them difficult to collect with traditional skimmers.

DESMI makes strong contribution to cleanup research

In general, oil spill recovery is more complex and challenging for LSFOs than for HFOs and other oil types. Using dispersants and in-situ burning may have limited potential, and mechanical recovery is largely dependent on the choice of skimmer system, according to a 2020 report from Norwegian research institute SINTEF.

SINTEF calls for more systematic testing and documentation of different skimmer concepts, and DESMI Ro-Clean is doing exactly this by contributing to skimmer testing under the EU IMAROS 2 project (IMpacts And Response Options regarding low sulphur marine fuel oil Spills). DESMI has provided oil spill response solutions designed and manufactured in Denmark since the early 1970s and are proud to take the equipment evolution further and overcome evolving challenges.

We were one of only three companies chosen to test the skimmer at the Norwegian Coastal Administration's (Kystverket) test facility in Horten on IMAROS 2 which focuses on improving the capacities of mechanical recovery. And early results indicate that we have a working solution; one that is commercially available and can be applied immediately.

Octopus exceeds test expectations with LSFOs

On IMAROS 2, we are testing our DESMI Octopus LSFO concept which has brush belts designed to allow oil to flow towards the skimmer. This means that it can recover oil with very different viscosities than most other skimmers, and it can recover high-viscosity oils with low adhesion where belt skimmers typically fail. In the initial tests, the unique Octopus concept surpassed expectations by successfully collecting the three types of LSFO selected by the IMAROS 2 project committee while maintaining very high efficiency even in wave actions.

The efficient skimmer performance is due in part to the brush design, but also to the fact that the DESMI Octopus solution is a complete package which also includes our renowned DOP screw pump. The DOP is able to handle and transfer the thick and highly viscous material; a very important point in efficient oil recovery. The free-floating Octopus LSFO skimmer can optionally be integrated with existing boom systems as an inline skimmer in our Speed Sweep system or in the standard RO-BOOM sweep system, efficiently collecting LSFOs despite their limited flowability – and greatly reducing the investments needed to tackle LSFO spills.

For all skimmers tested on the IMAROS 1 project, recovery was poor for LSFOs with very high pour points. On IMAROS 2, the Octopus LSFO skimmer has delivered very promising recovery performance with these very challenging oils.

Solution commercially available today

Given the IMO 2020 cap, LSFO spills will become more common – and require specialist recovery tools. Many oil responder organisations currently do not have these tools, but with the DESMI Octopus LSFO skimmer concept, they can get an IMAROS 2 proven solution that is showing significant promise in dealing with LSFOs and protecting marine environments globally.

The Octopus solution is commercially available today as part of DESMI Ro-Clean's extensive portfolio of proven environmental technology solutions for all spill conditions.

For more information about the DESMI Ro-Clean, please visit our website www.desmiro-clean.com or contact Managing Director Henrik Knudsen at hekn@desmi.com or via +45 91 37 34 44.

We are more than happy to help you increase organisational preparedness against LSFOs.