Industrial furnaces differ from boilers in two ways that matter: the flame and its combustion products often contact the product directly, and much of the heat transfer is radiant. Both change when moving to hydrogen.
The specific advantage in furnaces: hydrogen combustion produces only water vapour. No CO₂, no soot, no sulphur, no particulates. In baking, ceramics, heat treatment and food drying, that means the product no longer contacts fossil combustion products.
The difference almost nobody mentions: radiation
A natural gas flame is luminous because it carries incandescent soot particles, and those particles radiate heat very effectively. A hydrogen flame produces no soot: it is nearly transparent, radiates less in the visible and near-infrared, and transfers a greater share of its heat by convection.
In a boiler this is barely noticeable. In a furnace where heating is predominantly radiant, the temperature profile can shift. The remedy is not complex — readjusting burner geometry and position, revisiting zone control — but it must be designed in. Projects that ignore this end up with uneven heating and a disappointed customer.
Furnace atmosphere: the other side of water vapour
- Processes where it helps or is neutral: baking, where steam is desirable in the early phase; most heat treatment; glass melting; many ceramic firing curves.
- Processes needing evaluation: precision drying, humidity-sensitive ceramic firing and controlled-atmosphere processes. Here extraction is resized or the process moves to indirect heating.
Suitability by furnace type
| Furnace type | Suitability | What to check |
|---|---|---|
| Baking and food | Very high | Steam usually beneficial; removes combustion product contact |
| Industrial drying | High | Resize extraction for added humidity |
| Ceramics and brick | High | Firing curve and high-temperature refractory |
| Metal heat treatment | High | Atmosphere and zone control |
| High-radiation furnaces | Medium | Burner redesign for lower flame radiation |
How to convert without stopping production
- Measure. Actual furnace consumption, temperature curve and a product quality baseline. Without a baseline there is no way to prove savings later.
- Convert one zone or one shift.
- Run a complete cycle and compare consumption, uniformity, quality and cycle time against the baseline.
- Scale on your own data, not on a supplier's projection.
What to ask any supplier, including us: how many kilowatt-hours of electricity per kilogram of hydrogen produced, under what measured conditions, and how much additional electrical capacity the plant must contract. Without those three figures, no savings calculation is verifiable.
Frequently asked questions
Can hydrogen be used in furnaces where the flame contacts the product?
It depends on the product. Hydrogen combustion yields only water vapour, with no CO₂ and no soot, which in food and ceramic furnaces removes contamination from combustion products entirely. But that same water vapour raises humidity inside the furnace, and humidity-sensitive processes such as certain drying and firing curves need evaluation or a move to indirect heating.
Why might my furnace heat differently on hydrogen?
Because of flame luminosity. A natural gas flame contains incandescent soot particles that radiate strongly; a hydrogen flame produces almost no soot, radiates less and transfers proportionally more heat by convection. In furnaces where heating is predominantly radiant, the temperature profile can shift and burner geometry or zone control must be readjusted.
What happens to the refractory lining?
Increased water vapour in the furnace atmosphere can affect certain silica-alumina refractories at high temperature. In most industrial installations this is not an issue, but in high-temperature furnaces the installed refractory specification should be reviewed before conversion.
Can conversion start with a single zone?
Yes, and it is usually the best way to start. In multi-zone furnaces one zone is converted first, then fuel consumption, temperature uniformity and product quality are measured across a complete production cycle. The rest is decided on your own data rather than on a supplier projection.
How long does a furnace conversion take?
The physical work on the burner and instrumentation is measured in days and normally fits inside an already planned maintenance shutdown. What sets the real schedule is the preparatory phase: measuring current consumption, sizing the electrolyser and validating available electrical capacity.
Talk to the engineers who build it
We manufacture the equipment in Medellín, Colombia, and we size it against your actual thermal load — not a generic brochure figure.
Contact the team