Reinventing regasification

Online Editor

John Bell discusses how digital twin technology can optimise LNG regasification terminals and the implications for European energy security and net-zero ambitions

Regasification is the process of converting liquified natural gas (LNG) back to natural gas at atmospheric temperatures. Since natural gas is often located thousands of miles from where it is needed, it must be cooled to around -162°C and transported by refrigerated ships as a liquid. When the refrigerated LNG arrives at its destination, it is converted back into a gaseous state in specially built terminals, called regasification terminals.

Regasification of LNG plays a critical role in the global economy. Natural gas, much of which is liquified and regasified before use, accounts for around a quarter of global energy generation. In 2021, Europe imported 155 billion cubic metres of natural gas from Russia, almost 40% of its total gas consumption. However, since it invaded Ukraine in early 2022, Russia has reduced its natural gas exports to Europe and indefinitely shut down the Nord Stream 1 pipeline.

Therefore, Europe is trying to wean itself off Russian natural gas, and one way it is doing so is by buying more LNG from other producers. However, there is a significant issue. While there is enough LNG on the market, regasification terminals in Europe can only regasify around half of the natural gas the continent needs.

European countries are building more regasification terminals quickly to convert LNG into natural gas. For example, Germany, the biggest buyer of Russian gas in Europe, has just announced a fifth floating terminal to increase capacity. Unfortunately, this increase in infrastructure risks locking in future emissions, seriously undermining Europe's transition to net zero emissions. Also, operators are running existing terminals at full capacity due to the need to regasify as much LNG as possible. Pushing these assets harder than they have ever been pushed increases the risk of an issue arising, leading to the temporary shutdown of the asset or, worse, a significant safety issue.

Digital twin technology offers a solution

How can Europe reduce its reliance on Russian gas in the short term without risking the safety of existing regasification plants through overuse? How can the continent increase natural gas production without compromising its long-term net-zero ambitions?

One solution is to increase operational efficiency to extend the lifespan of current regasification terminals to avoid building new ones. Regasification plants can be optimised using digital twins, virtual representations of a physical, real-world object. To create a digital twin of an asset, engineers first build a detailed model and then pair it with data, including inspection and sensor data. This data is then fed into the model to create a structural digital twin which can run near real-time simulations, analyse performance issues and suggest improvements that engineers can make to the original asset.

Digital twin technology can help operators of regasification terminals overcome a significant challenge. As a result of cumbersome legacy technology, current asset integrity management tools offer an incomplete picture of the integrity of the condition of assets.

In contrast, due to the fact it is fed with near real-time data from the asset, digital twin technology provides a clear picture of asset health which operators can use to pinpoint safety critical issues down to the square cm. Such detail offers a more effective, data-driven approach, which allows operators to fix problems before they escalate. As a result, digital twin technology can reduce regasification terminal downtime and maximise uptime, allowing the asset to produce more natural gas to meet Europe's needs.

Successful deployment

Digital twins have already been successfully used to improve the efficiency of European regasification plants. For example, Akselos is currently using digital twin technology to optimise a major European regasification terminal that is crucial for the continent's energy security.

In the project's first phase, Akselos is building a digital twin of an open rack vaporiser (ORV), a critical component of the terminal, which uses seawater flowing on the surface panels of numerous heat exchanger tubes to vaporise LNG to be regasified.

It is hoped that the digital twin can help identify stressed pipes in ORV, a widespread issue. Some pipes become stressed due to regasification and bend out of shape. In other cases, pipes can maintain their shape but come under high pressure if they are located next to the area of natural gas output.

These issues are significant as, if left untreated, they can worsen, causing unplanned downtime or even a full-scale breakdown of the ORV. Akselos' digital twin will allow operators to address the issues before they escalate, maximising uptime and increasing the flow of natural gas to a continent in desperate need.

Looking ahead

LNG terminals contain multiple ORVs, which could be analysed using digital twin technology in the same way as Akselos' project. Were these digital twins built, issues may be found that could be resolved in advance to mitigate unplanned downtime, improve asset efficiency and increase natural gas output.

Additional opportunities exist to optimise regasification terminals using digital twin technology beyond ORVs. Regasifier terminals contain other components vital to their successful operation, including compressors, gas turbines and water pumps, which could be enhanced using digital twin technology.

Further afield, there are currently 28 large-scale and 8 small-scale regasification terminals in Europe, with more potentially on the horizon. Operators could use digital twin technology to increase their efficiency, which would, in the long term, help Europe regasify more natural gas to ensure its energy security without undermining its net zero ambitions.

John Bell is with Akselos

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