Elengy showcased its innovative work at LNG2026 in Doha
Elengy took part in the 21st edition of the international LNG2026 conference in Doha and used this opportunity to present an innovative study carried out in response to a client request: assessing the feasibility of receiving “ultra-cold” LNG — that is, LNG delivered at temperatures below current industry standards and with a higher nitrogen content.
Conventional LNG, composed mainly of methane, has an equilibrium temperature close to –160°C. Before liquefaction, the gas is purified to remove impurities and adjust its composition. However, as gas fields mature, the composition of raw wellhead gas can change, particularly with increasing nitrogen content, making it more difficult to meet usual specifications without modifying upstream facilities.
Since nitrogen condenses at a lower temperature than methane, gas with higher nitrogen content requires liquefaction at an even lower temperature. To avoid complex and costly investments, some producers are now considering delivering colder LNG, potentially reaching –165°C with up to 1.5 mol% nitrogen.
In response to these developments, Elengy analyzed the possibility of receiving this non‑conventional LNG at the Fos Cavaou LNG terminal. Simulations showed that the main challenge is condensation in the annular space (the space between the inner and outer tanks of LNG storage tanks).
LNG tanks—consisting of a metallic inner wall, porous insulation, and an external concrete shell—are particularly sensitive to very low temperatures. When LNG at –165°C is unloaded, the inner wall can drop below the normal methane boiling point (–161.5°C). In such conditions, the BOG present in the annular space may condense, posing a potential risk to the integrity of both the insulation and the concrete shell.
Two mitigation options were studied: reducing tank pressure and injecting nitrogen into the annular space. The latter, theoretically promising, could lower the condensation temperature of the BOG. However, reaching the required nitrogen concentration would take around 10 days of continuous injection, with no guarantee of success due to convection movements within the annular space. At this stage, the level of uncertainty remains too high to consider this solution operational.
In conclusion, this in‑depth study once again demonstrates Elengy’s ability to listen to its clients and thoroughly analyze their operational needs. By exploring ambitious technical scenarios and evaluating innovative solutions, Elengy’s teams reaffirm their commitment to anticipating LNG market developments and adapting proactively.
Although annular condensation remains a critical challenge today, the work carried out illustrates Elengy’s continuous improvement approach and its dedication to developing safe, reliable, and high‑performance solutions. By pursuing these research efforts and maintaining dialogue with producers, Elengy continues to support the transformation of the global LNG market while guaranteeing the safety and integrity of its infrastructures.