Haldor Topsøe


You have successfully submitted your enquiry. Someone from our company will respond ASAP

SCR DeNOx and Oxidation Catalysts for the Power Industry

Through almost a century of dedication to catalysis and with a strong commitment to fundamental research, Haldor Topsøe has developed efficient and reliable solutions to emission problems.


Email Address
Nymøllevej 55,
DK 2800 Kgs. Lyngby,
Fax Number
More links

Through almost a century’s dedication to catalysis and with a strong commitment to fundamental research, Haldor Topsøe has developed efficient and reliable solutions to emission problems. A comprehensive knowledge gained from years of worldwide experience has made the company a leading supplier of catalysts and innovative technologies.

Topsøe is one of the world’s largest manufacturers of SCR DeNOx catalysts and supplies catalysts, process knowledge and equipment for removal of NOx from boilers, gas turbines, gas and diesel engines, incinerators, as well as chemical units.

The SCR reference list consists of more than 900 catalyst installations, of which the largest is in an SCR plant fitted on a 1,200MW coal-fired boiler, treating more than 5,000,000Nm3/hr of flue gas.

SCR DeNOx systems

With more than 20 years of experience within SCR system design, Topsøe is the optimum partner, with in-house know-how and experience from many projects. The SCR DeNOx catalyst is the heart of the SCR system, but the dosing and mixing of the correct amount of ammonia are also very important issues, which can be designed by the company as well. Topsøe has developed the patented STARMIXERTM for optimisation of ammonia injection, combined with perfect mixing and a minimum pressure loss.

Loading of a DNX® module for a gas turbine.
Loading of a DNX® module for a coal-fired power station.
The surface on a Topsøe DNX® catalyst.
Topsøe DeNOx cassettes.

SCR DeNOx catalysts

Topsøe DNX® catalysts are a unique series, with the highest activity combined with the lowest SO2 oxidation on the market today. The fibre-reinforced, ceramic titania support makes the DNX catalysts strong and durable; combined with a special pore structure, which provides an unmatched resistance towards poisoning, this ensures a long service life.

SCR DeNOx for gas turbines

The DNX series of catalysts span an operating temperature range from 170°C to 580°C, or 340°F to 1,080°F. Their unique structure allows almost unlimited temperature ramping rates, which makes the DNX catalyst the perfect choice for gas-turbine applications. Topsøe’s diverse gas turbine experience ranges from IGCC and combined-cycle sources to simple cycle gas turbine applications.

DeNOx catalysts for biomass applications

Topsøe has many installations on boilers firing 100% biomass, as well as installations on boilers with co-combustion of biomass with coal. Experience demonstrates that by choosing the right plant configuration and proper catalyst formulation, negative effects can be limited. Biomass can be co-combusted with coal without any noticeable impact on catalyst lifetime when operating with a DNX from Topsøe.

DeNOx systems for diesel engines

For decades, Topsøe has supplied DeNOx systems for engines, leading to an impressive track record of more than 100 installations on both two and four-stroke stationary and marine engines operating on all possible fuel types.

Today, Topsøe offers the most compact and cost-effective DeNOx solutions for any engine type. Years of experience have been integrated into Topsøe’s well-proven system design and DNX® catalyst, developed especially to resist temperature shocks, vibrations and poisons found in engine off-gasses.

The catalyst is supplied in easily-installed, lightweight cassettes and everything from the basic description of system parts to complete system design can be included in the scope of supply.

Oxidation catalysts for combined CO and NOx reduction

Topsøe also offers a series of oxidation catalysts, specifically designed for abatement of carbon monoxide. These are prepared from the same unique base as the DNX SCR catalysts, combined with deep-impregnation of palladium. This provides a uniquely high oxidation activity with an unsurpassed stability, as well as when operating in sulphur and chlorine-containing gases.

The palladium-based catalysts also oxidise ammonia into molecular nitrogen and may be fitted after the SCR catalyst to remove ammonia-slip excursions that may otherwise come from SCRs operating in unstable conditions.


Nymøllevej 55
DK 2800 Kgs. Lyngby

Email address
Fax Number
Haldor Topsøe Inc
17629 El Camino Real
United States of America

Email address
Fax Number