Energy from Paper Sludge: Criteria and Hazardous Air Pollutants

Abstract

The paper-manufacturing industry generates more than 90,000,000 t of sludge annually in the United States, the disposal of which is a complex environmental issue. Test burns of pelletized and dried paper-mill sludge were performed in a small institutional boiler for the purpose of determining environmental feasibility of the operation. The sludge was from a facility processing 100 secondary fiber (40 postconsumer), and was co-fired with wood chips. Emission rates of various criteria and hazardous air pollutants were measured during the burns and compared to regulatory limits. Results indicated that criteria pollutant emissions from this 2.9 MW (10,000,000 Btu/h) operation were well within regulatory limits with the exception of particulate material. Emission control such as a baghouse or electrostatic precipitator would be needed for a facility performing energy recovery from sludge. Organic hazardous air-pollutant emissions were also well below mass rates that would qualify the boiler as a major source under the Clean Air Act Amendments of 1990, with the largest emissions being formaldehyde, followed by acetaldehyde, acrolein, and naphthalene.