EU-Funded Project Brings New Coating Solution to Market

An aluminium-based coating for offshore energy installations, developed under the EU-funded ACORN project and is said to provide better protection and to be more environmentally friendly, has reached commercial stage.

The innovative coating solution, purposed for offshore wind, oil & gas, wave and tidal energy structures, has been developed by a team of researchers from the UK, Spain, Sweden, Denmark, and the Netherlands under the EUR 1.3 million project, with approx. EUR 1 million provided by the EU.

“Steel structures in marine environments are subject to many forms of degradation, two of the most problematic being corrosion and biofouling,” said researcher Henry Begg of the EU-funded ACORN project. “Although coatings to protect against such conditions exist within the shipping industry, where ships can be periodically dry-docked for maintenance, offshore structures are required to be moored in the water for extended periods of time and without ongoing preventative maintenance.”

To rectify this structural issue, Begg and the ACORN project team have developed the durable, non-paint protective coating that extends the lifetime of marine structures.

When the new coating is used, not only do these structures enjoy an extended and virtually maintenance-free lifespan of over 20 years, the need for supplementary (and costly) cathodic protection is also reduced – or even avoided, according to the team behind the project.

The ACORN solution bases its technology on thermally sprayed aluminium (TSA). TSA is a coating with proven, long-term resistance to corrosion in offshore environments. This TSA coating is then enhanced with a range of environmentally friendly, active anti-fouling substances that do not need to be released into the water.

Instead, they act locally from within the coating to prevent the attachment of biofouling organisms. The substances are added in very small concentrations, allowing them to be gradually exposed at the active surface of the coating as the TSA corrodes (typically at a rate of <10µm/year).

The eco-friendly anti-fouling substances were specifically chosen for their performance, commercial availability and regulatory approval for use in EU waters. In order to ensure the anti-fouling carriers were capable of withstanding the offshore conditions, researchers also evaluated their resistance to seawater corrosion, UV radiation damage and settlement of fouling organisms, with a particular focus on barnacle colonisation.

“Barnacles represent one of the most damaging biofouling species and can block a structure’s key access points, cut through protective paints and promote the settlement of further marine fouling organisms,” Begg explained. “We ultimately chose TSA because of its excellent track record in the oil and gas sector for providing long-term corrosion protection. Not only does it corrode at a very slow and predictable rate, unlike paints, it also provides local ‘sacrificial’ protection that protects the steel substrate even if the coating is damaged.”