Nitrogen Oxide: Well-known Car Manufacturer Trials Clean Air Technology in Prague City Center

Reduction of over 95% in harmful nitrogen oxides possible


Pasching (Austria), October 14th, 2021. A highly efficient system for cleaning ambient air is about to begin operating in the center of Prague, where it will remove noxious nitrogen oxides (NOx). The technology can reduce the level of nitrogen oxides by more than 95%, making it ideally suited to permanent deployment at locations where vehicle bans could be imposed. Developed by Austrian company Krajete GmbH, the centerpiece of the technology is a low-maintenance filter based on aluminum silicate materials. Installation of the equipment has been commissioned by a well-known car manufacturer. The company is looking to find out more about the technology as a potential means of reducing exhaust gas emissions from internal combustion engines. Alternatively, the nitrogen oxides bound by the filter could be used as a cost-effective basis for fertilizers.


Over 98% of vehicles in Germany and Austria still run on fossil fuels – even though the number of registered fully-electric cars is growing all the time. The nitrogen oxides (NOx) emitted by the former continues to pose a massive environmental problem. In addition to statutory thresholds, vehicle bans are increasingly being imposed at particular locations in order to cut NOx pollution. But such measures do not go far enough. However, a novel solution is now available – an innovative technology that simply filters NOx out of the air. The system, which was developed by Krajete GmbH, has now been deployed by a major carmaker in Prague city center.


95% Efficiency

The technology makes use of a naturally occurring mineral from the aluminum silicate class of substances, which binds NOx under certain conditions and extracts them from the air. The material’s decisive advantage lies in the low level of maintenance required. The equipment was put through its paces in 2019/2020 in the German city of Heilbronn, where it not only achieved outstanding results in terms of NOx reduction, but also operated almost without interruption. Over the course of one and half years, the device was only switched off once for a few hours for maintenance purposes. “Now we’re going to install the equipment in a compact container in the heart of Prague’s tourist district – where NOx pollution has the greatest economic impact on the city,” explains Alexander Krajete, CEO of Krajete GmbH. “We have already demonstrated that our technology can filter more than 95% of nitrogen oxides out of the air. So a sufficiently scaled-up system will deliver significant improvements in air quality in major urban centers.” As it turns out, the city of Prague is following the project closely, and will have comprehensive real-time access to the data generated by the device, which is still currently designed to run as a pilot system.


The technology is being installed on the initiative of a major European car manufacturer which is aiming to address the root cause of the NOx problem – the exhaust pipe. According to Alexander Krajete: “This underlines the core advantage of our technology – it functions just as well with the high levels of direct NOx emissions produced by engines as with diluted concentrations found generally in ambient air.”


Adsorption Cuts Emissions

Another advantage of the system is the fully recyclable adsorption cartridge. As Alexander Krajete points out: “Once the bound NOx has been removed – in order to produce fertilizer, for example – the adsorbent is ready to be used again. It doesn’t produce any hazardous waste.” This is a key argument in favor of the technology’s deployment on a larger scale. Another carmaker already has plans to do this and has ordered a system 15 times bigger than the pilot device.


Fueled by strong interest from car manufacturers and public authorities, Krajete is working to enhance the adsorption properties of the filter cartridge. Initial tests have shown that supplementing aluminum silicate with other adsorbent materials can help to remove other environmentally harmful gases from the air. This research finding is hugely significant from an economic viewpoint. Car manufacturers from Central Europe have picked up on this, and potential customers from the Benelux countries and the UK have also turned to Krajete GmbH for support in resolving specific problems related to the filtration of gases such as exhaust fumes.


Photos available at; higher-definition images on request


About Krajete GmbH (updated: October 2021)

The Pasching-based company specializes in two core business:

  1. Air purification and exhaust gas cleaning aimed at removing nitrous oxides, carbon dioxide, carbon monoxide and volatile organic components (VOC, or fine particulates) from small and large emission sources (including exhausts and chimneys).
  2. Direct use of CO2 to produce methane by means of gas fermentation using specific microorganisms from the archaea domain

Creating a closed material cycle with the highest possible level of energy efficiency is the overarching focus of the company’s activities.


Krajete GmbH – contact:

Dr. Alexander Krajete

Prinz Eugen Strasse 66

4061 Pasching, Austria

Tel. +43 (0)699 17266820



Editing and publication:

PR&D – Public Relations for Research & Education

Dr. Barbara Bauder

Kollersteig 68

3400 Klosterneuburg, Austria

Tel. +43 (0)664 1576350