Cement plant environmental technology for achieving high SO2 removal

The EPA has adopted revised emission limits to the National Emission Standards for Hazardous Air Pollutants (NESHAP) for the Portland Cement Manufacturing Industry and also revised emission limits to the New Source Performance Standards (NSPS) for Portland Cement Plants. These changes revise the emission limits for specified air pollutants for new and existing cement plants. The NESHAP regulations address the emission limits for materials such as mercury, total hydrocarbons (THC), hydrochloric acid (HCl), and particulate matter. The New Source Performance Standards (NSPS) address particulate matter, opacity, nitrogen oxides (NOx), and sulfur dioxide (SO₂). Herein, a case study is presented in which a novel environmental technology was utilized to help achieve greater than 90% SO₂ removal efficiency in a cement plant located in the United States. A slurry scrubber was specified for this application due to its unique ability to achieve high removal efficiencies for SO₂_rich waste gases, using a low cost reagent. Additional capabilities of this system specific to the cement industry are also discussed. These capabilities include: (1) hot gas quenching particulate removal; and (2) resistance to the corrosive, abrasive, and thermally intense environments often found in cement plants.