Use of continuous mercury monitors at coal-fired utilities

Phosphonium Chloromercurate Room Temperature Ionic Liquids of Variable Composition

“…As polynuclear chloromercurate species are prone to dissociation by elevated temperature, a dissociating effect of the acetonitrile solvent can be assumed. This is supported by the fact that the reaction products (5) and (6) also show the same maximum wavelength as observed in (4).…”

“…One of the prepared compositions is best described as ILs with a single cation and anion species (2), and another one as a liquid with one cation and an anion which potentially is constituted of a variety of polynuclear aggregates (4). The other reaction products also would count as mixtures of molecular (or rather weakly coordinated) HgCl 2 in the chloromercurate IL [P 66614 ]{HgCl 3 }, although at low enough temperatures these compositions could count as true ILs.…”

UV-Absorption-Based Measurements of Ozone and Mercury: An Investigation on Their Mutual Interferences

“…Currently, the EPA-accepted methods for Hg measurement in the United States are manual procedures based on wet-chemistry, such as EPA Methods 29 and 101A (for total mercury) and the Ontario Hydro Method (for speciated mercury) (Laudal et al, 2004). However, continuous mercury monitors (CMMs) have distinct advantages over these manual methods in that CMMs are able to provide a real-time or near-real-time response for Hg measurements and to perform long-term emission measurement to truly characterize a process' temporal emissions.…”

“…The EPA's Environmental Technology Verification (ETV) program (USEPA, 2001) identified sulfur dioxide (SO 2 ), nitrogen oxides (NO X ), hydrogen chloride (HCl), and chlorine (Cl 2 ) as interference gases by assessing the CMMs' responses to each gas, as well as to a mixture of the gases. Although pretreatment or conditioning systems can be used to remove or negate the effects of these interfering gases before sample delivery to the detectors (Laudal et al, 2004), they may increase the complexity and cost of the instrumentation and impair the real-time feature of the CMMs.…”

Pilot-and Full-Scale Demonstration of Advanced Mercury Control Technologies for Lignite-Fired Power Plants

“…SCR catalysts were tested for their ability to oxidize Hg; results were mixed. Mercury speciation sampling conducted upstream and downstream of SCR catalysts at power plants that fire bituminous and subbituminous coals (17) showed evidence of mercury oxidation across SCR catalysts when firing bituminous coals. However, when firing subbituminous coals, the results indicate limited oxidation.…”