Novel Routes for cost-effective Environmentally Acceptable Lubricants

Lubricants are essential for a wide range of industries (from textiles to the navy, household, metal forming, etc.). Along with the ever-increasing consumption of lubricants, there are concerns about their sustainability at the level of production, use, and impact on the environment. Despite the many chemical pathways for preparing environmentally friendly lubricants (EAL), there are still not enough fully compatible with system components such as seals, bearings, or commonly available coatings/materials to replace mineral oils.

Currently, available EAL formulations that could address the current challenges cannot enter the market due to the high costs of raw materials from which they are made. Limited EAL compatibility and high manufacturing costs are critical factors hampering the broader use of current EAL formulations in many markets.

The REAL project will focus on the maritime industry and, more specifically, on stern propeller lubricants. Shipping is an important segment supporting the worldwide circulation of goods and raw materials. When lubricating the propellers, oil regularly leaks into the surrounding water. The current regulation (VGP-Vessel General Permit) prohibits ships sailing into American waters from using non-ecological lubricants that pollute their waters. Additional restrictions are gradually being added to this restriction, creating economic pressure to use environmentally acceptable EAL lubricants. More than 80,000 vessels are currently affected.

The current EAL in this application faces three main disadvantages compared to the mineral oils used so far:

• Poor hydrolytic stability: the penetration of seawater into the propeller housing creates an acidic environment that accelerates the corrosion of internal metal parts and accelerates the formation of sludge.
• Significant change in viscosity with change in pressure and temperature: poor lubrication performance under load (reduction of lubricant viscosity due to shear instability) of existing EALs has led to a significant increase in propeller bearing failures. It is a substantial problem in the market, and new solutions need to be implemented as soon as possible.
• The non-Newtonian character (dilettant fluid) of some EALs causes an increased number of propeller failures