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To link to full-text access for this article, visit this link: http://dx.doi.org/10.1016/j.jenvman.2006.06.022 Byline: Evan J. Granite, Mark C. Freeman, Richard A. Hargis, William J. O'Dowd, Henry W. Pennline Keywords: Mercury; Flue gas; Sorbent; Activated carbon; Thief Process Abstract: The Thief Process is a cost-effective variation to activated carbon injection (ACI) for removal of mercury from flue gas. In this scheme, partially combusted coal from the furnace of a pulverized coal power generation plant is extracted by a lance and then re-injected into the ductwork downstream of the air preheater. Recent results on a 500-lb/h pilot-scale combustion facility show similar removals of mercury for both the Thief Process and ACI. The tests conducted to date at laboratory, bench, and pilot-scales demonstrate that the Thief sorbents exhibit capacities for mercury from flue gas streams that are comparable to those exhibited by commercially available activated carbons. A patent for the process was issued in February 2003. The Thief sorbents are cheaper than commercially-available activated carbons; exhibit excellent capacities for mercury; and the overall process holds great potential for reducing the cost of mercury removal from flue gas. The Thief Process was licensed to Mobotec USA, Inc. in May of 2005. Author Affiliation: United States Department of Energy, National Energy Technology Laboratory, P.O. Box 10940 MS 58-106, Pittsburgh, PA 15236-0940, USA Article History: Received 7 December 2005; Revised 18 April 2006; Accepted 29 June 2006

Analysis of capital asset pricing model of valuation, to ascertain degree of risk involved in empirical asset pricing, is presented.

The usage of relentless uninsurable risk for solving problems of asset pricing problems in economic depressions is presented.

We develop and test a new approach to assess defined benefit (DB) pension plan solvency risk in the presence of extreme market movements. Our method captures both the ‘fat-tailed’ nature of asset returns and their correlation with discount rate changes. We show that the standard assumption of constant discount rates leads to dramatic underestimation of future projections of pension plan solvency risk. Failing to incorporate leptokurtosis into asset returns also leads to downward biased estimates of risk, but this is less pronounced than the time-varying discount rate effect. Further modifying the model to capture the correlation between asset returns and the discount rate provides additional improvements in the projection of future pension plan solvency. This reduces the perceived future risk of underfunding because of the negative correlation between interest rate changes and asset returns. These results have important implications for those with responsibility for balancing risk against expected return when seeking to improve the current poor funding positions of DB pension schemes. [ABSTRACT FROM AUTHOR]

A dilution sampler was used to examine the effects of dilution ratio and residence time on fine-particle emissions from a pilot-scale pulverized coal combustor. Measurements include the particle size distribution from 0.003 to 2.5 μm, PM2.5 mass, and PM2.5 composition (OC/EC, major ions, and elemental). Heated filter samples were also collected simultaneously at stack temperatures in order to compare the dilution sampler measurements with standard stack sampling methodologies. Measurements were made both before and after the bag house, the particle control device used on the coal combustor, and while firing three different coal types and one coal-biomass blend. The PM2.5 mass emission rates measured using the dilution sampler agreed to within experimental uncertainty with those measured with the hot-filter sampler. Relative to the heated filter sample, dilution did increase the PM2.5 mass fraction of selenium for all fuels tested, as well as ammonium and sulfate for selected fuels. However, the additional particulate mass created by gas-to-particle conversion of these species is within the uncertainty of the gravimetric analysis used to determine the overall mass emission rate. The enrichment of PM2.5 selenium caused by dilution did not vary with dilution ratio and residence time. The enrichment of PM2.5 sulfate and ammonium varied with fuel composition and dilution ratio but not residence time. For example, ammonium was only enriched in diluted acidic aerosol samples. A comparison of the PM2.5 emission profiles for each of the fuels tested underscores how differences in PM2.5 composition are related to the fuel ash composition. When sampling after the bag house, the particle size distribution and total particle number emission rate did not depend on residence time and dilution ratio because of the much lower particle number concentrations in diluted sample and the absence of nucleation. These results provide new insight into the effects of dilution sampling on measurements of fine particle emissions, providing important data for the ongoing effort of the EPA and ASTM to define a standardized dilution sampling methodology for characterizing emissions from stationary combustion sources. [ABSTRACT FROM AUTHOR]