AIRCOAT Results: A New Coating Solution For Reducing Maritime Shipping Emissions

After 4 years, the AIRCOAT Horizon 2020 project will present its research approach, developments and final results on Wednesday 16 March at its Virtual Final Event during Oceanology International in London (15-17 March 2022).

Since 2018, the AIRCOAT team has been working on a new coating solution aiming to create a passive air layer for ship hulls. The new technology will help to prevent biofouling (accumulation of microorganisms, plants, algae, or small animals) and reduce drag, thus increasing fuel efficiency and reducing gas emissions of maritime shipping.

The AIRCOAT technology consists of a structured foil that retains air when submerged under water. Due to the lower viscosity of air (low resistance to deformation) in comparison to water and the air barrier, drag reduction and a limited attachment of fouling organisms are expected. The foil aims also to avoid the release of biocide anti-fouling substances into the water. 

Johannes Oeffner, project coordinator of AIRCOAT and team leader at Fraunhofer CML will open the conference at 9.30 am CET:

“We’ve developed production lines and testing facilities, produced kilometres of foil, coated a research vessel and applied a test patch to a container ship, performed a vast number of calculations and simulations and spent many hours with hydrodynamic and biofouling experiments. We’ve tackled a lot of challenges, had to make some compromises and learned a lot which will help advancing AIRCOAT further for being a future ship efficiency technology.”

AIRCOAT is responding to one of the main challenges of the EU Green Deal: reducing by at least 50% by 2050 the emissions from shipping. Today, maritime transport still emits around 940 million tonnes of CO2 every year. This is about 2.5% of global greenhouse gas (GHG) emissions. Biofouling is an important factor for increasing fuel consumption and consequently CO2 emissions for maritime transport, it reduces up to 10% the velocity of a ship per year. Many solutions exist today to reduce biofouling or drag but none of them combine both features.

Professor Thomas Schimmel, Scientific Coordinator of AIRCOAT and Director at the Institute of Applied Physics at the Karlsruher Institute of Technology (KIT) will introduce during the conference the bio-inspiration methodology that AIRCOAT foil is using:

“It was amazing to understand the mechanism, how the plant keeps a layer of air under water and to produce first artificial air-keeping samples in our lab – which by the way still are keeping the air layer even after years under water. But this was just the beginning. It was the step from the plant to the lab. The step from the lab to the ship had still to be performed, and progress has been achieved during the past four years. Starting with small, fragile samples on the centimeter scale, we meanwhile produce elastic foils on the kilometre scale – using a novel roll-to-roll process developed in our lab in Karlsruhe. And the structures which in the beginning were on the scale of one millimeter are now on the micrometer scale.”

The conference will include the presentation of AIRCOAT results, such as the variety of different surface structures that have been developed, produced, and investigated experimentally by the AIRCOAT research team. The realisation of air retention on the foil over long periods of time with appropriate surface structures and in various aqueous environments remains an important challenge. The main influence parameters are the material of the foil, geometry and size of the surface structure. During the project, two experiments were done in real maritime environment, the first one a small vessel in Malta and the second one on a container ship in Romania. These were important steps towards the production and application of air retaining surfaces.

The conference will conclude with performance predictions and simulations made on the global fleet that could create a solution such as AIRCOAT foil, and the future opportunities created by the research results.
Source: AIRCOAT