Abstract |
This document reviews the state of the art of air emissions from charcoal manufacture. The composition, quality, and rate of emissions, and their environmental effects are described. Charcoal is the solid material remaining after the pyrolysis of carbonaceous materials, primarily hardwoods. It is produced in both batch and continuous facilities and then briquetted. During the manufacturing process, emissions of particulate, carbon monoxide, hydrocarbons, and nitrogen oxides are released. To evaluate the hazard potential of representative sources defined for batch kilns, continuous furnaces, and briquetting operations, source severity was defined as the ratio of the time-averaged maximum ground level pollutant concentration to a hazard factor. For criteria pollutants, the hazard factor is the ambient air quality standard; for noncriteria pollutants, it is a reduced TLV. Source severities range for controlled batch kilns from 0.016 to 3.7, for continuous furnaces from 0.0097 to 4.6, and for briquetting operations from 0.27 to 1.6. Batch kilns do not typically have emission control devices; however, some kilns use afterburners. Continuous furnaces are believed to use some level of afterburning to reduce particulate carbon monoxides, and hydrocarbons. Briquetting operations control particulate emissions via centrifugal collection or fabric filtration. |