Expanding The Use Of Environmentally Acceptable Lubricants In The Maritime Industry

The importance of hazardous oil spillages into marine waters has trigger US EPA (United States Environmental Protection Agency) to launch the 2013 Vessel General Permit (VGP). The 2013 VGP establishes new rules forcing the use of environmentally acceptable lubricants (EAL) in all oil-to-sea interfaces unless technically infeasible. This regulation applies to all vessels bigger than 24 m operating within US Coastline. Available environmentally acceptable lubricants (EAL) are often incompatible with existing components of ships designed for conventional lubricants. This results in reduced performance, increased damage to components and accelerated degradation of seals. These challenges prevent extensive implementation of EAL in the ship industry. A whole new approach is therefore necessary to increase and optimize the use of new environmentally acceptable lubricants. The purpose of the eSEAL project was to solve these challenges by basic research on the effects of additives used in seals and lubricants on the performance of systems consisting of seal, EAL and counterpart. The work developed in the project included long-term compatibility of the new proposed seal materials in different EAL formulations, lab scale tribological performance of the new proposed solutions, design and construction of a large scale test rig for testing commercially available products in real conditions and selection of the best seal-EAL-countermaterial systems. The large scale tests have been supported by lab scale testing and characterization that has led to the final decision of selecting the most appropriate seal materials for the thrusters. The results generated in the eSEAL project are of high value for replacing harmful mineral oils in the maritime industry and contributing to use of more environmental acceptable solutions for cleaner oceans.

The eSEAL project has effectively encouraged the collaboration between the industrial partners (Trelleborg and Brunvoll) and the R&D partners (SINTEF and NTNU). Through this collaboration new products have been developed and are ready to the market. The new products will encourage the use of more environmentally acceptable products in the maritime sector and minimize the use of harmful and contaminant mineral oils.

A 2010 presented study at the Arctic & Marine Oil Spill Program Technical Seminar estimated that marine shipping discharges approximately 37 to 61 million litres of lubricating oil within the 4,700 ports and harbours of the world to the environment annually, primarily through stern tube leakage and operational discharges. This has triggered the United States Environmental Protection Agency to establish more restrictive laws for using conventional lubricants in marine service, forcing the use of environmentally acceptable lubricants (EAL) in all oil-to-sea interfaces. The currently available EALs are often incompatible with existing vessel components designed for conventional lubricants, resulting in low performance, increased component damage and accelerated degradation of seals. These challenges are preventing widespread of EALs in the marine shipping market, and therefore an entirely new approach is needed to increase and optimize the use of these lubricants. A large number of possible combinations of materials (seals-counterparts-lubricants) for use in the maritime industry make it difficult for the industries. Thus, this project will focus at establishing a more general understanding of the effects of the additives used in the EAL and seal materials. This will enable us to build a broad toolbox that provides shipping industries the basis for choosing proper sealing and counterpart materials. Besides the aim of understanding the underlying chemo-mechanical mechanisms, a validation program will be developed to establish a realistic and targeted test program according to the industry requirements. SINTEF, along with NTNU, established their Tribology Laboratory in 2008, and now have strong competence in tribological challenges (wear, friction, lubrication). Designated tribological equipment will be used in the project to understand the degradation mechanisms of lubricant at nanoscale.