For Particulate Matter emission control in high temperature exhaust streams, such as biomass and coal boilers and heaters, usual dedusters, such as regular cyclones and multicyclones are not able to reduce emissions to present emission limits, due to its low efficiency, particularly for small particles (< 10µm). This usually implies the investment in a complementary and final stage deduster. These boilers, particularly coal boilers, are associated with high gas flow rates, which significantly increases the investment needed for a particulate trap.  

Bag filters (BF) are very efficient dedusters but can be very maintenance demanding, implying frequent cleaning and change of filter elements. In addition to high temperatures, biomass and coal combustion frequently releases burning particles, which damages filter elements and result in immediate increase in emissions. Solving this problem means spending money but also downtime in production.

Electrostatic Precipitators  (ESPs) are robust equipments and are very effective for a given range of dust resistivity. However, efficiency frequently drops outside that range as a consequence of temperature changes.  Ultimately, ESPs' present and future retrofitting high investment cost is out of reach for many companies.

Venturi Scrubbers are alternative end stage dedusters, but at the cost of secondary wet pollution, which by itself restricts its usage, unless there is already an infrastructure to treat the liquid efluent.