Low-investment cost emissions control technology with a compact footprint
Preventing pollutants from reaching the atmosphere plays an important role in the drive to net zero. Regardless of the type of fuel used – whether conventional, like coal or gas, or alternative, like biomass or refuse-derived fuel (RDF) – the combustion process is accompanied by the formation of polluted gases. Flue gases contain many components that are harmful to all living organisms.
Dry Sorbent Injection (DSI) and Activated Carbon Injection (ACI) are flue gas treatment methods based on injecting dry reagent material directly into the flue gas duct. The aim is mainly to reduce acid gases, mercury and PCDD/Fs (dioxins and furans). Combining this with the use of fabric filters also achieves minimal dust emissions in flue gases, capturing even fine dust particles including PM2.5 and PM10. This system can be used for many industrial applications and for a wide range of fuels, including coal, pet coke and biomass.
The baghouse approach involves using a filter to limit the solid particles carried by the flue gas to a required level.
DSI is a sulfur dioxide (SO2) sulfur trioxide (SO3), hydrogen chloride and hydrogen fluoride reduction system that uses an alkali sorbent as the injection material. Sorbents used can be lime or bicarbonate – bicarbonate is used for high removal levels of HCI and SO2.
ACI is a mercury reduction system – activated carbon captures mercury through adsorption. It also adsorbs dioxin and furans.
There are injection ports and lances for the sorbents and/or activated carbon upstream of the filter. The sorbents/carbon are conveyed from silos to the flue gas duct by dedicated devices. The reagents mix with fly ash, and then settle on the filter bags, creating a dust filter layer, significantly extending the contact time between the pollutants and the sorbent.
The system can be ‘tailor-made’ by evaluating:
- The influence of temperature on the physical and chemical parameters of the injected sorbent as well as on the efficiency of pollutant reduction.
- The timing of gas flow between the injection point and the dedusting device.
- The shape and routing of the flue gas flow path, where reagent is fed ahead of baghouse.
- The influence of devices installed in the flue gas path, including cyclones.
- Baseline concentrations of pollutants.
Cost-effective and convenient
- The simplicity of this method makes it possible to meet emission requirements for acid gases with low investment cost.
- Using a dedusting device not only allows low emissions of dust pollutants, but also increases the effectiveness of methods for reducing other gaseous pollutants.
- Operating costs can be optimized by adding a post-reaction product recirculation system.
- We can deliver super-efficient filters or make your flue gas almost dustless, with a small footprint area (we can use long bags up to 10m). The cleaning system has low pressure, which prolongs bag life, and air distribution manifolds with variable nozzles sizes for even cleaning of all bags.
- We provide a comprehensive study of potential dry sorbent dosing locations, including CFD (computational fluid dynamics) calculations, to optimize the process.
Fired power plants and paper mills are among the industrial plants that get the most benefit from this approach. It’s also valuable for the waste-to-energy sector, cement industry and steel mills.
With years of experience in the field of combustion processes and the associated mechanisms of pollution formation, we can choose the most effective flue gas cleaning concepts for customers. And we can optimize the way the boiler and the flue gas cleaning installation work together.