NewEcotube (NET) NOx Reduction System

The complete nitrogen oxide reduction (deNOx) system offered by ICS is based on a modified Ecotube System technology, developed in cooperation with the Swedish company Ecomb AB.

Between 2015 and 2023, ICS delivered NET installations for 19 boilers across Poland (including PEC Suwałki, MPEC Włocławek, PGNiG Termika Pruszków, and Energetyka Lubin). This solution, based on ICS patent no. 243551, represents a unique combination of primary and secondary NOx reduction methods, providing high efficiency while simultaneously optimizing the combustion process.

Two-stage NOx reduction technology

The deNOx system combines:

• Primary method – based on air stratification, flue gas recirculation, and combustion optimization. This enables so-called volumetric combustion, which ensures a uniform temperature distribution and better emission control.
• Secondary method – SNCR (Selective Non-Catalytic Reduction) – selective non-catalytic reduction of nitrogen oxides through the injection of a reagent (ammonia water) directly into the furnace chamber.

Thanks to the synergy of both methods, the NOx reduction process in the NewEcoTube (NET) technology is efficient, stable, and automatically adapted to the actual operating conditions of the boiler.

How the NET technology works

The NET system uses the combined injection of:

• a mixture of air and recirculated flue gases,
• and ammonia water supplied with compressed air, injected through specially designed lances located at specific levels and on the walls of the boiler.

This allows for precise control of the NOx reduction process while increasing turbulence and ensuring uniform combustion conditions.

Key advantages of the NET installation

1. Increased turbulence and flue gas homogenization – uniform temperature distribution and optimal conditions for NOx reduction.
2. Combustion stratification – separation of primary and secondary air ensures more complete combustion and reduced emissions.
3. Complete burnout of combustible compounds – lower energy losses and extended boiler component lifetime.
4. Efficient NOx reduction via SNCR method – controlled injection of a 24.5% ammonia solution provides high efficiency with low reagent consumption.

System configuration

Each boiler is equipped with:

• a process gas fan,
• a process air fan, which replace traditional secondary air fans.

The process gas (a mixture of secondary air and flue gases, or either medium separately) is introduced into the combustion chamber under a pressure of several kilopascals through the deNOx lance system, located on the front, rear, and upper boiler walls.