Trace Element Emissions from Coal-Fired Power Plants

Abstract

The emission rates for 27 major, minor and trace elements from four coal-fired electrical generating stations are presented. The flow rates of each element in each process stream entering and leaving the power plant are given for three of the stations. The exit streams include bottom ash, collected ash and fly ash and vapors in the exhausted flue gases. Elemental material balances were calculated to assess the reliability of the results. The elemental compositions of the particulates in the flue gas were determined as a function of particle size for two stations, one of which was included in the previous material balance study. The two stations studied during this phase used hot-side and cold-side electrostatic precipitators, respectively, to collect fly ash. The concentration effects were evaluated to determine whether the gas temperature during particulate collection affects the distribution characteristics of the elements enriched at the fly ash surfaces.

Distribution of mercury during simulated in-situ oil shale retorting

“…Volatile halogenated hydrocarbons (i.e., halogenated alkanes, alkenes, and benzenes are ubiquitous groundwater pollutants (1-5), The major causes of groundwater contamination by such chemicals include leachates from chemical waste dumps (6), spills (7), infiltration of polluted surface waters (8,9), and leaching from the ground surface (e.g., pesticides (4)). Recent studies have shown that volatile halogenated hydrocarbons are rapidly transported in the ground and that many of these compounds are quite resistant to chemical and/or biological transformation under conditions typical for the subsurface (8)(9)(10)(11)(12).…”

“…The high volatility of Hg at temperatures encountered in fossil-fuel combustion processes has led to numerous studies of Hg mobilization in coal-and oil-fired power plants (1)(2)(3)(4)(5)(6)(7). More recently, coal conversion (8)(9)(10) and oil shale (10)(11)(12)(13)(14)(15)(16)(17) processes have been investigated.…”

Toxic Substances From Coal Combustion-a Comprehensive Assessment

“…For supermicron particles, often known as bulk fly ash, an important concern is the forms of occurrence of trace elements on or within the particle matrix and the consequences of these forms of occurrence for leachability of potentially toxic trace elements during fly ash disposal or reutilization [37][38][39][40][41]. Vaporized trace elements that redeposit onto the surface of supermicron particles are more likely to leach into moisture sources that non-volatilized trace elements bound within particle fragments.…”