The transition to renewable energy sources poses various challenges. For instance, due to their volatility, there is a growing need for transporting and storing renewable energy. Hydrogen is often considered for this.
Compressor technology shows numerous applications that require oil-free compression to maintain high gas purity levels, including hydrogen in fuel cell applications. Reciprocating crosshead compressors can deliver and store hydrogen at high pressure. However, relevant sealing materials such as fluoropolymers and thermoplastic polymers for rider bands and piston rings yield significant wear and friction under high loads. Additionally, concerns have been raised about the adverse effects of the bioaccumulation and persistence of per- and polyfluoroalkyl substances (PFAS) like many fluoropolymers once released into the environment. This has led to the proposal to ban these substances within the European Union. Therefore, it is necessary to experimentally investigate the tribological behavior of self-lubricating sealing materials under realistic compressor conditions to eventually find alternative PFAS-free sealing materials with suitable oil-free tribological properties.
The paper outlines a specialized tribometer designed to analyze friction and wear of sealing materials for reciprocating compressors. The tribological system components, including the forces, movements, and gas influence the frictional behavior of material pairings. The tribometer can provide a realistic compression atmosphere while continuously monitoring friction and wear. The research helps to identify materials that endure high-pressure compression, exhibit low friction and wear, and comply with PFAS-free requirements.