Retrofitting of NOx – reduction systems


PURItech GmbH’s reputation across the continent has grown, through our committed team with many years’ experience, an understanding of emissions systems and a desire to exceed our customer’s requirements ensures you receive the best service and know-how.

We are very proud of our contribution to combat harmful particulates and gases, the PURINOX SCRT™ – The perfect Euro VI upgrade system for Bus – Retrofit and the Backfitting of Municipal Vehicles such as refuse trucks.

We have refined Selective Catalytic Reduction Technology SCRT™  in all components, our technology achieves excellent results with conversion rates of NOx, CO, HC & PM above 95%!

We welcome you to contact us to discuss your fleet requirements and better understand how partnering with PURItech GmbH puts your needs first; from design through to fitment and aftersales support.

You can make contact via phone and email;

  • +49 7742 978 97 – 12

    UK +44 (0) 7305 662 401

  • customerservice@puritech.de

    UK neil.koston@puritech.uk

PURINOX by PURItech is suitable for Clean Air Zones, Low Emission Zones & Ultra Low Emission Zones operated by UK local governments

Economic advantages of a bus retrofit

Cleaning and maintaining the air we breathe is at the top of most government’s political agendas. Heavy duty diesel vehicles have been identified as key contributors of harmful emissions and over the last 20+ years emissions regulations have evolved to the current Euro VI standard.

Understanding the financial impact on a business to purchase a new vehicle fleet and the difficulty of recycling old vehicles, retrofitting (upgrading older vehicles with new technology) is seen as the best all-round solution.

Some governments and local authorities subsidise this cost, but even without receiving a subsidy, you can retrofit more than 15 buses for the cost of a single new bus!

With many UK cities following London’s example, with the introduction of Clean Air Zones, Low Emissions Zones and Ultra Low Emission Zones, operating vehicles that are pre-Euro VI will carry charges.

Reliable technology in PURINOX SCRT™ systems

You may already know other SCRT systems. Why choose to fit PURINOX?

  • PURINOX excels at operating in gas exhaust temperatures between 160 – 180°C, reducing NOx emissions by more than 95%, (10% more than Euro VI requirements) without the inclusion of a heating catalyst or exhaust gas flap.
  • In addition, our solution for the AdBlue™ injection eliminates crystalization.
  • The PURItech retrofit solution is a very safe investment and impresses with:
    1. Easy cleaning of the DPF
    2. Possibility to replace the SCR
  • As a result, PURINOX is the most reliable and efficient retrofit solution to bring buses from Euro 3, 4, 5 and EEV to a standard equivalent to Euro 6, both economically and technically!
PURINOX Schnittbild

Cleanliness through PURINOX SCRT™

Our system has 6 key elements to ensure emissions are effectively reduced. The adjoining sectional shows the hardware structure. The PURINOX system combines a Diesel Oxidisation Catalyst (DOC), Diesel Particulate Filter (DPF), Selective Catalytic Reduction catalyst (SCR) and an Ammonia Slip Catalyst (ASC). Additional components are the AdBlue™ mixing section and an Electronic Control Unit (ECU) which “piggy backs” your existing ECU without compromising the On Board Diagnostics (OBD) system.

  • Exhaust gases first pass through the DOC, where Carbon Monoxide (CO) and Hydrocarbons (HC) are converted to Carbon Dioxide (CO2)
  • The DPF is a porous ceramic filter, which allows gases to pass through tiny perforations in it’s walls, whilst trapping fine carbon and soot Particle Matter (PM) within it’s chambers
  • AdBlue is injected into the chamber between the DPF and SCR, which has been manufactured to create a cyclone to ensure even dispersement of the fluid which becomes ammonia at high temperature
  • The ammonia reacts with harmful Nitrous Oxides (NOx) and Nitrous Dioxides (NO2) within the SCR which converts them to harmless nitrogen and water
  • The ASC is coated to ensure that any ammonia that has passed through the SCR is emitted safely
Emission Reduction

As a result, the conversion solution from PURItech eliminates

  • Fine dust by particle number (PN) and particle mass (PM)
  • Nitrogen oxides (NOx)
  • Nitrogen dioxide (NO2)
  • Hydrocarbons (HC)
  • Carbon monoxide (CO)

almost completely.


Die NOx – Abscheidung optimieren

PURINOX - 95% NOx reduction at 160-180°C (Benchmark)