“In the future, a substantial portion of combustion will be replaced by electricity-based technology, such as heat pumps and electric boilers,” said Joonas Kattelus, chief technology officer, Oilon Group. “This is especially true in low-temperature applications. There are still many applications where combustion is necessary. In ships and planes, for example, fuels are an excellent way to store energy. They can also be used to balance out the supply and demand for heating. In such applications, replacing fuels exclusively with batteries is not sensible. Correspondingly, process and industrial applications will continue to require the high output temperatures provided by combustion technology far into the future.

Fuel is the single largest factor

As a rule, gaseous fossil fuels generate lower emissions than liquid fossil fuels. When fired, fuel oils release not only CO₂ but also sulfur dioxide, nitrogen oxides, and various particulate emissions, such as soot. Compared to oil, natural gas burns cleaner, and it has zero sulfur dioxide and soot emissions.

According to Kattelus, the majority of the company’s portfolio was recognized as sustainable. This included all products that fire sustainable fuels, traditional and low-NO_x natural gas burners, and startup and support burners delivered to waste incineration facilities and plants that utilize biofuels.

“This breakdown was based on the idea that if we replace coal combustion with natural gas in China, for example, we achieve a massive one-off reduction in NO_x, particle, and CO emissions,” he said. 

Kattelus estimates coal combustion generates roughly twice as much CO₂ as firing natural gas.

Like any fossil fuel, natural gas combustion does produce CO₂ emissions, which increases and intensifies the greenhouse effect. According to Kattelus, Oilon has managed to reduce the other emissions to such a low level that combustion itself is extremely clean.

Russia’s war of aggression against Ukraine has dramatically changed the global energy landscape. This shift speaks for phasing out natural gas as an energy source. The idea is further supported by the fact that renewable fuels typically have lower CO₂ emissions than fossil fuels.

“Currently, governments around the world are especially interested in hydrogen,” Kattelus said. “Hydrogen can be produced through electrolysis with sustainable electricity, such as wind power. In this application, it serves as a form of energy storage.” 

From the combustion standpoint, hydrogen is clean, as its combustion product is water. However, hydrogen burns very intensely and with a hot flame. The hotter the flame, the more harmful nitrogen oxides, or NO_x compounds, are formed. In Oilon ACE burners, NO_x emissions are minimized with combustion air and fuel staging, which results in a wide, cool flame. Additionally, the flue gases generated during combustion are directed back into the flame inside the boiler, further cooling down the flame.

Hydrogen is not a foolproof solution. Current infrastructure is unsuitable for hydrogen storage and transportation without extensive retrofits, and hydrogen requires additional attention to safety. One alternative to clean hydrogen is synthetic methane made from hydrogen. Methane has almost the same exact properties as natural gas, which allows it to be used directly in current systems. Hydrogen can also be used to produce ammonia, which is completely free of CO₂ emissions. Ammonia is not without its problems: It is toxic and has high NO_x emissions.

“Operators in the Far East seem to be especially interested in ammonia,” said Kattelus. “In Japan and South Korea, people are investigating new solutions. In large coal plants, ammonia is seen as a fuel of the future, and many boiler manufacturers have already asked if their boilers could be converted to ammonia use.”

Adopting renewable fuels requires investments. According to Tapio Murtonen, chief business officer, Oilon, if you want to use another fuel in an Oilon industrial burner, a new burner is typically required. In process and power plant burners, a less extensive retrofit is required.

“In a typical retrofit project, we will install the necessary fuel lances and valve units and make some adjustments to the automation,” added Murtonen.