According to McIlvaine, the largest product segment is absorbers, which remove acid gases such as HCl, SO2, and HF. Absorbers, adsorbers and biofilters are used to capture odours and volatile organic compounds. Dry scrubbers including spray driers, sorbent injection and circulating dry scrubbers are used for acid gas removal in competition with absorbers. Venturi and sump scrubbers are used to remove mechanically generated particulate from crushing, screening, and transfer of bulk solids.
McIlvaine reports that incineration including waste-to-energy applications is the largest single market for scrubbers and adsorbers, with more countries outside the US placing a higher priority placed on converting municipal waste to energy. Wastewater is also a growing application with its consequent air quality problems. Some wastewater plants invest more than US$1 million in air pollution control equipment.
Other important industries in the world market include cement plants and industrial boilers, with recent US air toxic standards for cement plants requiring nearly 100 scrubbers. An Industrial Boiler MACT Standard in the US will require scrubbers for industrial boilers burning coal and biomass.
Outside the US, one third of the market for scrubbers and adsorbers in 2011 is likely to be in East Asia. China is investing heavily to clean up the emissions from steel and mining operations, and is also building record numbers of wastewater treatment plants featuring odour control equipment on many of them. China also produces more than 50 percent of the world’s cement.