Toxic organic emissions from coal combustion

Atmospheric fluidized bed combustion (AFBC) is considered to be an environm entally favorable combustion technology where the control of emissions can be integrated into the combustion system. FBC operates at low temperatures, 800-900 degrees C, to prevent thermal NO formation and to favor the sulfur removal by the sorbent, but it has not been taken into account that when c oal is burnt, not only NOx, SOx rind COx are emitted. In addition, volatile organic pollutants (VOCs) are emitted. From these VOCs, the polycyclic aro matic hydrocarbons (PAHs) constitute one of the most dangerous compounds be cause of the possibility of interacting with biological nucleophiles. It is expected that new legislation about the regulation on PAH emissions will b e very restrictive. In this work, PAH emissions from coal AI;BC as a functi on of the coal combustion variables (combustion temperature, gas flow and p ercentage of excess oxygen) are reported. In addition, the effect of bed na ture on PAH emissions is also assessed. Polyaromatic hydrocarbon emissions at the standard conditions used at the A FBC power stations are assessed by the study carried Out in an AFBC laborat ory pilot plant. The PAHs listed by the US EPA as priority pollutants are a nalyzed by fluorescence spectroscopy (FS) at the synchronous mode. (C) 2000 Elsevier Science B.V. All rights reserved.