Flameless Combustion: The Solution

Direct combustion disadvantage

Waste gas streams are often produced at low energy content (Lower Heating Values or LHV), insufficient to maintain direct flame based combustion without addition of other combustible gases. Direct combustion solutions therefore create a number of issues:

  • Additional combustible gas requirement
  • High temperature combustion zone (temperatures above 1400 °C
  • Incomplete combustion

Proprietary Technology Solution

The technology WTE-Tech has developed is based on the concept of Flameless Combustion. Flameless Combustion (FC) is a mode of auto oxidation in which oxidation takes place above auto-ignition temperature (650-700 °C) and below adiabatic flame based combustion temperatures (1950-2000 °C).

Under conditions of FC any hydrocarbon containing steam is intensively mixed with the required amount of combustion air (mixing only at the furnace inlet, no pre-mixing). In the combustion chamber, kept at temperatures above auto-ignition temperature a homogeneous oxidation reaction takes place in the gas phase, utilizing the full volume of the combustion chamber.

Preferably temperatures are kept at a level of 900- 1200 °C, in any case at temperatures below 1400 °C to avoid NOx formation.

Options for treatment / utilization


(1800+ °C)
Waste energy: High CO2


Simple design
Low invest


Continuous additional gas required
High operational cost
Highest TCO
NOx, SOx, PM pollution
High CO2

Direct Combustion

(1500+ °C)
Pollution: (NOx, PM)
Waste energy: High CO2


Effective for very low-energy off-gas (<0,5%v CH4)
Zero pollution
Good energy recovery
Only start-up gas required


Max HC content critical for safeguarding
Dilution required
Big volumes / system
Higher investment
Contaminant sensitivity

Flameless Combustion

(1000+ °C)
Pollution: Zero
Waste energy: Minimum CO2


Effective for wide range HC content (1,5-15%v CH4)
Zero pollution
Max energy recovery
Only start-up gas required
Compact furnace design
No safeguarding risk
Lowest TCO
No contaminant sensitivity


Higher investment