Challenges to overcome in the hydrogen combustion

Posted on: 01 / 01 / 2021 | 0 Comentarios | Tags: Challenges on the hydrogen combustion, Combustión de hidrógeno, Desafíos de la combustión de hidrógeno, E&M Combustión, Hydrogen combustion, Hydrogen Combustion Systems

“Challenges to overcome in the hydrogen combustion” is the title of the opinion article at the Free Tribune published by the newspaper EMPRESA XXI. Hydrogen has gained space in today’s industrial world. CEO of E&M Combustión, Iñigo Béjar, details in this article some of the challenges so that “industrial plants can use hydrogen as fuel avoiding any risks that it may pose.”

In the coming years we face a new challenge in the transformation of our energy model with decarbonisation as a fundamental element for improving the environment, but also as a new way of understanding industrial relations and improving our production processes. The element called to contribute to this change in the energy model is called Hydrogen. Various hydrogen generation technologies can make this fuel not only environmentally friendly, but also profitable in the short term. All these technologies come together in the same point of consumption: the combustion of hydrogen. For this reason, research and improvement of hydrogen combustion is presented as a fundamental aspect in its value chain.

A great challenge that we face at a time when we have not yet built new power plants or industrial plants to use hydrogen as an energy source is the adaptation of existing plants to this new fuel. Among the technical challenges that hydrogen combustion presents us are its higher flow rate and flame temperature, as well as higher NOx emissions with respect to natural gas, for example, as well as flame invisibility and greater possibility of leakage than in other fuels.

One of the aspects to take into account in the design of an installation is the low calorific value of hydrogen, so it will be necessary to redesign and adapt the supply pipes to the points of consumption. In addition, for the design of the combustion equipment we have to take into account their low density, so it is important for the design of the burners to control the speed of gas at the injection points and the possible speed of return of the flame. It is also necessary to study the adaptation of the flames in the different hearths of the boiler or thermal generation equipment to observe the consequences of a flame temperature higher than other gases.

The challenge of reducing NOx emissions

Although it is a key element for the decarbonisation of the industry, we cannot fail to observe the increase in NOx emissions – another of those known as greenhouse gases – generated by hydrogen. In fact, the reduction of NOx formation is one of the factors that will have to be worked on in the coming years. We can find ourselves before the situation that current burners, without the correction of NOx emission reduction systems, exceed the values ​​set by European regulations.

From our experience in E&M Combustion with hydrogen combustion systems we propose the flue gas recirculation to reduce the temperature of the flame and consequently decrease the thermal NOx. Another alternative that we have successfully tested is the blend with natural gas. Flame detection is also a challenge with great consequences, since hydrogen flames are invisible to the spectrum of human vision, and a fire could easily go unnoticed, so it will be necessary to use specific flame detection and flickering systems.

It will also be necessary to take all the necessary security measures in the facilities, mainly with regard to leaks. Hydrogen leaks can represent a real challenge due to the small size of its molecules, in pipes and valve connections. Finally, to minimize the risk of explosion, an effective alternative is to manufacture the burners and gas lines with elements that comply with the ATEX anti-explosive regulations.

It is foreseeable that in the coming years we will face the transformation of numerous facilities that now consume other types of fuels. It is important to have basic support in accompanying companies in the incorporation of this new fuel into their industrial processes, since although studies show that hydrogen is neither more dangerous nor more explosive than other types of gas, it persists a perception in society in this sense, so that everything we do to avoid accidents and eliminate this perception will benefit the development of this technology itself.

Iñigo Béjar, General Manager of E&M Combustion
Abstract Whitepaper Hydrogen Combustion Systems to Decarbonize Industry