Hydrogen in Natural Gas: A Safety-Critical Application

Why moving to 20% hydrogen injection will require an even greater focus on safety 

‘Hydrogen is central to reaching net zero emissions because it can abate 80 gigatons of CO2 by 2050’. That’s according to the Hydrogen Council, who published the ‘Hydrogen for Net Zero’ report.‘ 

The Hydrogen Council is not the only body that wants to see a rapid uptake in our use of hydrogen; governments, environmentalists, NGOs and industry alike are working to replace our consumption of fossil fuels with hydrogen as a green alternative. 

At present, a significant proportion of the hydrogen we produce is generated from natural gas, using a process of steam methane reforming.  This is the so-called ‘grey hydrogen’.  If the carbon dioxide by-products from this process are captured and safely stored, then it is considered to be carbon neutral and the end product is termed ‘blue hydrogen’.  Truly ‘green hydrogen’ must be produced using renewable energy sources and a process of electrolysis.

Much of the focus has, understandably, been on how we will be able to generate and distribute hydrogen at scale, and which applications represent the best potential.  This does, however, raise another equally important consideration: the need to increase our use of hydrogen efficiently and profitably while maintaining – or, preferably, improving – safety standards. 

Hydrogen volatility 

Although hydrogen has been used as an industrial process gas for many years, its adoption as a fuel for transport, power generation and domestic gas is relatively new.  In particular, when injected into the natural gas network, it can create several potential problems.  These include: 

Explosion riskHydrogen is a volatile gas and is odorless and colorless, making it difficult to detect without specialized instruments. 

Embrittlement of metal surfaces in pipelines, compressors etc. The gas can reduce the tensile ductility of some metals, leading to stress fracture formation, with the danger of leaks occurring.

Penetration of elastomer seals Hydrogen is a small molecule, which can penetrate the elastomer seals that are widely used in pipeline equipment. If pressure is released, the hydrogen molecules can expand, increasing the risk of gas leaks.

Process efficiency Incorrect blending of hydrogen and natural gas can have an impact on the combustion efficiency of gas turbines, increasing costs and potentially creating safety risks.

The good news is that all of these issues are known and can be resolved using the appropriate materials and management technologies.  In particular, in-line monitoring of process conditions during production, distribution and combustion is critical.  This includes a range of parameters, with trace moisture measurement being one of the most important. It plays a key role in maintaining gas quality, ensuring system efficiency and safety, and supporting compliance with both commercial requirements and regulatory standards.  

Dew-point analyzers for hydrogen monitoring 

There are various technologies for measuring hydrocarbon and water dew point; some have been in use in differing forms for many years.  However, not all dew-point analyzers are suitable for use in monitoring hydrogen injection in natural gas, especially with regard to electrical safety certification.

Compared to natural gas, hydrogen has a wider flammability range when mixed with air. It also requires significantly less energy for combustion – just 0.02 milli-Joules (mJ), which is less than 10% of the energy needed to ignite natural gas (0.29 mJ). In some circumstances, even a static discharge can be sufficient to ignite a hydrogen–air mixture.  Unlike a traditional natural gas operation, it is critical that any electrical equipment used in an environment where hydrogen may be present has a high explosion protection safety level.  Not all electrical equipment – including analyzer systems – that is currently installed on natural gas sites will conform to the explosion protection (Ex) safety requirements for hydrogen. 

Careful equipment selection is therefore important.  Our latest Michell Instruments hydrocarbon dew-point analyzers, for example, are Ex certified for use in hydrogen environments without the need for modification; these include natural gas applications with at least 20% hydrogen content.  They produce extremely accurate, repeatable and consistent results and are certified to ATEX, IECEx, UKEX and NEC505 standards. 

The range includes:

Self-Calibrating Trace Moisture Analyzer - Michell QMA401

Process Moisture Analyzer - Michell QMA601 Self-Calibrating Fast Moisture Measurement

The QMA401 and QMA601 with quartz crystal microbalance system

Condumax Dew-Point Analyzer – Michell CD603

Portable Dew-Point Tester – Michell CDP301

The Condumax CD603 and CDP301 chilled mirror instruments 

We are the world’s leading experts in moisture monitoring and measurement.  We have eight different technologies covering all moisture applications, backed by unrivalled technical and customer support.  To learn more, talk to one of our application specialists today