Control Technologies for Particulate and Tar Emissions from Coal Converters

摘要

The report gives results of a characterization of solid and tar particulate emissions in raw product gases from several types of coal gasifiers, in terms of their total quantities, chemical composition, and size distribution. Fixed-bed gasifiers produce the smallest particulate loadings, about 3 g/cu m. Entrained-bed gasifiers produce the largest, about 110 g/cu m. Control technologies for particulate emissions were assessed with respect to the limitations of the control device and to existing and proposed regulations. Fabric filters were not suitable where tar particulates were found or at higher than 300 C. Electrostatic precipitators operated as high as 1100 C. Rotary cyclones showed the widest range of applicability. Conventional cyclones were most economical for particles larger than 50 microns. Solid and tar particulate emissions collected for 250,000 scfd of a medium-Btu gas contained up to 1.6 million kg of particulate containing about 400 ppm of organic compounds which were benezene extractable. Naphthalenes and three-ring aromatic compounds each showed compositions of about 15 ppm. More than a dozen other classes of compounds were identified in the analyses of the organic material deposited on the particulate matter.