Gas quality tracking in the era of decarbonization

As the global energy landscape evolves, gas quality issues are becoming more prominent due to the diversification of supplies, e.g., new LNG terminals, unconventional gas sources, and decentralized green fuel injections (hydrogen, substitute natural gas).

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The global energy landscape is rapidly evolving and is likely to transform more in the next ten years than it has over the past hundred. In fact, the primary driver for this change – decarbonization, is considered to be one of the biggest transformations in modern history, on par with the industrial revolution, electrification, and computerization. But as the world’s energy sector moves away from fossil fuels, oil & gas companies are faced with unique opportunities and novel challenges that they need to address in transformative ways. 

For example, one of the tenets of the decarbonization effort is to replace traditional fuels like natural gas with substitutes like biomethane and hydrogen. But not all gasses are the same. The calorific value of biogas is usually 5-10 % lower than that of natural gas while the thermal content of hydrogen is approximately one-third that of natural gas when compared volumetrically. So, in the case of hydrogen blending, the traditional natural gas user will need to burn more hydrogen molecules than natural gas molecules to meet the same energy need. The challenge is compounded further by the fact that the vast majority of the existing equipment were optimized for natural gas, not hydrogen blends, and definitely not pure hydrogen. In other words, gas operators must not only make sure that they are transporting the natural gas blended with hydrogen safely but also that it is still suitable for stoves, heaters, boilers, and other equipment being used by customers. 

The shift to decarbonization means that operators now need to track the thermal values or heat content of the gas being delivered, ensuring that it stays within the acceptable range. Gas quality tracking is certainly nothing new, but the need for it is growing rapidly. Gas quality issues are becoming more prominent due to the diversification of supplies, e.g., new LNG terminals, unconventional gas sources, and decentralized green fuel injections (hydrogen, substitute natural gas).

Hydraulic modelling vs statistical modelling

Operators have the choice of simplistic statistical methods or hydraulic modelling to perform Gas Quality tracking. While statistical methods on the surface may seem like a quicker and easier option, this can also be misleading. In a bid for haste and simplicity, operators could potentially overlook three major benefits that hydraulic modelling brings to the table.  

First, every gas distribution company already performs hydraulic modelling and has done so for decades. They have already invested in the software and have the expertise in-house, so why not leverage this investment to also perform gas quality tracking? In other words, why onboard another type of model and procedure when you already have one that can be enhanced to perform the function?  

Secondly, hydraulic models also offer information that statistical models never will, such as pressure and flowing velocity at the delivery sites. These details help operators make more informed decisions when planning their network operations, especially to ensure they are transporting the blended hydrogen gas safely. For example, a hydraulically based gas quality tracker would display thermal values for gas at the deliveries along with delivery pressure. A statistical gas quality tracker would be ignorant of delivery pressure.  

Thirdly, since modelling is a daily task, and the hydraulic models are kept up to date, the models feeding the gas quality tracker are always relevant. In other words, the gas quality tracker will not become outdated because the models keep pace with system changes. Statistical method models may not be able to do the same.

Improve efficiency, empower your energy transition with DNV

To meet market needs, DNV has been researching ways to offer gas quality tracking information in a way that can be easy for non-engineers and non-hydraulic modelers to use. Our subject matter experts work with grid operators to empower them to operate their grid flexibly and more efficiently as they prepare for blended gases and multiple sources.   

By creating a simplified interface and “wrapping” that around our hydraulic engine, a bespoke gas quality tracker can be created relatively quickly. For those familiar with the DNV hydraulic products, this is done by using the Synergi Gas Solver, which consumes the Synergi Gas hydraulic models created by the companies’ modelling subject matter experts.

Synergi Gas Solver is of course not limited to Gas Quality tracking. It can be leveraged for an almost unlimited array of engineering and operations tasks such as capacity calculations, decommissioning strategies, and other timely challenges. Moreover, Synergi Gas Solver can be programmed using a variety of modern languages such as C#, C++, and Python as well. By using Python and leveraging the multitude of libraries the Solver is accessible without the need for sophisticated programming skills. As the market continues to evolve, we look forward to working with our customers to learn more about their requirements for gas quality tracking and showing them how to leverage the same hydraulic modelling program they have relied on for decades!  So, if you are seeking to get the most out of your Synergi Gas application and unleash the potential of Solver for Gas Quality Tracking, simply drop me a note at kevin.hemingway@dnv.com or reach out to your local DNV rep and we will get back to you.