Reference · France · 2026

SNCR system on a 2.5 MW biomass boiler – France

Turnkey DeNOx SNCR system for a newly installed biomass boiler: two injection lances, dosing skid with PLC control panel, urea solution storage and preparation. NOx limit met at the acceptance measurement.

Ecotherm SNCR dosing skid with two metering pumps and lance cooling blower – 2.5 MW biomass boiler, France

2.5 MWThermal capacity

< 300mg/Nm³ NOx at stack

2Injection lances

Oct 2026Commissioning

The project

Ecotherm delivered a turnkey DeNOx SNCR system for a 2.5 MW biomass boiler installed in France. The goal was to bring nitrogen oxides down from 450–500 mg/Nm³ to below 300 mg/Nm³, referred to 6% O₂: a 33–40% reduction, well within the operating range of SNCR technology, with no catalyst and no changes to the flue gas line downstream of the boiler.

We handled supply, installation, connection to the boiler and commissioning, including dosing calibration and operator training. At the acceptance measurement in October 2026, NOx emissions were within the required limit.

How the system works

Injection into the boiler

Two atomising lances inject the urea solution into the post-combustion zone, where the flue gas is between 850 and 950 °C – the window in which the reaction with NOx is most effective. The lances are cooled by a dedicated blower; each line has a pressure gauge and a flow meter to check the flow rate.

Dosing skid

The metering pumps, with stainless steel pump heads, are driven by frequency inverters, with safety valves and pulsation dampeners on the delivery line. The electrical panel with PLC and operator panel is mounted directly on the skid, together with the cooling blower.

Reagent storage and preparation

Urea and demineralised water are stored in 1,000-litre IBC containers with transfer pumps and level monitoring. A mixing unit with agitator and automatic dosing prepares the solution to be injected.

Control

Dosing is automatic and adjusts to the emissions measured at the stack.

Turnkey scope of supply

Urea and demineralised water storage: transfer pumps, multi-level monitoring, connection piping
Mixing unit: automatic dosing, electric agitator, stainless steel frame
Dosing skid: inverter-driven metering pumps, safety valves, pulsation dampeners
Injection: 2 atomising lances, cooling blower, pressure gauges and flow meters
Control panel: PLC with operator panel, wired on the skid
Piping: stainless steel urea line to the lances
Installation and connection to the boiler
Commissioning: dosing calibration and operator training

Plant data

Technical data

Sector	Biomass boiler
Country	France
Technology	SNCR – selective non-catalytic reduction
Thermal capacity	2.5 MW
Flue gas flow	≈ 5,000 Nm³/hdry, 6% O₂ – design value
Inlet NOx	450–500 mg/Nm³6% O₂ – design value
Stack NOx limit	< 300 mg/Nm³6% O₂
Result	Limit metacceptance measurement, October 2026
Injection points	2 lances
Reagent	40% urea solutionconcentration set from the PLC
Scope	Turnkey
Commissioning	October 2026

Reagent

Urea concentration set from the PLC

This plant runs on a 40% urea solution. The mixing unit automatically prepares the solution in the ratio set by the operator on the panel: if the available reagent changes – for example 32.5% technical-grade urea – the concentration is simply updated in the PLC, with no mechanical changes.

More concentrated solutions crystallise at higher temperatures, around 0 °C at 40%: this is why storage and preparation are installed in a frost-protected room.

Plant photos

SNCR dosing skid with PLC control panel and operator panel – biomass boiler, France — Dosing skid with PLC panel and operator panel.

Urea solution storage in IBCs with mixing unit, agitator and containment basin – SNCR system, France — Urea storage in IBCs: mixing unit with agitator on the left, storage tank on its containment basin on the right.

Two SNCR urea injection lances installed on the 2.5 MW biomass boiler, with pressure gauges and atomising lines – France — The two injection lances on the boiler, with pressure gauges on the urea and atomising air lines.

Need to bring a biomass boiler within NOx limits?

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