In this market, absorbers are likely to constitute the largest segment with revenues of over US$1 billion, due to Asia rapidly expanding industries that are the major purchasers of absorbers, such as incinerators, steel mills, municipal wastewater plants, chemical plants and refineries. Absorbers are used to capture acid gases such as SO2, HF, and HCl, while adsorbers and biofilters are used to remove H2S and volatile organic compounds. They are also used for odour control in food plants and municipal wastewater treatment facilities. Absorbers are widely used in the chemical and petroleum refinery industries. A big application for dry scrubbers in East Asia is municipal waste incineration, and the cement industry is also an important market. A recent contract for a new cement plant in East Asia included dry scrubbers to remove the SO2 and HCl. Particulate scrubbers include low pressure drop spray towers, fluid bed scrubbers, and high pressure drop venturis, and East Asia uses particulate scrubbers in some applications where other regions have switched to fabric filters.