Ozone destruct units are used to convert residual ozone gas back into oxygen before discharge.
They are commonly used on ozone contact tanks, off-gas lines, enclosed ozone processes and
industrial ozone systems where excess ozone must be safely managed.
Ozone destructors are not selected by ozone generator size alone. The correct unit depends on
the actual off-gas conditions, including gas flow rate, ozone concentration, humidity, temperature,
pressure drop, duty cycle and discharge arrangement.
Ozone destruct units help manage ozone-containing gas from contact tanks, treatment chambers,
off-gas lines and other process points before the gas is discharged.
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Selected around the duty
Selection depends on the off-gas flow rate, ozone concentration, humidity, temperature,
operating pattern and installation conditions.
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Part of safe system design
A destructor should be considered alongside ventilation, ambient ozone monitoring,
alarms, interlocks and safe discharge routing.
Ozone destructors for off-gas control
In many ozone systems, not all ozone is consumed within the process. Some ozone may remain in the gas phase
and leave the treatment zone as residual ozone or off-gas. This is especially common in ozone water treatment
systems where ozone is injected into water and any undissolved gas is separated or vented from a contact tank.
An ozone destructor provides a controlled method of breaking down this residual ozone before discharge.
In simple terms, it helps convert ozone (O3) back into oxygen (O2).
Where ozone destruct units are used
Ozone destruct units may be required in a range of commercial and industrial ozone systems, including:
ozone contact tanks
ozone water treatment systems
process water and wastewater systems
food processing and hygiene systems
aquaculture and recirculating water systems
laboratory and pilot ozone systems
enclosed ozone chambers
off-gas lines from ozone injection systems
industrial ozone generator installations
Not every ozone system requires the same type of destructor. The application, off-gas condition and installation
environment all need to be reviewed before the correct arrangement can be selected.
Catalytic and thermal ozone destructors
Ozone destructors are commonly based on catalytic or thermal destruction. The most suitable option depends on the
process conditions and the nature of the ozone-containing gas.
Destructor type
How it works
Typical consideration
Catalytic ozone destructor
Uses catalyst media to accelerate ozone decomposition back to oxygen.
Gas quality, moisture, contamination and temperature must be considered.
Thermal ozone destructor
Uses heat to accelerate the breakdown of ozone into oxygen.
May be selected where process conditions require a more robust thermal approach.
Wet off-gas vs dry ozone gas
One of the most important selection questions is whether the ozone-containing gas is wet or dry.
Dry ozone gas from an ozone generator line is different from wet off-gas from a water contact tank.
Wet off-gas may contain water vapour, mist, aerosols or condensate. This can affect the suitability of
a catalytic destructor and may require moisture separation, drainage, suitable materials or a different
configuration.
Ozone destruct units should be selected around the actual off-gas conditions of the ozone system.
Selection information normally required
To identify the correct ozone destruct unit, Ozcon would normally review the actual ozone system duty rather than
selecting a unit from ozone generator output alone.
Selection factor
Why it matters
Off-gas flow rate
Determines the required gas handling capacity of the destructor.
Ozone concentration
Affects the ozone load and suitability of the destructor type.
Wet or dry gas
Wet off-gas may require moisture management or a suitable configuration.
Temperature and humidity
Can affect catalytic performance, condensation and system stability.
Pressure drop
Must suit the venting arrangement and avoid creating process issues.
Duty cycle
Continuous industrial systems may require a more robust arrangement than intermittent systems.
Discharge route
The venting location and installation environment affect safe system design.
Ozone destruct units for water treatment systems
Ozone destructors are often used in ozone water treatment systems because not all ozone gas necessarily dissolves
into the water. Any undissolved ozone may leave the contact stage and must be managed correctly.
A typical ozone water treatment arrangement may include an ozone generator, oxygen supply, ozone injection system,
static mixer or contact tank, off-gas separation, ozone destruct unit, dissolved ozone monitoring, ambient ozone
monitoring and control interlocks.
In this type of system, the ozone destructor is not just an accessory. It is part of the process safety and
off-gas control strategy.
Related ozone equipment
Ozone destructors are often specified alongside other ozone system components. Depending on the application,
the wider system may also require:
Ozone destructors should be selected around the system duty
Ozcon can help review ozone destructor requirements for ozone water treatment, process water,
wastewater, food hygiene, aquaculture, odour control and specialist industrial ozone systems.
