Asphalt roofing plants
The manufacture of asphalt paper and shingles consists of impregnating felt with preheated asphalt. The impregnation is accomplished by continuously saturating a sheet of felt paper in an asphalt bath heated to 200 to 260ºC. The saturation fumes are sucked out by an exhaust fan and expelled into the atmosphere. These fumes can be divided into two (2) categories:
- Gaseous and condensable organic compounds, in the form of a fine tar mist, produced by the felt saturation process, including small amounts of polycyclic aromatic compounds;
- Gaseous and particulate compounds produced by the drying of organic products used in manufacturing.
The main source of air pollution comes from a cloud of white fumes resulting from the evaporation and subsequent condensation of the COCs from the asphalt. Since 1992, Biothermica has been supplying the patented BIOTOX® process adapted for the treatment of asphalt paper and asphalt shingle fumes. It is recognized as a world leader in this particular application. Improvements made to the basic technology consist primarily in a fume recirculation system and an innovative control philosophy.