EPA is proposing to sharply reduce emissions of nitrogen oxides from nitric acid plants, the first update in four decades. The agency’s proposal, published in the Federal Register on Oct. 14, would set a limit of 0.5 lb of nitrogen oxides per ton of nitric acid produced, calculated as a 30-day emission rate average, down 83% from the existing limit of 3 lb of nitrogen oxides per ton of acid produced. The standard has not been revised since it was adopted in 1971, and the last review took place in 1984. About 70% of the nitric acid produced in the U.S. is consumed as an intermediate in the manufacture of ammonium nitrate, which is used in fertilizers. Environmental groups sued the agency in 2009 for failing to review the air pollution standard for nitric acid plants every eight years, as required by the Clean Air Act. EPA is obligated by a court deadline to issue a final rule by Nov. 15. There are currently 40 nitric acid facilities in the U.S., and another six plants are expected to be built in the next five years.
Source: http://pubs.acs.org
