Evaluation of Storage Effects on Commercial, Biodegradable, Synthetic or Bio-sourced Hydraulic Fluid

Bio-mass petroleum products are a reality. The U.S. Army has been involved in the development of biodegradable hydraulic products since the 1990s concentrating on industrial type hydraulic fluid, but will bio-based hydraulic fluids be able to stand the test of time? Executive Order 13101¹ endorses the use of bio-mass materials, to reduce dependence on natural resources, utilize renewable resources, and create a new outlet(s) for agricultural products. Even though military equipment is exempt from this executive order, the Fuels and Lubricants Technology Team (FLTT) is being responsive so that military equipment can utilize such a product without a sacrifice in performance.

This paper identifies the chemical and physical properties exhibited by bio-based hydraulic fluids before and after four to five years in storage. It is expected that the bio-based hydraulic fluids will show signs of oxidation and degradation as a result of long-term storage. The test results demonstrated that bio-based hydraulic fluids, as formulated, are not stable and degrade over time.