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Nozzles and spray lances for pollutant abatement

Spray solutions for reducing nitrogen oxides, sulfur oxides, and other pollutants in industrial flue gas: from DeNOx denitrification to DeSOx desulfurization, through to flue gas conditioning with water vapor.

Treating gaseous emissions is now an essential requirement for power plants, cement plants, waste incinerators, chemical plants, and merchant vessels.

Increasingly stringent environmental regulations impose strict limits on nitrogen oxides (NOx), sulfur oxides (SOx) and other acidic compounds, pushing operators to integrate effective, reliable abatement systems into their production processes.

At the heart of these systems are nozzles and spray lances: seemingly simple components on which the efficiency of the entire process actually depends.
Poor reagent distribution, an uncalibrated droplet spectrum, or a lance positioned at the wrong point of the duct can drastically reduce abatement effectiveness, increase reagent consumption, and cause maintenance issues.

We design and manufacture nozzles and spray lances for three key applications in pollutant abatement:

DeNOx

Reduction of nitrogen oxides

DeSOx

Reduction of sulfur oxides

Treatment of fumes from industry using steam from water

Cooling and humidification of gases to support abatement and filtration processes

Thanks to an engineering-driven approach backed by CFD simulations and laboratory testing, we can calibrate droplet spectrum, flow rate and injection geometry according to the specific conditions of each plant, giving operators a single point of contact for the entire flue gas treatment process.

Industries

Nozzles and lances for DeNOx denitrification

DeNOx reduces nitrogen oxides (NOx) present in flue gas by injecting a reducing agent (ammonia water or urea solution) directly into the gas stream. The reagent reacts chemically with NOx, reducing it to nitrogen and water vapor.

Process effectiveness depends on two critical factors: the correct temperature window for injection and an optimal droplet spectrum that ensures uniform mixing between the reagent and the flue gas without excess unreacted ammonia (NH3 slip).

Main DeNOx processes

SNCR | Selective Non-Catalytic Reduction

The reagent is injected directly into the hot flue gas, at temperatures between 950°C and 1,050°C.

SCR | Selective Catalytic Reduction

The reagent is injected at lower temperatures, between 300°C and 400°C, before reacting on a catalyst. Enables higher abatement efficiency.

Denitrification in long kiln

A special application of the SNCR process, with multi-stage injection, typical of rotary kilns in cement plants.

Nozzles and systems for DeSOx desulfurization

DeSOx reduces sulfur oxides (SOx) and other acidic compounds, such as hydrochloric acid (HCl) and hydrofluoric acid (HF), present in flue gas.

The principle is similar to DeNOx: a reagent — typically a lime/limestone suspension or slurry — is injected into the gas stream to chemically neutralize the pollutants.

DeSOx is also central to the maritime industry, where EGCS (Exhaust Gas Cleaning System) scrubbing systems are used to reduce sulfur oxides in marine engine exhaust gases to comply with IMO regulations.

Discover our solutions for the maritime industry

Main DeSOx processes

Wet desulfurization

Injection of a lime or limestone suspension into an absorber, for maximum removal efficiency.

Semi-dry desulfurization

Injection of lime slurry into the spray absorber, with lower water consumption than the wet process.

Dry desulfurization

Cooling and humidification of the flue gas to support the separation of SOx and HCl in dry-circulation scrubbers (covered in more detail in the following section dedicated to water vapor conditioning).

Dilution and conditioning of industrial flue gas with water vapor

Before reaching DeNOx, DeSOx systems or filters, industrial flue gas is often cooled and conditioned by injecting atomized water or water vapor.
This process, also known as gas cooling & conditioning, is not just a preliminary step; it directly impacts the efficiency of the entire downstream abatement system.

Why flue gas conditioning improves pollutant abatement:

Protects downstream filters

Lowers flue gas temperature before it reaches bag or electrostatic filters, preventing damage.

Increases dust capture efficiency

At lower temperatures, dust particles have a greater capacity to absorb pollutants such as mercury.

Reduces reagent consumption

Bringing the flue gas closer to the dew point increases the reaction potential between hydrated lime and SOx, reducing the amount of reagent required.

Lowers energy consumption

A smaller flue gas volume reduces the workload on the induced draft (ID) fan.

This application is particularly common in cement plants, where flue gas conditioning simultaneously supports the removal of dust, mercury and sulfur oxides, helping reduce both emissions and operating costs.

The difference from generic cooling lies in the objective: here, flow rate, temperature, and droplet spectrum are calibrated specifically to support downstream pollutant abatement, not just to lower the flue gas temperature.

How to choose the right nozzle for industrial emission abatement

Choosing the correct nozzle depends on several technical factors, specific to each plant:

Required reagent flow rate
Droplet spectrum needed for reaction or evaporation
Available pressure drops in the line
Chemical compatibility of materials with the reagent used
Duct or stack geometry and dimensions

Our technical team supports operators in designing the most suitable injection system, using CFD simulations and laboratory testing to validate spray distribution before installation.

Request a CFD simulation

Recommended nozzles for DeNOx, DeSOx and water vapor treatment processes

Spray lances

PNR Italia spraying lances are flexible and adaptable tools to every customer’s need and guarantee optimal positioning and alignment of the spray in the fume ducts.

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Related case studies

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Giovanni Zorzoli

Cooling, humidification & DeNOx specialist

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