Project ideas: VB Project Idea - Assessment of innovative anticorrosive and antifouling coatings for the maritime sector
VB Project Idea - Assessment of innovative anticorrosive and antifouling coatings for the maritime sector
We have a double goal, to support both valorisation and innovative research:
Creating a platform for testing the performance of ship coatings in North Sea conditions (VALORISATION OBJECTIVE)
Using the data we obtain on this platform for modelling the interaction between coat, ship metal and environmental conditions to enhance our understanding of corrosion onset and progression, and of the role of marine bacteria in the onset of fouling (RESEARCH OBJECTIVE)
1. Construction of a (physical) test platform in the Port of Ostend with comparison of different paint types (copper based / with nanotubes / with organic molecules as biocides/...).
2. Analysis of the technical variables linked to surface preparation (blasting, grinding, wire brushing etc.) which have a profound impact on the performance of the coating. This will provide insight into why (under which conditions) and how (by which mechanism) coating ageing is accelerated and failure starts to occur. Therefore, we will measure parameters such as surface profile, roughness, type of grit used to blast the surface, salt levels, moisture, steel temperature, a etc... The impact of humidity, temperature, drying/curing conditions etc… during the application and drying will also be evaluated.
3. The mechanisms by which metallic materials corrode in sea water are complex and not fully understood since they are dependent of (1) the chemical composition, (2) the metallurgical characteristics such as the microstructure and final surface preparation of the materials and (3) the numerous environmental variables that can be present in the marine atmosphere during a ship lifetime that include water salinity, pH, dissolved oxygen concentration, temperature...As such, we study the interaction between coating degradation and the initial phases of corrosion.
4.Tests on microfouling comprise the analysis of microbial communities, using both quantitative (flow cytometry) and qualitative (metagenomics and metabolomics) approaches as well as more conventional testing electron microscopic analysis, fluorescent in situ hybridization, biochemical analysis of slime composition.
5. Accelerated ageing of antifouling coatings will enable us to assess the physicochemical behaviour and the antifouling performance of these coatings after five to ten years.
6. Predictive models will be developed that are able to represent the time history of the degradation of coating and the subsequent development of corrosion. In addition, these models are meant to be practical mathematical relations to be decision support tools for maintenance/repair planning. Finally, these results will be combined, by way of a comprehensive overall life cycle analysis.
Creation of a test platform for objective comparison of antifouling and anticorrosion paints on ship hulls and inside ship tanks.
A performance analysis of several typical paint types used for anticorrosion or antifouling
Formulation predictive models for anticorrosive and/or antifouling coating behavior, coating ageing and the interaction between fouling and corrosion onset
Formulation of a comparative life cycle analysis for different paint types
Scientific publications and a conference in corrosion and fouling
One of the main threats to a ship is steel corrosion: in the western world, damage by corrosion is estimated at 4% of the gross national product (GNP), and approximately 5 tons of steel per second is lost through corrosion. In the Oil and Gas Industry (North Sea production platforms) 60% of all maintenance costs are related to corrosion, directly or indirectly (1993). 90% of ships failures are attributed to corrosion (Melchers, 1999). Corrosion is a major cause of marine structural failures: it results in loss of structural strength at local and global levels, and leads to fatigue failure and stress corrosion cracking. Consequently, the costs pertaining to corrosion are sky high: a 2006 study indicates that the US Navy alone incurred 2.44 billion dollars’ worth of damage due to corrosion; for the U.S. marine shipping industry, the annual corrosion-related costs were estimated at $2.7 billion. The latter cost is associated with new construction ($1.12 billion), maintenance and repairs ($ 810 million), and corrosion-related downtime ($ 785 million). For the whole U.S. economy, the 1998 cost of corrosion amounted to $275.7 billion in 1998 alone (see overview on the cost of corrosion in De Baere et al. 2013).
But coatings protect not only against hull corrosion. Finding proper ways to tackle biofouling (the growth of organisms on the outside of a ship's hull) is another of the challenges which the shipping industry is facing. The presence of often large numbers of organisms (barnacles, macrophytes, mollusks, ...) after all has a large effect upon the hydrodynamic shape and friction of a ship. In practical terms: every tonne of heavy fuel oil that is not consumed on board means an effective saving of 3.3 tonnes of CO2 emissions in the ship. On a fuel consumption of 300 tonnes per day (e.g. by. Emma Maersk), a reduction in consumption by 15% leads to an emission reduction of 150 tonnes of CO2 per day . Improving the antifouling performance of a coating system therefore leads to significant savings in the consumption of fossil fuels.
In addition, among the fouling on the ship's hull are plenty of rather annoying species. Some of them are invasive hitchhikers, which should be kept from undertaking long journeys towards other ecosystems. All in all, estimates of the Marine Environment Protection Committee (MEPC), a committee under the auspices of the International Maritime Organisation (IMO), indicate a total cost of more than $ 5.7 billion per year, to be paid by governments worldwide and by the maritime sector, due to the increased fuel consumption, to repair costs and the possible consequences for man and the environment of the measures to be taken. These costs could be greatly diminished with good antifouling coating systems.
Lastly, organismal growth on the outer side of the hull, from sulfur-oxidizing bacteria to barnacle species (figure 4), may assist in coating breakdown and thereby the corrosion risk of the hull’s steel. A good antifouling coating should therefore also help to prevent this kind of corrosion.In conclusion: the better the coating, the smaller the costs and the smaller the burden it presents for the environment.But who decides what is the best coating? Nowadays, the only information comes from the producers' own research labs - which all demonstrate the superiority of the own product - leaving ship owners to do their own, time-consuming and expensive tests.
Hence the double goal of the project:
- creating an objective test platform for testing the adequacy and the performance of ship coatings in North Sea conditions (VALORISATION OBJECTIVE)
- using the data we obtain on this platform for modelling the interaction between coat, ship metal and environmental conditions to enhance our understanding of corrosion onset and progression, as well as for investigating a less known element in the chain of events in fouling formation: the microbial phase (RESEARCH OBJECTIVE)
 Melchers, R. E. (1999). Corrosion uncertainty modelling for steel structures. Journal of Constructional Steel Research, 52(1), 3-19.
 De Baere, K., Verstraelen, H., Rigo, P., Van Passel, S., Lenaerts, S., & Potters, G. (2013). Study on alternative approaches to corrosion protection of ballast tanks using an economic model. Marine Structures, 32, 1-17.
 Lewthwaite, J. C., Molland, A. F., & Thomas, K. W. (1985). An investigation into the variation of ship skin frictional resistance with fouling. Royal Institution of Naval Architects Transactions, 127
Reduce carbon emissions
Chalmers University of Technology, Department of Shipping and Marine Technology - Sweden
Northumbria University, Faculty of Engineering and Environment, Department of Mechanical and Construction Engineering - Great Britain
Abertay University, The SIMBIOS Centre, School of Science, Engineering and Technology - Great Britain
Institute for Agriculture and Fisheries Research (ILVO) - Belgium
Geniaal bvba - Belgium
Acotec NV - Belgium