2000
Installation and start up EnviNOx® test in a commercial HNO3 production plant
Uhde
Uhde
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A world-leading solution for reduction of N2O and NOx emissions
Clean air, strong impact.
The urgency of the climate crisis is reshaping how industries must act today. Greenhouse gas emissions, air pollution, and increasingly strict regulations demand innovative, sustainable solutions – not tomorrow, but now.
Nitrous oxide (N2O) is a powerful greenhouse gas – nearly 300 times more potent than CO2. Major industrial sources include processes such as nitric acid production, and removing these N2O emissions has a huge impact. With the patented EnviNOx® technology, thyssenkrupp Uhde provides tailored solutions to significantly cut N2O and NOx emissions close to zero. As NOx (nitrogen oxides) cause smog and respiratory diseases, this ensures compliance with the strictest environmental regulations while supporting climate goals.
With over a century of experience in chemical plant engineering and construction, we deliver a proven, reliable, and durable emission reduction technology. Due to its modular design philosophy, EnviNOx® integrates seamlessly into diverse industrial processes and is already in use at over 60 chemical plants worldwide. Recognized as an EU nominated Best Available Technology (BAT), EnviNOx® pays off ecologically as well as economically.
Your benefits: easy installation, cost efficiency, and rapid ROI
Seamless integration: EnviNOx® can be easily implemented in existing plants with minimal investment and low operating costs.
Tailored solutions: A modular design enables customized configurations to match your operational and business requirements.
Reliable performance: Durable, long-life catalysts and a hazard-free process minimize risks while lowering long-term costs.
Quick return on investment: Significant emission reductions and potential carbon credit revenues accelerate payback time.
What sets us apart
From first idea to complete solution: everything from a single source
With experience from over 3,000 chemical plants and projects delivered worldwide, thyssenkrupp Uhde is your full-service partner for high-performance, future-ready solutions. From initial concept to long-term operation, we deliver everything you need – engineering, technology, integration, and support.
Our EnviNOx® system is based on a set of process modules that can be tailored and scaled to your exact needs, cutting N2O and NOx emissions down to near zero. With more than 60 systems successfully installed across various industries, EnviNOx® stands for proven technology, robust quality, and smooth implementation.
We don’t just provide a product – we provide a complete solution.
Maximum abatement efficiency
Highest N2O & NOx abatement rate (up to 100%) even at low/moderate temperatures
Durable & safe
Non-toxic, long-life catalyst
We offer a broad engineering know-how in the field of chemical plants and are continuously developing solutions for a greener world.
Sounds interesting? We look forward to listening to your story, your challenge or your vision. We will be happy to answer your questions or talk about realization possibilities!
Built on experience, driven by innovation - 27 years and counting
2003
First installation of commercial EnviNOx® for N2O decomposition and NOx reduction at LAT Nitrogen (formerly known as AMI and Borealis), Linz, Austria.
2006
Startup of first commercial EnviNOx® Variant 2 reactor (using NH3 and natural gas as reducing agents) with zero NOx emissions and single digit ppm N2O emissions at Abu Qir Fertilizers Co., Alexandria, Egypt. At the same time, the project marked the world's first N2O or rather CO2 emissions trading project at an HNO3 plant under the flexible mechanisms of the Kyoto protocol.
2007
Nominated as “Best Available Technique” (BAT) in the EU, solidifying its status as an industry leader.
2010
First EnviNOx® installation in a Caprolactam production plant
2012
Listed by EPA as “Best Available Control Technology” (BACT) in the US.
EnviNOx® units have reduced N2O equivalent to 100 million tons of CO2 greenhouse gases.
2020s
Continued innovation, integrating improved catalysts and modular designs for enhanced performance.
2024
Development of the EnviNOx® honeycomb catalyst for the treatment of exhaust gases from NH3 combustion, e.g. in ammonia cracking plants, ammonia-fueled gas turbines, or ammonia-powered marine engines
2027
First application in an ammonia cracking plant
Case studies for various applications of EnviNOx®
How did the integration into the running production work? How do the installed EnviNOx® systems perform in day-to-day operations? Here you can find some real-life examples for our world-class emission reduction at work.
Case study: Arxada
Case study: Arxada
Arxada wanted to reduce their greenhouse gas emissions (GHG) at Visp plant Switzerland. Now, one EnviNOx® system saves up to 600,000 t/year of CO2-equivalents, which is comparable to taking every Swiss passenger car off the road – twice.
The successful implementation of EnviNOx® has led to the desired decrease in greenhouse gas emissions at the Visp site. Specifically, the project has exceeded the performance guarantees and reliably removes NOx emissions and N2O emissions to almost 0 ppmv.
Olivier Lambrechts, President, Nutrition, Care and Environmental (NCE) at ArxadaWe strive for excellence in all aspects of our business, and EnviNOx® was the perfect match for us. The whole project clearly exceeded our expectations.
Case study: Orica
Case study: Orica
Three EnviNOx® systems for Orica brought down greenhouse gas emissions (GHG) at their Kooragang facilities by nearly 50 % and contribute to decarbonize hard-to-abate industries in Australia.
This reduction represents a significant portion of all GHG emissions from the chemical industry in Australia. As of February 2025, Orica has successfully eliminated one million tonnes of CO2-equivalent emissions from the site, underscoring the project’s long-term impact.
Bertus de Villiers, Vice President Continuous Manufacturing at OricaPartnering with thyssenkrupp Uhde has enabled us to reduce emissions by nearly 50%, giving our business a boost.
Have we sparked your interest or do you have any questions?
We look forward to your message!
Get in touch today!
Get in touch today!
Taking a look at our EnviNOx® FAQs may already help you!
Technical FAQs
Initially developed for nitric acid plants, EnviNOx® technology is applicable in practically every industrial operation which produces either N2O or NOx or both N2O and NOx in a waste gas stream. This includes caprolactam and adipic acid production, pharmaceuticals and food additive manufacturing, and many others. A relatively new area is the treatment of exhaust gases from engines and gas turbines combusting ammonia, for example in green fuel applications.
EnviNOx® has a strong track record of reducing NOx to exceptionally low levels – typically to below 1 ppmv. N₂O emissions are also generally reduced to single-digit ppmv concentrations. This outstanding performance future-proofs any plant equipped with EnviNOx® technology against virtually any conceivable tightening of emission limits.
In practically all cases, the operation of the rest of the plant remains unaffected by the integration of an EnviNOx® unit. In some instances, where the burden of NOx and N2O contaminants is particularly high, the temperature increase across the EnviNOx® system may be significant. This can have a positive effect, as higher temperatures enhance power recovery in a gas turbine. However, in some cases, the permissible operating temperatures of downstream equipment may be exceeded. thyssenkrupp Uhde takes this possibility into account during engineering and can offer cost-effective solutions to ensure that such situations do not arise in practice.
Operation & Maintenance FAQs
An EnviNOx® unit is fully automated. During normal operation, no operator intervention is required, as the control system automatically adjusts the flows of reducing agents in response to changes in inlet concentrations of N2O and NOx, as well as fluctuations in plant load. As with virtually any unit operation, some operator involvement is necessary during start-up to bring the EnviNOx® unit online. Initial training is provided by thyssenkrupp Uhde during commissioning and first start-up.
The EnviNOx® system does not require specialist third-party support. No special maintenance is necessary, and normal operation involves minimal operator intervention – tasks that can be handled by plant personnel. However, thyssenkrupp Uhde is always available to assist with any questions that may arise.
The EnviNOx® system typically comprises a pressure vessel (the EnviNOx® reactor), a mixer for adding reducing agents into the off-gas stream, and standard flow, pressure, and temperature measurement and control instrumentation, along with analyzers. No EnviNOx®-specific maintenance is required.
Project Management FAQs
EnviNOx® technology was originally developed with retrofitting in mind, aiming to enhance NOx and N2O abatement performance in existing plants. Since its first commercial application, the technology has been continuously refined to enable its use in nitric acid plants with virtually any tail gas temperature. EnviNOx® has also been successfully adapted for retrofit applications in caprolactam and adipic acid plants, as well as in food additive production facilities, achieving significant reductions in nitrogen oxide emissions. Naturally, EnviNOx® technology is equally well suited for use in new plants.
It depends. Implementing an EnviNOx® system can be as easy as replacing the catalyst in an existing reactor, or as complex as installing additional heat exchangers and a new reactor while decommissioning existing equipment. thyssenkrupp Uhde will assess the options for your plant, always aiming to deliver the most cost-effective solution tailored to your specific requirements.
Typical implementation times are around 12 months. Fast-tracking may be possible to reduce this time.