Clean Air Technologies to reduce emissions for a Greener Tomorrow with HJS USA
Leading clean air innovation since 1976. HJS USA develops cutting-edge exhaust technology for all vehicles. We partner with you to reduce emissions and meet air quality standards. Breathe easier, achieve your clean air goals.
Reducing emissions in your industry
We have the exhaust aftertreatment solution for your vessel to prodect your investment, your health, and the environment with our certified generator and main engine upgrades.
Yachts
Enjoy breathing clean air while staying in the most beautiful places in the world. Increase your ship’s value with the latest emission reduction technology.
Commercial Vessels
Stay compliant with our certified exhaust aftertreatment solutions.
Work in progress. Check back soon or contact us today.
About our company
Founded in 1976, HJS fights for clean air. We develop and install technology to reduce emissions from vehicles, helping cities meet air quality standards and creating a greener future.
Innovation
For over 45 years, HJS has been setting national and international standards as an innovative company with emission technologies for the Diesel engines.
Sustainability
HJS develops today the technology for your mobility of tomorrow. And we do this successfully since the 1980s.
Flexibility
A strong R&D team combined with our own state-of-the-art manufacturing facility allows us to deliver cost effective high-end products. With the flexibility you expect.
Quality
Our customers expect the highest quality standards – for every single component. And that’s what we deliver. For over 45 years.
SCRT® – Innovative Emission Control for Modern Diesel Vehicles
Trailblazing Partnership for Clean Diesel Innovation
Patented state-of-the-art technology by HJS, Daimler, and Johnson Matthey — setting new benchmarks in emission standards.
Together, these three technology leaders unite their expertise in vehicle engineering, catalysis, and filtration — creating a unique partnership that drives innovation in emission control.
HJS Emission Technology
Germany’s leading specialist in exhaust aftertreatment, backed by over 45 years of innovation in filter systems and catalytic technology.
Daimler AG
A global pioneer in the industry, setting the benchmark for emission standards and sustainable powertrain solutions for Diesel engines.
Johnson Matthey
The world leader in catalytic technologies, with more than 200 years of experience in sustainable chemistry and advanced material solutions.
AdBlue®-based Selective Catalytic Reduction (SCR) technology
Precision Dosing for Maximum NOₓ Reduction
Efficient nitrogen oxide reduction begins with the precise injection of AdBlue® (a 32.5% urea solution) ahead of the SCR catalyst.
- Thermal decomposition into ammonia (NH₃)
- Catalytic conversion of NOₓ into nitrogen (N₂) and water (H₂O)
- Smart control for optimal conversion efficiency
- Reduced consumption through exact dosing
NOₓ Reduction
High-efficiency conversion of nitrogen oxides — proven under real-world driving conditions
Integrated
All system components developed and manufactured in-house to guarantee best durability and performance
Compact Design
Filter and catalyst combined in one integrated system – for compact design
Diesel Particulate Filter with Sintered Metal or Silicon Carbide
HJS filter systems are based on filter modules made of high-quality ceramic substrates treated with a unique coating of platinum to allow for a better reactivity.
The filter system can replace the original silencer as well as being used in addition to the existing silencer (wet and dry exhaust).
Particulate Filtration
Almost complete elimination of soot particles from the exhaust flow
Without external cleaning
Low maintenance costs and long life combined
*under normal conditions
Intervention with engine control
No compatibility issues as system status can be checked any time on the HJS control unit
News & Updates from HJS USA
Explore our news for product updates, industry insights, and success stories driving a greener future.