Contents Notes |
In 1993 and 1994, Carnot conducted several test programs to characterize hazardous air pollutant (HAP) emissions from gas-fired utility boilers, utility turbines and industrial turbines used for natural gas transmissions. Among the compounds measured were 15 trace metals, polycyclic aromatic hydrocarbons, polychlorinated biphenyls, polychlorinated dibenzo-p-dioxins, polychlorinated dibenzofurans, formaldehyde, benzene, toluene, as well as hydrocarbons, NOx and CO. The air toxics data collected from these test programs were then used to assess the public health risk. Analysis of most of the air samples indicated that hazardous air pollutants cannot be detected by the current analytical methods or they are emitted at levels well below the 1990 Clean Air Act Amendment regulation of 10 tons per year for industrial sources. The screening health risk assessment studies revealed that these levels will not pose significant carcinogenic or non-carcinogenic public health risk. Parametric testing at various operating conditions indicated that HAP emissions do not vary significantly with load and excess air level for utility boilers. However, the load at which a given gas turbine is operated can have a strong effect on the emission of benzene, toluene, formaldehyde, hydrocarbons, CO and NOx. |