TotalEnergies emphasises TBN and sulfated ash balance in gas engine oils

At a presentation during the inaugural ALIA/F&L Asia Lubricant Exhibition held in Kuala Lumpur, Malaysia, on September 9, Desmond Chan, regional head of Industrial (Inland) Lubricants at TotalEnergies, emphasised the vital role of natural gas in the global energy mix. Despite projections showing a slight decrease in natural gas’ share from 24% in 2020 to 20% by 2040, TotalEnergies reaffirmed its long-term commitment to this crucial energy source through its specialised gas engine lubricants.

Chan also highlighted the company’s crucial role in the natural gas value chain, including through specialised lubricants designed for natural gas engines. Natural gas engines have over two dozen lubrication points, where lubricants are critical for reducing friction, dissipating heat, sealing gas, preventing rust, and cleaning dirt, soot, and sludge throughout the gas engine pipeline.

A typical gas engine lubricant is made up primarily of base oil (88% to 92%), with Group II base oils being the most common. These oils are favoured for their low sulfur content and high viscosity index (VI), making them particularly suitable for natural gas engines.

Beyond base oils, Chan stressed the importance of additives that enhance lubricant performance. Key additives include detergents, which neutralise acids produced during combustion, and antioxidants, which prevent harmful chain reactions from free radicals. Anti-wear agents form a protective film that reduces metal-to-metal contact, while anti-foam agents maintain the lubricant’s integrity by releasing trapped air.

One of the most critical components, Chan explained, is the Total Base Number (TBN), which measures the level of detergent additives and the lubricant’s ability to neutralise acids. As the TBN diminishes over time, ash is produced during the neutralisation process. While ash cushions metal parts and prevents valve recession, excessive sulfated ash can lead to harmful combustion chamber deposits, causing engine knocking or detonation. Chan noted that maintaining sulfated ash levels below 1%, as required by OEM standards, is essential. 

Chan also underscored the difficulty of balancing TBN and sulfated ash levels in natural gas engine lubricants. To meet this challenge, TotalEnergies has developed the NATERIA series of gas engine oils, designed to accommodate various ash levels and gas types, ensuring optimal performance across all gas engines.