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Decarbonisation is high on agendas for 2022, worldwide agreements have been put in place to phase out fossil fuels. With this, the pursuit of a carbon neutral energy industry is well underway, but is the pipeline industry prepared? Hydrogen is at the forefront of this shift, helping to reshape the energy industry and holding the key to reaching climate change targets for several organisations. At COP26, hydrogen featured heavily in carbonfree pledges. According to the International Renewable Energy Agency (IRENA), hydrogen-based fuels will be pivotal, eventually making up to 60% of the energy mix by 20501. The increasing requirement to transport hydrogen and hydrogen blends will have a significant impact on the pipeline industry. Transporting hydrogen by pipelines is the most cost-effective method for the energy industry in the long run as outlined by the World Economic Forum2. Pipeline operators had previously looked at meeting future energy demands using natural gas from traditional sources like domestic production, imported gas and liquefied natural gas (LNG). This move to hydrogen presents pipeline operators with core questions like:
• How will the existing pipeline
infrastructure cope with the increased volumes required to meet energy demand?
• How can we manage unplanned
events like compressor outages or supply failure?
• How does an operator keep track
of the blended gas quality to ensure customer delivery is on-spec?
Pipeline simulation is capable of accurately modelling different blends of hydrogen and can be used as a powerful decision support tool to answer all these questions and more. This helps to not only keep the pipelines running safely, but to also optimise the transition to hydrogen by removing guesswork and areas of uncertainty for pipeline operators.
Hydrogen modelling in pipeline simulation
Core challenges hydrogen presents
Accuracy
Although hydrogen is an excellent opportunity for the energy industry to decarbonise, it also presents pipeline operators with some core challenges. Pipeline simulation can be used offline for planning, capacity analysis and detailed transient studies or online using real-time data from DCS and SCADA systems. Here, we’ve outlined some of the ways these capabilities will be key to overcoming the challenges of hydrogen.
When selecting pipeline simulation software for modelling hydrogen and hydrogen blends, there are two main aspects to consider: accuracy and useability. 1. Equations of state
Hydrogen/natural gas blends need to be accurately modelled all the way from 0% to 100% hydrogen. Older equations of state are based on the critical properties of the individual components, therefore they do not include interaction coefficients for hydrogen. Modern cubic equations like GERG2004 are explicitly fit to the behaviour of mixtures, including hydrogen blends. 2. Pipe equations
Pipe equations determine the friction factor of a pipe or how much pressure drop there will be due to friction for a given flowrate. Panhandle was specifically developed for natural gas and is restricted to a specific range of pipe diameters. The Colebrook-White equation is known to be accurate for hydrogen blends. The fluid doesn’t have much impact on the friction factor if there’s either single-phase liquid or singlephase vapour flow. Useability
This can be difficult to quantify so objective tests are required. This can be a time-consuming process once you have established why you need the application, evaluate the time it takes to get the results required, and the level of expertise required. Most users of the system would benefit from built-in applications and an intuitive user interface to get the best out of a simulation system.
Understanding if existing infrastructure will cope Many hydrogen projects will feature repurposed natural gas pipelines. A group of European pipeline operators in Germany has unveiled plans to build a 1,200km hydrogen grid by 2030 with 90% of the project focused on using existing natural gas pipelines (Recharge News)3. A blend of 25% hydrogen will reduce the energy density of natural gas by approximately 15%. This means that volumetric demand will need to increase by 15% to meet the same energy demand. Take a pipeline currently transporting natural gas for example, pipeline operators need to know if the network will cope with future demand and how hydrogen will impact capacity. A pipeline capacity could be constrained by:
• Supply locations • Network topology • Demand pressure requirements
eg at the extreme of a network with an industrial consumer with a minimum delivery pressure requirement of 3,500 kPa
• Compressor capacity to cope with increased volume
References Get in touch Share your news and views... 1 https://www.irena.org/newsroom/pressreleases/2021/Oct/Green-Hydrogen-Fuels-to-Enable-Up-to-80-of-Global-Shipping-Emission-Cuts-by-2050-removed 2 Email newsdesk@the-eic.com • Phone +44 (0)20 7091 8600 https://www.weforum.org/agenda/2020/12/can-we-crack-the-hydrogen-puzzle-this-time-around/ 3
https://www.rechargenews.com/transition/german-pipeline-operators-present-plan-for-world-s-largest-hydrogen-grid/2-1-810731