Our fabric filter technology has proven its worth in many different areas of application and industries. Even in difficult applications, separation rates of over 99.9% are achieved. The spectrum ranges from small and medium filters, for example in industrial applications or waste incineration plants, to large filters with up to 10,000 filter bags in large coal-fired power stations. The solid and effective structure means they can be used in extreme conditions, with low maintenance and at the same time large availability. As well as for pure dust separation, fabric filters can also be used in combination with activated carbon as an entrained flow absorber to remove gaseous pollutants such as mercury or dioxins.

Our fabric filters are comprised of several filter compartments with parallel flow. Individual compartments can be temporarily deactivated without interrupting the operation of the overall plant. The flue gas penetrates the filter bags from outside to inside, while the dust particles are held back. The dust forms a filter cake on the surface of the filter bag, which effectively supports separation. The filter cake is removed from the bags at regular intervals by means of a compressed air pulse. The dust removed is fed via a hopper beneath the compartment to an ash removal system. When selecting the most suitable ash removal system, Steinmüller Babcock Environment relies on its decades of experience and recommends the suitable solution for each individual case. In this way we avoid critical interfaces.

The separation behaviour, cleanability, pressure loss characteristics and lifetime of the filter bags depend on the filter medium used. We know the perfect filter material for every application. We also use our many years of expertise in configuring the inlet flow in the filter compartments. Here, the particular challenge is to distribute the flue gas flow equally among the filter bags, avoiding  an upward flow sweeping previously separated dusts with it. The inlet flow via a baffle plate, developed by Steinmüller Babcock Environment, provides the ideal solution for the even distribution of the gas flow, with a very low pressure loss.

• High dust separation rate of up to 99.9 %
• Low clean gas dust content of < 1 mg/Nm3
• Simultaneous gaseous pollutant removal possible
• Treatment of large volume flows
• Fully-automated cleaning of the filter bags online during operation
• Exchange of defective filter bags possible during ongoing operation
• No restrictions in the separation of dust with a high specific electrical dust resistance
• Various possibilities of applications in all areas of industry and energy production
• Individual selection of the filter bag material to the operation conditions

The function of dust separation in electrostatic precipitators is based on an electric field that is built up between the high-voltage discharging electrodes and the earthed collecting plates. When flue gas flows through the electrostatic precipitator, the dust particles become electrically charged and are collected at the plates through the effect of the electric field. Fine dust can be removed very successfully from the gas in this manner.

Dry Electrostatic precipitators are mostly built horizontally and can vary in size, depending on their purpose. For dust separation behind a large coal-fired power station, an electrostatic precipitator can reach half the size of a football pitch. Smaller electrostatic precipitators are installed behind biomass-fired boilers in the timber industry or in waste incineration plants. Electrostatic precipitators are also used advantageously in industrial applications where no flue gases from combustion processes need to be treated. In various areas of the steel industry, in sinter cooler systems, in room and converter dedusting and in arc and blast furnaces, electrostatic dust separation also makes sense. In resource recovery processes, for example in cement plants, coal refining plants or chemical and petrochemical plants, electrostatic dedusting plays a valuable role by recycling the precipitated product.  

In plants with large quantities of dust we achieve efficient separation rates of well over 99.95%. This means that we achieve a clean gas dust content that is well below 10 mg/Nm3. Values that are noticeably below the common guidelines on emissions protection, and which also recommend the electrostatic separation technology for the future. A particular advantage of the technology is the low pressure loss and thus the low energy requirements of the plant. 

The high voltage used in the electrostatic precipitator affects only the solid matter in the flue gas and can be controlled on demand. This drastically reduces energy consumption during off-peak plant operation and when the dust can be easily separated.

The collecting plates, made from profiled steel sheets and up to 16 metres in height, and the discharge electrodes carrying the high voltage, in the form of welded pipe constructions, are robust and unbreakable – malfunctions caused by broken electrodes belong in the past. Cleaning takes place fully automatically by means of a robust tumble hammer system. All bearings of the internal rotating parts are specially protected. Low flue gas flow rates of approx. 1m/s prevent erosion of the electrostatic precipitator internals. The result: more robust, low-wear operation with high availibilities and low maintenance and servicing requirements.

With impressive values, the most modern lignite fired power station in the world, in Neurath (Germany), demonstrates the advantages of electric dedusting. The high-voltage units of the electrostatic separator are designed for a maximum total output of 5,500 kW. Thanks to our intelligent output control, with controlled clean gas dust content, we require only 750 kW of power, thus saving more than 85 % of energy.

• High levels of dust separation of over 99.95%
• Low clean gas dust content of < 10mg/Nm3
• Low pressure loss
• Energy-optimised plant operation, adapted to the clean gas dust content
• Robust and reliable technology
• Operation at high temperatures of up to 450° C
• High volume flows of up to 4.5 million Nm3/h can be achieved
• High availabilities with low maintenance and servicing requirements
• Diverse application areas in all sectors of industry and energy generation
• Reliable electrical charging thanks to unbreakable discharge electrodes

Semidry flue gas desulphurisation: low investment costs, optimised plant technology
Choosing the right process for a DeSOx plant always depends on the particular case of application. The semidry method is suitable for plants up to 1 million Nm³/h. Here, an aqueous absorbent suspension , usually a calcium hydrate suspension with high reactivity, is injected into the flue gas flow. The acidic pollutant gases react with the absorbent to become salts, while at the same time the water of the lime milk evaporates and the flue gas cools before leaving the absorber. The reaction product is a dry mixture of calcium salts and unreacted lime. The mixture is usually separated in a downstream fabric filter from the flue gas, a partial flow can be recirculated for better efficiencies. 

The main design feature of the spray absorber is a cylinder above a conical discharge section. The raw gas distributer is positioned above it, containing the centrally-arranged rotary atomiser. The calcium hydrate suspension is fed to the rotary atomiser. There, an atomised spray with very fine droplets is generated by a rapidly rotating atomiser wheel and distributed evenly into the flue gas flow. The spray absorber is designed to provide a sufficient reaction time between flue gas pollutants and absorbent to bind the SO2 and dry the solid reaction product.

The use of the rotary atomiser as a complete unit, including drive motor, has an economic benefit: In the event of a neccessary maintenance of the atomizer, the complete unit can be replaced in a short time, allowing uninterrupted operations of  the boiler plant.

• Use in plants up to approx. 1 million Nm³/h
• Reduced investment costs
• Good utilisation of the absorbent used
• Optimised plant technology

Limestone-gypsum desulphurisation: lime scrubbing with an end product
Wet flue gas desulphurisation is usually based on the use of calcareous absorbents (for example limestone, calcium hydrate, quicklime or chalk). Industrially, the use of limestone as an absorbent has prevailed in the area of power stations. The limestone-gypsum method produces gypsum as an end product, which is marketable for industrial re-use. So-called lime scrubbing reliably removes sulphur dioxide, hydrogen chloride, hydrogen fluoride, and ash from the flue gases and is one of the most widely used desulphurisation methods. Steinmüller Babcock Environment has 120 reference plants worldwide for this technology, with absorber sizes of up to 3.2 million Nm3/h respectively 1,100 MWel.

The reaction of sulphur dioxide with limestone in the form of suspension is initiated in a spray tower that acts as an absorber. The absorber is divided into three distinct zones, the absorber sump, the contact zone and the absorber head. In the bottom area, the absorber sump, the lime suspension is agitated, supplemented with fresh absorbent, and ventilated. The agitation supports the dissolving of the limestone in the suspension, promotes the even crystallisation of the gypsum, and at the same time prevents the solid material from settling. To oxidise the sulphur dioxide to sulphate (gypsum), finely-distributed oxygen is required. Therefore air is blown into the absorber sump in front of the agitators and distributed or dispersed very finely in the suspension with the agitator flow.

The solid absorbent for the process can either be supplied as powder or ground in a milling unit at the power plant. In the lime milk dosing station the ground limestone is mixed with water before it is injected into the absorber sump.

From the absorber sump some suspension is pumped to the dewatering unit, where the dewatered gypsum is extracted as a marketable product. The surplus water is reused within the limestone/gypsum process.

The flue gas enters the absorber above the sump, and flows upwards through the contact zone. Here are many levels with spray nozzles, which disperse the scrubbing suspension from the sump very finely into the flue gases.

In the contact zone the gaseous sulphur dioxide from the flue gas is dissolved into the scrubbing liquid. After flowing through the contact zone, the flue gas reaches the absorber head and passes through horizontal droplet separators where liquid droplets are removed. When leaving the absorber the cleaned gas is saturated with water vapour has been cooled down to the respective saturation temperature.

• Lowest absorbent costs
• Marketable product (gypsum)
• Best plant availability
• Optimised material and plant concepts
• Worldwide references for all power station sizes and fuels

The SCR (Selective Catalytic Reduction) method is considered to be one of the most economical processes for achieving the NOX removal levels of over 90 % required today. The availability, reliability and efficiency of each plant depend on the solution installed in each case – a task for experts. Steinmüller Babcock Environment places the SCR reactor directly downstream the firing (high-dust position) or downstream the flue gas scrubbing (tail-end position). We denitrify with the required operating temperatures of 180-430° C, depending on the type of plant and sulphur load of the flue gas. We have used our technology successfully in steam generators that are fired with coal, oil, biofuels or waste fuels. Other applications, for example after cement furnaces, are in preparation.

When retrofitting existing large steam generators, we adapt the economiser outlet temperature to the required operating temperature of the catalyser with a low load. We have successful references for all possible methods, for example for the modification of an existing economiser, the retrofitting of new eco-bundles downstream from the catalyst, or eco bypasses on the water or gas side.

When Steinmüller Babcock Environment retrofits an SCR system, this includes the whole package. We retrofit the entire flue gas routing including the installation of  suitable heating surfaces for the regenerative air preheater , the optimisation  of the electrostatic precipitator inlet ducting and the new installation or modification of the induced draught fans. Our SCR reactors are flexible and can be equipped with all catalysts on the market, which provides our customers with a clear competitive advantage when it comes to replacing catalyst elements at the end of their lifetime. For even more flexible catalyst management, we may also install reactors with reserve levels upon request. The intelligent layout of the SCR reactors and the catalyser ensures not only the NOX separation and – if required - the destruction of dioxins and furans, but also contributes significantly to mercury removal: Depending on the inlet conditions  the catalyst can oxidise  more than 90 % of metallic mercury constraints; the oxidised mercury can then be removed in the downstream wet scrubbers. This provides a further decisive advantage, since mercury emission limits are becoming ever more important in Europe. 


The expertise of Steinmüller Babcock Environment is based on many years of experience and our pioneering role in the field of environmental technology. In 1985 we built Europe’s first commercial high dust SCR plant, and also the world’s first tail-end SCR plant. This long-term experience has allowed valuable findings to flow into the further development of our technology.

In order to continue meeting the high demands for separation efficiencies for different types of fuel, while at the same time ensuring the long life of the catalysts, we optimise our plants with the help of flow models (scale 1:15) and by means of CFD simulation calculations. We achieve ideal homogenisation of both the flue gas velocity and the NOX concentration in the flue gases.  Injection and mixing of NH3, NH2OH or UREA into the flue gas is very homogeneous too,thanks to our patented DIVA® mixer. It is a worthwhile investment for several reasons: we achieve high levels of NOx removal, the optimal utilisation of the catalyst activity, and low dust deposits in the flue gas ducts and on the catalyser for high dust applications.


The comprehensive service provided by Steinmüller Babcock Environment includes individualised catalyst management. Due to the deposits of certain flue gas components and contact with certain substances, catalyst activity gradually declines over time. At the latest when the maximum permitted NH3 slip has been reached, the activity of the catalyst must be increased. This is possible by means of regeneration, by installing an additional catalyst layer in the reserve level, or by replacing old catalyst layers. We assess the lifespan for you and plan the most economical timeing for stocking up on catalyst volume or replacement. You are always on the safe side with our expertise.