DNV GL introduces new tool to facilitate LNG fuel adoption

DNV GL has developed a new online tool called PKI Methane Number Calculator that is effective to match fuel quality with the engine requirements.

LNG usage can reduce greenhouse gas emissions, however, its varying composition is the main hindrance towards its widespread acceptance. Unsuitable LNG usage can lead to engine damage and failure.

The PKI (Propane Knock Index) Methane Number Calculator can reduce this barrier. The tool can be incorporated to a wide range of engine types and also the entire supply chain by engine manufacturers, ship and truck owners and traders.

DNV GL has developed an algorithm to quantify the effect of LNG quality on engine knock. Engine knock is the auto-ignition of the unburned fuel mixture ahead of propagating flame in the engine cylinder.

The algorithm provides accurate results of the impact of variations in fuel quality on engine knock than traditional tools.

The algorithm can be readily incorporated into an engine-control system.

DNV GL oil and gas senior vice president Liv Hovem said: “As LNG is produced at different locations around the world, using an assortment of production technologies, its composition can vary considerably.

"Determining its fitness-for-purpose can be difficult and the consequences of mismatching fuel quality to a specific ship engine can cause potentially dangerous effects such as significant loss of performance, engine shutdown and even damage.

“Knowledge of the knock characteristics of LNG fuels is therefore crucial for suppliers and traders to provide reliable and efficient products and to break down the perceived barriers of adopting LNG.”

DNV GL oil and gas head of gas quality and energy transition Johan Knijp said: “DNV GL’s PKI Methane Number Calculator applies a generic method to quantify the knock resistance of LNG. The methodology behind the knock characterisation calculator has been developed with an eye towards serving as the basis for a robust standard.”

The knock resistance of LNG features a methane number, which is similar to the octane number used in gasoline engines. Users need to enter LNG composition information such as nitrogen, methane, ethane, propane and n-butane.

The tool will calculate a PKI methane number that can be matched with the engine specification.

Hovem stated: “Step-by-step DNV GL is facilitating the removal of barriers, hindering the safe and efficient adoption of LNG as fuel and the creation of an open and free LNG marketplace.”

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Image: DNV GL tool to improve LNG fuel adoption. Photo: Courtesy of DNV GL