Emissions of primary concern for coal-fueled diesel cogeneration and electric power plants are nitrogen oxides, sulfur dioxide, particulate matter, and aromatic hydrocarbons. In addition, the exhaust particulate size distribution and ash content are relevant to durability of the exhaust valves, turbocharger, and other engine components. This paper summarizes preliminary measurements of “uncontrolled” emissions in the exhaust of a Cooper-Bessemer 33-cm (13-in.) bore, 400 rpm, single-cylinder research engine, operated on “engine-grade” coal-water fuel (0.5 percent ash, 1 percent sulfur, 8 μm mean size coal). Based on these results, we present a preliminary evaluation of emission control options for satisfying hypothetical future emission standards for 2–50 MW power plants. The paper describes coal-diesel component subsystems such as (a) “reburning” for reducing NOx and hydrocarbon emissions, (b) high- and low-temperature injection of calcium sorbents for SO2 capture, and (c) high-temperature bag filters for control of fine particles. The expected performance of a conceptual, integrated control system is presented.
The need for measuring worker exposure to various toxic materials in the workplace atmosphere demands that appropriate tested methods be available for determining the exposure levels. A critical part of the protocol for testing methods is the preparation of test atmospheres of these toxic materials. For many types of samples, it is frequently sufficient to test analytical procedures on spiked samples, but this is strictly not true for measurements of industrial hygiene samples. For instance, adsorption of compounds onto a sorbent such as charcoal or silica gel may be weaker when the material is deposited from solution than when it is adsorbed as a vapor from a moving air stream. Storage stability is also frequently affected by the method of deposition onto the collecting medium. Material may adhere to the sampling tube or filter cassette during sampling. High humidity effects cannot be adequately tested on spiked samples. Another important area of interest is the collection of materials that may be present in both particulate and vapor phases at the concentration levels of interest. Frequently, vapor pressure data are not available, and a determination of whether vapor/particulate mixtures must be measured can be made only by preparing and sampling test atmospheres.The preparation of synthetic atmospheres for nonreactive gases and vapors is relatively straightforward, but the preparation of fumes, aerosols, and particulates is considerably more difficult. For purposes of industrial hygiene sampling, a polydisperse aerosol containing respirable-size particles is required. This paper describes some of the techniques used to generate synthetic atmospheres of toxic materials. The work was part of a study supported by the National Institute for Occupational Safety and Health to develop and validate methods for sampling and analysis of various materials found in the workplace atmosphere and was a joint effort of SRI International and Arthur D. Little, Inc. Emphasis was placed on reproducible and reliable generation techniques that could be used for a wide variety of compounds. Unique methods were devised for certain difficult materials. Over 230 compounds were studied, including gases, vapors, fumes, and 0-8412-0539-6/80/47-120-001$05.00/0
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.