Catalytic plants

Exhaust Gas and Waste Air Treatment

Industrial processes generate exhaust gases that pollute the environment if not treated.

Steuler Equipment Engineering has over 35 years of experience in developing, planning, manufacturing, installing, commissioning, servicing and maintaining high-performance catalytic scrubbers with over 1,500 satisfied customers around the world.

We attach particular importance to maximizing operational reliability, offering high levels of flexibility and ensuring that the plant can be cost-effectively expanded in the future. Economical, reliable plant operation is made possible thanks to the user-friendly control system, which can either be operated locally on site or remotely over the Internet.

Our performance spectrum

The complete range of catalytic scrubbers covers industrial pollution control applications in

  • Natural gas, biogas or diesel-powered engine, turbine and combustion plants
  • Greenhouse CO2 fertilization systems
  • Chemical, petrochemical and metallurgical processing plants
  • Hazardous waste and residue incineration plants
  • Other processes

Our applied technologies

Our tried-and-tested technologies for the catalytic treatment of exhaust air and solvents include:

  • NOx reduction using SCR and SNCR processes
  • Dioxin reduction
  • Catalytic oxidation plants for volatile organic compounds (VOC) and carbon monoxide (CO)

Selective catalytic reduction (SCR)

Selective catalytic reduction of nitrogen oxides (NOx) from flue gases or process exhaust gases is used whenever high nitrogen oxide conversion rates are needed, a low pressure drop is desired and operating temperatures lie between 180°C and 500°C.

Urea solution, ammonia solution or ammonia gas are injected as reducing agents, reliably lowering the level of nitrogen oxides to below the stipulated values.

Selective non-catalytic reduction (SNCR)

Selective non-catalytic reduction of nitrogen oxides (NOx) is used when exhaust gas temperatures are between 850 and 1,050°C. Here, a reducing agent is used that reacts with the nitrogen oxides (NOx) to form innocuous nitrogen (N2) and water. Aqueous urea or ammonia solution is generally used, and injected directly into the hot exhaust stream via special lances.

Catalytic oxidation

Catalyst-assisted oxidation makes it possible to fully oxidize volatile hydrocarbons (VOCs) in the exhaust air from temperatures as low as 320°C. It allows exhaust streams to be purified extremely energy efficiently, resulting in lower energy costs and CO2 emissions compared to other thermal processes. Our catalytic oxidation plants are usually equipped with a natural gas burner or electrical air heater, allowing them to be flexibly adjusted for a wide range of operating conditions. An efficient gas-gas heat exchanger is fitted in order to recover the introduced heat. This enables the plant to be operated autothermally even at low pollutant concentrations.

In an ideal situation, no additional energy is required for VOC oxidation as a result.

Catalytic processes – the underlying technology

How do catalytic processes work in general?

Above a certain temperature, the pollutants from upstream processes that are present in the exhaust air decompose into harmless substances. Because this generally only starts to happen at very high temperatures (in the region of 700 – 1,200 °C), it would take a great deal of energy to heat the exhaust stream to these levels.

In order to get around this, catalysts are used to lower the reaction temperature and thus reduce the amount of energy that needs to be added. In this way, reaction temperatures can be lowered to between 180 and 500 °C, resulting in significant reductions in energy consumption, CO2 emissions and operating costs.

For the conversion of the pollutants to occur within the operating temperature window of the catalyst, the exhaust gas must first be brought to this temperature. This is generally achieved using a gas-gas heat exchanger, which transfers the energy from the already treated gas to the cold exhaust stream. With the help of a natural gas burner or an electrical heating element, the temperature of the exhaust gas is then adjusted to match the operating temperature of the catalyst.