There is plenty of enthusiasm around hydrogen as a possible alternative fuel to natural gas in combustion processes. Some hope it can eventually replace natural gas in applications such as utility boilers. However, any transition to 100% hydrogen has plenty of challenges to overcome due to it having such fundamentally different combustion characteristics. This gives rise to safety, pollution, performance, and operational issues.
Consequently, hydrogen blends are seen as a more realistic objective, at least over the short term. Current burners and boiler infrastructure can successfully accommodate a few percent by volume of hydrogen. For larger blends, modifications may be needed.
Due to the decarbonization benefits that could be realized by switching from natural gas to hydrogen, many utilities, power producers, and industrial sites are investigating the concept of at least blending some hydrogen into their systems. Let’s take a look at the realities of hydrogen firing in boilers and any changes that might have to be made.
Long History
Far from being new and novel, boilers have been running on hydrogen for many decades. Hydrogen-based boilers are often found in refineries and chemical plants where hydrogen is available as a byproduct of other processes.
The logic behind this is simple. If the hydrogen is there, why waste it when it can be used in boilers as a way to reduce the overall fuel bill for the facility? Consequently, best practices already exist for the firing of hydrogen and hydrogen blends in industrial boilers.
“Most manufacturers have experience in dealing with the nuances of hydrogen and can advise you on how best to burn it by itself or in combination with natural gas,” said Gerardo Lara, vice president of Fired Boiler Sales at Rentech Boiler Systems Inc. of Abilene, Texas.